/*
 * jQuery JSONP Core Plugin 2.1.4 (2010-11-17)
 * 
 * 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
  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 ) + encodeURIComponent( 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() {
              /loaded|complete/.test( script.readyState ) && 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 );