<template>
    <div class="zoom">
        <div>
            <svg ref="svg"
                v-bind:class="{ 'cut-canvas': true, 'canvas--rect': mode === 'rect', 'canvas--free': mode === 'free' }"
                xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
                <image ref="image" v-if="loaded" xmlns:xlink="http://www.w3.org/1999/xlink" v-bind:xlink:href="image" x="0" y="0" />
                <!-- This slot may contain annotation data -->
                <slot></slot>
                <shape-rect ref="rect" v-show="loaded &amp;&amp; mode == 'rect'"
                    v-bind:paper="paper" v-bind:original-annotation="annotation"></shape-rect>
                <shape-free ref="free" v-show="loaded &amp;&amp; mode == 'free'"
                    v-bind:paper="paper" v-bind:original-annotation="annotation"></shape-free>
            </svg>
        </div>
        <div class="zoomer">
            <div class="btn-group-vertical" role="group" aria-label="...">
                <button @click="zoomIn" type="button" class="btn btn-default"><i class="fa fa-plus" aria-hidden="true"></i></button>
                <button @click="zoomOut" type="button" class="btn btn-default"><i class="fa fa-minus" aria-hidden="true"></i></button>
            </div>
        </div>
        <div class="mode-controls">
            <div class="btn-group" role="group" aria-label="...">
                <button @click="mode = 'rect'" type="button" v-bind:class="{ btn: true, 'btn-default': true, 'btn-primary': mode === 'rect'}">
                    <svg width="24" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" x="0px" y="0px" viewBox="0 0 512 512" enable-background="new 0 0 512 512" xml:space="preserve"><g><rect x="352" y="432" width="64" height="48"/><polygon points="416,352 416,96 176,96 176,160 352,160 352,352 160,352 160,32 96,32 96,96 32,96 32,160 96,160 96,416 480,416 480,352"/></g><text x="0" y="527" fill="#000000" font-size="5px" font-weight="bold" font-family="'Helvetica Neue', Helvetica, Arial-Unicode, Arial, Sans-serif">Created by Bluetip Design</text><text x="0" y="532" fill="#000000" font-size="5px" font-weight="bold" font-family="'Helvetica Neue', Helvetica, Arial-Unicode, Arial, Sans-serif">from the Noun Project</text></svg>
                </button>
                <button @click="mode = 'free'" type="button" v-bind:class="{ btn: true, 'btn-default': true, 'btn-primary': mode === 'free'}">
                    <svg width="24" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" x="0px" y="0px" viewBox="0 0 30 30" xml:space="preserve"><g transform="translate(-450 -380)"><g xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><path d="M453,395c0,2.209,1.79,4,4,4c1.307,0,2.455-0.635,3.186-1.604l7.121,4.069C467.11,401.938,467,402.456,467,403    c0,2.209,1.79,4,4,4c2.209,0,4-1.791,4-4s-1.791-4-4-4c-1.307,0-2.455,0.635-3.186,1.604l-7.121-4.069    c0.196-0.473,0.307-0.99,0.307-1.534s-0.11-1.062-0.307-1.534l7.121-4.069c0.73,0.969,1.879,1.604,3.186,1.604    c2.209,0,4-1.791,4-4s-1.791-4-4-4c-2.21,0-4,1.791-4,4c0,0.544,0.11,1.062,0.307,1.534l-7.121,4.069    c-0.73-0.969-1.879-1.604-3.186-1.604C454.79,391,453,392.791,453,395z M471,400c1.654,0,3,1.346,3,3s-1.346,3-3,3s-3-1.346-3-3    S469.346,400,471,400z M471,384c1.654,0,3,1.346,3,3s-1.346,3-3,3s-3-1.346-3-3S469.346,384,471,384z M460,395    c0,1.654-1.346,3-3,3s-3-1.346-3-3s1.346-3,3-3S460,393.346,460,395z"/></g></g><text x="0" y="45" fill="#000000" font-size="5px" font-weight="bold" font-family="'Helvetica Neue', Helvetica, Arial-Unicode, Arial, Sans-serif">Created by Hea Poh Lin</text><text x="0" y="50" fill="#000000" font-size="5px" font-weight="bold" font-family="'Helvetica Neue', Helvetica, Arial-Unicode, Arial, Sans-serif">from the Noun Project</text></svg>
                </button>
            </path>
        </div>
    </div>
</template>

<script>

    import Snap from 'snapsvg'
    import ShapeRect from './ShapeRect.vue'
    import ShapeFree from './ShapeFree.vue'

    export default {
        props: {
            image: String,
            annotation: {
                type: Object,
                default: function () {
                    return null;
                }
            },
            tooltip: {
                type: Boolean,
                default: function () {
                    return false;
                }
            },
        },
        components: {
            shapeRect: ShapeRect,
            shapeFree: ShapeFree
        },
        data() {
            return {
                paper: null,
                loaded: false,
                mode: 'rect',
                viewport: { width: 0, height: 0 },
                viewBox: [0 , 0, 0, 0],
                zoomFactor: 0.1,
                scale: 1,
                imgMinSize: 0,
                imageWidth: 0,
                imageHeight: 0,
            }
        },
        watch: {
            mode: function(mode) {
                this.reset();
                if (mode === 'free') {
                    this.handleDrawFree();
                }
                if (mode === 'rect') {
                    this.handleDrawRect();
                }
            },
            loaded: function(loaded) {
                if (!loaded) { return; }

                if (this.annotation) {
                    this.loadAnnotation();
                } else {
                    if (this.mode === 'free') {
                        this.handleDrawFree();
                    }
                    if (this.mode === 'rect') {
                        this.handleDrawRect();
                    }
                }
            },
            annotation: function(annotation) {
                this.reset();
                if (!this.annotation) { return; }
                this.loadAnnotation();
            }
        },
        mounted() {

            var img = new Image();
            img.onload = (e) => {

                this.paper = new Snap(this.$refs.svg);

                this.imgMinSize = Math.min(img.width, img.height);

                // FIXME
                // Image is actually NOT loaded at this step
                setTimeout(() => {

                    console.log('Viewport: %s x %s',
                        this.paper.node.clientWidth, this.paper.node.clientHeight);

                    var viewBox = [0 , 0, img.width, img.height];
                    var viewport = {
                        width: this.paper.node.clientWidth,
                        height: this.paper.node.clientHeight
                    };

                    Object.assign(this, {
                        imageWidth: img.width,
                        imageHeight: img.height,
                        viewBox: viewBox,
                        viewport: viewport,
                    });

                    var handlerSize = 15 * Math.min(viewBox[2], viewBox[3]) / viewport.width;

                    this.$refs.rect.handlerSize = handlerSize;
                    this.$refs.free.handlerRadius = handlerSize / 2;

                    this.paper.attr({"viewBox": this.viewBox});

                    this.loaded = true;

                }, 100);

            }
            img.src = this.image;

        },
        methods: {

            reset: function() {
                // Clear shapes
                this.$refs.rect.clear();
                this.$refs.free.clear();

                this.removeEventHandlers();

                if (this.mode === 'free') {
                    this.handleDrawFree();
                }
                if (this.mode === 'rect') {
                    this.handleDrawRect();
                }
            },

            removeEventHandlers: function() {
                this.paper.unmousedown();
                this.paper.unmousemove();
                this.paper.unmouseup();
                this.paper.unclick();
            },

            loadAnnotation: function() {
                if (this.annotation.fragment.length > 0) {
                    var pieces = this.annotation.fragment.split(';');
                    var path = pieces[0];
                    var mode = pieces[1].toLowerCase();

                    this.mode = mode;

                    this.$nextTick(() => {
                        path = this.denormalizePath(path);
                        if (mode === 'free') {
                            this.$refs.free.fromSVGPath(path, this.tooltip);
                        }
                        if (mode === 'rect') {
                            this.$refs.rect.fromSVGPath(path, this.tooltip);
                        }
                    });
                }
            },

            getCenter: function() {
                return {
                    x: this.viewBox[0] + (this.viewBox[2] / 2),
                    y: this.viewBox[1] + (this.viewBox[3] / 2)
                }
            },

            resetZoom: function() {
                this.scale = 1;
                this.viewBox = [0, 0, this.imageWidth, this.imageHeight];
                this.paper.attr({ "viewBox": this.viewBox });
            },

            zoomIn: function() {

                if ( this.scale === 9) { this.scale--; return; }

                var center = this.getCenter();
                var scaleFactor = this.zoomFactor * this.scale;

                var viewBoxW = this.imgMinSize - (this.imgMinSize * scaleFactor);
                var viewBoxH = viewBoxW;

                const viewBoxPrev = this.viewBox.slice(0);

                this.viewBox[0] = center.x - viewBoxW / 2;
                this.viewBox[1] = center.y - viewBoxH / 2;
                this.viewBox[2] = viewBoxW;
                this.viewBox[3] = viewBoxH;

                this.scale++;

                // this.paper.attr({ "viewBox": this.viewBox });

                this.$refs.rect.hideTooltip();
                Snap.animate(
                    viewBoxPrev, this.viewBox,
                    (viewBox) => this.paper.attr({ "viewBox": viewBox }),
                    300, mina.easeinout,
                    () => this.$refs.rect.showTooltip()
                );
            },

            zoomOut: function() {

                if (this.scale === 1) { this.resetZoom(); return; }

                var center = this.getCenter();
                var scaleFactor = this.zoomFactor * (this.scale - 1);

                var viewBoxW = this.imgMinSize - (this.imgMinSize * scaleFactor);
                var viewBoxH = viewBoxW;

                var topX = center.x - viewBoxW / 2;
                var topY = center.y - viewBoxH / 2;

                const viewBoxPrev = this.viewBox.slice(0);

                this.viewBox[0] = topX; //deal with X and Y
                this.viewBox[1] = topY;
                this.viewBox[2] = viewBoxW;
                this.viewBox[3] = viewBoxH;

                this.scale--;

                // this.paper.attr({ "viewBox": this.viewBox });

                this.$refs.rect.hideTooltip();
                Snap.animate(
                    viewBoxPrev, this.viewBox,
                    (viewBox) => this.paper.attr({ "viewBox": viewBox }),
                    300, mina.easeinout,
                    () => this.$refs.rect.showTooltip()
                );
            },

            zoomOffset: function() {
                return {
                    x: this.viewport.width / this.viewBox[2],
                    y: this.viewport.height / this.viewBox[3]
                };
            },

            computeOffset: function(e) {
                var rect = this.$refs.image.getBoundingClientRect();
                var zoomOffset = this.zoomOffset();
                var offsetX = (e.clientX - rect.left) / Math.min(zoomOffset.x, zoomOffset.y);
                var offsetY  = (e.clientY - rect.top) / Math.min(zoomOffset.x, zoomOffset.y);

                return { x: offsetX, y: offsetY };
            },

            computeHandlerSize: function(e) {
                return 60 * Math.min(this.viewBox[2], this.viewBox[3]) / this.imageWidth;
            },

            normalizePath: function(path) {

                var xRatio = 100 / this.imageWidth;
                var yRatio = 100 / this.imageHeight;

                if (isNaN(xRatio) || isNaN(yRatio)) {
                    throw new Error('Ratio should be a number.');
                }

                var normalizeMatrix = Snap.matrix(xRatio, 0, 0, yRatio, 0, 0);

                path = Snap.path.map(path, normalizeMatrix).toString();

                if (path.search(/[z|Z]/gi) === -1) {
                    path += " Z";
                }

                return path;
            },

            denormalizePath: function(path) {

                var xRatio = this.imageWidth / 100;
                var yRatio = this.imageHeight / 100;

                if (isNaN(xRatio) || isNaN(yRatio)) {
                    throw new Error('Ratio should be a number.');
                }

                var transformMatrix = Snap.matrix(xRatio, 0, 0, yRatio, 0, 0);

                path = Snap.path.map(path, transformMatrix).toString();

                if (path.search(/[z|Z]/gi) === -1) {
                    path += " Z";
                }

                return path;
            },

            toSVGPath: function() {
                if (this.mode === 'free') {
                    this.$refs.free.toSVGPath();
                }
                if (this.mode === 'rect') {
                    this.$refs.rect.toSVGPath();
                }
            },

            handleDrawFree: function() {

                this.removeEventHandlers();

                var clickTimeout;

                var clickHandler = function (offsetX, offsetY) {
                    clickTimeout = null;
                    this.$refs.free.addPoint(offsetX, offsetY);
                }

                this.paper.click((e) => {
                    if (clickTimeout) { return; }
                    if (!$(e.target).is('image')) { return; }
                    if (this.$refs.free.closed) { return; }

                    var offset = this.computeOffset(e);
                    var offsetX = offset.x;
                    var offsetY = offset.y;
                    clickTimeout = setTimeout(clickHandler.bind(this, offsetX, offsetY), 190);
                });

            },

            handleDrawRect: function() {

                this.removeEventHandlers();

                var startPosition = { x: 0, y: 0 };
                var currentPosition = { x: 0, y: 0 };
                var canDraw = false;

                var computeOffset = (e) => {
                    var rect = this.$refs.image.getBoundingClientRect();
                    var zoomOffset = this.zoomOffset();
                    var offsetX = (e.clientX - rect.left) / Math.min(zoomOffset.x, zoomOffset.y);
                    var offsetY  = (e.clientY - rect.top) / Math.min(zoomOffset.x, zoomOffset.y);

                    return { x: offsetX, y: offsetY };
                }

                this.paper.mousedown((e) => {

                    if (this.$refs.rect.width > 0 && this.$refs.rect.height > 0) { return; }

                    startPosition = computeOffset(e);
                    canDraw = true;
                });

                this.paper.mousemove((e) => {

                    if (!canDraw) { return; }

                    var x, y;
                    currentPosition = computeOffset(e);

                    /* bas -> droite */
                    var width = Math.abs(currentPosition.x - startPosition.x);
                    var height = Math.abs(startPosition.y - currentPosition.y);

                    if (currentPosition.y > startPosition.y && currentPosition.x > startPosition.x) {
                        x = startPosition.x;
                        y = startPosition.y;
                    }

                    /* haut -> droite */
                    if (currentPosition.y < startPosition.y && currentPosition.x > startPosition.x) {
                        x = currentPosition.x - width;
                        y = currentPosition.y;
                    }

                    /* haut -> gauche */
                    if (currentPosition.y < startPosition.y && currentPosition.x < startPosition.x) {
                        x = currentPosition.x;
                        y = currentPosition.y;
                    }

                    /* bas -> gauche */
                    if (currentPosition.y > startPosition.y && currentPosition.x < startPosition.x) {
                        x = currentPosition.x
                        y = currentPosition.y - height;
                    }

                    if(!x || !y) { return; }

                    Object.assign(this.$refs.rect, {
                        x: x,
                        y: y,
                        width: width,
                        height: height,
                    });
                });

                this.paper.mouseup((e) => {

                    if (!canDraw) { return; }

                    canDraw = false;

                    if (this.$refs.rect.width === 0 && this.$refs.rect.height === 0) {
                        var currentPosition = computeOffset(e);
                        Object.assign(this.$refs.rect, {
                            x: currentPosition.x,
                            y: currentPosition.y,
                            width: this.imgMinSize / 4,
                            height: this.imgMinSize / 4,
                        });
                    }

                    this.$nextTick(() => {
                        this.$refs.rect.addResizeHandlers();
                        this.$refs.rect.addTooltip();
                    });

                });
            }
        }
    }

</script>

<style scoped>
.zoom {
    position: relative;
}
.zoomer {
    position: absolute;
    bottom: 30px;
    right: 30px;
}
.cut-canvas {
    width: 100%;
    height: 600px;
}
.canvas--rect:hover {
    cursor: crosshair;
}
.canvas--free:hover {
    cursor: pointer;
}
.mode-controls {
    position: absolute;
    top: 15px;
    left: 15px;
}
.mode-controls .btn > svg {
    margin-top: 4px;
}
.mode-controls .btn-primary > svg {
    fill: #fff;
}

</style>
