import * as core from '../core';

const tempPoint = new core.Point();
const tempPolygon = new core.Polygon();

/**
 * Base mesh class
 * @class
 * @extends PIXI.Container
 * @memberof PIXI.mesh
 */
export default class Mesh extends core.Container
{
    /**
     * @param {PIXI.Texture} texture - The texture to use
     * @param {Float32Array} [vertices] - if you want to specify the vertices
     * @param {Float32Array} [uvs] - if you want to specify the uvs
     * @param {Uint16Array} [indices] - if you want to specify the indices
     * @param {number} [drawMode] - the drawMode, can be any of the Mesh.DRAW_MODES consts
     */
    constructor(texture, vertices, uvs, indices, drawMode)
    {
        super();

        /**
         * The texture of the Mesh
         *
         * @member {PIXI.Texture}
         * @private
         */
        this._texture = null;

        /**
         * The Uvs of the Mesh
         *
         * @member {Float32Array}
         */
        this.uvs = uvs || new Float32Array([0, 0,
                1, 0,
                1, 1,
                0, 1]);

        /**
         * An array of vertices
         *
         * @member {Float32Array}
         */
        this.vertices = vertices || new Float32Array([0, 0,
                100, 0,
                100, 100,
                0, 100]);

        /*
         * @member {Uint16Array} An array containing the indices of the vertices
         */
        //  TODO auto generate this based on draw mode!
        this.indices = indices || new Uint16Array([0, 1, 3, 2]);

        /**
         * Version of mesh uvs are dirty or not
         *
         * @member {number}
         */
        this.dirty = 0;

        /**
         * Version of mesh indices
         *
         * @member {number}
         */
        this.indexDirty = 0;

        /**
         * The blend mode to be applied to the sprite. Set to `PIXI.BLEND_MODES.NORMAL` to remove
         * any blend mode.
         *
         * @member {number}
         * @default PIXI.BLEND_MODES.NORMAL
         * @see PIXI.BLEND_MODES
         */
        this.blendMode = core.BLEND_MODES.NORMAL;

        /**
         * Triangles in canvas mode are automatically antialiased, use this value to force triangles
         * to overlap a bit with each other.
         *
         * @member {number}
         */
        this.canvasPadding = 0;

        /**
         * The way the Mesh should be drawn, can be any of the {@link PIXI.mesh.Mesh.DRAW_MODES} consts
         *
         * @member {number}
         * @see PIXI.mesh.Mesh.DRAW_MODES
         */
        this.drawMode = drawMode || Mesh.DRAW_MODES.TRIANGLE_MESH;

        // run texture setter;
        this.texture = texture;

        /**
         * The default shader that is used if a mesh doesn't have a more specific one.
         *
         * @member {PIXI.Shader}
         */
        this.shader = null;

        /**
         * The tint applied to the mesh. This is a [r,g,b] value. A value of [1,1,1] will remove any
         * tint effect.
         *
         * @member {number}
         * @memberof PIXI.mesh.Mesh#
         */
        this.tintRgb = new Float32Array([1, 1, 1]);

        /**
         * A map of renderer IDs to webgl render data
         *
         * @private
         * @member {object<number, object>}
         */
        this._glDatas = {};
    }

    /**
     * Renders the object using the WebGL renderer
     *
     * @private
     * @param {PIXI.WebGLRenderer} renderer - a reference to the WebGL renderer
     */
    _renderWebGL(renderer)
    {
        renderer.setObjectRenderer(renderer.plugins.mesh);
        renderer.plugins.mesh.render(this);
    }

    /**
     * Renders the object using the Canvas renderer
     *
     * @private
     * @param {PIXI.CanvasRenderer} renderer - The canvas renderer.
     */
    _renderCanvas(renderer)
    {
        renderer.plugins.mesh.render(this);
    }

    /**
     * When the texture is updated, this event will fire to update the scale and frame
     *
     * @private
     */
    _onTextureUpdate()
    {
        /* empty */
    }

    /**
     * Returns the bounds of the mesh as a rectangle. The bounds calculation takes the worldTransform into account.
     *
     */
    _calculateBounds()
    {
        // TODO - we can cache local bounds and use them if they are dirty (like graphics)
        this._bounds.addVertices(this.transform, this.vertices, 0, this.vertices.length);
    }

    /**
     * Tests if a point is inside this mesh. Works only for TRIANGLE_MESH
     *
     * @param {PIXI.Point} point - the point to test
     * @return {boolean} the result of the test
     */
    containsPoint(point)
    {
        if (!this.getBounds().contains(point.x, point.y))
        {
            return false;
        }

        this.worldTransform.applyInverse(point, tempPoint);

        const vertices = this.vertices;
        const points = tempPolygon.points;
        const indices = this.indices;
        const len = this.indices.length;
        const step = this.drawMode === Mesh.DRAW_MODES.TRIANGLES ? 3 : 1;

        for (let i = 0; i + 2 < len; i += step)
        {
            const ind0 = indices[i] * 2;
            const ind1 = indices[i + 1] * 2;
            const ind2 = indices[i + 2] * 2;

            points[0] = vertices[ind0];
            points[1] = vertices[ind0 + 1];
            points[2] = vertices[ind1];
            points[3] = vertices[ind1 + 1];
            points[4] = vertices[ind2];
            points[5] = vertices[ind2 + 1];

            if (tempPolygon.contains(tempPoint.x, tempPoint.y))
            {
                return true;
            }
        }

        return false;
    }

    /**
     * The texture that the mesh uses.
     *
     * @member {PIXI.Texture}
     * @memberof PIXI.mesh.Mesh#
     */
    get texture()
    {
        return this._texture;
    }

    /**
     * Sets the texture the mesh uses.
     *
     * @param {Texture} value - The value to set.
     */
    set texture(value)
    {
        if (this._texture === value)
        {
            return;
        }

        this._texture = value;

        if (value)
        {
            // wait for the texture to load
            if (value.baseTexture.hasLoaded)
            {
                this._onTextureUpdate();
            }
            else
            {
                value.once('update', this._onTextureUpdate, this);
            }
        }
    }

    /**
     * The tint applied to the mesh. This is a hex value. A value of 0xFFFFFF will remove any tint effect.
     *
     * @member {number}
     * @memberof PIXI.mesh.Mesh#
     * @default 0xFFFFFF
     */
    get tint()
    {
        return core.utils.rgb2hex(this.tintRgb);
    }

    /**
     * Sets the tint the mesh uses.
     *
     * @param {number} value - The value to set.
     */
    set tint(value)
    {
        this.tintRgb = core.utils.hex2rgb(value, this.tintRgb);
    }
}

/**
 * Different drawing buffer modes supported
 *
 * @static
 * @constant
 * @type {object}
 * @property {number} TRIANGLE_MESH
 * @property {number} TRIANGLES
 */
Mesh.DRAW_MODES = {
    TRIANGLE_MESH: 0,
    TRIANGLES: 1,
};