var GetTilesWithin = require('./GetTilesWithin');
var Color = require('../../../display/color');

/**
 * Draws a debug representation of the layer to the given Graphics. This is helpful when you want to
 * get a quick idea of which of your tiles are colliding and which have interesting faces. The tiles
 * are drawn starting at (0, 0) in the Graphics, allowing you to place the debug representation
 * wherever you want on the screen.
 *
 * @param {Graphics} graphics - The target Graphics object to draw upon.
 * @param {object} styleConfig - An object specifying the colors to use for the debug drawing.
 * @param {Color|null} [styleConfig.tileColor=blue] - Color to use for drawing a filled rectangle at
 * non-colliding tile locations. If set to null, non-colliding tiles will not be drawn.
 * @param {Color|null} [styleConfig.collidingTileColor=orange] - Color to use for drawing a filled
 * rectangle at colliding tile locations. If set to null, colliding tiles will not be drawn.
 * @param {Color|null} [styleConfig.faceColor=grey] - Color to use for drawing a line at interesting
 * tile faces. If set to null, interesting tile faces will not be drawn.
 * @param {LayerData} layer - [description]
 */
var RenderDebug = function (graphics, styleConfig, layer)
{
    if (styleConfig === undefined) { styleConfig = {}; }

    // Default colors without needlessly creating Color objects
    var tileColor = styleConfig.tileColor !== undefined
        ? styleConfig.tileColor
        : new Color(105, 210, 231, 150);
    var collidingTileColor = styleConfig.collidingTileColor !== undefined
        ? styleConfig.collidingTileColor
        : new Color(243, 134, 48, 200);
    var faceColor = styleConfig.faceColor !== undefined
        ? styleConfig.faceColor
        : new Color(40, 39, 37, 150);

    var tiles = GetTilesWithin(0, 0, layer.width, layer.height, null, layer);

    for (var i = 0; i < tiles.length; i++)
    {
        var tile = tiles[i];

        var tw = tile.width;
        var th = tile.height;
        var x = tile.pixelX;
        var y = tile.pixelY;

        var color = tile.collides ? collidingTileColor : tileColor;
        if (color !== null)
        {
            graphics.fillStyle(color.color, color.alpha / 255);
            graphics.fillRect(x, y, tw, th);
        }

        // Inset the face line to prevent neighboring tile's lines from overlapping
        x += 1;
        y += 1;
        tw -= 2;
        th -= 2;

        if (faceColor !== null)
        {
            graphics.lineStyle(1, faceColor.color, faceColor.alpha / 255);
            if (tile.faceTop) { graphics.lineBetween(x, y, x + tw, y); }
            if (tile.faceRight) { graphics.lineBetween(x + tw, y, x + tw, y + th); }
            if (tile.faceBottom) { graphics.lineBetween(x, y + th, x + tw, y + th); }
            if (tile.faceLeft) { graphics.lineBetween(x, y, x, y + th); }
        }
    }
};

module.exports = RenderDebug;