/*
// 
// ImageSaver
// JSActions helper script
// capture specified rect and returns input stream.
//
// Original auther:  KUMAGAI Kentaro <ku@ido.nu>
//
// Released under the Creative Commons Attribution-ShareAlike licence.
// http://creativecommons.org/licenses/by-sa/3.0/
//
*/

var ImageSaver = {
	VERSION: "0.0.1",

	GUI: {
		style: null,	// to change cursor to crosshair.
		status: null,
		from: null,
		to: null,
		rect: null,
		onkeypress: null,
		onmousedown: null,
		onmousemove: null,
		on_rect_selected: null,

		saving_text: 'Saving...',

		dim: {
				x: {prop: 'width', origin: 'left'},
				y: {prop: 'height', origin: 'top'}
		},

		show_text: function (text) {
			var doc = window._content.document;
			
			var d = doc.createElement('div');
			d.innerHTML = text;
			d.style.position = 'fixed';
			d.style.top = '2px';
			d.style.right = '2px';
			d.style.color = 'white';
			d.style.backgroundColor = '#E72D89';
			d.style.padding = '5px';
			d.style.zIndex = 2100000000;

			doc.body.appendChild(d);
			this.status = d;
		},
		close_text_delayed: function (html, duration) {
			duration = duration || 20 * 1000;

			this.status.innerHTML = html;
			this.status.style.backgroundColor = '#0063DC';
			window.setTimeout( function () {
				this.status.parentNode.removeChild( this.status );
			}.bind(this), duration );
		},
		update_rect: function (e) {
			var to = {x: e.clientX, y: e.clientY};

			var x, y;
			for ( var n in this.dim ) {
				var v = this.dim[n];
				var t;
				if ( ( t = to[n] - this.from[n] ) < 0 ) {
					this.rect.style[v.origin] = (this.from[n] + t) + 'px';
				}
				this.rect.style[v.prop] = Math.abs(t) + 'px';
			}
				
			this.rect.style.height = (to.y - this.from.y ) + 'px';
		},
		start_select_rect: function ( on_rect_selected ) {
			this.on_rect_selected = on_rect_selected;
			this.onkeypress = this.key_pressed.bind(this);
			this.onmousemove = this.update_rect.bind(this);
			this.onmousedown = this.select_rect.bind(this);

			var d = window._content.document;
			d.addEventListener( 'click', this.onclick, true );
			d.addEventListener( 'keypress', this.onkeypress, true );
			d.addEventListener( 'mousedown', this.onmousedown, true );

			var s = d.createElement('style');
			s.innerHTML = '* {cursor: crosshair !important;}';
			d.body.appendChild(s);
			this.style = s;
		},

		cancel_capture: function (e) {
			this.stop_event_listening();

			this.show_text('');
			this.close_text_delayed('Canceled', 3 * 1000);
		},

		cleanup: function ( html ) {
			this.close_text_delayed(html);
		},

		stop_event_listening: function () {
			var d = window._content.document;
			d.removeEventListener( 'click', this.onclick, true );
			d.removeEventListener( 'keypress', this.onkeypress, true );
			d.removeEventListener( 'mousedown', this.onmousedown, true );
			if ( this.onmousemove ) { 
				d.removeEventListener( 'mousemove', this.onmousemove, true );
			}
			this.style.parentNode.removeChild( this.style );

			if ( this.rect ) {
				this.rect.parentNode.removeChild(this.rect);
			}
		},

		select_rect: function (e) {
			if ( this.from == null ) {
				this.from = {x: e.clientX, y: e.clientY};

				var d = window._content.document;
				this.rect = d.createElement('div');
				this.rect.style.outlineWidth = '2px';
				this.rect.style.outlineStyle = 'dotted';
				this.rect.style.outlineColor = '#0063DC';
				this.rect.style.backgroundColor = '#0063DC';
				this.rect.style.opacity = '0.5';
				this.rect.style.position = 'fixed';
				this.rect.style.width = '0px';
				this.rect.style.height = '0px';
				this.rect.style.zIndex = 2100000000;
				this.rect.style.top = this.from.y + 'px',
				this.rect.style.left = this.from.x + 'px',
				d.body.appendChild(this.rect);

				d.addEventListener( 'mousemove', this.onmousemove, true );
			} else if ( this.to == null ) {
				this.to = {x: e.clientX, y: e.clientY};

				var rect = {};
				["top", "left", "width", "height"].forEach( function(n) {
					rect[n] = parseInt( this.rect.style[n] );
				}.bind(this) );

				this.stop_event_listening();
				this.on_rect_selected( rect );
			}
			return false;
		},
		onclick: function (e) {
			e.preventDefault();
			return false;
		},

		key_pressed: function(e) {
			if ( e.keyCode == e.DOM_VK_ESCAPE ) {
				this.cancel_capture();
				return false;
			}
			return true;
		},
	},
	
	capture_rect: function ( canvas_stream_reader ) {
		this.GUI.start_select_rect(
			function (rect) {
				var canvas_stream = this.capture(rect);

				this.GUI.show_text( this.GUI.saving_text );

				var title = (window._content.document.title);

				canvas_stream_reader.apply(this, [
					canvas_stream,
					title
				] );

				this.destroy_canvas(this.canvas);
			}.bind(this)
		);
	},
	copy: function ( rect ) {
	},

	/**	
		need to call destroy_canvas() to delete canvas.
		@return nsIInputStream of canvas
	 **/
	capture: function (rect) {
		rect = rect || {
			left: 		0,
			top:		0,
			width: 		window._content.document.width,
			height:		window._content.document.height
		};

		this.create_canvas(rect);

		var ctx = this.canvas.getContext("2d");
		ctx.clearRect(0, 0, rect.width, rect.height);
		ctx.save();
		ctx.scale(1.0, 1.0);

		var	x1 = rect.left + window.pageXOffset;
		var	x2 = rect.left + rect.width + window.pageXOffset;
		var	y1 = rect.top + window.pageYOffset;
		var	y2 = rect.top + rect.height + window.pageYOffset;

		ctx.drawWindow(window._content, x1, y1, x2, y2, "rgb(255,255,255)");
		ctx.restore();

		try {
			var url = this.canvas.toDataURL("image/png");
		} catch(ex) {
			return alert("This feature requires Firefox 2.0.\n" + ex);
		}
		const IO_SERVICE = Components.classes['@mozilla.org/network/io-service;1']
				.getService(Components.interfaces.nsIIOService);
		url = IO_SERVICE.newURI(url, null, null);

		var channel = IO_SERVICE.newChannelFromURI( url );
		var input = channel.open();

		return input;
	},
	create_canvas: function (rect) {
		var d = window._content.document;
		var canvas = d.createElement('canvas');
		canvas.setAttribute("id", "svcanvas");
		canvas.style.display = "inline";
		canvas.width = rect.width;
		canvas.height = rect.height;

		var statusbar = ( top.document.getElementById('status-bar') );
		var body = ( d.getElementsByTagName('body') );

		var p = body[0];
		p.appendChild(canvas);
		
		this.canvas = canvas;
	},
	destroy_canvas: function (canvas) {
		canvas.parentNode.removeChild(canvas);
		//canvas.style.display = "none";
		//canvas.width = 1;
		//canvas.height = 1;
	}

};