# modules/xmp_metadata.js

    /* global jsPDF */
    /** ====================================================================
     * jsPDF XMP metadata plugin
     * Copyright (c) 2016 Jussi Utunen, u-jussi@suomi24.fi
     *
     * Permission is hereby granted, free of charge, to any person obtaining
     * a copy of this software and associated documentation files (the
     * "Software"), to deal in the Software without restriction, including
     * without limitation the rights to use, copy, modify, merge, publish,
     * distribute, sublicense, and/or sell copies of the Software, and to
     * permit persons to whom the Software is furnished to do so, subject to
     * the following conditions:
     *
     * The above copyright notice and this permission notice shall be
     * included in all copies or substantial portions of the Software.
     *
     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
     * ====================================================================
     */
    /**
    * @name xmp_metadata
    * @module
    */
    (function (jsPDFAPI) {
        'use strict';

        var postPutResources = function () {
            var xmpmeta_beginning = '<x:xmpmeta xmlns:x="adobe:ns:meta/">';
            var rdf_beginning = '<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"><rdf:Description rdf:about="" xmlns:jspdf="' + this.internal.__metadata__.namespaceuri + '"><jspdf:metadata>';
            var rdf_ending = '</jspdf:metadata></rdf:Description></rdf:RDF>';
            var xmpmeta_ending = '</x:xmpmeta>';
            var utf8_xmpmeta_beginning = unescape(encodeURIComponent(xmpmeta_beginning));
            var utf8_rdf_beginning = unescape(encodeURIComponent(rdf_beginning));
            var utf8_metadata = unescape(encodeURIComponent(this.internal.__metadata__.metadata));
            var utf8_rdf_ending = unescape(encodeURIComponent(rdf_ending));
            var utf8_xmpmeta_ending = unescape(encodeURIComponent(xmpmeta_ending));

            var total_len = utf8_rdf_beginning.length + utf8_metadata.length + utf8_rdf_ending.length + utf8_xmpmeta_beginning.length + utf8_xmpmeta_ending.length;

            this.internal.__metadata__.metadata_object_number = this.internal.newObject();
            this.internal.write('<< /Type /Metadata /Subtype /XML /Length ' + total_len + ' >>');
            this.internal.write('stream');
            this.internal.write(utf8_xmpmeta_beginning + utf8_rdf_beginning + utf8_metadata + utf8_rdf_ending + utf8_xmpmeta_ending);
            this.internal.write('endstream');
            this.internal.write('endobj');
        };

        var putCatalog = function () {
            if (this.internal.__metadata__.metadata_object_number) {
                this.internal.write('/Metadata ' + this.internal.__metadata__.metadata_object_number + ' 0 R');
            }
        };

    	/**
    	* Adds XMP formatted metadata to PDF
    	*
    	* @name addMetadata
    	* @function
    	* @param {String} metadata The actual metadata to be added. The metadata shall be stored as XMP simple value. Note that if the metadata string contains XML markup characters "<", ">" or "&", those characters should be written using XML entities.
    	* @param {String} namespaceuri Sets the namespace URI for the metadata. Last character should be slash or hash.
    	* @returns {jsPDF} jsPDF-instance
    	*/
        jsPDFAPI.addMetadata = function (metadata, namespaceuri) {
            if (typeof this.internal.__metadata__ === 'undefined') {
                this.internal.__metadata__ = {
                    metadata :  metadata,
                    namespaceuri : namespaceuri || "http://jspdf.default.namespaceuri/"
                };
                this.internal.events.subscribe(
                    'putCatalog',
                    putCatalog
                );

                this.internal.events.subscribe(
                    'postPutResources',
                    postPutResources
                );
            }
            return this;
        };
    }(jsPDF.API));