/**
 * @class Visual map display
 * @param {object} [options]
 * @param {int} [options.width=ROT.DEFAULT_WIDTH]
 * @param {int} [options.height=ROT.DEFAULT_HEIGHT]
 * @param {int} [options.fontSize=15]
 * @param {string} [options.fontFamily="monospace"]
 * @param {string} [options.fontStyle=""] bold/italic/none/both
 * @param {string} [options.fg="#ccc"]
 * @param {string} [options.bg="#000"]
 * @param {int} [options.fps=25]
 * @param {float} [options.spacing=1]
 * @param {float} [options.border=0]
 * @param {string} [options.layout="rect"]
 */
ROT.Display = function(options) {
	var canvas = document.createElement("canvas");
	this._context = canvas.getContext("2d");
	this._data = {};
	this._dirty = false; /* false = nothing, true = all, object = dirty cells */
	this._options = {};
	this._backend = null;
	
	var defaultOptions = {
		width: ROT.DEFAULT_WIDTH,
		height: ROT.DEFAULT_HEIGHT,
		layout: "rect",
		fontSize: 15,
		fps: 25,
		spacing: 1,
		border: 0,
		fontFamily: "monospace",
		fontStyle: "",
		fg: "#ccc",
		bg: "#000"
	};
	for (var p in options) { defaultOptions[p] = options[p]; }
	this.setOptions(defaultOptions);
	this.DEBUG = this.DEBUG.bind(this);
	
	this._interval = setInterval(this._tick.bind(this), 1000/this._options.fps);
}

/**
 * Debug helper, ideal as a map generator callback. Always bound to this.
 * @param {int} x
 * @param {int} y
 * @param {int} what
 */
ROT.Display.prototype.DEBUG = function(x, y, what) {
	var colors = [this._options.bg, this._options.fg];
	this.draw(x, y, null, null, colors[what % colors.length]);
}

/**
 * Clear the whole display (cover it with background color)
 */
ROT.Display.prototype.clear = function() {
	this._data = {};
	this._dirty = true;
}

/**
 * @see ROT.Display
 */
ROT.Display.prototype.setOptions = function(options) {
	for (var p in options) { this._options[p] = options[p]; }
	if (options.width || options.height || options.fontSize || options.fontFamily || options.spacing || options.layout) {
		if (options.layout) { 
			this._backend = new ROT.Display[options.layout.capitalize()](this._context);
		}

		var font = (this._options.fontStyle ? this._options.fontStyle + " " : "") + this._options.fontSize + "px " + this._options.fontFamily;
		this._context.font = font;
		this._backend.compute(this._options);
		this._context.font = font;
		this._context.textAlign = "center";
		this._context.textBaseline = "middle";
		this._dirty = true;
	}
	return this;
}

/**
 * Returns currently set options
 * @returns {object} Current options object 
 */
ROT.Display.prototype.getOptions = function() {
	return this._options;
}

/**
 * Returns the DOM node of this display
 * @returns {node} DOM node
 */
ROT.Display.prototype.getContainer = function() {
	return this._context.canvas;
}

/**
 * Compute the maximum width/height to fit into a set of given constraints
 * @param {int} availWidth Maximum allowed pixel width
 * @param {int} availHeight Maximum allowed pixel height
 * @returns {int[2]} cellWidth,cellHeight
 */
ROT.Display.prototype.computeSize = function(availWidth, availHeight) {
	return this._backend.computeSize(availWidth, availHeight, this._options);
}

/**
 * Compute the maximum font size to fit into a set of given constraints
 * @param {int} availWidth Maximum allowed pixel width
 * @param {int} availHeight Maximum allowed pixel height
 * @returns {int} fontSize
 */
ROT.Display.prototype.computeFontSize = function(availWidth, availHeight) {
	return this._backend.computeFontSize(availWidth, availHeight, this._options);
}

/**
 * @param {int} x
 * @param {int} y
 * @param {string} ch 
 * @param {string} [fg] foreground color
 * @param {string} [bg] background color
 */
ROT.Display.prototype.draw = function(x, y, ch, fg, bg) {
	if (!fg) { fg = this._options.fg; }
	if (!bg) { bg = this._options.bg; }
	this._data[x+","+y] = [x, y, ch, fg, bg];
	
	if (this._dirty === true) { return; } /* will already redraw everything */
	if (!this._dirty) { this._dirty = {}; } /* first! */
	this._dirty[x+","+y] = true;
}

/**
 * Draws a text at given position. Optionally wraps at a maximum length. Currently does not work with hex layout.
 * @param {int} x
 * @param {int} y
 * @param {string} text May contain color/background format specifiers, %c{name}/%b{name}, both optional. %c{}/%b{} resets to default.
 * @param {int} [maxWidth] wrap at what width?
 * @returns {int} lines drawn
 */
ROT.Display.prototype.drawText = function(x, y, text, maxWidth) {
	var fg = null;
	var bg = null;
	var cx = x;
	var cy = y;
	var lines = 1;
	if (!maxWidth) { maxWidth = this._options.width-x; }

	var tokens = ROT.Text.tokenize(text, maxWidth);

	while (tokens.length) { /* interpret tokenized opcode stream */
		var token = tokens.shift();
		switch (token.type) {
			case ROT.Text.TYPE_TEXT:
				for (var i=0;i<token.value.length;i++) {
					this.draw(cx++, cy, token.value.charAt(i), fg, bg);
				}
			break;

			case ROT.Text.TYPE_FG:
				fg = token.value || null;
			break;

			case ROT.Text.TYPE_BG:
				bg = token.value || null;
			break;

			case ROT.Text.TYPE_NEWLINE:
				cx = x;
				cy++;
				lines++
			break;
		}
	}

	return lines;
}

/**
 * Timer tick: update dirty parts
 */
ROT.Display.prototype._tick = function() {
	if (!this._dirty) { return; }

	if (this._dirty === true) { /* draw all */
		this._context.fillStyle = this._options.bg;
		this._context.fillRect(0, 0, this._context.canvas.width, this._context.canvas.height);

		for (var id in this._data) { /* redraw cached data */
			this._draw(id, false);
		}

	} else { /* draw only dirty */
		for (var key in this._dirty) {
			this._draw(key, true);
		}
	}

	this._dirty = false;
}

/**
 * @param {string} key What to draw
 * @param {bool} clearBefore Is it necessary to clean before?
 */
ROT.Display.prototype._draw = function(key, clearBefore) {
	var data = this._data[key];
	if (data[4] != this._options.bg) { clearBefore = true; }

	this._backend.draw(data, clearBefore);
}