# modules/annotations.js

    /* 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);