/**
 * Farbtastic Color Picker 1.2
 * © 2008 Steven Wittens
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

//Adapted to uniform style with jQuery UI widgets and slightly change behavior
//TODO:
// - remove duplicated code by replacing it with jquery.colorUtils and modern jQuery
// - uniform code style

jQuery.fn.farbtastic = function (callback) {
	$.farbtastic(this, callback);
	return this;
};

jQuery.farbtastic = function (container, callback) {
	var container = $(container).get(0);
	return container.farbtastic || (container.farbtastic = new jQuery._farbtastic(container, callback));
}

jQuery._farbtastic = function (container, callback) {
	// Store farbtastic object
	var fb = this;

	// Insert markup
	$(container).html('<div class="farbtastic ui-widget-content"><div class="color"></div><div class="wheel"></div><div class="overlay"></div><div class="h-marker marker"></div><div class="sl-marker marker"></div></div>');
	$(container).addClass('ui-widget');
	var e = $('.farbtastic', container);
	fb.wheel = $('.wheel', container).get(0);
	// Dimensions
	fb.radius = 84;
	fb.square = 100;
	fb.width = 194;

	// Fix background PNGs in IE6
	if (navigator.appVersion.match(/MSIE [0-6]\./)) {
		$('*', e).each(function () {
			if (this.currentStyle.backgroundImage != 'none') {
				var image = this.currentStyle.backgroundImage;
				image = this.currentStyle.backgroundImage.slice(5, image.length - 2);
				$(this).css({
					'backgroundImage': 'none',
					'filter': "progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, sizingMethod=crop, src='" + image + "')"
				});
			}
		});
	}

	/**
	 * Link to the given element(s) or callback.
	 */
	fb.linkTo = function (callback) {
		// Unbind previous nodes
		if (typeof fb.callback == 'object') {
			$(fb.callback).unbind('keyup', fb.updateValue);
		}

		// Reset color
		fb.color = null;

		// Bind callback or elements
		if (typeof callback == 'function') {
			fb.callback = callback;
		}
		else if (typeof callback == 'object' || typeof callback == 'string') {
			fb.callback = $(callback);
			fb.callback.bind('keyup', fb.updateValue);
			if (fb.callback.get(0).value) {
				fb.setColor(fb.callback.get(0).value);
			}
		}
		return this;
	}
	fb.updateValue = function (event) {
		if (this.value != fb.color) {
			fb.setColor(this.value);
		}
	}

	/**
	 * Change color with HTML syntax #123456
	 */
	fb.setColor = function (color) {
		var rgb = $.colorUtil.getRGB( color );
		if (fb.color != color && rgb) {
			rgb = rgb.slice( 0 ); //make a clone
			//TODO: rewrite code so that this is not needed
			rgb[0] /= 255;
			rgb[1] /= 255;
			rgb[2] /= 255;
			fb.color = color;
			fb.rgb = rgb;
			fb.hsl = fb.RGBToHSL(fb.rgb);
			fb.updateDisplay();
		}
		return this;
	}

	/**
	 * Change color with HSL triplet [0..1, 0..1, 0..1]
	 */
	fb.setHSL = function (hsl) {
		fb.hsl = hsl;
		fb.rgb = fb.HSLToRGB(hsl);
		fb.color = fb.pack(fb.rgb);
		fb.updateDisplay();
		return this;
	}

	/////////////////////////////////////////////////////

	/**
	 * Retrieve the coordinates of the given event relative to the center
	 * of the widget.
	 */
	fb.widgetCoords = function (event) {
		var ref = $( fb.wheel ).offset();
		return {
			x: event.pageX - ref.left - fb.width / 2,
			y: event.pageY - ref.top - fb.width / 2
		};
	}

	/**
	 * Mousedown handler
	 */
	fb.mousedown = function (event) {
		// Capture mouse
		if (!document.dragging) {
			$(document).bind('mousemove', fb.mousemove).bind('mouseup', fb.mouseup);
			document.dragging = true;
		}

		// Check which area is being dragged
		var pos = fb.widgetCoords(event);
		fb.circleDrag = Math.max(Math.abs(pos.x), Math.abs(pos.y)) * 2 > fb.square;

		// Process
		fb.mousemove(event);
		return false;
	}

	/**
	 * Mousemove handler
	 */
	fb.mousemove = function (event) {
		// Get coordinates relative to color picker center
		var pos = fb.widgetCoords(event);

		// Set new HSL parameters
		if (fb.circleDrag) {
			var hue = Math.atan2(pos.x, -pos.y) / 6.28;
			if (hue < 0) hue += 1;
			fb.setHSL([hue, fb.hsl[1], fb.hsl[2]]);
		}
		else {
			var sat = Math.max(0, Math.min(1, -(pos.x / fb.square) + .5));
			var lum = Math.max(0, Math.min(1, -(pos.y / fb.square) + .5));
			fb.setHSL([fb.hsl[0], sat, lum]);
		}
		return false;
	}

	/**
	 * Mouseup handler
	 */
	fb.mouseup = function () {
		// Uncapture mouse
		$(document).unbind('mousemove', fb.mousemove);
		$(document).unbind('mouseup', fb.mouseup);
		document.dragging = false;
	}

	/**
	 * Update the markers and styles
	 */
	fb.updateDisplay = function () {
		// Markers
		var angle = fb.hsl[0] * 6.28;
		$('.h-marker', e).css({
			left: Math.round(Math.sin(angle) * fb.radius + fb.width / 2) + 'px',
			top: Math.round(-Math.cos(angle) * fb.radius + fb.width / 2) + 'px'
		});

		$('.sl-marker', e).css({
			left: Math.round(fb.square * (.5 - fb.hsl[1]) + fb.width / 2) + 'px',
			top: Math.round(fb.square * (.5 - fb.hsl[2]) + fb.width / 2) + 'px'
		});

		// Saturation/Luminance gradient
		$('.color', e).css('backgroundColor', fb.pack(fb.HSLToRGB([fb.hsl[0], 1, 0.5])));

		// Linked elements or callback
		if (typeof fb.callback == 'object') {
			// Set background/foreground color
			$(fb.callback).css({
				backgroundColor: fb.color,
				color: fb.hsl[2] > 0.5 ? '#000' : '#fff'
			});

			// Change linked value
			$(fb.callback).each(function() {
				if ( $( this ).val() != fb.color) {
					$( this ).val( fb.color ).change();
				}
			});
		}
		else if (typeof fb.callback == 'function') {
			fb.callback.call(fb, fb.color);
		}
	}

	/* Various color utility functions */
	fb.pack = function (rgb) {
		var r = Math.round(rgb[0] * 255);
		var g = Math.round(rgb[1] * 255);
		var b = Math.round(rgb[2] * 255);
		return '#' + (r < 16 ? '0' : '') + r.toString(16) +
					 (g < 16 ? '0' : '') + g.toString(16) +
					 (b < 16 ? '0' : '') + b.toString(16);
	}

	fb.HSLToRGB = function (hsl) {
		var m1, m2, r, g, b;
		var h = hsl[0], s = hsl[1], l = hsl[2];
		m2 = (l <= 0.5) ? l * (s + 1) : l + s - l*s;
		m1 = l * 2 - m2;
		return [this.hueToRGB(m1, m2, h+0.33333),
				this.hueToRGB(m1, m2, h),
				this.hueToRGB(m1, m2, h-0.33333)];
	}

	fb.hueToRGB = function (m1, m2, h) {
		h = (h < 0) ? h + 1 : ((h > 1) ? h - 1 : h);
		if (h * 6 < 1) return m1 + (m2 - m1) * h * 6;
		if (h * 2 < 1) return m2;
		if (h * 3 < 2) return m1 + (m2 - m1) * (0.66666 - h) * 6;
		return m1;
	}

	fb.RGBToHSL = function (rgb) {
		var min, max, delta, h, s, l;
		var r = rgb[0], g = rgb[1], b = rgb[2];
		min = Math.min(r, Math.min(g, b));
		max = Math.max(r, Math.max(g, b));
		delta = max - min;
		l = (min + max) / 2;
		s = 0;
		if (l > 0 && l < 1) {
			s = delta / (l < 0.5 ? (2 * l) : (2 - 2 * l));
		}
		h = 0;
		if (delta > 0) {
			if (max == r && max != g) h += (g - b) / delta;
			if (max == g && max != b) h += (2 + (b - r) / delta);
			if (max == b && max != r) h += (4 + (r - g) / delta);
			h /= 6;
		}
		return [h, s, l];
	}

	// Install mousedown handler (the others are set on the document on-demand)
	$('*', e).mousedown(fb.mousedown);

		// Init color
	fb.setColor('#000000');

	// Set linked elements/callback
	if (callback) {
		fb.linkTo(callback);
	}
}
