var utils = require('../../utils');

/* Esoteric Software SPINE wrapper for pixi.js */

spine.Bone.yDown = true;
AnimCache = {};

/**
 * A class that enables the you to import and run your spine animations in pixi.
 * Spine animation data needs to be loaded using the AssetLoader or SpineLoader before it can be used by this class
 * See example 12 (http://www.goodboydigital.com/pixijs/examples/12/) to see a working example and check out the source
 *
 * @class
 * @extends DisplayObjectContainer
 * @namespace PIXI
 * @param url {string} The url of the spine anim file to be used
 */
function Spine(url) {
    DisplayObjectContainer.call(this);

    this.spineData = AnimCache[url];

    if (!this.spineData) {
        throw new Error('Spine data must be preloaded using SpineLoader or AssetLoader: ' + url);
    }

    this.skeleton = new spine.Skeleton(this.spineData);
    this.skeleton.updateWorldTransform();

    this.stateData = new spine.AnimationStateData(this.spineData);
    this.state = new spine.AnimationState(this.stateData);

    this.slotContainers = [];

    for (var i = 0, n = this.skeleton.drawOrder.length; i < n; i++) {
        var slot = this.skeleton.drawOrder[i];
        var attachment = slot.attachment;
        var slotContainer = new DisplayObjectContainer();
        this.slotContainers.push(slotContainer);
        this.addChild(slotContainer);

        if (attachment instanceof spine.RegionAttachment) {
            var spriteName = attachment.rendererObject.name;
            var sprite = this.createSprite(slot, attachment);
            slot.currentSprite = sprite;
            slot.currentSpriteName = spriteName;
            slotContainer.addChild(sprite);
        }
        else if (attachment instanceof spine.MeshAttachment) {
            var mesh = this.createMesh(slot, attachment);
            slot.currentMesh = mesh;
            slot.currentMeshName = attachment.name;
            slotContainer.addChild(mesh);
        }
        else {
            continue;
        }

    }

    this.autoUpdate = true;
};

Spine.prototype = Object.create(DisplayObjectContainer.prototype);
Spine.prototype.constructor = Spine;
module.exports = Spine;

Object.defineProperties(Spine.prototype, {
    /**
     * If this flag is set to true, the spine animation will be autoupdated every time
     * the object id drawn. The down side of this approach is that the delta time is
     * automatically calculated and you could miss out on cool effects like slow motion,
     * pause, skip ahead and the sorts. Most of these effects can be achieved even with
     * autoupdate enabled but are harder to achieve.
     *
     * @member {boolean}
     * @memberof Spine#
     * @default true
     */
    Object.defineProperty(Spine.prototype, 'autoUpdate', {
        get: function () {
            return (this.updateTransform === Spine.prototype.autoUpdateTransform);
        },

        set: function (value) {
            this.updateTransform = value ? Spine.prototype.autoUpdateTransform : DisplayObjectContainer.prototype.updateTransform;
        }
    }
});

/**
 * Update the spine skeleton and its animations by delta time (dt)
 *
 * @param dt {number} Delta time. Time by which the animation should be updated
 */
Spine.prototype.update = function (dt) {
    this.state.update(dt);
    this.state.apply(this.skeleton);
    this.skeleton.updateWorldTransform();

    var drawOrder = this.skeleton.drawOrder;
    for (var i = 0, n = drawOrder.length; i < n; i++) {
        var slot = drawOrder[i];
        var attachment = slot.attachment;
        var slotContainer = this.slotContainers[i];

        if (!attachment) {
            slotContainer.visible = false;
            continue;
        }

        var type = attachment.type;
        if (type === spine.AttachmentType.region) {
            if (attachment.rendererObject) {
                if (!slot.currentSpriteName || slot.currentSpriteName !== attachment.name) {
                    var spriteName = attachment.rendererObject.name;
                    if (slot.currentSprite !== undefined) {
                        slot.currentSprite.visible = false;
                    }
                    slot.sprites = slot.sprites || {};
                    if (slot.sprites[spriteName] !== undefined) {
                        slot.sprites[spriteName].visible = true;
                    }
                    else {
                        var sprite = this.createSprite(slot, attachment);
                        slotContainer.addChild(sprite);
                    }
                    slot.currentSprite = slot.sprites[spriteName];
                    slot.currentSpriteName = spriteName;
                }
            }

            var bone = slot.bone;

            slotContainer.position.x = bone.worldX + attachment.x * bone.m00 + attachment.y * bone.m01;
            slotContainer.position.y = bone.worldY + attachment.x * bone.m10 + attachment.y * bone.m11;
            slotContainer.scale.x = bone.worldScaleX;
            slotContainer.scale.y = bone.worldScaleY;

            slotContainer.rotation = -(slot.bone.worldRotation * spine.degRad);

            slot.currentSprite.tint = utils.rgb2hex([slot.r,slot.g,slot.b]);
        }
        else if (type === spine.AttachmentType.skinnedmesh) {
            if (!slot.currentMeshName || slot.currentMeshName !== attachment.name) {
                var meshName = attachment.name;
                if (slot.currentMesh !== undefined) {
                    slot.currentMesh.visible = false;
                }

                slot.meshes = slot.meshes || {};

                if (slot.meshes[meshName] !== undefined) {
                    slot.meshes[meshName].visible = true;
                }
                else {
                    var mesh = this.createMesh(slot, attachment);
                    slotContainer.addChild(mesh);
                }

                slot.currentMesh = slot.meshes[meshName];
                slot.currentMeshName = meshName;
            }

            attachment.computeWorldVertices(slot.bone.skeleton.x, slot.bone.skeleton.y, slot, slot.currentMesh.vertices);

        }
        else {
            slotContainer.visible = false;
            continue;
        }
        slotContainer.visible = true;

        slotContainer.alpha = slot.a;
    }
};

/**
 * When autoupdate is set to yes this function is used as pixi's updateTransform function
 *
 * @private
 */
Spine.prototype.autoUpdateTransform = function () {
    this.lastTime = this.lastTime || Date.now();
    var timeDelta = (Date.now() - this.lastTime) * 0.001;
    this.lastTime = Date.now();

    this.update(timeDelta);

    DisplayObjectContainer.prototype.updateTransform.call(this);
};

/**
 * Create a new sprite to be used with spine.RegionAttachment
 *
 * @param slot {spine.Slot} The slot to which the attachment is parented
 * @param attachment {spine.RegionAttachment} The attachment that the sprite will represent
 * @private
 */
Spine.prototype.createSprite = function (slot, attachment) {
    var descriptor = attachment.rendererObject;
    var baseTexture = descriptor.page.rendererObject;
    var spriteRect = new Rectangle(descriptor.x,
                                        descriptor.y,
                                        descriptor.rotate ? descriptor.height : descriptor.width,
                                        descriptor.rotate ? descriptor.width : descriptor.height);
    var spriteTexture = new Texture(baseTexture, spriteRect);
    var sprite = new Sprite(spriteTexture);

    var baseRotation = descriptor.rotate ? Math.PI * 0.5 : 0.0;
    sprite.scale.set(descriptor.width / descriptor.originalWidth, descriptor.height / descriptor.originalHeight);
    sprite.rotation = baseRotation - (attachment.rotation * spine.degRad);
    sprite.anchor.x = sprite.anchor.y = 0.5;

    slot.sprites = slot.sprites || {};
    slot.sprites[descriptor.name] = sprite;
    return sprite;
};

/**
 *
 * @param slot {spine.Slot} The slot to which the attachment is parented
 * @param attachment {spine.RegionAttachment} The attachment that the sprite will represent
 * @private
 */
Spine.prototype.createMesh = function (slot, attachment) {
    var descriptor = attachment.rendererObject;
    var baseTexture = descriptor.page.rendererObject;
    var texture = new Texture(baseTexture);

    var strip = new Strip(texture);
    strip.drawMode = Strip.DrawModes.TRIANGLES;
    strip.canvasPadding = 1.5;

    strip.vertices = new Float32Array(attachment.uvs.length);
    strip.uvs = attachment.uvs;
    strip.indices = attachment.triangles;

    slot.meshes = slot.meshes || {};
    slot.meshes[attachment.name] = strip;

    return strip;
};