(function($) {
    $.fn.annotatorPNG = function(options) {
        var settings = $.extend({
            heightCanvas: "600px",
            widthCanvas: "800px",
            textButtonSave: "Save Image",
        }, options);


        function getCanvas() {
            let $annotatorPNG = $(document).find("." + flagAnnotatorPNG);
            let $canvasAnnotation = $($annotatorPNG.find("canvas." + flagCanvasAnnotation)[0]);
            let canvas = $canvasAnnotation.data(keyFabric);
            return canvas;
        }

        function deleteSelectedObjects() {
            let canvas = getCanvas();
            const activeObject = canvas.getActiveObject();
            if (activeObject) {
                console.log("active object type:", activeObject.type);
                if (activeObject.type === 'activeSelection') {
                    activeObject.forEachObject(function(obj) {
                        canvas.remove(obj);
                    });
                    canvas.discardActiveObject();
                } else {
                    canvas.remove(activeObject);
                }
                canvas.requestRenderAll();
            }
        }

        return this.each(function() {
            let $annotatorPNG = $(this);
            let $toolbox = $annotatorPNG.find("." + flagToolbox);
            let $inputUploadImage = $toolbox.find("." + flagUploadImage);
            let $buttonAddArrow = $toolbox.find("." + flagAddArrow);
            let $buttonAddTextbox = $toolbox.find("." + flagAddTextbox);
            let $selectAddSymbol = $toolbox.find("." + flagAddSymbol);
            let $inputColourPicker = $toolbox.find("." + flagColourPicker);
            let $buttonEraseMode = $toolbox.find("." + flagEraseMode);
            let $buttonSaveImage = $toolbox.find("." + flagSaveImage);
            let $containerAnnotation = $annotatorPNG.find("." + flagContainerAnnotation);
            let $canvasAnnotation = $containerAnnotation.find("." + flagCanvasAnnotation);
            
            // Default values
            $inputUploadImage.val('');

            const symbols = ['Orange Arrow.png'];
            symbols.forEach(symbol => {
                $selectAddSymbol.append($("<option>", {
                    value: symbol,
                    text: symbol.replace('.png', ''),
                }));
            });
            
            $inputColourPicker.val('#ff0000');

            $buttonEraseMode.textContent = "Erase Mode";
            $annotatorPNG.data(keyIsEraseMode, false);

            $buttonSaveImage.text(settings.textButtonSave);
            
            $canvasAnnotation.css({
                height: settings.heightCanvas,
                width: settings.widthCanvas,
            });
            console.log("canvas: ", $canvasAnnotation[0]);
            var canvas = new fabric.Canvas($canvasAnnotation[0], {
                // containerClass: flagContainerAnnotation,
            });
            canvas.clear();
            canvas.selection = true;
            $canvasAnnotation.data(keyFabric, canvas);
           
            // Triggers
            if (!$inputUploadImage.hasClass(flagInitialised)) {
                $inputUploadImage.addClass(flagInitialised);
                $inputUploadImage.on("change", function(event) {
                    console.log("File uploaded:", event.target.files[0]);
                    const file = event.target.files[0];
                    if (!file) {
                        return;
                    }
                    if (!(file.type == 'image/png')) {
                        alert("Please upload a PNG file.");
                        throw new Error("Invalid file type.");
                        return;
                    }
                    const reader = new FileReader();
                    let canvas = getCanvas();
                    reader.onload = function(eventReader) {
                        fabric.Image.fromURL(eventReader.target.result, function(image) {
                            canvas.setBackgroundImage(image, canvas.renderAll.bind(canvas), {
                                scaleX: settings.widthCanvas.replace('px', '') / image.width,
                                scaleY: settings.heightCanvas.replace('px', '') / image.height,
                            });
                        });
                    };
                    reader.readAsDataURL(file);
                });
            }
            
            if (!$buttonAddArrow.hasClass(flagInitialised)) {
                $buttonAddArrow.addClass(flagInitialised);
                $buttonAddArrow.on("click", function() {
                    console.log("Add Arrow clicked");
                    let canvas = getCanvas();
                    const arrow = new fabric.Path('M 0 0 L 200 100', {
                        fill: $inputColourPicker.val(),
                        stroke: $inputColourPicker.val(),
                        strokeWidth: 2,
                        left: 100,
                        top: 100,
                        selectable: true,
                    });
                    canvas.add(arrow);
                    canvas.renderAll();
                });
            }

            if (!$buttonAddTextbox.hasClass(flagInitialised)) {
                $buttonAddTextbox.addClass(flagInitialised);
                $buttonAddTextbox.on("click", function() {
                    console.log("Add Textbox clicked");
                    let canvas = getCanvas();
                    const textbox = new fabric.Textbox('Type here', {
                        left: 100,
                        top: 100,
                        width: 150,
                        fontSize: 20,
                        fill: $inputColourPicker.val(),
                        selectable: true,
                    });
                    canvas.add(textbox);
                    canvas.renderAll();
                });
            }

            if (!$selectAddSymbol.hasClass(flagInitialised)) {
                $selectAddSymbol.addClass(flagInitialised);
                $selectAddSymbol.on("change", function() {
                    console.log("Add Symbol changed:", this.value);
                    if (this.value) {
                        let canvas = getCanvas();
                        fabric.Image.fromURL(`symbols/${this.value}`, function(image) {
                            image.set({
                                left: 100,
                                top: 100,
                                scaleX: 0.5,
                                scaleY: 0.5,
                            });
                            canvas.add(image);
                        });
                        this.value = '';
                    }
                });
            }

            if (!$inputColourPicker.hasClass(flagInitialised)) {
                $inputColourPicker.addClass(flagInitialised);
                $inputColourPicker.on("change", function() {
                    console.log("Colour Picker changed:", this.value);
                    let canvas = getCanvas();
                    canvas.renderAll();
                    const activeObject = canvas.getActiveObject();
                    if (activeObject) {
                        if (activeObject.type === 'textbox') {
                            activeObject.set('fill', this.value);
                        } else {
                            activeObject.set('fill', this.value);
                            activeObject.set('stroke', this.value);
                        }
                        canvas.renderAll();
                    }
                });
            }

            if (!$buttonEraseMode.hasClass(flagInitialised)) {
                $buttonEraseMode.addClass(flagInitialised);
                $buttonEraseMode.data(keyIsEraseMode, false);
                $buttonEraseMode.on("click", function() {
                    console.log("Erase Mode clicked");
                    let isEraseMode = $annotatorPNG.data(keyIsEraseMode);
                    isEraseMode = !isEraseMode;
                    $annotatorPNG.data(keyIsEraseMode, isEraseMode);
                    console.log("Erase Mode:", isEraseMode);
                    this.textContent = isEraseMode ? 'Exit Erase Mode' : 'Erase Mode';
                    
                    if (isEraseMode) {
                        deleteSelectedObjects();
                        
                        canvas.selection = false;
                        canvas.isDrawingMode = false;
                        
                        canvas.defaultCursor = 'crosshair';
                        canvas.hoverCursor = 'crosshair';
                    } else {
                        canvas.selection = true;
                        canvas.defaultCursor = 'default';
                        canvas.hoverCursor = 'move';
                    }
                });
            }
            

            if (!$canvasAnnotation.hasClass(flagInitialised)) {
                $canvasAnnotation.addClass(flagInitialised);
                // Object selection in erase mode
                $canvasAnnotation.on('selection:created', function() {
                    console.log("Selection created");
                    let isEraseMode = $annotatorPNG.data(keyIsEraseMode);
                    if (isEraseMode) {
                        deleteSelectedObjects();
                    }
                });

                // Object click in erase mode
                $canvasAnnotation.on('mouse:down', function(event) {
                    console.log("Canvas mouse down:", event);
                    let isEraseMode = $annotatorPNG.data(keyIsEraseMode);
                    if (isEraseMode && event.target) {
                        let canvas = getCanvas();
                        canvas.remove(event.target);
                        canvas.requestRenderAll();
                    }
                });

                // Prevent dragging in erase mode
                $canvasAnnotation.on('object:moving', function(event) {
                    console.log("Canvas object moving:", event);
                    let isEraseMode = $annotatorPNG.data(keyIsEraseMode);
                    if (isEraseMode) {
                        let canvas = getCanvas();
                        event.target.setCoords();
                        canvas.remove(event.target);
                        canvas.requestRenderAll();
                    }
                });
            }

            if (!$buttonSaveImage.hasClass(flagInitialised)) {
                $buttonSaveImage.addClass(flagInitialised);
                $buttonSaveImage.on("click", function() {
                    let canvas = getCanvas();
                    if (window.confirm("Please ensure there is no sensitive information or PII in your annotations. Do you want to proceed with saving?")) {
                        const dataURL = canvas.toDataURL({
                            format: 'png',
                            quality: 1
                        });

                        // Output
                        console.log("Base64 string:", dataURL);
                    
                        let a = document.createElement('a');
                        a.style.display = 'none';
                        a.href = dataURL;
                        a.download = settings.fileName;

                        /* Download image
                        document.body.appendChild(a);
                        a.click();
                        document.body.removeChild(a);
                        */

                        alert("Image saved as Base64 string. Check the console for the output.");
                    }
                });
            }
        });
    };
}(jQuery));