/*
 * jQuery JSONP Core Plugin 2.1.2 (2010-06-20)
 * 
 * http://code.google.com/p/jquery-jsonp/
 *
 * Copyright (c) 2010 Julian Aubourg
 *
 * This document is licensed as free software under the terms of the
 * MIT License: http://www.opensource.org/licenses/mit-license.php
 */
( function( $ , setTimeout ) {
	
	// ###################### UTILITIES ##
	
	// Noop
	function noop() {
	}
	
	// Generic callback for firefox & opera
	function genericCallback( data ) {
		lastValue = [ data ];
	}

	// Add script to document
	function appendScript( node ) {
		head.insertBefore( node , head.firstChild );
	}
	
	// Call if defined
	function callIfDefined( method , object , parameters ) {
		return method && method.apply( object.context || object , parameters );
	}
	
	// Give joining character given url
	function qMarkOrAmp( url ) {
		return /\?/ .test( url ) ? "&" : "?";
	}
	
	var // String constants (for better minification)
		STR_ASYNC = "async",
		STR_CHARSET = "charset",
		STR_EMPTY = "",
		STR_ERROR = "error",
		STR_JQUERY_JSONP = "_jqjsp",
		STR_ON = "on",
		STR_ONCLICK = STR_ON + "click",
		STR_ONERROR = STR_ON + STR_ERROR,
		STR_ONLOAD = STR_ON + "load",
		STR_ONREADYSTATECHANGE = STR_ON + "readystatechange",
		STR_REMOVE_CHILD = "removeChild",
		STR_SCRIPT_TAG = "<script/>",
		STR_SUCCESS = "success",
		STR_TIMEOUT = "timeout",
		
		// Shortcut to jQuery.browser
		browser = $.browser,
		
		// Head element (for faster use)
		head = $( "head" )[ 0 ] || document.documentElement,
		// Page cache
		pageCache = {},
		// Counter
		count = 0,
		// Last returned value
		lastValue,
		
		// ###################### DEFAULT OPTIONS ##
		xOptionsDefaults = {
			//beforeSend: undefined,
			//cache: false,
			callback: STR_JQUERY_JSONP,
			//callbackParameter: undefined,
			//charset: undefined,
			//complete: undefined,
			//context: undefined,
			//data: "",
			//dataFilter: undefined,
			//error: undefined,
			//pageCache: false,
			//success: undefined,
			//timeout: 0,
			//traditional: false,		
			url: location.href
		};
	
	// ###################### MAIN FUNCTION ##
	function jsonp( xOptions ) {
		
		// Build data with default
		xOptions = $.extend( {} , xOptionsDefaults , xOptions );
		
		// References to xOptions members (for better minification)
		var completeCallback = xOptions.complete,
			dataFilter = xOptions.dataFilter,
			callbackParameter = xOptions.callbackParameter,
			successCallbackName = xOptions.callback,
			cacheFlag = xOptions.cache,
			pageCacheFlag = xOptions.pageCache,
			charset = xOptions.charset,
			url = xOptions.url,
			data = xOptions.data,
			timeout = xOptions.timeout,
			pageCached,
			
			// Abort/done flag
			done = 0,
			
			// Life-cycle functions
			cleanUp = noop;
		
		// Create the abort method
		xOptions.abort = function() { 
			! done++ &&	cleanUp(); 
		};

		// Call beforeSend if provided (early abort if false returned)
		if ( callIfDefined( xOptions.beforeSend, xOptions , [ xOptions ] ) === false || done ) {
			return xOptions;
		}
			
		// Control entries
		url = url || STR_EMPTY;
		data = data ? ( (typeof data) == "string" ? data : $.param( data , xOptions.traditional ) ) : STR_EMPTY;
			
		// Build final url
		url += data ? ( qMarkOrAmp( url ) + data ) : STR_EMPTY;
		
		// Add callback parameter if provided as option
		callbackParameter && ( url += qMarkOrAmp( url ) + escape(callbackParameter) + "=?" );
		
		// Add anticache parameter if needed
		! cacheFlag && ! pageCacheFlag && ( url += qMarkOrAmp( url ) + "_" + ( new Date() ).getTime() + "=" );
		
		// Replace last ? by callback parameter
		url = url.replace( /=\?(&|$)/ , "=" + successCallbackName + "$1" );
		
		// Success notifier
		function notifySuccess( json ) {
			! done++ && setTimeout( function() {
				cleanUp();
				// Pagecache if needed
				pageCacheFlag && ( pageCache [ url ] = { s: [ json ] } );
				// Apply the data filter if provided
				dataFilter && ( json = dataFilter.apply( xOptions , [ json ] ) );
				// Call success then complete
				callIfDefined( xOptions.success , xOptions , [ json , STR_SUCCESS ] );
				callIfDefined( completeCallback , xOptions , [ xOptions , STR_SUCCESS ] );
			} , 0 );
		}
		
		// Error notifier
	    function notifyError( type ) {
	    	! done++ && setTimeout( function() {
	    		// Clean up
	    		cleanUp();
				// If pure error (not timeout), cache if needed
				pageCacheFlag && type != STR_TIMEOUT && ( pageCache[ url ] = type );
				// Call error then complete
				callIfDefined( xOptions.error , xOptions , [ xOptions , type ] );
				callIfDefined( completeCallback , xOptions , [ xOptions , type ] );
	    	} , 0 );
	    }
	    
		// Check page cache
		pageCacheFlag && ( pageCached = pageCache[ url ] ) 
			? ( pageCached.s ? notifySuccess( pageCached.s[ 0 ] ) : notifyError( pageCached ) )
			:
			// Initiate request
			setTimeout( function( script , scriptAfter , timeoutTimer ) {
				
				if ( ! done ) {
				
					// If a timeout is needed, install it
					timeoutTimer = timeout > 0 && setTimeout( function() {
						notifyError( STR_TIMEOUT );
					} , timeout );
					
					// Re-declare cleanUp function
					cleanUp = function() {
						timeoutTimer && clearTimeout( timeoutTimer );
						script[ STR_ONREADYSTATECHANGE ]
							= script[ STR_ONCLICK ]
							= script[ STR_ONLOAD ]
							= script[ STR_ONERROR ]
							= null;
						head[ STR_REMOVE_CHILD ]( script );
						scriptAfter && head[ STR_REMOVE_CHILD ]( scriptAfter );
					};
					
					// Install the generic callback
					// (BEWARE: global namespace pollution ahoy)
					window[ successCallbackName ] = genericCallback;

					// Create the script tag
					script = $( STR_SCRIPT_TAG )[ 0 ];
					script.id = STR_JQUERY_JSONP + count++;
					
					// Set charset if provided
					if ( charset ) {
						script[ STR_CHARSET ] = charset;
					}
					
					// Callback function
					function callback( result ) {
						( script[ STR_ONCLICK ] || noop )();
						result = lastValue;
						lastValue = undefined;
						result ? notifySuccess( result[ 0 ] ) : notifyError( STR_ERROR );
					}
										
					// IE: event/htmlFor/onclick trick
					// One can't rely on proper order for onreadystatechange
					// We have to sniff since FF doesn't like event & htmlFor... at all
					if ( browser.msie ) {
						
						script.event = STR_ONCLICK;
						script.htmlFor = script.id;
						script[ STR_ONREADYSTATECHANGE ] = function() {
							script.readyState == "loaded" && callback();
						};
						
					// All others: standard handlers
					} else {					
					
						script[ STR_ONERROR ] = script[ STR_ONLOAD ] = callback;
						
						browser.opera ?
							
							// Opera: onerror is not called, use synchronized script execution
							( ( scriptAfter = $( STR_SCRIPT_TAG )[ 0 ] ).text = "jQuery('#" + script.id + "')[0]." + STR_ONERROR + "()" )
							
							// Firefox: set script as async to avoid blocking scripts (3.6+ only)
							: script[ STR_ASYNC ] = STR_ASYNC;
							
						;
					}
					
					// Set source
					script.src = url;
					
					// Append main script
					appendScript( script );
					
					// Opera: Append trailing script
					scriptAfter && appendScript( scriptAfter );
				}
				
			} , 0 );
		
		return xOptions;
	}
	
	// ###################### SETUP FUNCTION ##
	jsonp.setup = function( xOptions ) {
		$.extend( xOptionsDefaults , xOptions );
	};

	// ###################### INSTALL in jQuery ##
	$.jsonp = jsonp;
	
} )( jQuery , setTimeout );