<template>

    <svg>

        <defs>

            <path v-bind:id="annotationHref" ref="path" v-bind:d="path" class="path"></path>

        </defs>

        <g ref="g" filter="url(#shadow)">

            <use v-bind:xlink:href="annotationSelector" v-bind:stroke-width="strokeWidth * 2" class="stroke-bg" />

            <use v-bind:xlink:href="annotationSelector" v-bind:stroke-width="strokeWidth" class="stroke-fg" />

            <circle ref="handlers"

                v-for="(point, key) in points"

                :key="key"

                v-show="!readonly"

                v-bind:data-key="key"

                v-bind:cx="point.x"

                v-bind:cy="point.y"

                v-bind:r="strokeWidth * 2"

                v-bind:stroke-width="strokeWidth"

                v-bind:class="{ handler: true, 'handler--first': key === 0 &amp;&amp; !closed }"></circle>

        <g>

    </svg>

</template>

<script>

    import Snap from 'snapsvg'

    import tooltip from './mixins/tooltip'

    import save from './mixins/save'

    export default {

        mixins: [ tooltip, save ],

        props: [

            'paper',

            'original-annotation',

            'original-path',

            'readonly',

            'stroke-width',

        ],

        data() {

            return {

                path: '',

                closed: false,

                points: [],

            }

        },

        computed: {

            annotationHref: function() {

                if (this.originalAnnotation) {

                    return 'annotation-path-' + this.originalAnnotation.annotation_guid;

                } else {

                    return 'annotation-path-new';

                }

            },

            annotationSelector: function() {

                return '#' + this.annotationHref;

            }

        },

        mounted() {

            if (this.originalPath) {

                this.fromSVGPath(this.originalPath, false);

                var g = new Snap(this.$refs.g);

                g.click(() => this.$emit('click'));

            }

        },

        watch: {

            closed: function(closed) {

                if (closed) {

                    this.path += ' Z';

                }

            },

            // Redraw the path when the points have changed

            points: function(points) {

                var path = "M";

                if (points.length <= 1) {

                    return;

                }

                path += points[0].x + ',' + points[0].y;

                for (var i = 0; i < points.length; i++) {

                    if (i == 0) continue;

                    var pointInfos = points[i];

                    var lPath = "L" + pointInfos.x + "," + pointInfos.y;

                    path += " " + lPath;

                }

                if (this.closed) { path += ' Z'; }

                this.path = path;

            }

        },

        methods: {

            addPoint: function(x, y) {

                this.points.push({ x: x, y: y });

                // Attach events to last point once DOM has been refreshed

                // @link https://vuejs.org/v2/guide/reactivity.html

                this.$nextTick(() => {

                    var handler = this.$refs.handlers[this.$refs.handlers.length - 1];

                    this.addResizeHandler(handler);

                });

            },

            clear: function() {

                this.destroyTooltip();

                Object.assign(this, {

                    points: [],

                    closed: false,

                    path: ''

                });

            },

            getTooltipTarget: function() {

                return this.$refs.path;

            },

            fromSVGPath: function(pathString, tooltip) {

                var segments = Snap.parsePathString(pathString);

                var points = [];

                // Don't use this.addPoint to avoid

                // race condition when registering events

                segments.map((segment) => {

                    if (segment[0] !== 'Z') {

                        points.push({ x: segment[1], y: segment[2] });

                    }

                });

                this.points = points;

                this.closed = true;

                this.$nextTick(() => {

                    this.addResizeHandlers();

                    if (tooltip) {

                        // FIXME Race condition with destroy

                        setTimeout(() => this.addTooltip(), 250);

                    }

                });

            },

            toSVGPath: function() {

                return this.$parent.normalizePath(this.path) + ';FREE'

            },

            addResizeHandler: function(handler) {

                var self = this;

                var circle = new Snap(handler);

                var isDragged = false;

                circle.click((e) => {

                    var key = parseInt(circle.attr('data-key'), 10);

                    if (key === 0 && this.points.length > 2) {

                        this.closed = true;

                        this.$nextTick(() => {

                            // FIXME Race condition with destroy

                            setTimeout(() => this.addTooltip(), 250);

                        });

                    }

                });

                // Remove point on double click

                circle.dblclick((e) => {

                    var circle = new Snap(e.target);

                    var key = parseInt(circle.attr('data-key'), 10);

                    this.points.splice(key, 1);

                });

                var dragEvents = {

                    onMove: function(dx, dy, x, y, e) {

                        isDragged = true;

                        var offset = self.$parent.computeOffset(e);

                        this.attr({ cx: offset.x, cy: offset.y });

                        var key = parseInt(this.attr('data-key'), 10);

                        // Must use splice for reactivity to work

                        // @see https://vuejs.org/v2/guide/list.html#Mutation-Methods

                        self.points.splice(key, 1, { x: offset.x, y: offset.y });

                    },

                    onStart: () => this.hideTooltip(),

                    onEnd: function(e) {

                        if (!isDragged) { return; }

                        isDragged = false;

                        self.showTooltip();

                    }

                }

                circle.drag(dragEvents.onMove, dragEvents.onStart, dragEvents.onEnd);

            },

            addResizeHandlers: function() {

                this.$refs.handlers.forEach((handler) => this.addResizeHandler(handler));

            }

        }

    }

</script>

<style scoped>

.handler {

    fill: #fff;

    stroke: #000;

}

.path {

    stroke: inherit;

    stroke-width: inherit;

    fill: inherit;

    transform: inherit;

}

.stroke-fg {

    stroke: #000;

    fill: transparent;

}

.stroke-fg:hover {

    cursor: pointer;

    fill: #c5f2ff;

    opacity: 0.25;

    stroke-opacity: 1;

}

.stroke-bg {

    stroke: #fff;

    fill: transparent;

}

.handler--first {

    fill: yellow;

}

</style>