/**
 * Remote Scripting Library
 * Copyright 2005 modernmethod, inc
 * Under the open source BSD license
 * http://www.modernmethod.com/sajax/
 */

/*jshint camelcase:false, onevar:false */
/*global alert */
( function ( mw ) {

/**
 * if sajax_debug_mode is true, this function outputs given the message into
 * the element with id = sajax_debug; if no such element exists in the document,
 * it is injected.
 */
function debug( text ) {
	if ( !window.sajax_debug_mode ) {
		return false;
	}

	var e = document.getElementById( 'sajax_debug' );

	if ( !e ) {
		e = document.createElement( 'p' );
		e.className = 'sajax_debug';
		e.id = 'sajax_debug';

		var b = document.getElementsByTagName( 'body' )[0];

		if ( b.firstChild ) {
			b.insertBefore( e, b.firstChild );
		} else {
			b.appendChild( e );
		}
	}

	var m = document.createElement( 'div' );
	m.appendChild( document.createTextNode( text ) );

	e.appendChild( m );

	return true;
}

/**
 * Compatibility wrapper for creating a new XMLHttpRequest object.
 */
function createXhr() {
	debug( 'sajax_init_object() called..' );
	var a;
	try {
		// Try the new style before ActiveX so we don't
		// unnecessarily trigger warnings in IE 7 when
		// set to prompt about ActiveX usage
		a = new XMLHttpRequest();
	} catch ( xhrE ) {
		try {
			a = new window.ActiveXObject( 'Msxml2.XMLHTTP' );
		} catch ( msXmlE ) {
			try {
				a = new window.ActiveXObject( 'Microsoft.XMLHTTP' );
			} catch ( msXhrE ) {
				a = null;
			}
		}
	}
	if ( !a ) {
		debug( 'Could not create connection object.' );
	}

	return a;
}

/**
 * Perform an AJAX call to MediaWiki. Calls are handled by AjaxDispatcher.php
 *   func_name - the name of the function to call. Must be registered in $wgAjaxExportList
 *   args - an array of arguments to that function
 *   target - the target that will handle the result of the call. If this is a function,
 *            if will be called with the XMLHttpRequest as a parameter; if it's an input
 *            element, its value will be set to the resultText; if it's another type of
 *            element, its innerHTML will be set to the resultText.
 *
 * Example:
 *    sajax_do_call( 'doFoo', [1, 2, 3], document.getElementById( 'showFoo' ) );
 *
 * This will call the doFoo function via MediaWiki's AjaxDispatcher, with
 * (1, 2, 3) as the parameter list, and will show the result in the element
 * with id = showFoo
 */
function doAjaxRequest( func_name, args, target ) {
	var i, x;
	var uri;
	var post_data;
	uri = mw.util.wikiScript() + '?action=ajax';
	if ( window.sajax_request_type === 'GET' ) {
		if ( uri.indexOf( '?' ) === -1 ) {
			uri = uri + '?rs=' + encodeURIComponent( func_name );
		} else {
			uri = uri + '&rs=' + encodeURIComponent( func_name );
		}
		for ( i = 0; i < args.length; i++ ) {
			uri = uri + '&rsargs[]=' + encodeURIComponent( args[i] );
		}
		//uri = uri + '&rsrnd=' + new Date().getTime();
		post_data = null;
	} else {
		post_data = 'rs=' + encodeURIComponent( func_name );
		for ( i = 0; i < args.length; i++ ) {
			post_data = post_data + '&rsargs[]=' + encodeURIComponent( args[i] );
		}
	}
	x = createXhr();
	if ( !x ) {
		alert( 'AJAX not supported' );
		return false;
	}

	try {
		x.open( window.sajax_request_type, uri, true );
	} catch ( e ) {
		if ( location.hostname === 'localhost' ) {
			alert( 'Your browser blocks XMLHttpRequest to "localhost", try using a real hostname for development/testing.' );
		}
		throw e;
	}
	if ( window.sajax_request_type === 'POST' ) {
		x.setRequestHeader( 'Method', 'POST ' + uri + ' HTTP/1.1' );
		x.setRequestHeader( 'Content-Type', 'application/x-www-form-urlencoded' );
	}
	x.setRequestHeader( 'Pragma', 'cache=yes' );
	x.setRequestHeader( 'Cache-Control', 'no-transform' );
	x.onreadystatechange = function () {
		if ( x.readyState !== 4 ) {
			return;
		}

		debug( 'received (' + x.status + ' ' + x.statusText + ') ' + x.responseText );

		//if ( x.status != 200 )
		//	alert( 'Error: ' + x.status + ' ' + x.statusText + ': ' + x.responseText );
		//else

		if ( typeof target === 'function' ) {
			target( x );
		} else if ( typeof target === 'object' ) {
			if ( target.tagName === 'INPUT' ) {
				if ( x.status === 200 ) {
					target.value= x.responseText;
				}
				//else alert( 'Error: ' + x.status + ' ' + x.statusText + ' (' + x.responseText + ')' );
			} else {
				if ( x.status === 200 ) {
					target.innerHTML = x.responseText;
				} else {
					target.innerHTML = '<div class="error">Error: ' + x.status +
						' ' + x.statusText + ' (' + x.responseText + ')</div>';
				}
			}
		} else {
			alert( 'Bad target for sajax_do_call: not a function or object: ' + target );
		}
	};

	debug( func_name + ' uri = ' + uri + ' / post = ' + post_data );
	x.send( post_data );
	debug( func_name + ' waiting..' );

	return true;
}

/**
 * @return {boolean} Whether the browser supports AJAX
 */
function wfSupportsAjax() {
	var request = createXhr();
	var supportsAjax = request ? true : false;
	request = undefined;
	return supportsAjax;
}

// Expose + Mark as deprecated
var deprecationNotice = 'Sajax is deprecated, use jQuery.ajax or mediawiki.api instead.';

// Variables
mw.log.deprecate( window, 'sajax_debug_mode', false, deprecationNotice );
mw.log.deprecate( window, 'sajax_request_type', 'GET', deprecationNotice );
// Methods
mw.log.deprecate( window, 'sajax_debug', debug, deprecationNotice );
mw.log.deprecate( window, 'sajax_init_object', createXhr, deprecationNotice );
mw.log.deprecate( window, 'sajax_do_call', doAjaxRequest, deprecationNotice );
mw.log.deprecate( window, 'wfSupportsAjax', wfSupportsAjax, deprecationNotice );

}( mediaWiki ) );
