//
// Jala Project [http://opensvn.csie.org/traccgi/jala]
//
// Copyright 2004 ORF Online und Teletext GmbH
//
// Licensed under the Apache License, Version 2.0 (the ``License'');
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an ``AS IS'' BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// $Revision$
// $LastChangedBy$
// $LastChangedDate$
// $HeadURL$
//


/**
 * @fileoverview 
 * A parser script that converts GNU Gettext .po files into plain JavaScript objects
 * for use with jala.I18n. To run it either start the build script of HopKit
 * or call it directly using the JavaScript shell of Rhino:
 * <code>java -cp rhino.jar org.mozilla.javascript.tools.shell.Main PoParser.js <input> <output> [namespace]</code>
 * 
 * The accepted arguments are:
 * <ul>
 * <li><code>input</code>: Either a single .po file or a directory containing multiple files</li>
 * <li><code>output</code>: The directory where to put the generated message files</li>
 * <li><code>namespace</code>: An optional namespace in which the generated message object will reside
 * (eg. if the namespace is called "jala", the messages will be stored in global.jala.messages)</li>
 * </ul>
 */


/**
 * Constructs a new PoParser instance.
 * @class Instances of this class can generate JavaScript message files out
 * of GNU Gettext .po files for use with jala.I18n (and possibly other internationalization
 * environments too).
 * @param {String} handler An optional namespace where the parsed messages should be stored
 * @returns A newly created instance of PoParser
 * @constructor
 */
var PoParser = function(namespace) {
   /**
    * An array containing the parsed messages
    * @type Array
    */
   this.messages = [];

   /**
    * The locale key string (eg. "de_AT") of the .po file
    * @type String
    */
   this.localeKey = null;

   /**
    * The namespace (optional) where to store the generated messages
    * @type String
    */
   this.namespace = namespace;
   return this;
};

/**
 * A regular expression for splitting the contents of a .po file into
 * single lines
 * @type RegExp
 */
PoParser.REGEX_LINES = /\r\n|\r|\n|\u0085|\u2028|\u2029/;

/**
 * A regular expression for parsing singular message keys
 * @type RegExp
 */
PoParser.REGEX_MSGID = /^\s*msgid(?!_plural)\s+\"(.*)\"\s*$/;

/**
 * A regular expression for parsing plural message keys
 * @type RegExp
 */
PoParser.REGEX_MSGID_PLURAL = /^\s*msgid_plural\s+\"(.*)\"\s*$/;

/**
 * A regular expression for parsing message key continuations
 * @type RegExp
 */
PoParser.REGEX_MSG_CONT = /^\s*\"(.*)\"\s*$/;

/**
 * A regular expression for parsing a message translation
 * @type RegExp
 */
PoParser.REGEX_MSGSTR = /^\s*msgstr(?:\[(\d)\])?\s+\"(.*)\"\s*$/;

/**
 * A regular expression used to detect lines other than whitespace
 * and comments
 * @type RegExp
 */
PoParser.REGEX_DATA = /^\s*msg/;

PoParser.isData = function(str) {
   return PoParser.REGEX_DATA.test(str);
};

/**
 * Reads the file passed as argument, assuming that it is UTF-8 encoded
 * @param {java.io.File} file The file to read
 * @returns The contents of the file
 * @type java.lang.String
 */
PoParser.readFile = function(file) {
   var inStream = new java.io.InputStreamReader(new java.io.FileInputStream(file), "UTF-8");
   var buffer = new java.lang.reflect.Array.newInstance(java.lang.Character.TYPE, 2048);
   var read = 0;
   var r = 0;
   while ((r = inStream.read(buffer, read, buffer.length - read)) > -1) {
      read += r;
      if (read == buffer.length) {
         // grow input buffer
         var newBuffer = new java.lang.reflect.Array.newInstance(java.lang.Character.TYPE, buffer.length * 2);
         java.lang.System.arraycopy(buffer, 0, newBuffer, 0, buffer.length);
         buffer = newBuffer;
      }
   }
   inStream.close();
   return new java.lang.String(buffer, 0, read);
}

/**
 * Parses the PO file passed as argument into the messages array
 * of this PoParser instance.
 * @param {java.io.File} file The .po file to parse
 */
PoParser.prototype.parse = function(file) {
   // parse the locale key out of the file name
   var fileName = file.getName();
   if (!(this.localeKey = fileName.substring(0, fileName.indexOf(".")))) {
      throw "Invalid PO file name: " + fileName;
   }

   // read the PO file content and parse it into messages
   var content = PoParser.readFile(file);
   var start = new Date();
   var lines = content.split(PoParser.REGEX_LINES);
   var idx = -1;
   var line = null;
   var m, value, nr;
   var msg;

   var hasMoreLines = function() {
      return idx < lines.length - 1;
   };

   var nextLine = function() {
      return (line = lines[idx += 1]) != null;
   };

   var getContinuation = function(str) {
      var nLine;
      while ((nLine = lines[idx + 1]) != null) {
         if ((m = nLine.match(PoParser.REGEX_MSG_CONT)) != null) {
            str += m[1];
            nextLine();
         } else {
            break;
         }
      }
      return str;
   }

   while (nextLine()) {
      if ((m = line.match(PoParser.REGEX_MSGID)) != null) {
         value = getContinuation(m[1]);
         if (value) {
            msg = this.messages[this.messages.length] = new Message(value);
         }
      } else if ((m = line.match(PoParser.REGEX_MSGID_PLURAL)) != null) {
         value = getContinuation(m[1]);
         if (value && msg != null) {
            msg.pluralKey = value;
         }
      } else if ((m = line.match(PoParser.REGEX_MSGSTR)) != null) {
         nr = m[1];
         value = getContinuation(m[2]);
         if (value && msg != null) {
            nr = parseInt(nr, 10);
            msg.translations[nr || 0] = value;
         }
      }
   }
   return;
};

/**
 * Converts the array containing the parsed messages into a message
 * catalog script file and saves it on disk.
 * @param {java.io.File} outputDir The directory where the message
 * file should be saved
 */
PoParser.prototype.writeToFile = function(output) {
   var buf = new java.lang.StringBuffer();
   // write header
   buf.append('/**\n');
   buf.append(' * Instantiate the messages namespace if it\'s not already existing\n');
   buf.append(' */\n');
	var objPath = "";
   if (this.namespace) {
      objPath += this.namespace;
      buf.append('if (!global.' + objPath + ') {\n');
      buf.append('   global.' + objPath + ' = {};\n');
      buf.append('}\n');
      objPath += ".";
   }
   objPath += "messages";
   buf.append('if (!global.' + objPath + ') {\n');
   buf.append('   global.' + objPath + ' = {};\n');
   buf.append('}\n\n');

   buf.append('/**\n');
   buf.append(' * Messages for locale "' + this.localeKey + '"\n');
   buf.append(' */\n');
   objPath += "." + this.localeKey;
   buf.append('global.' + objPath + ' = {\n');
   // write messages
   for (var i=0;i<this.messages.length; i++) {
      this.messages[i].write(buf);
   }
   // write footer
   buf.append('};\n');

   // write the message catalog into the outFile
   var file = new java.io.File(output, objPath + ".js");
   var writer = new java.io.FileWriter(file);
   writer.write(buf.toString());
   // writer.write(buf.toString().getBytes("UTF-8"));
   writer.close();
   print("generated messages file " + file.getAbsolutePath());
   return;
};

/**
 * Constructs a new message object containing the singular- and
 * plural key plus their translations
 * @param {String} singularKey The singular key of the message
 * @returns A newly created Message instance
 * @constructor
 */
var Message = function(singularKey) {
   this.singularKey = singularKey;
   this.pluralKey = null;
   this.translations = [];
   return this;
}

/**
 * Dumps this message as JavaScript literal key-value pair(s)
 * @param {java.lang.StringBuffer} buf The buffer to append the dumped
 * string to
 */
Message.prototype.write = function(buf) {
   var writeLine = function(key, value) {
      buf.append('   "');
      buf.append(key);
      buf.append('": "');
      if (value !== null && value !== undefined) {
         buf.append(value);
      }
      buf.append('",\n');
   };

   if (this.singularKey != null) {
      writeLine(this.singularKey, this.translations[0]);
      if (this.pluralKey != null) {
         writeLine(this.pluralKey, this.translations[1]);
      }
   }
   return;
}

/**
 * Main script body
 */
if (arguments.length < 2) {
   print("Usage:");
   print("PoParser.js <input> <output> [namespace]");
   print("<input>: Either a single .po file or a directory containing .po files");
   print("<output>: The directory where the generated messages files should be stored");
   print("[namespace]: An optional global namespace where the messages should be");
   print("             stored (eg. a namespace like 'jala' will lead to messages");
   print("             stored in global.jala.messages by their locale.");
   quit();
}

var input = new java.io.File(arguments[0]);
var output = new java.io.File(arguments[1]);
var namespace = arguments[2];

// check if the output destination is a directory
if (output.isFile()) {
   print("Invalid arguments: the output destination must be a directory.");
   quit();
}

if (namespace && namespace.indexOf(".") != -1) {
   print("Invalid arguments: Please don't specify complex object paths, as this");
   print("would corrupt the messages file.");
   quit();
}

// parse the PO file(s) and create the message catalog files
var parser;
if (input.isDirectory()) {
   var files = input.listFiles();
   var file;
   for (var i=0;i<files.length;i++) {
      file = files[i];
      if (file.getName().endsWith(".po")) {
         parser = new PoParser(namespace);
         parser.parse(file);
         parser.writeToFile(output);
      }
   }
} else {
   parser = new PoParser(namespace);
   parser.parse(input);
   parser.writeToFile(output);
}