/* global jsPDF */
/**
 * @license
 * Copyright (c) 2014 Steven Spungin (TwelveTone LLC)  steven@twelvetone.tv
 *
 * Licensed under the MIT License.
 * http://opensource.org/licenses/mit-license
 */

/**
 * jsPDF Annotations PlugIn
 *
 * There are many types of annotations in a PDF document. Annotations are placed
 * on a page at a particular location. They are not 'attached' to an object.
 * <br />
 * This plugin current supports <br />
 * <li> Goto Page (set pageNumber and top in options)
 * <li> Goto Name (set name and top in options)
 * <li> Goto URL (set url in options)
 * <p>
 * 	The destination magnification factor can also be specified when goto is a page number or a named destination. (see documentation below)
 *  (set magFactor in options).  XYZ is the default.
 * </p>
 * <p>
 *  Links, Text, Popup, and FreeText are supported.
 * </p>
 * <p>
 * Options In PDF spec Not Implemented Yet
 * <li> link border
 * <li> named target
 * <li> page coordinates
 * <li> destination page scaling and layout
 * <li> actions other than URL and GotoPage
 * <li> background / hover actions
 * </p>
 * @name annotations
 * @module
 */

/*
    Destination Magnification Factors
    See PDF 1.3 Page 386 for meanings and options

    [supported]
	XYZ (options; left top zoom)
	Fit (no options)
	FitH (options: top)
	FitV (options: left)

	[not supported]
	FitR
	FitB
	FitBH
	FitBV
 */
(function (jsPDFAPI) {
	'use strict';

	var notEmpty = function (obj) {
		if (typeof obj != 'undefined') {
			if (obj != '') {
				return true;
			}
		}
	};

	jsPDF.API.events.push(['addPage', function (addPageData) {
		var pageInfo = this.internal.getPageInfo(addPageData.pageNumber);
		pageInfo.pageContext.annotations = [];
	}]);

	jsPDFAPI.events.push(['putPage', function (putPageData) {
		var getHorizontalCoordinateString = this.internal.getCoordinateString;
		var getVerticalCoordinateString = this.internal.getVerticalCoordinateString;
		var pageInfo = this.internal.getPageInfoByObjId(putPageData.objId);
		var pageAnnos = putPageData.pageContext.annotations;

		var anno, rect, line;
		var found = false;
		for (var a = 0; a < pageAnnos.length && !found; a++) {
			anno = pageAnnos[a];
			switch (anno.type) {
				case 'link':
					if (notEmpty(anno.options.url) || notEmpty(anno.options.pageNumber)) {
						found = true;
					}
					break;
				case 'reference':
				case 'text':
				case 'freetext':
					found = true;
					break;
			}
		}
		if (found == false) {
			return;
		}

		this.internal.write("/Annots [");
		for (var i = 0; i < pageAnnos.length; i++) {
			anno = pageAnnos[i];

			switch (anno.type) {
				case 'reference':
					// References to Widget Annotations (for AcroForm Fields)
					this.internal.write(' ' + anno.object.objId + ' 0 R ');
					break;
				case 'text':
					// Create a an object for both the text and the popup
					var objText = this.internal.newAdditionalObject();
					var objPopup = this.internal.newAdditionalObject();

					var title = anno.title || 'Note';
					rect = "/Rect [" + getHorizontalCoordinateString(anno.bounds.x) + " " + getVerticalCoordinateString(anno.bounds.y + anno.bounds.h) + " " + getHorizontalCoordinateString(anno.bounds.x + anno.bounds.w) + " " + getVerticalCoordinateString(anno.bounds.y) + "] ";
					line = '<</Type /Annot /Subtype /' + 'Text' + ' ' + rect + '/Contents (' + anno.contents + ')';
					line += ' /Popup ' + objPopup.objId + " 0 R";
					line += ' /P ' + pageInfo.objId + " 0 R";
					line += ' /T (' + title + ') >>';
					objText.content = line;

					var parent = objText.objId + ' 0 R';
					var popoff = 30;
					rect = "/Rect [" + getHorizontalCoordinateString(anno.bounds.x + popoff) + " " + getVerticalCoordinateString(anno.bounds.y + anno.bounds.h) + " " + getHorizontalCoordinateString(anno.bounds.x + anno.bounds.w + popoff) + " " + getVerticalCoordinateString(anno.bounds.y) + "] ";
					line = '<</Type /Annot /Subtype /' + 'Popup' + ' ' + rect + ' /Parent ' + parent;
					if (anno.open) {
						line += ' /Open true';
					}
					line += ' >>';
					objPopup.content = line;

					this.internal.write(objText.objId, '0 R', objPopup.objId, '0 R');

					break;
				case 'freetext':
					rect = "/Rect [" + getHorizontalCoordinateString(anno.bounds.x) + " " + getVerticalCoordinateString(anno.bounds.y) + " " + getHorizontalCoordinateString(anno.bounds.x + anno.bounds.w) + " " + getVerticalCoordinateString(anno.bounds.y + anno.bounds.h) + "] ";
					var color = anno.color || '#000000';
					line = '<</Type /Annot /Subtype /' + 'FreeText' + ' ' + rect + '/Contents (' + anno.contents + ')';
					line += ' /DS(font: Helvetica,sans-serif 12.0pt; text-align:left; color:#' + color + ')';
					line += ' /Border [0 0 0]';
					line += ' >>';
					this.internal.write(line);
					break;
				case 'link':
					if (anno.options.name) {
						var loc = this.annotations._nameMap[anno.options.name];
						anno.options.pageNumber = loc.page;
						anno.options.top = loc.y;
					} else {
						if (!anno.options.top) {
							anno.options.top = 0;
						}
					}

					rect = "/Rect [" + getHorizontalCoordinateString(anno.x) + " " + getVerticalCoordinateString(anno.y) + " " + getHorizontalCoordinateString(anno.x + anno.w) + " " + getVerticalCoordinateString(anno.y + anno.h) + "] ";

					line = '';
					if (anno.options.url) {
						line = '<</Type /Annot /Subtype /Link ' + rect + '/Border [0 0 0] /A <</S /URI /URI (' + anno.options.url + ') >>';
					} else if (anno.options.pageNumber) {
						// first page is 0
						var info = this.internal.getPageInfo(anno.options.pageNumber);
						line = '<</Type /Annot /Subtype /Link ' + rect + '/Border [0 0 0] /Dest [' + info.objId + " 0 R";
						anno.options.magFactor = anno.options.magFactor || "XYZ";
						switch (anno.options.magFactor) {
							case 'Fit':
								line += ' /Fit]';
								break;
							case 'FitH':
								line += ' /FitH ' + anno.options.top + ']';
								break;
							case 'FitV':
								anno.options.left = anno.options.left || 0;
								line += ' /FitV ' + anno.options.left + ']';
								break;
							case 'XYZ':
							default:
								var top = getVerticalCoordinateString(anno.options.top);
								anno.options.left = anno.options.left || 0;
								// 0 or null zoom will not change zoom factor
								if (typeof anno.options.zoom === 'undefined') {
									anno.options.zoom = 0;
								}
								line += ' /XYZ ' + anno.options.left + ' ' + top + ' ' + anno.options.zoom + ']';
								break;
						}
					}

					if (line != '') {
						line += " >>";
						this.internal.write(line);
					}
					break;
			}
		}
		this.internal.write("]");
	}]);

	/**
	* @name createAnnotation
	* @function
	* @param {Object} options 
	*/
	jsPDFAPI.createAnnotation = function (options) {
		var pageInfo = this.internal.getCurrentPageInfo();
		switch (options.type) {
			case 'link':
				this.link(options.bounds.x, options.bounds.y, options.bounds.w, options.bounds.h, options);
				break;
			case 'text':
			case 'freetext':
				pageInfo.pageContext.annotations.push(options);
				break;
		}
	}

	/**
	 * Create a link
	 *
	 * valid options
	 * <li> pageNumber or url [required]
	 * <p>If pageNumber is specified, top and zoom may also be specified</p>
	 * @name link
	 * @function
	 * @param {number} x
	 * @param {number} y
	 * @param {number} w
	 * @param {number} h
	 * @param {Object} options
	 */
	jsPDFAPI.link = function (x, y, w, h, options) {
		var pageInfo = this.internal.getCurrentPageInfo();
		pageInfo.pageContext.annotations.push({
			x: x,
			y: y,
			w: w,
			h: h,
			options: options,
			type: 'link'
		});
	};

	/**
	 * Currently only supports single line text.
	 * Returns the width of the text/link
	 *
	 * @name textWithLink
	 * @function
	 * @param {string} text
	 * @param {number} x
	 * @param {number} y
	 * @param {Object} options
	 * @returns {number} width the width of the text/link
	 */
	jsPDFAPI.textWithLink = function (text, x, y, options) {
		var width = this.getTextWidth(text);
		var height = this.internal.getLineHeight() / this.internal.scaleFactor;
		this.text(text, x, y, options);
		//TODO We really need the text baseline height to do this correctly.
		// Or ability to draw text on top, bottom, center, or baseline.
		y += height * .2;
		this.link(x, y - height, width, height, options);
		return width;
	};

	//TODO move into external library
	/**
	* @name getTextWidth
	* @function
	* @param {string} text
	* @returns {number} txtWidth
	*/
	jsPDFAPI.getTextWidth = function (text) {
		var fontSize = this.internal.getFontSize();
		var txtWidth = this.getStringUnitWidth(text) * fontSize / this.internal.scaleFactor;
		return txtWidth;
	};

	return this;

})(jsPDF.API);
