// Invoice generator
// Animation scripts
// elements
// function get_elements() {
    // buttons
var btn_defaults_inv = document.getElementById("btn_defaults_inv");
var btn_defaults_est = document.getElementById("btn_defaults_est");
var btn_defaults_pay = document.getElementById("btn_defaults_pay");
// form type, type divs
var mycurrency = '';
var currency = document.getElementById("mycurrency");
var div_currency = document.getElementById('div_currency_else');
var currency_else  = document.getElementById("currency_else");
var my_type_1 = document.getElementById("my_form_type_1");
var my_type_2 = document.getElementById("my_form_type_2");
var div_inv = document.getElementById("div_INVOICE");
var div_est = document.getElementById("div_ESTIMATE");
var div_pay = document.getElementById("div_PAYMENT-PLAN");
// my business
var my_b_name = document.getElementById('my_b_name');
var my_b_address1 = document.getElementById('my_b_address1');
var my_b_address2 = document.getElementById('my_b_address2');
var my_b_address3 = document.getElementById('my_b_address3');
var my_b_address4 = document.getElementById('my_b_address4');
var my_b_address5 = document.getElementById('my_b_address5');
var my_b_email = document.getElementById('my_b_email');
var my_b_number = document.getElementById('my_b_number');
// my business bank account
var bank_name = document.getElementById('bank_name');
var bank_AC_name = document.getElementById('bank_AC_name');
var bank_AC_no = document.getElementById('bank_AC_no');
var bank_SC = document.getElementById('bank_SC');
// contracted business
var to_b_name = document.getElementById('to_b_name');
var to_b_code = document.getElementById('to_b_code');
var to_b_address1 = document.getElementById('to_b_address1');
var to_b_address2 = document.getElementById('to_b_address2');
var to_b_address3 = document.getElementById('to_b_address3');
var to_b_address4 = document.getElementById('to_b_address4');
var to_b_address5 = document.getElementById('to_b_address5');
var to_b_email = document.getElementById('to_b_email');
var to_b_phone = document.getElementById('to_b_phone');
// client receiving services
var client_name = document.getElementById('client_name');
var client_contact = document.getElementById('client_contact');
var client_address1 = document.getElementById('client_address1');
var client_address2 = document.getElementById('client_address2');
var client_address3 = document.getElementById('client_address3');
var client_address4 = document.getElementById('client_address4');
// invoice
// billable rate and durations
var inv_date = document.getElementById('inv_date');
// var div_inv_goods = document.getElementById('div_inv_goods');
var div_inv_goods = document.getElementById('tbl_inv_goods');
var inv_type_goods = document.getElementById('inv_type_goods');
var inv_goods_n = document.getElementById('inv_goods_n');
var inv_goods_max = 1;
var div_inv_services = document.getElementById('div_inv_services');
// var div_inv_services = document.getElementById('tbl_inv_services');
var inv_type_services = document.getElementById('inv_type_services');
var inv_services_n = document.getElementById('inv_services_n');
var inv_services_max = 1;
var inv_services_children = [1];
var inv_type_both = document.getElementById('inv_type_both');
// estimate
// billable rate and durations
var est_date = document.getElementById('est_date');
// var div_est_goods = document.getElementById('div_est_goods');
var div_est_goods = document.getElementById('tbl_est_goods');
var est_type_goods = document.getElementById('est_type_goods');
var est_goods_n = document.getElementById('est_goods_n');
var est_goods_max = 1;
var div_est_services = document.getElementById('div_est_services');
// var div_est_services = document.getElementById('tbl_est_services');
var est_type_services = document.getElementById('est_type_services');
var est_services_n = document.getElementById('est_services_n');
var est_services_max = 1;
var est_services_children = [1];
var est_type_both = document.getElementById('est_type_both');
// payment plan
var pay_n = document.getElementById('pay_n');
var pay_discretisation = document.getElementById('pay_discretisation');
var div_pay_type = document.getElementById('div_pay_type');
var paytype_linear = document.getElementById('paytype_linear');
var paytype_multiplier = document.getElementById('paytype_multiplier');
var paytype_mult_max = 1
var paytype_random = document.getElementById('paytype_random');
var paytype_random_max = 1
var div_paytype_linear = document.getElementById('div_paytype_linear');
var div_paytype_multiplier = document.getElementById('div_paytype_multiplier');
var div_paytype_random = document.getElementById('div_paytype_random');
var div_payscheme = document.getElementById('div_payscheme');
var div_payscheme_linear = document.getElementById('div_payscheme_linear');
var div_payscheme_multiplier = document.getElementById('div_payscheme_multiplier');
var payscheme_linear = document.getElementById('payscheme_linear');
var payscheme_multiplier = document.getElementById('payscheme_multiplier');
var payscheme_mult_max = 1;
var pay_disc_type_absolute = document.getElementById('pay_disc_type_absolute');
var pay_disc_type_relative = document.getElementById('pay_disc_type_relative');
// }
// get_elements();
//document.onload = function() {
function reload_page() {
    // let my_types = ['inv', 'est'];
    for (let i = 1; i <= max(inv_services_max, est_services_max); i++) {
        change_incremental_phrase('inv', i);
        change_incremental_phrase('est', i);
        change_rate_discretisation('inv', i);
        change_rate_discretisation('est', i);
    }
    update_pay_durndisc();
    show_services('inv');
    show_services('est');
    show_goods_services('inv');
    show_goods_services('est');
    show_paytypes();
    show_schemes();
    update_currency();
    change_form_type(1);
}

reload_page();
// toggle_incremental_weeks('inv', 'Yes', 1);
// toggle_incremental_weeks('est', 'Yes', 1);

// element methods
btn_defaults_inv.addEventListener("click", function () {
    fill_default();
});
btn_defaults_est.addEventListener("click", function () {
    fill_default("ESTIMATE");
});
btn_defaults_pay.addEventListener("click", function () {
    fill_default("PAYMENT-PLAN");
});

function change_form_type(input_id) {
    let mytype = document.getElementById("my_form_type_" + input_id);
    console.log('mytype = '); 
    console.log(mytype);
    set_select(document.getElementById("my_form_type_" + (input_id == 1 ? 2 : 1)), get_select_text(mytype));
    let my_options = mytype.getElementsByTagName('option');
    if (mytype.value == '0' || mytype.value == '') {
        for (let i = 1; i < my_options.length; i++) {
            let temp_div = document.getElementById("div_" + my_options[i].innerText);
            temp_div.style.display = 'inline-block';
        }
    } else {
        for (let i = 1; i < my_options.length; i++) {
            if (mytype.value == i.toString()) {
                let temp_div = document.getElementById("div_" + my_options[i].innerText);
                temp_div.style.display = 'inline-block';
            } else {
                let temp_div = document.getElementById("div_" + my_options[i].innerText);
                temp_div.style.display = 'none';
            }
        }
    }
}
function store() {
    let formtype = get_select_text(my_type_1);
    localStorage.setItem('form_type', formtype);
    localStorage.setItem('currency', mycurrency);
    // Your business
    localStorage.setItem('my_b_name', my_b_name.value);
    localStorage.setItem('my_b_address1', my_b_address1.value);
    localStorage.setItem('my_b_address2', my_b_address2.value);
    localStorage.setItem('my_b_address3', my_b_address3.value);
    localStorage.setItem('my_b_address4', my_b_address4.value);
    localStorage.setItem('my_b_address5', my_b_address5.value);
    localStorage.setItem('my_b_email', my_b_email.value);
    localStorage.setItem('my_b_number', my_b_number.value);
    // Your business' bank
    localStorage.setItem('bank_name', bank_name.value);
    localStorage.setItem('bank_AC_name', bank_AC_name.value);
    localStorage.setItem('bank_AC_no', bank_AC_no.value);
    localStorage.setItem('bank_SC', bank_SC.value);
    // Recipient business
    localStorage.setItem('to_b_name', to_b_name.value);
    localStorage.setItem('to_b_code', to_b_code.value);
    localStorage.setItem('to_b_address1', to_b_address1.value);
    localStorage.setItem('to_b_address2', to_b_address2.value);
    localStorage.setItem('to_b_address3', to_b_address3.value);
    localStorage.setItem('to_b_address4', to_b_address4.value);
    localStorage.setItem('to_b_address5', to_b_address5.value);
    localStorage.setItem('to_b_email', to_b_email.value);
    localStorage.setItem('to_b_phone', to_b_phone.value);
    // Recipient client
    localStorage.setItem('client_name', client_name.value);
    localStorage.setItem('client_contact', client_contact.value);
    localStorage.setItem('client_address1', client_address1.value);
    localStorage.setItem('client_address2', client_address2.value);
    localStorage.setItem('client_address3', client_address3.value);
    localStorage.setItem('client_address4', client_address4.value);
    
    let dogoods, doservices;
    switch (formtype) {
        case 'INVOICE':
            localStorage.setItem('date', inv_date.value);
            dogoods = inv_type_goods.checked;
            localStorage.setItem('bool_goods', dogoods);
            if (dogoods) {
                let mygoods_n = [];
                let mygoods_q = [];
                let mygoods_v = [];
                let ngoods = Number(inv_goods_n.value);
                localStorage.setItem('goods_n', ngoods.toString())
                for (let i = 1; i <= ngoods; i++) {
                    let si = i.toString();
                    mygoods_n.push(document.getElementById('inv_name_g' + si).value);
                    mygoods_q.push(document.getElementById('inv_quantity_g' + si).value);
                    mygoods_v.push(document.getElementById('inv_value_g' + si).value);
                }
                localStorage.setObj('mygoods_n', mygoods_n);
                localStorage.setObj('mygoods_q', mygoods_q);
                localStorage.setObj('mygoods_v', mygoods_v);
            }
            doservices = inv_type_services.checked;
            localStorage.setItem('bool_services', doservices);
            if (doservices) {
                let nservices = Number(inv_services_n.value);
                localStorage.setItem('services_n', nservices.toString());
                let rate_disc = [];
                // let durn_disc = [];
                let rate = [];
                let sub_quantity = [];
                let description = [];
                let quantity = [];
                localStorage.setItem('week1', document.getElementById('inv_week1_s1').value);
                for (let i = 1; i <= nservices; i++) {
                    let si = i.toString();
                    let rate_disc_quantity = document.getElementById('inv_ratedisc_quantity_s' + si).value;
                    let temp_discrate = get_select_text(document.getElementById('inv_disc_rate_s' + si)).toUpperCase();
                    if (rate_disc_quantity == "1") {
                        rate_disc.push([temp_discrate, temp_discrate + 'S']); //  + 's'
                    } else {
                        let temp = 'x' + rate_disc_quantity + ' ' + temp_discrate + 'S';
                        rate_disc.push([temp, temp]);
                    }
                    rate.push(document.getElementById('inv_rate_s' + si).value);
                    sub_quantity.push(document.getElementById('inv_sub_quantity_s' + si).value);
                    description.push([]);
                    quantity.push([]);
                    for (let j = 1; j <= Number(sub_quantity[i - 1]); j++) {
                        let sj = j.toString();
                        description[i - 1].push(document.getElementById('inv_description_s' + si + '_' + sj).value);
                        quantity[i - 1].push(document.getElementById('inv_quantity_s' + si + '_' + sj).value);
                    }
                }
                localStorage.setObj('ratediscs', rate_disc);
                // localStorage.setObj('durndiscs', durn_disc);
                localStorage.setObj('rates', rate);
                // localStorage.setObj('durn_disc_qs', durn_disc_quantity);
                localStorage.setObj('descriptions', description);
                localStorage.setObj('quantities', quantity);
                localStorage.setObj('subservice_quantities', sub_quantity);
            } else {
                let temp = document.getElementById('inv_name_g1').value;
                localStorage.setItem('week1', temp.substring(0, min(8, temp.length)).toUpperCase());
            }
            break;
        case 'ESTIMATE':
            localStorage.setItem('date', est_date.value);
            dogoods = est_type_goods.checked;
            localStorage.setItem('bool_goods', dogoods);
            if (dogoods) {
                let mygoods_n = [];
                let mygoods_q = [];
                let mygoods_v = [];
                let ngoods = Number(est_goods_n.value);
                localStorage.setItem('goods_n', ngoods.toString())
                for (let i = 1; i <= ngoods; i++) {
                    let si = i.toString();
                    mygoods_n.push(document.getElementById('est_name_g' + si).value);
                    mygoods_q.push(document.getElementById('est_quantity_g' + si).value);
                    mygoods_v.push(document.getElementById('est_value_g' + si).value);
                }
                localStorage.setObj('mygoods_n', mygoods_n);
                localStorage.setObj('mygoods_q', mygoods_q);
                localStorage.setObj('mygoods_v', mygoods_v);
            }
            doservices = est_type_services.checked;
            localStorage.setItem('bool_services', doservices);
            if (doservices) {
                let nservices = Number(est_services_n.value);
                localStorage.setItem('services_n', nservices.toString());
                let rate_disc = [];
                // let durn_disc = [];
                let rate = [];
                let sub_quantity = [];
                let description = [];
                let quantity = [];
                localStorage.setItem('week1', document.getElementById('est_week1_s1').value);
                for (let i = 1; i <= nservices; i++) {
                    let si = i.toString();
                    let rate_disc_quantity = document.getElementById('est_ratedisc_quantity_s' + si).value;
                    let temp_discrate = get_select_text(document.getElementById('est_disc_rate_s' + si)).toUpperCase();
                    if (rate_disc_quantity == "1") {
                        rate_disc.push([temp_discrate, temp_discrate + 'S']); //  + 's'
                    } else {
                        let temp = 'x' + rate_disc_quantity + ' ' + temp_discrate + 'S';
                        rate_disc.push([temp, temp]);
                    }
                    // durn_disc.push(get_select_text(document.getElementById('est_disc_durn_s' + si)));
                    rate.push(document.getElementById('est_rate_s' + si).value);
                    sub_quantity.push(document.getElementById('est_sub_quantity_s' + si).value);
                    description.push([]);
                    quantity.push([]);
                    for (let j = 1; j <= Number(sub_quantity[i - 1]); j++) {
                        let sj = j.toString();
                        description[i - 1].push(document.getElementById('est_description_s' + si + '_' + sj).value);
                        quantity[i - 1].push(document.getElementById('est_quantity_s' + si + '_' + sj).value);
                    }
                }
                localStorage.setObj('ratediscs', rate_disc);
                // localStorage.setObj('durndiscs', durn_disc);
                localStorage.setObj('rates', rate);
                // localStorage.setObj('durn_disc_qs', durn_disc_quantity);
                localStorage.setObj('descriptions', description);
                localStorage.setObj('quantities', quantity);
                localStorage.setObj('subservice_quantities', sub_quantity);
            } else {
                let temp = document.getElementById('est_name_g1').value;
                localStorage.setItem('week1', temp.substring(0, min(8, temp.length)).toUpperCase());
            }
            break;
        case 'PAYMENT-PLAN':
            let npayments = Number(pay_n.value);
            localStorage.setItem('payments_n', npayments.toString());
            localStorage.setItem('description', document.getElementById('pay_description').value);
            localStorage.setItem('week1', localStorage.description.substring(0, min(12, localStorage.description.length)).toUpperCase());
            if (paytype_linear.checked) {
                localStorage.setItem('paytype', 'linear');
                localStorage.setItem('pay_value_unit', document.getElementById('pay_linear_unit').value);
            } else if (paytype_multiplier.checked) {
                localStorage.setItem('paytype', 'multiplier');
                localStorage.setItem('pay_value_unit', document.getElementById('pay_mult_unit').value);
                let pay_multiplier = [];
                for (let i = 1; i <= npayments; i++) {
                    let si = i.toString();
                    pay_multiplier.push(document.getElementById('paytype_mult_' + si).value);
                }
                localStorage.setObj('multiplier', pay_multiplier);
            } else {
                localStorage.setItem('paytype', 'random');
                let pay_value = [];
                for (let i = 1; i <= npayments; i++) {
                    let si = i.toString();
                    pay_value.push(document.getElementById('paytype_value_' + si).value);
                }
                localStorage.setObj('value', pay_value);
            }
            let date = [date2str(new Date(document.getElementById('pay_date').value))];
            let discretisation = get_select_text(pay_discretisation);
            let disc_quantity = Number(document.getElementById('pay_disc_quantity').value);
            if (payscheme_linear.checked) {
                localStorage.setItem('payscheme', 'linear');
                if (npayments > 1) {
                    for (let i = 2; i <= npayments; i++) {
                        date.push(date2str(increment_date(new Date(date[i - 2]), discretisation, disc_quantity)));
                    }
                }
                // payscheme = 'linear';
            } else { // if payscheme_multiple.checked
                localStorage.setItem('payscheme', 'multiple');
                // payscheme = 'multiple';
                if (pay_disc_type_absolute.checked) {
                    for (let i = 1; i <= npayments; i++) {
                        date.push(date2str(increment_date(new Date(date[0]), discretisation, disc_quantity * document.getElementById('payscheme_mult_' + i.toString()).value)));
                    }
                } else { // relative
                    for (let i = 1; i <= npayments; i++) {
                        date.push(date2str(increment_date(new Date(date[i - 1]), discretisation, disc_quantity * document.getElementById('payscheme_mult_' + i.toString()).value)));
                    }
                }
            }
            localStorage.setItem('disc_quantity', disc_quantity.toString());
            localStorage.setItem('discretisation', discretisation);
            localStorage.setObj('dates', date);
            break;
        default:
            // error - please select form type
            break;
    }
    // store_btec_invoice(); // used to work for JLR in emergency - test?
}

function increment_date(date0, discretisation, quantity) {
    // let y0 = Number(date0.substring(0, 4));
    // let m0 = Number(date0.substring(5, 2));
    // let d0 = Number(date0.substring(8, 2));
    let y0 = date0.getFullYear();
    let m0 = date0.getMonth();
    let d0 = date0.getDate();
    // let new_date = '';
    switch (discretisation) {
        case 'Year':
            return new Date(y0 + quantity, m0, d0);
        case 'Month':
            return new Date(y0, m0 + quantity, d0);
        case 'Week':
            return new Date(y0, m0, d0 + quantity * 7);
        default: // case 'Day':
            return new Date(y0, m0, d0 + quantity);
    }
}

function date2str(date_in) {
    return date_in.getFullYear().toString() + '-' + (date_in.getMonth() + 1).toString().padStart(2, '0') + '-' + date_in.getDate().toString().padStart(2, '0');
}

Storage.prototype.setObj = function(key, obj) {
    return this.setItem(key, JSON.stringify(obj))
}
Storage.prototype.getObj = function(key) {
    return JSON.parse(this.getItem(key))
}

function store_btec_invoice() {
    localStorage.setItem('rate', document.getElementById('inv_rate_s1').value);
    localStorage.setItem('date', inv_date.value);

    let nweeks = document.getElementById('inv_durndisc_quantity_s1').value;
    localStorage.setItem('nweeks', nweeks);
    localStorage.setItem('week1', document.getElementById('inv_ratedisc_quantity_s1').value);
    localStorage.setItem('hours1', document.getElementById('inv_quantity_s1_1').value);
    if (nweeks > 1) {
        localStorage.setItem('hours2', document.getElementById('inv_quantity_s1_2').value);
    }
    if (nweeks > 2) {
        localStorage.setItem('hours3', document.getElementById('inv_quantity_s1_3').value);
    }
    if (nweeks > 3) {
        localStorage.setItem('hours4', document.getElementById('inv_quantity_s1_4').value);
    }
    if (nweeks == 5) {
        localStorage.setItem('hours5', document.getElementById('inv_quantity_s1_5').value);
    }
}

function fill_default(mytype = "INVOICE") {
    // set_form_type(mytype);
    set_select(my_type_1, mytype); 
    // set_select(my_type_2, mytype); // redundant?
    change_form_type(1);
    fill_defaults_me();
    fill_defaults_JLR();
    // fill_defaults_demo();
    currency.value = '£';
    switch (mytype) {
        case "INVOICE":
            fill_defaults_inv();
            break;
        case "ESTIMATE":
            fill_defaults_est();
            break;
        case "PAYMENT-PLAN":
            fill_defaults_pay();
            break;         
    }
}

function fill_defaults_me() {
    my_b_name.value = "Precision And Research Technology Systems Limited";
    my_b_address1.value = "Unit 12a";
    my_b_address2.value = 'Somers Road';
    my_b_address3.value = 'Rugby';
    my_b_address4.value = 'Warwickshire';
    my_b_address5.value = 'CV22 7DH';
    my_b_email.value = 'edward.middletonsmith@gmail.com';
    my_b_number.value = 13587499;
    bank_name.value = 'Starling';
    bank_AC_name.value = "Precision And Research Technology Systems Limited";
    bank_AC_no.value = 40168366;
    bank_SC.value = '60-83-71';
}

function fill_defaults_JLR() {
    to_b_name.value = 'Contechs Technical Resourcing Limited';
    to_b_code.value = 'Contechs';
    to_b_address1.value = '2 Sable Court';
    to_b_address2.value = 'Southfields Business Park';
    to_b_address3.value = 'Basildon';
    to_b_address4.value = 'Essex';
    to_b_address5.value = "SS15 6SR";
    to_b_email.value = 'account@contechs.co.uk';
    to_b_phone.value = "01268 582900";
    client_name.value = "Jaguar Land Rover";
    // Chassis Business Process Analyst
    // client_contact.value = "Andrew Coldwell";
    // client_contact.value = "Pamela Spencer";
    // Component And Systems Software Engineer
    client_contact.value = "Simon Bant";
    client_address1.value = "Banbury Road";
    client_address2.value = "Gaydon";
    client_address3.value = "Warwickshire";
    client_address4.value = "CV35 0RR";
}

function fill_defaults_demo() {
    bank_AC_no.value = 12345678;
    bank_SC.value = '01-23-45';
    to_b_name.value = 'Company Limited';
    to_b_code.value = 'Company';
    to_b_address1.value = '123 Road Drive';
    to_b_address2.value = 'Company Business Park';
    to_b_address3.value = 'Central Region';
    to_b_address4.value = 'Greater London';
    to_b_address5.value = 'W1 9AA';
    to_b_email.value = 'account@company.co.uk';
    to_b_phone.value = "01234 567890";
    client_name.value = "Company Limited";
    client_contact.value = "Mrs. Employer";
    client_address1.value = '123 Road Drive';
    client_address2.value = 'Company Business Park';
    client_address3.value = 'Greater London';
    client_address4.value = 'W1 9AA';
}

function clear_me() {
    my_b_name.value = "";
    my_b_address1.value = "";
    my_b_address2.value = '';
    my_b_address3.value = '';
    my_b_address4.value = '';
    my_b_address5.value = '';
    my_b_email.value = '';
    my_b_number.value = '';
    bank_name.value = '';
    bank_AC_name.value = "";
    bank_AC_no.value = '';
    bank_SC.value = '';
}

function clear_recipient() {
    to_b_name.value = '';
    to_b_code.value = '';
    to_b_address1.value = '';
    to_b_address2.value = '';
    to_b_address3.value = '';
    to_b_address4.value = '';
    to_b_address5.value = "";
    to_b_email.value = '';
    to_b_phone.value = "";
    client_name.value = "";
    client_contact.value = "";
    client_address1.value = "";
    client_address2.value = "";
    client_address3.value = "";
    client_address4.value = "";
}

function clear_invest(this_form_type) {
    let tft = this_form_type;
    document.getElementById(tft + '_date').value = '';
    document.getElementById(tft + '_type_goods').checked = false;
    document.getElementById(tft + '_type_services').checked = false;
    document.getElementById(tft + '_goods_n').value = '1';
    document.getElementById(tft + '_name_g1').value = '';
    document.getElementById(tft + '_value_g1').value = '';
    document.getElementById(tft + '_quantity_g1').value = '';
    let goods_max = 0;
    switch (tft) {
        case 'inv':
            goods_max = inv_goods_max;
            inv_goods_max = 1;
            break;
        case 'est':
            goods_max = est_goods_max;
            est_goods_max = 1;
            break;
    }
    if (goods_max > 1) {
        for (let i = 2; i <= goods_max; i++) {
            document.getElementById('div_' + tft + '_good_' + i.toString()).remove();
        }
    }
    document.getElementById(tft + '_services_n').value = '1';
    set_select(document.getElementById(tft + '_disc_rate_s1'), 'Hour');
    document.getElementById(tft + '_ratedisc_quantity_s1').value = '';
    document.getElementById(tft + '_rate_s1').value = '0';
    set_select(document.getElementById(tft + '_disc_durn_s1'), 'Week');
    document.getElementById(tft + '_durndisc_quantity_s1').value = '1';
    document.getElementById(tft + '_sub_quantity_s1').value = '1';
    document.getElementById(tft + '_increment_yes_s1').checked = true;
    document.getElementById(tft + '_increment_no_s1').checked = false;
    document.getElementById(tft + '_baseID_s1').value = '';
    document.getElementById(tft + '_week1_s1').value = '';
    document.getElementById(tft + '_description_s1_1').value = '';
    document.getElementById(tft + '_quantity_s1_1').value = '';
    let services_max = 0;
    let services_children = [];
    switch (tft) {
        case 'inv':
            services_max = inv_services_max;
            services_children = inv_services_children;
            inv_services_max = 1;
            inv_services_children = [1];
            break;
        case 'est':
            services_max = est_services_max;
            services_children = est_services_children;
            est_services_max = 1;
            est_services_children = [1];
            break;
    }
    if (services_max > 1) {
        for (let i = 2; i <= services_max; i++) {
            document.getElementById('div_' + tft + '_service_' + i.toString()).remove();
        }
    }
    if (services_children[0] > 1) {
        for (let i = 2; i <= services_children[0]; i++) {
            document.getElementById('div_' + tft + '_service_1_' + i.toString()).remove();
        }
    }
}

function clear_pay() {
    pay_n.value = '';
    document.getElementById('pay_description').value = '';
    paytype_linear.checked = true;
    paytype_multiplier.checked = false;
    paytype_random.checked = false;
    document.getElementById('pay_linear_unit').value = '';
    document.getElementById('pay_date').value = '';
    payscheme_linear.checked = true;
    payscheme_multiplier.checked = false;
    if (paytype_mult_max > 1) {
        for (let i = 2; i <= paytype_mult_max; i++) {
            document.getElementById('div_payscheme_mult_' + i.toString()).remove();
        }
    }
    set_select(pay_discretisation, 'Month');
    document.getElementById('pay_disc_quantity').value = '';
    pay_disc_type_absolute.checked = false;
    pay_disc_type_relative.checked = false;
    document.getElementById('payscheme_mult_1').value = '';
    if (payscheme_mult_max > 1) {
        for (let i = 2; i <= payscheme_mult_max; i++) {
            document.getElementById('div_payscheme_mult_' + i.toString()).remove();
        }
    }
}

function clear_form() {
    clear_me();
    clear_recipient();
    clear_invest('inv');
    clear_invest('est');
    clear_pay();
    set_select(my_type_1, '-');
    // set_select(my_type_2, '-'); // redundant?
    reload_page();
}

function fill_defaults_inv() {
    // .dispatchEvent(new Event('change'));
    let nowtime = new Date(Date.now());
    inv_date.value = date2str(new Date(nowtime.getFullYear(), nowtime.getMonth(), -1));
    inv_type_goods.checked = false;
    inv_type_services.checked = true;
    // inv_type_services.dispatchEvent(new Event('change'));
    show_goods_services('inv');
    // inv_services_max = 1;
    // inv_services_children = [1];
    inv_services_n.value = "1";
    show_services('inv'); 
    document.getElementById('inv_ratedisc_quantity_s1').value = "1";
    set_select(document.getElementById('inv_disc_rate_s1'), "Hour");
    change_rate_discretisation('inv', 1);
    // Chassis Business Process Analyst
    // document.getElementById('inv_rate_s1').value = "20.33";
    // RADs Software Engineer
    document.getElementById('inv_rate_s1').value = "23.94";
    document.getElementById('inv_durndisc_quantity_s1').value = "1";
    set_select(document.getElementById('inv_disc_durn_s1'), 'Week');
    change_rate_discretisation('inv', 1);
    document.getElementById('inv_sub_quantity_s1').value = "4";
    show_discs('inv', "s", 1, 4);
    document.getElementById('inv_increment_yes_s1').checked = true;
    toggle_incremental_weeks('inv', 'Yes', 1);
    document.getElementById('inv_baseID_s1').value = "Contractor services - week ";
    change_incremental_phrase('inv', 1);
    document.getElementById('inv_week1_s1').value = "1";
    change_incremental_phrase('inv', 1);
    for (let i = 1; i <= 4; i++) {
        let si = i.toString();
        document.getElementById('inv_quantity_s1_' + si).value = "40";
    }
    update_currency();
}

// function fill_defaults_inv() {
//     // .dispatchEvent(new Event('change'));
//     let nowtime = new Date(Date.now());
//     inv_date.value = date2str(new Date(nowtime.getFullYear(), nowtime.getMonth(), -1));
//     inv_type_goods.checked = true;
//     show_goods_services('inv');
//     // inv_goods_max = 1;
//     inv_goods_n.value = "4";
//     // inv_goods_n.dispatchEvent(new Event('change'));
//     show_goods('inv');
//     let names = ['chicken', 'pies', '3d printers', "Tierney's used panties"];
//     for (let i = 1; i <= 4; i++) {
//         let si = i.toString();
//         console.log('si = ' + si);
//         document.getElementById('inv_name_g' + si).value = names[i - 1];
//         document.getElementById('inv_value_g' + si).value = (5 * i).toString();
//         document.getElementById('inv_quantity_g' + si).value = (60 / i).toString();
//     }
//     inv_type_services.checked = true;
//     // inv_type_services.dispatchEvent(new Event('change'));
//     show_goods_services('inv');
//     // inv_services_max = 1;
//     // inv_services_children = [1];
//     inv_services_n.value = "2";
//     show_services('inv'); 
//     document.getElementById('inv_ratedisc_quantity_s1').value = "1";
//     set_select(document.getElementById('inv_disc_rate_s1'), "Day");
//     change_rate_discretisation('inv', 1);
//     document.getElementById('inv_rate_s1').value = "20.33";
//     document.getElementById('inv_durndisc_quantity_s1').value = "6";
//     set_select(document.getElementById('inv_disc_durn_s1'), 'Year');
//     change_rate_discretisation('inv', 1);
//     document.getElementById('inv_sub_quantity_s1').value = "4";
//     show_discs('inv', "s", 1, 4);
//     document.getElementById('inv_increment_yes_s1').checked = true;
//     toggle_incremental_weeks('inv', 'Yes', 1);
//     document.getElementById('inv_baseID_s1').value = "Contractor services - year ";
//     change_incremental_phrase('inv', 1);
//     document.getElementById('inv_week1_s1').value = "1";
//     change_incremental_phrase('inv', 1);
//     for (let i = 1; i <= 4; i++) {
//         let si = i.toString();
//         document.getElementById('inv_quantity_s1_' + si).value = "40";
//     }
//     set_select(document.getElementById('inv_disc_rate_s2'), "Minute"); 
//     change_rate_discretisation('inv', 2);
//     document.getElementById('inv_rate_s2').value = "30";
//     document.getElementById('inv_durndisc_quantity_s2').value = "3";
//     set_select(document.getElementById('inv_disc_durn_s2'), 'Month');
//     change_rate_discretisation('inv', 2);
//     document.getElementById('inv_sub_quantity_s2').value = "5";
//     show_discs('inv', "s", 2, 5);
//     document.getElementById('inv_increment_yes_s2').checked = true;
//     toggle_incremental_weeks('inv', 'Yes', 2);
//     document.getElementById('inv_baseID_s2').value = "Contractor services - month ";
//     change_incremental_phrase('inv', 2);
//     document.getElementById('inv_week1_s2').value = "9";
//     change_incremental_phrase('inv', 2);
//     for (let i = 1; i <= 5; i++) {
//         let si = i.toString();
//         document.getElementById('inv_quantity_s2_' + si).value = "50";
//     }
//     update_currency();
// }

function fill_defaults_est() {
    let nowtime = new Date(Date.now());
    est_date.value = date2str(new Date(nowtime.getFullYear(), nowtime.getMonth(), -1));
    est_type_goods.checked = true;
    show_goods_services('est');
    est_goods_n.value = "4";
    show_goods('est');
    let names = ['Airplanes', 'Seats', 'Turbines', 'Safety manuals']; // ['pork chops', 'juice', 'European children', 'DMT'];
    for (let i = 1; i <= 4; i++) {
        let si = i.toString();
        console.log('si = ' + si);
        document.getElementById('est_name_g' + si).value = names[i - 1];
        document.getElementById('est_value_g' + si).value = (7 * i).toString();
        document.getElementById('est_quantity_g' + si).value = (1200 / i).toString();
    }
    est_type_services.checked = true;
    show_goods_services('est');
    est_services_n.value = "2";
    show_services('est'); 
    document.getElementById('est_ratedisc_quantity_s1').value = "1";
    set_select(document.getElementById('est_disc_rate_s1'), "Minute");
    change_rate_discretisation('est', 1);
    document.getElementById('est_rate_s1').value = "200";
    document.getElementById('est_durndisc_quantity_s1').value = "6";
    set_select(document.getElementById('est_disc_durn_s1'), 'Week');
    change_rate_discretisation('est', 1);
    document.getElementById('est_sub_quantity_s1').value = "3";
    show_discs('est', "s", 1, 3);
    document.getElementById('est_increment_yes_s1').checked = true;
    toggle_incremental_weeks('est', 'Yes', 1);
    document.getElementById('est_baseID_s1').value = "Contractor services - week ";
    change_incremental_phrase('est', 1);
    document.getElementById('est_week1_s1').value = "1";
    change_incremental_phrase('est', 1);
    for (let i = 1; i <= 3; i++) {
        let si = i.toString();
        document.getElementById('est_quantity_s1_' + si).value = "19.50";
    }
    set_select(document.getElementById('est_disc_rate_s2'), "Week"); 
    change_rate_discretisation('est', 2); 
    document.getElementById('est_rate_s2').value = "35";
    document.getElementById('est_durndisc_quantity_s2').value = "3";
    set_select(document.getElementById('est_disc_durn_s2'), 'Week');
    change_rate_discretisation('est', 2);
    document.getElementById('est_sub_quantity_s2').value = "2";
    show_discs('est', "s", 2, 2);
    document.getElementById('est_increment_yes_s2').checked = true;
    toggle_incremental_weeks('est', 'Yes', 2);
    document.getElementById('est_baseID_s2').value = "Contractor services - week ";
    change_incremental_phrase('est', 2);
    document.getElementById('est_week1_s2').value = "15";
    change_incremental_phrase('est', 2);
    for (let i = 1; i <= 2; i++) {
        let si = i.toString();
        document.getElementById('est_quantity_s2_' + si).value = "25";
    }
    update_currency();
}

function fill_defaults_pay() {
    // .dispatchEvent(new Event('change'));
    pay_n.value = '24'; // redundant
    show_payschemes();
    document.getElementById('pay_description').value = 'Blackmail Repayments';
    paytype_linear.checked = true;
    paytype_multiplier.checked = false;
    paytype_random.checked = false;
    change_paytype('linear');
    document.getElementById('pay_linear_unit').value = '200';
    let nowtime = new Date(Date.now());
    pay_date.value = date2str(new Date(nowtime.getFullYear(), nowtime.getMonth(), -1));
    payscheme_linear.checked = false;
    payscheme_multiplier.checked = true;
    change_payscheme('multiplier');
    set_select(pay_discretisation, 'Month');
    update_pay_durndisc();
    document.getElementById('pay_disc_quantity').value = '1';
    pay_disc_type_absolute.checked = false;
    pay_disc_type_relative.checked = true;
    change_pay_disctype('relative');
    for (let i = 1; i <= 24; i++) {
        document.getElementById('payscheme_mult_' + i.toString()).value = 1 + ((i - 1) % 3);
    }
}

currency.addEventListener('change', function() {
    show_currency_else();
    // update currency symbols throughout
    update_currency();
});

currency_else.addEventListener('change', function() {
    show_currency_else();
    // update currency symbols throughout
    update_currency();
});

function show_currency_else() {
    mycurrency = get_select_text(currency);
    switch (mycurrency) {
        case 'Other':
            div_currency.style.display = 'inline-block';
            mycurrency = currency_else.value;
            break;
        default:
            div_currency.style.display = 'none';
            // mycurrency = get_select_text(currency);
            break;
    }
}

function update_currency() {
    // let mycurrency = currency.value;
    mycurrency = currency.value;
    // if (mycurrency == '-') {
    //     mycurrency = '';
    // }
    // invoice
    for (let i = 1; i <= inv_goods_max; i++) {
        let si = i.toString();
        document.getElementById('inv_value_g' + si).innerText = 'Value [' + mycurrency + ']:';
    }
    for (let i = 1; i <= inv_services_max; i++) {
        let si = i.toString();
        let mylabel = document.getElementById('inv_rate_s' + si + '_label');
        let temp = mylabel.innerText;
        mylabel.innerText = 'Rate [' + mycurrency + temp.substring(temp.indexOf(']'), temp.length);
    }
    // estimate
    for (let i = 1; i <= est_goods_max; i++) {
        let si = i.toString();
        let mylabel = document.getElementById('est_value_g' + si);
        mylabel.innerText = 'Value [' + mycurrency + ']:';
    }
    for (let i = 1; i <= est_services_max; i++) {
        let si = i.toString();
        let mylabel = document.getElementById('est_rate_s' + si + '_label');
        let temp = mylabel.innerText;
        mylabel.innerText = 'Rate [' + mycurrency + temp.substring(temp.indexOf(']'), temp.length);
    }
    // payment-plan
    document.getElementById('pay_linear_unit_label').value = 'Unit payment [' + mycurrency + ']';
    document.getElementById('pay_mult_unit_label').value = 'Unit payment [' + mycurrency + ']';
    if (paytype_multiplier.checked) {
        for (let i = 1; i <= paytype_mult_max; i++) {
            let si = i.toString();
            document.getElementById('paytype_mult_' + si + '_label').innerText = 'Payment ' + si + ' [' + mycurrency + ']';
        }
    }
    if (paytype_random.checked) {
        for (let i = 1; i <= paytype_random_max; i++) {
            let si = i.toString();
            document.getElementById('paytype_value_' + si + '_label').innerText = 'Payment ' + si + ' [' + mycurrency + ']';
        }
    }
}

// invoice
function show_services(this_form_type) {
    let N = Number(document.getElementById(this_form_type + '_services_n').value);
    let services_max = 0;
    switch (this_form_type) {
        case 'inv':
            services_max = inv_services_max;
            break;
        case 'est':
            services_max = est_services_max;
            break;
    }
    if (N > services_max) {
        for (let i = services_max + 1; i <= N; i++) {
            let si = String(i);
            let child_div = document.createElement('div');
            // child_div.outerHTML = '<div id="div_inv_service_'+ si + '" class="div_service">';
            child_div.id = 'div_' + this_form_type + '_service_' + si;
            // child_div.className = "div_service"; - d
            let child_title = document.createElement('label');
            child_title.className = 'div_title';
            child_title.innerText = 'Service ' + si;
            let child_disc_rate_label = document.createElement('label');
            // child_disc_rate_label.outerHTML = '<label for="inv_disc_rate_s' + si + '">Invoice service rate discretisation:</label>';
            child_disc_rate_label.id = this_form_type + '_disc_rate_s' + si + '_label';
            child_disc_rate_label.innerText = 'Rate discretisation:';
            child_disc_rate_label.className = 'input_label label_title';
            let child_disc_durn_label = document.createElement('label');
            // child_disc_rate_label.outerHTML = '<label for="inv_disc_rate_s' + si + '">Invoice service rate discretisation:</label>';
            child_disc_durn_label.id = this_form_type + '_disc_rate_s' + si + '_label';
            child_disc_durn_label.innerText = 'Duration discretisation:';
            child_disc_durn_label.className = 'input_label label_title';
            // let child_break = document.createElement('br');
            let child_disc_rate_select = document.createElement('select');
            // child_disc_rate_select.outerHTML = '<select id="inv_disc_rate_s' + si+'"></select>'
            child_disc_rate_select.id = this_form_type + '_disc_rate_s' + si;
            let child_disc_durn_select = document.createElement('select');
            // child_disc_durn_select.outerHTML = '<select id="inv_disc_durn_s' + si+'"></select>'
            child_disc_durn_select.id = this_form_type + '_disc_durn_s' + si;
            let child_disc_rate_option_min = document.createElement('option');
            // child_disc_rate_option_min.outerHTML = '<option value="m">Minute</option>';
            child_disc_rate_option_min.value = 'm';
            child_disc_rate_option_min.innerText = 'Minute';
            let child_disc_rate_option_hr = document.createElement('option');
            // child_disc_rate_option_hr.outerHTML = '<option value="h">Hour</option>';
            child_disc_rate_option_hr.value = 'h';
            child_disc_rate_option_hr.innerText = 'Hour';
            child_disc_rate_option_hr.selected = true;
            let child_disc_rate_option_day = document.createElement('option');
            // child_disc_rate_option_day.outerHTML = '<option value="d">Day</option>';
            child_disc_rate_option_day.value = 'd';
            child_disc_rate_option_day.innerText = 'Day';
            let child_disc_rate_option_week = document.createElement('option');
            // child_disc_rate_option_week.outerHTML = '<option value="w">Week</option>';
            child_disc_rate_option_week.value = 'w';
            child_disc_rate_option_week.innerText = 'Week';
            let child_disc_durn_option_day = document.createElement('option');
            // child_disc_durn_option_month.outerHTML = '<option value="M">Month</option>';
            child_disc_durn_option_day.value = 'd';
            child_disc_durn_option_day.innerText = 'Day';
            let child_disc_durn_option_week = document.createElement('option');
            // child_disc_durn_option_month.outerHTML = '<option value="M">Month</option>';
            child_disc_durn_option_week.value = 'w';
            child_disc_durn_option_week.innerText = 'Week';
            let child_disc_durn_option_month = document.createElement('option');
            // child_disc_durn_option_month.outerHTML = '<option value="M">Month</option>';
            child_disc_durn_option_month.value = 'M';
            child_disc_durn_option_month.innerText = 'Month';
            let child_disc_durn_option_year = document.createElement('option');
            // child_disc_durn_option_year.outerHTML = '<option value="y">Year</option>';
            child_disc_durn_option_year.value = 'y';
            child_disc_durn_option_year.innerText = 'Year';
            child_disc_rate_select.appendChild(child_disc_rate_option_min);
            child_disc_rate_select.appendChild(child_disc_rate_option_hr);
            child_disc_rate_select.appendChild(child_disc_rate_option_day);
            child_disc_rate_select.appendChild(child_disc_rate_option_week);
            child_disc_rate_select.onchange = function () {
                change_rate_discretisation(this_form_type, i);
            };
            child_disc_durn_select.appendChild(child_disc_durn_option_day);
            child_disc_durn_select.appendChild(child_disc_durn_option_week);
            child_disc_durn_select.appendChild(child_disc_durn_option_month);
            child_disc_durn_select.appendChild(child_disc_durn_option_year);
            child_disc_durn_select.onchange = function () {
                change_rate_discretisation(this_form_type, i);
            };
            let child_disc_rate_quantity_label = document.createElement('label');
            // child_disc_rate_quantity_label.outerHTML = '<label for="inv_durndisc_quantity_s' + si + '">Quantity of duration discretisations:</label>';
            child_disc_rate_quantity_label.id = this_form_type + '_ratedisc_quantity_s' + si + '_label';
            child_disc_rate_quantity_label.innerText = 'Quantity of rate discretisations per minimum unit rate:';
            child_disc_rate_quantity_label.className = 'input_label label_title';
            let child_disc_rate_quantity = document.createElement('input');
            // child_disc_rate_quantity.outerHTML = '<input type="number" id="inv_durndisc_quantity_s' + si + '" class="rate" placeholder="1" step="1" min="1"/>';
            child_disc_rate_quantity.type = 'number';
            child_disc_rate_quantity.id = this_form_type + '_ratedisc_quantity_s' + si;
            child_disc_rate_quantity.value = "1";
            child_disc_rate_quantity.step = '1';
            child_disc_rate_quantity.min = '1';
            child_disc_rate_quantity.onchange = function() {
                change_rate_discretisation(this_form_type, i);
            };
            let child_rate_label = document.createElement('label');
            // child_rate_label.outerHTML = '<label for="inv_rate_s' + si + '">Rate [£ / duration discretisation]</label>';
            child_rate_label.id = this_form_type + '_rate_s' + si + '_label';
            child_rate_label.innerText = 'Rate [£ / Hour]';
            child_rate_label.className = 'input_label label_title';
            let child_rate = document.createElement('input');
            // child_rate.outerHTML = '<input type="number" id="inv_rate_s' + si + '" class="rate" placeholder="1" step="1"/>';
            child_rate.type = 'number';
            child_rate.id = this_form_type + '_rate_s' + si;
            // Chassis Business Process Analyst
            // child_rate.placeholder = "20.33";
            // RADs Software Engineer
            child_rate.placeholder = "23.94";
            child_rate.step = '0.001';
            child_rate.min = '0';
            let child_disc_durn_quantity_label = document.createElement('label');
            // child_disc_durn_quantity_label.outerHTML = '<label for="inv_durndisc_quantity_s' + si + '">Quantity of duration discretisations:</label>';
            child_disc_durn_quantity_label.id = this_form_type + '_durndisc_quantity_s' + si + '_label';
            child_disc_durn_quantity_label.innerText = 'Quantity of duration discretisations:';
            child_disc_durn_quantity_label.className = 'input_label label_title'
            let child_disc_durn_quantity = document.createElement('input');
            // child_disc_durn_quantity.outerHTML = '<input type="number" id="inv_durndisc_quantity_s' + si + '" class="rate" placeholder="1" step="1" min="1"/>';
            child_disc_durn_quantity.type = 'number';
            child_disc_durn_quantity.id = this_form_type + '_durndisc_quantity_s' + si;
            child_disc_durn_quantity.placeholder = "4";
            child_disc_durn_quantity.step = "0.001";
            child_disc_durn_quantity.min = "0.001";
            child_disc_durn_quantity.onchange = function() {
                show_discs(this_form_type, "s", i, Number(this.value));
            };
            let child_sub_quantity_label = document.createElement('label');
            // child_quantity_label.outerHTML = '<label for="inv_quantity_s' + si + '_1">Week 1:</label>';
            child_sub_quantity_label.id = this_form_type + '_sub_quantity_s' + si  + '_label';
            child_sub_quantity_label.innerText = 'Quantity of billing periods:';
            child_sub_quantity_label.className = 'input_label label_title';
            let child_sub_quantity = document.createElement('input');
            // child_quantity.outerHTML = '<input type="text" id="inv_quantity_s' + si + '_1" class="date_disc"/>';
            child_sub_quantity.type = 'number';
            child_sub_quantity.id = this_form_type + '_sub_quantity_s' + si;
            child_sub_quantity.onchange = function() {
                show_discs(this_form_type, 's', i, Number(this.value));
            }
            child_sub_quantity.placeholder = "4";
            child_sub_quantity.step = "1";
            child_sub_quantity.min = "1";
            // incremental
            let child_incremental_label = document.createElement('label');
            child_incremental_label.id = this_form_type + '_incremental_label_s' + si;
            child_incremental_label.innerText = 'Incremental duration discretisation IDs:';
            child_incremental_label.className = 'input_label label_title';
            let child_incremental_check_yes = document.createElement('input');
            child_incremental_check_yes.type = 'checkbox';
            child_incremental_check_yes.id = this_form_type + '_increment_yes_s' + si;
            child_incremental_check_yes.value = "Yes";
            child_incremental_check_yes.checked = true;
            child_incremental_check_yes.onchange = function () {
                toggle_incremental_weeks(this_form_type, 'Yes', i);
            };
            let child_incremental_check_yes_label = document.createElement('label');
            child_incremental_check_yes_label.id = this_form_type + '_increment_yes_s' + si + '_label';
            child_incremental_check_yes_label.innerText = "Yes";
            child_incremental_check_yes_label.className = 'input_subtitle';
            let child_incremental_check_no = document.createElement('input');
            child_incremental_check_no.type = 'checkbox';
            child_incremental_check_no.id = this_form_type + '_increment_no_s' + si;
            child_incremental_check_no.value = "No";
            child_incremental_check_no.checked = false;
            child_incremental_check_no.onchange = function () {
                toggle_incremental_weeks(this_form_type, 'No', i);
            };
            let child_incremental_check_no_label = document.createElement('label');
            child_incremental_check_no_label.id = this_form_type + '_increment_no_s' + si + '_label';
            child_incremental_check_no_label.innerText = "No";
            child_incremental_check_no_label.className = 'input_subtitle';
            let child_div_incremental = document.createElement('div');
            child_div_incremental.id = 'div_' + this_form_type + '_incremental_s' + si;
            child_div_incremental.className = 'tbl_container';
            let child_tbl_incremental = document.createElement('table');
            child_tbl_incremental.id = 'tbl_inv_incremental_s' + si;
            let child_tr_incremental = document.createElement('tr');
            let child_td_incremental_base = document.createElement('td');
            let child_div_incremental_base = document.createElement('div');
            child_div_incremental_base.className = 'div_input_label';
            let child_baseID_label = document.createElement('label');
            child_baseID_label.id = this_form_type + '_baseID_s' + si + '_label';
            child_baseID_label.innerText = 'Service description base (prefix):';
            child_baseID_label.className = 'input_label label_title';
            let child_baseID = document.createElement('input');
            child_baseID.type = 'text';
            child_baseID.id = this_form_type + '_baseID_s' + si;
            child_baseID.onchange = function () {
                change_incremental_phrase(this_form_type, i);
            }
            let child_td_incremental_suffix = document.createElement('td');
            let child_div_incremental_suffix = document.createElement('div');
            child_div_incremental_suffix.className = 'div_input_label';
            let child_week1_label = document.createElement('label');
            child_week1_label.id = this_form_type + '_week1_s' + si + '_label';
            child_week1_label.innerText = 'First week ID:';
            child_week1_label.className = 'input_label label_title';
            let child_week1 = document.createElement('input');
            child_week1.type = 'number';
            child_week1.id = this_form_type + '_week1_s' + si;
            child_week1.onchange = function () {
                change_incremental_phrase(this_form_type, i);
            };
            child_div_incremental_base.appendChild(child_baseID_label);
            child_div_incremental_base.appendChild(child_baseID);
            child_td_incremental_base.appendChild(child_div_incremental_base);
            child_tr_incremental.appendChild(child_td_incremental_base);
            child_div_incremental_suffix.appendChild(child_week1_label);
            child_div_incremental_suffix.appendChild(child_week1);
            child_td_incremental_suffix.appendChild(child_div_incremental_suffix);
            child_tr_incremental.appendChild(child_td_incremental_suffix);
            child_tbl_incremental.appendChild(child_tr_incremental);
            child_div_incremental.appendChild(child_tbl_incremental);

            // bringing it all together
            child_div.appendChild(child_title);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_disc_rate_label);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_disc_rate_select);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_disc_rate_quantity_label);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_disc_rate_quantity);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_rate_label);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_rate);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_disc_durn_label);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_disc_durn_select);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_disc_durn_quantity_label);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_disc_durn_quantity);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_sub_quantity_label);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_sub_quantity);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_incremental_label);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_incremental_check_yes);
            child_div.appendChild(child_incremental_check_yes_label);
            child_div.appendChild(child_incremental_check_no);
            child_div.appendChild(child_incremental_check_no_label);
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(document.createElement('br'));
            child_div.appendChild(child_div_incremental);
            child_div.appendChild(document.createElement('br'));
            // child_div.appendChild(child_div_service);
            let date_disc = 'week'; // get_select_text(document.getElementById(this_form_type + '_disc_durn_s' + si));
            let rate_disc = 'hour'; // get_select_text(document.getElementById(this_form_type + '_disc_rate_s' + si));
            child_div.appendChild(create_service_div(this_form_type, si, date_disc, rate_disc));

            switch (this_form_type) {
                case 'inv':
                    div_inv_services.appendChild(child_div);
                    inv_services_children.push(1);
                    inv_services_max++;
                    break;
                case 'est':
                    div_est_services.appendChild(child_div);
                    est_services_children.push(1);
                    est_services_max++;
                    break;
            }
        }
        update_currency();
    }
    for (let i = 1; i <= N; i++) {
        document.getElementById('div_' + this_form_type + '_service_' + String(i)).style.display = 'block'; // 'table';
    }
    if (N < inv_services_max) {
        for (let i = N + 1; i <= inv_services_max; i++) {
            document.getElementById('div_' + this_form_type + '_service_' + String(i)).style.display = 'none';
        }
    }
}

function create_service_div(this_form_type, i_str, date_disc, rate_disc) {
    
    let child_div_service = document.createElement('div');
    // child_div_service.outerHTML = '<div id="div_inv_service_' + i_str + '_1></div>';
    child_div_service.id = 'div_' + this_form_type + '_service_' + i_str;
    child_div_service.className = 'tbl_container';
    let child_tbl_service = document.createElement('table');
    child_tbl_service.id = 'tbl_' + this_form_type + '_service_' + i_str;
    let child_tr_service = create_sub_service_tr(this_form_type, i_str, "1", date_disc, rate_disc);
    child_tbl_service.appendChild(child_tr_service);
    child_div_service.appendChild(child_tbl_service);

    return child_div_service;
}

function show_goods(this_form_type) {
    let N = Number(document.getElementById(this_form_type + '_goods_n').value);
    let goods_max = 0;
    switch (this_form_type) {
        case 'inv':
            goods_max = inv_goods_max;
            break;
        case 'est':
            goods_max = est_goods_max;
            break;
    }
    if (N > goods_max) {
        for (let i = goods_max + 1; i <= N; i++) {
            // let child_div = create_good_div(this_form_type, String(i));
            let tr_good = create_sub_good_tr(this_form_type, String(i));

            switch (this_form_type) {
                case 'inv':
                    div_inv_goods.appendChild(tr_good);
                    inv_goods_max++;
                    break;
                case 'est':
                    div_est_goods.appendChild(tr_good);
                    est_goods_max++;
                    break;
            }
        }
        update_currency();
    }
    for (let i = 1; i <= N; i++) {
        document.getElementById('tr_' + this_form_type + '_good_' + String(i)).style.display = 'flex';
    }
    switch (this_form_type) {
        case 'inv':
            if (N < inv_goods_max && this_form_type == 'inv') {
                for (let i = N + 1; i <= inv_goods_max; i++) {
                    document.getElementById('tr_inv_good_' + String(i)).style.display = 'none';
                }
            }
            break;
        case 'est':
            if (N < est_goods_max && this_form_type == 'est') {
                for (let i = N + 1; i <= est_goods_max; i++) {
                    document.getElementById('tr_est_good_' + String(i)).style.display = 'none';
                }
            }
            break;
    }
}

function create_good_div(this_form_type, i_str) {
    let child_div = document.createElement('div');
    child_div.id = 'div_' + this_form_type + '_good_' + i_str;
    child_div.className = 'div_good tbl_container';
    let child_title = document.createElement('label');
    child_title.className = 'div_title';
    child_title.innerText = 'Good ' + i_str;
    let child_table = document.createElement('table');
    child_table.id = 'tbl_' + this_form_type + '_good_' + i_str;

    // bringing it all together
    child_div.appendChild(child_title);
    child_div.appendChild(document.createElement('br'));
    child_table.appendChild(create_sub_good_tr(this_form_type, i_str));
    child_div.appendChild(child_table);

    return child_div;
}

function create_sub_good_tr(this_form_type, i_str) {
    let el_tr = document.createElement('tr');
    el_tr.id = 'tr_' + this_form_type + '_good_' + i_str;
    let el_td_heading = document.createElement('td');
    // el_td_heading.style.width = '100px';
    let el_heading_label = document.createElement('label');
    el_heading_label.id = this_form_type + '_heading_g' + i_str + '_label';
    el_heading_label.innerText = 'Good ' + i_str;
    el_heading_label.className = 'input_label';
    el_heading_label.style.whiteSpace = 'nowrap';
    let el_td_name = document.createElement('td');
    let el_div_name = document.createElement('div');
    el_div_name.className = 'div_input_label';
    let el_name_label = document.createElement('label');
    // el_disc_rate_label.outerHTML = '<label for="inv_disc_rate_s' + i_str + '">Invoice service rate discretisation:</label>';
    el_name_label.id = this_form_type + '_name_g' + i_str + '_label';
    el_name_label.innerText = 'Name:';
    el_name_label.className = 'input_label';
    // let el_break = document.createElement('br');
    let el_name = document.createElement('input');
    // el_disc_rate_quantity.outerHTML = '<input type="number" id="inv_durndisc_quantity_s' + i_str + '" class="rate" placeholder="1" step="1" min="1"/>';
    el_name.type = 'text';
    el_name.id = this_form_type + '_name_g' + i_str;
    el_name.className = 'input_label';
    let el_td_value = document.createElement('td');
    let el_div_value = document.createElement('div');
    el_div_name.className = 'div_input_label';
    let el_value_label = document.createElement('label');
    // el_disc_rate_label.outerHTML = '<label for="inv_disc_rate_s' + i_str + '">Invoice service rate discretisation:</label>';
    el_value_label.id = this_form_type + '_value_g' + i_str + '_label';
    el_value_label.innerText = 'Value [£]:';
    el_value_label.className = 'input_label';
    // let el_break = document.createElement('br');
    let el_value = document.createElement('input');
    // el_disc_rate_quantity.outerHTML = '<input type="number" id="inv_durndisc_quantity_s' + i_str + '" class="rate" placeholder="1" step="1" min="1"/>';
    el_value.type = 'number';
    el_value.className = 'input_label';
    el_value.id = this_form_type + '_value_g' + i_str;
    el_value.placeholder = "20000";
    el_value.step = '0.01';
    let el_td_quantity = document.createElement('td');
    let el_div_quantity = document.createElement('div');
    el_div_name.className = 'div_input_label';
    let el_quantity_label = document.createElement('label');
    // el_disc_rate_label.outerHTML = '<label for="inv_disc_rate_s' + i_str + '">Invoice service rate discretisation:</label>';
    el_quantity_label.id = this_form_type + '_quantity_g' + i_str + '_label';
    el_quantity_label.innerText = 'Quantity of goods:';
    el_quantity_label.className = 'input_label';
    // let el_break = document.createElement('br');
    let el_quantity = document.createElement('input');
    // el_disc_rate_quantity.outerHTML = '<input type="number" id="inv_durndisc_quantity_s' + i_str + '" class="rate" placeholder="1" step="1" min="1"/>';
    el_quantity.type = 'number';
    el_quantity.id = this_form_type + '_quantity_g' + i_str;
    el_quantity.className = 'input_label';
    el_quantity.placeholder = "1";
    el_quantity.step = '1';
    el_quantity.min = '1';

    // el_div_heading.appendChild(el_heading_label);
    // el_td_heading.appendChild(el_div_heading);
    el_td_heading.appendChild(el_heading_label);
    el_tr.appendChild(el_td_heading);
    el_div_name.appendChild(el_name_label);
    el_div_name.appendChild(el_name);
    el_td_name.appendChild(el_div_name);
    el_tr.appendChild(el_td_name);
    el_div_value.appendChild(el_value_label);
    el_div_value.appendChild(el_value);
    el_td_value.appendChild(el_div_value);
    el_tr.appendChild(el_td_value);
    el_div_quantity.appendChild(el_quantity_label);
    el_div_quantity.appendChild(el_quantity);
    el_td_quantity.appendChild(el_div_quantity);
    el_tr.appendChild(el_td_quantity);

    return el_tr;
}

function change_rate_discretisation(this_form_type, service_index) { // , subservice_index
    // FUNCTION
    // following change of rate discretisation, update UI
    // ARGUMENTS
    // string this_form_type - 'inv' or 'est'
    // long service_index - index of service within form_type services
    // long subservice_index - index of subservice within service within form_type
    // OUTPUTS
    // METHODS
    // console.log('this form type = ' + this_form_type);
    // console.log('service index = ' + service_index.toString());
    let si = service_index.toString();
    // let ssi = subservice_index.toString();
    let elem_rate = document.getElementById(this_form_type + '_disc_rate_s' + si);
    let rate_quant = document.getElementById(this_form_type + '_ratedisc_quantity_s' + si).value;
    let new_rate = get_select_text(elem_rate);
    let elem_durn = document.getElementById(this_form_type + '_disc_durn_s' + si);
    let new_durn = get_select_text(elem_durn);
    let durn_quant = document.getElementById(this_form_type + '_durndisc_quantity_s' + si).value;
    let subservice_quantity = Number(document.getElementById(this_form_type + '_sub_quantity_s' + si).value);
    // assign rate text 
    document.getElementById(this_form_type + '_ratedisc_quantity_s' + si + '_label').innerText = 'Quantity of ' + new_rate.toLowerCase() + 's per minimum unit rate:'; // does not work
    if (rate_quant == "1") {
        document.getElementById(this_form_type + '_rate_s' + si + '_label').innerText = 'Rate [£ / ' + new_rate + ']:';
        for (let i = 1; i <= subservice_quantity; i++) {
            let sj = String(i);
            console.log('si = ' + si + ' + sj = ' +  sj);
            document.getElementById(this_form_type + '_quantity_s' + si + '_' + sj + '_label').innerText = new_rate + 's worked:';
        }
    } else {
        document.getElementById(this_form_type + '_rate_s' + si + '_label').innerText = 'Rate [£ / ' + rate_quant + ' ' + new_rate + 's]:';
        for (let i = 1; i <= subservice_quantity; i++) {
            let sj = String(i);
            console.log('si = ' + si + ' + sj = ' +  sj);
            document.getElementById(this_form_type + '_quantity_s' + si + '_' + sj + '_label').innerText = 'x' + rate_quant + ' ' + new_rate + 's worked:';
        }
    }
    document.getElementById(this_form_type + '_durndisc_quantity_s' + si + '_label').innerText = 'Quantity of ' + new_durn.toLowerCase() + 's per billing period:';
    if (durn_quant == "1") {
        document.getElementById(this_form_type + '_week1_s' + si + '_label').innerText = 'First ' + new_durn.toLowerCase() + ' ID:';
        document.getElementById(this_form_type + '_incremental_label_s' + si).innerText = 'Incremental ' + new_durn.toLowerCase() + ' IDs:';
        for (let i = 1; i <= subservice_quantity; i++) {
            let sj = String(i);
            console.log('si = ' + si + ' + sj = ' +  sj);
            document.getElementById(this_form_type + '_description_s' + si + '_' + sj + '_label').innerText = new_durn + ' ' + sj + ':';
        }
    } else {
        document.getElementById(this_form_type + '_week1_s' + si + '_label').innerText = 'First x' + durn_quant + ' ' + new_durn.toLowerCase() + 's ID:';
        document.getElementById(this_form_type + '_incremental_label_s' + si).innerText = 'Incremental x' + durn_quant + ' ' + new_durn.toLowerCase() + 's IDs:';
        for (let i = 1; i <= subservice_quantity; i++) {
            let sj = String(i);
            console.log('si = ' + si + ' + sj = ' +  sj);
            document.getElementById(this_form_type + '_description_s' + si + '_' + sj + '_label').innerText = 'x' + durn_quant + ' ' + new_durn.toLowerCase() + 's ' + sj + ':';
        }
    }
    // document.getElementById(this_form_type + '_week1_s' + si + '_label').innerText = 'First ' + new_durn.toLowerCase() + ' ID:';
    // document.getElementById(this_form_type + '_incremental_label_s' + si).innerText = 'Incremental ' + new_durn.toLowerCase() + ' IDs:';
    // for (let i = 1; i <= subservice_quantity; i++) {
    //     let sj = String(i);
    //     console.log('si = ' + si + ' + sj = ' +  sj);
    //     document.getElementById('inv_description_s' + si + '_' + sj + '_label').innerText = new_durn + ' ' + sj + ':';
    // }
}

function change_incremental_phrase(this_form_type, service_index) {
    let si = service_index.toString();
    let week1 = Number(document.getElementById(this_form_type + '_week1_s' + si).value);
    let baseID = document.getElementById(this_form_type + '_baseID_s' + si).value;
    let N;
    switch (this_form_type) {
        case 'inv':
            N = inv_services_children[service_index - 1];
            break;
        case 'est':
            N = est_services_children[service_index - 1];
            break;
    }
    for (let j = 1; j <= N; j++) {
        let myphrase = baseID + (week1 + j - 1).toString();
        let sj = j.toString();
        console.log('si = ' + si + ' + sj = ' + sj);
        let my_elem_str = this_form_type + '_description_s' + si + '_' + sj;
        console.log('my_elem_str = ' + my_elem_str);
        document.getElementById(my_elem_str).value = myphrase;
    }
}

function toggle_incremental_weeks(this_form_type, increment, service_index) {
    let si = service_index.toString();
    let check_yes = document.getElementById(this_form_type + '_increment_yes_s' + si);
    let check_no = document.getElementById(this_form_type + '_increment_no_s' + si);
    let div_increment = document.getElementById('div_' + this_form_type + '_incremental_s' + si);
    switch (increment) {
        case 'Yes':
            if (check_yes.checked) {
                check_no.checked = false;
                div_increment.style.display = 'flex';
                change_incremental_phrase(this_form_type, service_index);
            } else {
                check_no.checked = true;
                div_increment.style.display = 'none';
            }
            break;
        case 'No':
            if (check_no.checked) {
                check_yes.checked = false;
                div_increment.style.display = 'none';
            } else {
                check_yes.checked = true;
                div_increment.style.display = 'flex';
                change_incremental_phrase(this_form_type, service_index);
            }
            break;
    }
}

function show_discs(this_form_type, gvs, index, quantity) {
    switch (gvs) {
        case "g":
            break;
        case "s":
            let N;
            switch (this_form_type) {
                case 'inv':
                    N = inv_services_children[index - 1];
                    break;
                case 'est':
                    N = est_services_children[index - 1];
                    break;
            }
            let si = String(index);
            let service_table = document.getElementById('tbl_' + this_form_type + '_service_' + si); //'div_' + this_form_type + '_service_' + si);
            console.log('service_table id: ' + 'tbl_' + this_form_type + '_service_' + si);
            let date_disc = get_select_text(document.getElementById(this_form_type + '_disc_durn_s' + si));
            let rate_disc = get_select_text(document.getElementById(this_form_type + '_disc_rate_s' + si));
            if (quantity > N) {
                for (let i = N + 1; i <= quantity; i++) {
                    let sj = String(i);
                    let child_tr_service = create_sub_service_tr(this_form_type, si, sj, date_disc, rate_disc);
                    
                    service_table.appendChild(child_tr_service);

                    switch (this_form_type) {
                        case 'inv':
                            inv_services_children[index - 1]++;
                            break;
                        case 'est':
                            est_services_children[index - 1]++;
                            break;
                    }
                    console.log('new service div added');
                    if (document.getElementById(this_form_type + '_increment_yes_s' + si).checked) {
                        change_incremental_phrase(this_form_type, index);
                    }
                }
                change_rate_discretisation(this_form_type, index);
            }
            for (let i = 1; i <= quantity; i++) {
                // console.log("showing: " + 'tr_' + this_form_type + '_service_' + si + '_' + String(i));
                document.getElementById('tr_' + this_form_type + '_service_' + si + '_' + String(i)).style.display = 'table-row';
            }
            if (quantity < N) {
                for (let i = quantity + 1; i <= N; i++) {
                    document.getElementById('tr_' + this_form_type + '_service_' + si + '_' + String(i)).style.display = 'none';
                }
            }
            break;
    }
}

function create_sub_service_tr(this_form_type, i_str, j_str, date_disc, rate_disc) {
    let child_tr_service = document.createElement('tr');
    child_tr_service.id = 'tr_' + this_form_type + '_service_' + i_str + '_' + j_str;
    let child_td_description = document.createElement('td');
    let child_div_description = document.createElement('div');
    // child_div_service.outerHTML = '<div id="div_inv_service_' + i_str + '_' + j_str + '></div>';
    child_div_description.className = "div_input_label"
    child_div_description.id = "div_" + this_form_type + "_service_" + i_str + "_" + j_str;
    let child_description_label = document.createElement('label');
    // child_description_label.outerHTML = '<label for="inv_description_s' + i_str + '_' + j_str + '">Week 1:</label>';
    child_description_label.innerText = date_disc + " " + j_str + ":";
    child_description_label.id = this_form_type + '_description_s' + i_str + '_' + j_str + '_label';
    child_description_label.className = 'input_label';
    let child_description = document.createElement('input');
    // child_description.outerHTML = '<input type="text" id="inv_description_s' + i_str + '_' + j_str + '" class="date_disc"/>';
    child_description.type = "text";
    console.log('creating ' + this_form_type + '_description_s with i_str=' + i_str + ' + j_str=' + j_str);
    child_description.id = this_form_type + "_description_s" + i_str + "_" + j_str;
    child_description.className = "input_label";

    let child_td_quantity = document.createElement('td');
    let child_div_quantity = document.createElement('div');
    let child_quantity_label = document.createElement('label');
    // child_quantity_label.outerHTML = '<label for="inv_quantity_s' + i_str + '_' + j_str +'">Hours worked:</label>';
    child_quantity_label.id = this_form_type + '_quantity_s' + i_str + '_' + j_str + '_label';
    child_quantity_label.innerText = rate_disc + "s worked:";
    child_quantity_label.className = 'input_label';
    let child_quantity = document.createElement('input');
    // child_quantity.outerHTML = '<input type="text" id="inv_quantity_s' + i_str + '_' + j_str + '" class="date_disc"/>';
    child_quantity.type = "number";
    child_quantity.id = this_form_type + "_quantity_s" + i_str + "_" + j_str;
    child_quantity.className = "input_label";
    child_quantity.step = "0.001";
    // child_quantity.min = "0.001";

    child_div_description.appendChild(child_description_label);
    child_div_description.appendChild(child_description);
    child_td_description.appendChild(child_div_description);
    child_tr_service.appendChild(child_td_description);
    
    child_div_quantity.appendChild(child_quantity_label);
    child_div_quantity.appendChild(child_quantity);
    child_td_quantity.appendChild(child_div_quantity);
    child_tr_service.appendChild(child_td_quantity);

    return child_tr_service;
}

function show_goods_services(this_form_type) {
    let check_goods = document.getElementById(this_form_type + '_type_goods');
    let check_services = document.getElementById(this_form_type + '_type_services');
    let div_goods = document.getElementById('div_' + this_form_type + '_goods');
    let div_services = document.getElementById('div_' + this_form_type + '_services');
    if (check_goods.checked) {
        div_goods.style.display = 'inline-block';
    } else {
        div_goods.style.display = 'none';
    }
    if (check_services.checked) {
        div_services.style.display = 'inline-block';
    } else {
        div_services.style.display = 'none';
    }
}
// estimate
// perfectly encompassed by invoice code?

// payment plan
function show_payschemes() {
    let N = Number(pay_n.value);
    if (N > 1) {
        div_pay_type.style.display = 'inline-block';
        show_paytypes(N);
        div_payscheme.style.display = 'inline-block';
    }
}

function change_paytype(my_paytype) {
    let my_this, my_that1, my_that2;
    switch (my_paytype) {
        case 'linear':
            my_this = paytype_linear;
            my_that1 = paytype_multiplier;
            my_that2 = paytype_random;
            break;
        case 'multiplier':
            my_this = paytype_multiplier;
            my_that1 = paytype_linear;
            my_that2 = paytype_random;
            break;
        case 'random':
            my_this = paytype_random;
            my_that1 = paytype_multiplier;
            my_that2 = paytype_linear;
            break;
    }
    if (my_this.checked) {
        my_that1.checked = false;
        my_that2.checked = false;
    } else {
        if (!(my_that1.checked || my_that2.checked)) {
            my_this.checked = true;
        }
    }
    show_paytypes();
}

function show_paytypes(N = Number(pay_n.value)) {
    if (paytype_linear.checked) {
        div_paytype_linear.style.display = 'inline-block';
        div_paytype_multiplier.style.display = 'none';
        div_paytype_random.style.display = 'none';
    } else if (paytype_multiplier.checked) {
        div_paytype_linear.style.display = 'none';
        div_paytype_multiplier.style.display = 'inline-block';
        div_paytype_random.style.display = 'none';
        if (N > paytype_mult_max) {
            for (let i = 1 + paytype_mult_max; i <= N; i++) {
                let si = i.toString();
                let child_label = document.createElement('label');
                // child_label.outerHTML = "<label for='paytype_mult_" + si + "' + id='label_paytype_mult_" + si + "'>Payment multiplier" + si + ":</label>";
                child_label.id = 'paytype_mult_' + si + '_label';
                child_label.innerText = "Payment multiplier " + si + ":";
                child_label.className = 'input_label';
                let child_input = document.createElement('input');
                // child_input.outerHTML = "<input type='number' id='paytype_mult_" + si + "' placeholder='10' step='0.01'>";
                child_input.type = 'number';
                child_input.id = 'paytype_mult_' + si;
                child_input.value = '1';
                child_input.step = '0.001';

                div_paytype_multiplier.appendChild(child_label);
                div_paytype_multiplier.appendChild(child_input);
                div_paytype_multiplier.appendChild(document.createElement('br'));
                div_paytype_multiplier.appendChild(document.createElement('br'));
            }
            paytype_mult_max = N;
        } else if (N < paytype_mult_max) {
            for (let i = 1; i <= N; i++) {
                let si = i.toString();
                let element1 = document.getElementById("paytype_mult_" + si + '_label');
                element1.style.display = 'inline-block';
                let element2 = document.getElementById("paytype_mult_" + si);
                element2.style.display = 'inline-block';
            }
            for (let i = N + 1; i <= paytype_mult_max; i++) {
                let si = i.toString();
                let element1 = document.getElementById("paytype_mult_" + si + '_label');
                element1.style.display = 'none';
                let element2 = document.getElementById("paytype_mult_" + si);
                element2.style.display = 'none';
            }
        }
    } else {
        div_paytype_linear.style.display = 'none';
        div_paytype_multiplier.style.display = 'none';
        div_paytype_random.style.display = 'inline-block';
        if (N > paytype_random_max) {
            for (let i = 1 + paytype_random_max; i <= N; i++) {
                let si = String(i);
                let child_label = document.createElement('label');
                // child_label.outerHTML = "<label for='paytype_mult_" + si + "' + id='label_paytype_mult_" + si + "'>Payment multiplier" + si + ":</label>";
                child_label.id = 'paytype_value_' + si + '_label';
                child_label.innerText = "Payment " + si + " [£]:";
                child_label.className = 'input_label';
                let child_input = document.createElement('input');
                // child_input.outerHTML = "<input type='number' id='paytype_mult_" + si + "' placeholder='10' step='0.01'>";
                child_input.type = 'number';
                child_input.id = 'paytype_value_' + si;
                child_input.placeholder = '10';
                child_input.step = '0.01';

                div_paytype_random.appendChild(child_label);
                div_paytype_random.appendChild(child_input);
                div_paytype_random.appendChild(document.createElement('br'));
                div_paytype_random.appendChild(document.createElement('br'));
            }
            update_currency();
            paytype_random_max = N;
        } else if (N < paytype_random_max) {
            for (let i = 1; i <= N; i++) {
                let si = i.toString();
                let element1 = document.getElementById("label_paytype_value_" + si);
                element1.style.display = 'inline-block';
                let element2 = document.getElementById("paytype_value_" + si);
                element2.style.display = 'inline-block';
            }
            for (let i = N + 1; i <= paytype_random_max; i++) {
                let si = i.toString();
                let element1 = document.getElementById("label_paytype_value_" + si);
                element1.style.display = 'none';
                let element2 = document.getElementById("paytype_value_" + si);
                element2.style.display = 'none';
            }
        }
    }
}

function change_pay_disctype(my_disctype) {
    let my_this, my_that;
    switch (my_disctype) {
        case 'absolute':
            my_this = pay_disc_type_absolute;
            my_that = pay_disc_type_relative;
            break;
        case 'relative':
            my_this = pay_disc_type_relative;
            my_that = pay_disc_type_absolute;
            break;
    }
    if (my_this.checked) {
        my_that.checked = false;
    } else  {
        if (!my_that.checked) {
            my_that.checked = true;
        }
    }
}

function show_schemes(N = Number(pay_n.value)) {
    if (payscheme_linear.checked) {
        // div_payscheme_linear.style.display = 'inline-block';
        div_payscheme_multiplier.style.display = 'none';
    } else { // if (payscheme_multiplier.checked) {
        // div_payscheme_linear.style.display = 'none';
        div_payscheme_multiplier.style.display = 'inline-block';
        if (N > payscheme_mult_max) {
            for (let i = 1 + payscheme_mult_max; i <= N; i++) {
                let si = String(i);
                let child_div = document.createElement('div');
                child_div.id = 'div_payscheme_mult_' + si;
                let child_label = document.createElement('label');
                // child_label.outerHTML = "<label for='paytype_mult_" + si + "' + id='label_paytype_mult_" + si + "'>Payment multiplier" + si + ":</label>";
                child_label.id = 'payscheme_mult_' + si + '_label';
                child_label.innerText = "Payment minimum unit duration multiplier " + si + ":";
                child_label.className = 'input_label label_title';
                let child_input = document.createElement('input');
                // child_input.outerHTML = "<input type='number' id='paytype_mult_" + si + "' placeholder='10' step='0.01'>";
                child_input.type = 'number';
                child_input.id = 'payscheme_mult_' + si;
                child_input.value = '1';
                child_input.step = '1';
                child_input.min = '1';
                
                child_div.appendChild(child_label);
                child_div.appendChild(document.createElement('br'));
                child_div.appendChild(child_input);
                child_div.appendChild(document.createElement('br'));
                child_div.appendChild(document.createElement('br'));

                div_payscheme_multiplier.appendChild(child_div);
                div_payscheme_multiplier.appendChild(document.createElement('br'));
                div_payscheme_multiplier.appendChild(document.createElement('br'));
            }
            update_currency();
            payscheme_mult_max = N;
        } else if (N < payscheme_mult_max) {
            for (let i = 1; i <= N; i++) {
                document.getElementById("label_payscheme_mult_" + si).style.display = 'inline-block';
                document.getElementById("payscheme_mult_" + si).style.display = 'inline-block';
            }
            for (let i = N + 1; i <= payscheme_mult_max; i++) {
                document.getElementById("label_payscheme_mult_" + si).style.display = 'none';
                document.getElementById("payscheme_mult_" + si).style.display = 'none';
            }
        }
    }
}

function change_payscheme(my_payscheme) {
    let my_this, my_that;
    switch (my_payscheme) {
        case 'linear':
            my_this = payscheme_linear;
            my_that = payscheme_multiplier;
            break;
        case 'multiplier':
            my_this = payscheme_multiplier;
            my_that = payscheme_linear;
            break;
    }
    if (my_this.checked) {
        my_that.checked = false;
    } else {
        if (!(my_that.checked)) {
            my_this.checked = true;
        }
    }
    show_schemes();
}

function max(a, b) {
    if (a > b) {
        return a;
    } else {
        return b;
    }
}

function min(a, b) {
    return -1 * max(-a, -b);
}

function update_pay_durndisc() {
    let new_durndisc = get_select_text(pay_discretisation);
    document.getElementById('pay_disc_quantity_label').innerText = 'Quantity of ' + new_durndisc.toLowerCase() + 's in minimum unit duration:';
    // document.getElementById('pay_disc_type_label').innerText = 'Payment ' + new_durndisc.toLowerCase() + 's in minimum unit duration:';
}

// element interation
function get_select_text(html_elem) {
    let my_options = html_elem.getElementsByTagName('option');
    let new_text = '';
    for (let i = 0; i < my_options.length; i++) {
        if (my_options[i].value == html_elem.value) {
            console.log('my_options[i].value = ' + my_options[i].value + '= html_elem.value = ' + html_elem.value);
            new_text = my_options[i].innerText;
            break;
        }
    }
    // console.log(new_text);
    return new_text;
}

function set_select(select_elem, new_value) {
    let my_options = select_elem.getElementsByTagName('option');
    for (let i = 0; i < my_options.length; i++) {
        if (new_value == my_options[i].innerText) {
            my_options[i].selected = true;
        } else {
            my_options[i].selected = false;
        }
    }
}