/*
Copyright (c) 2008 NascomASLib Contributors.  See:
    http://code.google.com/p/nascomaslib

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.
*/

package classes.matuto.utils.form.upload {

	import flash.events.*;
	import flash.net.*;
	import flash.utils.ByteArray;
	import flash.utils.Endian;

	/**
	 * Take a fileName, byteArray, and parameters object as input and return ByteArray post data suitable for a UrlRequest as output
	 *
	 * @see http://marstonstudio.com/?p=36
	 * @see http://www.w3.org/TR/html4/interact/forms.html
	 * @see http://www.jooce.com/blog/?p=143
	 * @see http://www.jooce.com/blog/wp%2Dcontent/uploads/2007/06/uploadFile.txt
	 * @see http://blog.je2050.de/2006/05/01/save-bytearray-to-file-with-php/
	 *
	 * @author Jonathan Marston
	 * @version 2007.08.19
	 *
	 * This work is licensed under a Creative Commons Attribution NonCommercial ShareAlike 3.0 License.
	 * @see http://creativecommons.org/licenses/by-nc-sa/3.0/
	 *
	 */
	public class UploadPostHelper {

		/**
		 * Boundary used to break up different parts of the http POST body
		 */
		private static var _boundary:String = "";

		/**
		 * Get the boundary for the post.
		 * Must be passed as part of the contentType of the UrlRequest
		 */
		public static function getBoundary():String {

			if(_boundary.length == 0) {
				for (var i:int = 0; i < 0x20; i++ ) {
					_boundary += String.fromCharCode( int( 97 + Math.random() * 25 ) );
				}
			}

			return _boundary;
		}

		/**
		 * Create post data to send in a UrlRequest
		 */
		public static function getPostData(fileName:String, byteArray:ByteArray, uploadDataFieldName:String = "Filedata", parameters:Object = null):ByteArray {

			var i: int;
			var bytes:String;

			var postData:ByteArray = new ByteArray();
			postData.endian = Endian.BIG_ENDIAN;

			//add Filename to parameters
			if(parameters == null) {
				parameters = new Object();
			}
			parameters.Filename = fileName;

			//add parameters to postData
			for(var name:String in parameters) {
				postData = BOUNDARY(postData);
				postData = LINEBREAK(postData);
				bytes = 'Content-Disposition: form-data; name="' + name + '"';
				for ( i = 0; i < bytes.length; i++ ) {
					postData.writeByte( bytes.charCodeAt(i) );
				}
				postData = LINEBREAK(postData);
				postData = LINEBREAK(postData);
				postData.writeUTFBytes(parameters[name]);
				postData = LINEBREAK(postData);
			}

			//add Filedata to postData
			postData = BOUNDARY(postData);
			postData = LINEBREAK(postData);
			bytes = 'Content-Disposition: form-data; name="'+uploadDataFieldName+'"; filename="' + fileName + '";';
			for ( i = 0; i < bytes.length; i++ ) {
				postData.writeByte( bytes.charCodeAt(i) );
			}
			postData.writeUTFBytes(fileName);
			postData = QUOTATIONMARK(postData);
			postData = LINEBREAK(postData);
			bytes = 'Content-Type: application/octet-stream';
			for ( i = 0; i < bytes.length; i++ ) {
				postData.writeByte( bytes.charCodeAt(i) );
			}
			postData = LINEBREAK(postData);
			postData = LINEBREAK(postData);
			postData.writeBytes(byteArray, 0, byteArray.length);
			postData = LINEBREAK(postData);

			//add upload filed to postData
			postData = LINEBREAK(postData);
			postData = BOUNDARY(postData);
			postData = LINEBREAK(postData);
			bytes = 'Content-Disposition: form-data; name="Upload"';
			for ( i = 0; i < bytes.length; i++ ) {
				postData.writeByte( bytes.charCodeAt(i) );
			}
			postData = LINEBREAK(postData);
			postData = LINEBREAK(postData);
			bytes = 'Submit Query';
			for ( i = 0; i < bytes.length; i++ ) {
				postData.writeByte( bytes.charCodeAt(i) );
			}
			postData = LINEBREAK(postData);

			//closing boundary
			postData = BOUNDARY(postData);
			postData = DOUBLEDASH(postData);

			return postData;
		}

		/**
		 * Add a boundary to the PostData with leading doubledash
		 */
		private static function BOUNDARY(p:ByteArray):ByteArray {
			var l:int = UploadPostHelper.getBoundary().length;

			p = DOUBLEDASH(p);
			for (var i:int = 0; i < l; i++ ) {
				p.writeByte( _boundary.charCodeAt( i ) );
			}
			return p;
		}

		/**
		 * Add one linebreak
		 */
		private static function LINEBREAK(p:ByteArray):ByteArray {
			p.writeShort(0x0d0a);
			return p;
		}

		/**
		 * Add quotation mark
		 */
		private static function QUOTATIONMARK(p:ByteArray):ByteArray {
			p.writeByte(0x22);
			return p;
		}

		/**
		 * Add Double Dash
		 */
		private static function DOUBLEDASH(p:ByteArray):ByteArray {
			p.writeShort(0x2d2d);
			return p;
		}

	}
}