/*
 * OpenSearch ajax suggestion engine for MediaWiki
 *
 * uses core MediaWiki open search support to fetch suggestions
 * and show them below search boxes and other inputs
 *
 * by Robert Stojnic (April 2008)
 */

// Make sure wgMWSuggestTemplate is defined
if ( !mw.config.exists( 'wgMWSuggestTemplate' ) ) {
	mw.config.set( 'wgMWSuggestTemplate', mw.config.get( 'wgServer' ) + mw.config.get( 'wgScriptPath' )
		 + "/api.php?action=opensearch\x26search={searchTerms}\x26namespace={namespaces}\x26suggest" );
}

// search_box_id -> Results object
window.os_map = {};
// cached data, url -> json_text
window.os_cache = {};
// global variables for suggest_keypress
window.os_cur_keypressed = 0;
window.os_keypressed_count = 0;
// type: Timer
window.os_timer = null;
// tie mousedown/up events
window.os_mouse_pressed = false;
window.os_mouse_num = -1;
// if true, the last change was made by mouse (and not keyboard)
window.os_mouse_moved = false;
// delay between keypress and suggestion (in ms)
window.os_search_timeout = 250;
// these pairs of inputs/forms will be autoloaded at startup
window.os_autoload_inputs = ['searchInput', 'searchInput2', 'powerSearchText', 'searchText'];
window.os_autoload_forms = ['searchform', 'searchform2', 'powersearch', 'search'];
// if we stopped the service
window.os_is_stopped = false;
// max lines to show in suggest table
window.os_max_lines_per_suggest = 7;
// number of steps to animate expansion/contraction of container width
window.os_animation_steps = 6;
// num of pixels of smallest step
window.os_animation_min_step = 2;
// delay between steps (in ms)
window.os_animation_delay = 30;
// max width of container in percent of normal size (1 == 100%)
window.os_container_max_width = 2;
// currently active animation timer
window.os_animation_timer = null;
// whether MWSuggest is enabled. Set to false when os_MWSuggestDisable() is called
window.os_enabled = true;

/**
 * <datalist> is a new HTML5 element that allows you to manually
 * supply suggestion lists and have them rendered according to the
 * right platform conventions.  Opera as of version 11 has a fatal
 * problem: the suggestion lags behind what the user types by one
 * keypress.  (Reported as DSK-276870 to Opera's secret bug tracker.)
 * There are also problems with other browsers, including Firefox and
 * Safari: See bug 31602 for details.
 */
window.os_use_datalist = false;

/** Timeout timer class that will fetch the results */
window.os_Timer = function( id, r, query ) {
	this.id = id;
	this.r = r;
	this.query = query;
};

/** Property class for single search box */
window.os_Results = function( name, formname ) {
	this.searchform = formname; // id of the searchform
	this.searchbox = name; // id of the searchbox
	this.container = name + 'Suggest'; // div that holds results
	this.resultTable = name + 'Result'; // id base for the result table (+num = table row)
	this.resultText = name + 'ResultText'; // id base for the spans within result tables (+num)
	this.toggle = name + 'Toggle'; // div that has the toggle (enable/disable) link
	this.query = null; // last processed query
	this.results = null;  // parsed titles
	this.resultCount = 0; // number of results
	this.original = null; // query that user entered
	this.selected = -1; // which result is selected
	this.containerCount = 0; // number of results visible in container
	this.containerRow = 0; // height of result field in the container
	this.containerTotal = 0; // total height of the container will all results
	this.visible = false; // if container is visible
	this.stayHidden = false; // don't try to show if lost focus
};

/** Timer user to animate expansion/contraction of container width */
window.os_AnimationTimer = function( r, target ) {
	this.r = r;
	var current = document.getElementById(r.container).offsetWidth;
	this.inc = Math.round( ( target - current ) / os_animation_steps );
	if( this.inc < os_animation_min_step && this.inc >=0 ) {
		this.inc = os_animation_min_step; // minimal animation step
	}
	if( this.inc > -os_animation_min_step && this.inc < 0 ) {
		this.inc = -os_animation_min_step;
	}
	this.target = target;
};

/******************
 * Initialization
 ******************/

/** Initialization, call upon page onload */
window.os_MWSuggestInit = function() {
	if ( !window.os_enabled ) {
		return;
	}
	
	for( var i = 0; i < os_autoload_inputs.length; i++ ) {
		var id = os_autoload_inputs[i];
		var form = os_autoload_forms[i];
		element = document.getElementById( id );
		if( element != null ) {
			os_initHandlers( id, form, element );
		}
	}
};

/* Teardown, called when things like SimpleSearch need to disable MWSuggest */
window.os_MWSuggestTeardown = function() {
	for( var i = 0; i < os_autoload_inputs.length; i++ ) {
		var id = os_autoload_inputs[i];
		var form = os_autoload_forms[i];
		element = document.getElementById( id );
		if( element != null ) {
			os_teardownHandlers( id, form, element );
		}
	}
};

/* Call this to disable MWSuggest. Works regardless of whether MWSuggest has been initialized already. */
window.os_MWSuggestDisable = function() {
	window.os_MWSuggestTeardown();
	window.os_enabled = false;
}
	

/** Init Result objects and event handlers */
window.os_initHandlers = function( name, formname, element ) {
	var r = new os_Results( name, formname );
	var formElement = document.getElementById( formname );
	if( !formElement ) {
		// Older browsers (Opera 8) cannot get form elements
		return;
	}
	// event handler
	os_hookEvent( element, 'keyup', os_eventKeyup );
	os_hookEvent( element, 'keydown', os_eventKeydown );
	os_hookEvent( element, 'keypress', os_eventKeypress );
	if ( !os_use_datalist ) {
		// These are needed for the div hack to hide it if the user blurs.
		os_hookEvent( element, 'blur', os_eventBlur );
		os_hookEvent( element, 'focus', os_eventFocus );
		// We don't want browser auto-suggestions interfering with our div, but
		// autocomplete must be on for datalist to work (at least in Opera
		// 10.10).
		element.setAttribute( 'autocomplete', 'off' );
	}
	// stopping handler
	os_hookEvent( formElement, 'submit', os_eventOnsubmit );
	os_map[name] = r;
	// toggle link
	if( document.getElementById( r.toggle ) == null ) {
		// TODO: disable this while we figure out a way for this to work in all browsers
		/* if( name == 'searchInput' ) {
			// special case: place above the main search box
			var t = os_createToggle( r, 'os-suggest-toggle' );
			var searchBody = document.getElementById( 'searchBody' );
			var first = searchBody.parentNode.firstChild.nextSibling.appendChild(t);
		} else {
			// default: place below search box to the right
			var t = os_createToggle( r, 'os-suggest-toggle-def' );
			var top = element.offsetTop + element.offsetHeight;
			var left = element.offsetLeft + element.offsetWidth;
			t.style.position = 'absolute';
			t.style.top = top + 'px';
			t.style.left = left + 'px';
			element.parentNode.appendChild( t );
			// only now width gets calculated, shift right
			left -= t.offsetWidth;
			t.style.left = left + 'px';
			t.style.visibility = 'visible';
		} */
	}

};

window.os_teardownHandlers = function( name, formname, element ) {
	var formElement = document.getElementById( formname );
	if( !formElement ) {
		// Older browsers (Opera 8) cannot get form elements
		return;
	}

	os_unhookEvent( element, 'keyup', os_eventKeyup );
	os_unhookEvent( element, 'keydown', os_eventKeydown );
	os_unhookEvent( element, 'keypress', os_eventKeypress );
	if ( !os_use_datalist ) {
		// These are needed for the div hack to hide it if the user blurs.
		os_unhookEvent( element, 'blur', os_eventBlur );
		os_unhookEvent( element, 'focus', os_eventFocus );
		// We don't want browser auto-suggestions interfering with our div, but
		// autocomplete must be on for datalist to work (at least in Opera
		// 10.10).
		element.removeAttribute( 'autocomplete' );
	}
	// stopping handler
	os_unhookEvent( formElement, 'submit', os_eventOnsubmit );
};


window.os_hookEvent = function( element, hookName, hookFunct ) {
	if ( element.addEventListener ) {
		element.addEventListener( hookName, hookFunct, false );
	} else if ( window.attachEvent ) {
		element.attachEvent( 'on' + hookName, hookFunct );
	}
};

window.os_unhookEvent = function( element, hookName, hookFunct ) {
	if ( element.removeEventListener ) {
		element.removeEventListener( hookName, hookFunct, false );
	} else if ( element.detachEvent ) {
		element.detachEvent( 'on' + hookName, hookFunct );
	}
}

/********************
 *  Keyboard events
 ********************/

/** Event handler that will fetch results on keyup */
window.os_eventKeyup = function( e ) {
	var targ = os_getTarget( e );
	var r = os_map[targ.id];
	if( r == null ) {
		return; // not our event
	}

	// some browsers won't generate keypressed for arrow keys, catch it
	if( os_keypressed_count == 0 ) {
		os_processKey( r, os_cur_keypressed, targ );
	}
	var query = targ.value;
	os_fetchResults( r, query, os_search_timeout );
};

/** catch arrows up/down and escape to hide the suggestions */
window.os_processKey = function( r, keypressed, targ ) {
	if ( keypressed == 40 && !r.visible && os_timer == null ) {
		// If the user hits the down arrow, fetch results immediately if none
		// are already displayed.
		r.query = '';
		os_fetchResults( r, targ.value, 0 );
	}
	// Otherwise, if we're not using datalist, we need to handle scrolling and
	// so on.
	if ( os_use_datalist ) {
		return;
	}
	if ( keypressed == 40 ) { // Arrow Down
		if ( r.visible ) {
			os_changeHighlight( r, r.selected, r.selected + 1, true );
		}
	} else if ( keypressed == 38 ) { // Arrow Up
		if ( r.visible ) {
			os_changeHighlight( r, r.selected, r.selected - 1, true );
		}
	} else if( keypressed == 27 ) { // Escape
		document.getElementById( r.searchbox ).value = r.original;
		r.query = r.original;
		os_hideResults( r );
	} else if( r.query != document.getElementById( r.searchbox ).value ) {
		// os_hideResults( r ); // don't show old suggestions
	}
};

/** When keys is held down use a timer to output regular events */
window.os_eventKeypress = function( e ) {
	var targ = os_getTarget( e );
	var r = os_map[targ.id];
	if( r == null ) {
		return; // not our event
	}

	var keypressed = os_cur_keypressed;

	os_keypressed_count++;
	os_processKey( r, keypressed, targ );
};

/** Catch the key code (Firefox bug) */
window.os_eventKeydown = function( e ) {
	if ( !e ) {
		e = window.event;
	}
	var targ = os_getTarget( e );
	var r = os_map[targ.id];
	if( r == null ) {
		return; // not our event
	}

	os_mouse_moved = false;

	os_cur_keypressed = ( e.keyCode == undefined ) ? e.which : e.keyCode;
	os_keypressed_count = 0;
};


/** When the form is submitted hide everything, cancel updates... */
window.os_eventOnsubmit = function( e ) {
	var targ = os_getTarget( e );

	os_is_stopped = true;
	// kill timed requests
	if( os_timer != null && os_timer.id != null ) {
		clearTimeout( os_timer.id );
		os_timer = null;
	}
	// Hide all suggestions
	for( i = 0; i < os_autoload_inputs.length; i++ ) {
		var r = os_map[os_autoload_inputs[i]];
		if( r != null ) {
			var b = document.getElementById( r.searchform );
			if( b != null && b == targ ) {
				// set query value so the handler won't try to fetch additional results
				r.query = document.getElementById( r.searchbox ).value;
			}
			os_hideResults( r );
		}
	}
	return true;
};



/** Hide results from the user, either making the div visibility=hidden or
 * detaching the datalist from the input. */
window.os_hideResults = function( r ) {
	if ( os_use_datalist ) {
		document.getElementById( r.searchbox ).setAttribute( 'list', '' );
	} else {
		var c = document.getElementById( r.container );
		if ( c != null ) {
			c.style.visibility = 'hidden';
		}
	}
	r.visible = false;
	r.selected = -1;
};

window.os_decodeValue = function( value ) {
	if ( decodeURIComponent ) {
		return decodeURIComponent( value );
	}
	if( unescape ) {
		return unescape( value );
	}
	return null;
};

window.os_encodeQuery = function( value ) {
	if ( encodeURIComponent ) {
		return encodeURIComponent( value );
	}
	if( escape ) {
		return escape( value );
	}
	return null;
};

/** Handles data from XMLHttpRequest, and updates the suggest results */
window.os_updateResults = function( r, query, text, cacheKey ) {
	os_cache[cacheKey] = text;
	r.query = query;
	r.original = query;
	if( text == '' ) {
		r.results = null;
		r.resultCount = 0;
		os_hideResults( r );
	} else {
		try {
			var p = eval( '(' + text + ')' ); // simple json parse, could do a safer one
			if( p.length < 2 || p[1].length == 0 ) {
				r.results = null;
				r.resultCount = 0;
				os_hideResults( r );
				return;
			}
			if ( os_use_datalist ) {
				os_setupDatalist( r, p[1] );
			} else {
				os_setupDiv( r, p[1] );
			}
		} catch( e ) {
			// bad response from server or such
			os_hideResults( r );
			os_cache[cacheKey] = null;
		}
	}
};

/**
 * Create and populate a <datalist>.
 *
 * @param r       os_Result object
 * @param results Array of the new results to replace existing ones
 */
window.os_setupDatalist = function( r, results ) {
	var s = document.getElementById( r.searchbox );
	var c = document.getElementById( r.container );
	if ( c == null ) {
		c = document.createElement( 'datalist' );
		c.setAttribute( 'id', r.container );
		document.body.appendChild( c );
	} else {
		c.innerHTML = '';
	}
	s.setAttribute( 'list', r.container );

	r.results = [];
	r.resultCount = results.length;
	r.visible = true;
	for ( i = 0; i < results.length; i++ ) {
		var title = os_decodeValue( results[i] );
		var opt = document.createElement( 'option' );
		opt.value = title;
		r.results[i] = title;
		c.appendChild( opt );
	}
};

/** Fetch namespaces from checkboxes or hidden fields in the search form,
    if none defined use wgSearchNamespaces */
window.os_getNamespaces = function( r ) {
	var namespaces = '';
	var elements = document.forms[r.searchform].elements;
	for( i = 0; i < elements.length; i++ ) {
		var name = elements[i].name;
		if( typeof name != 'undefined' && name.length > 2 && name[0] == 'n' &&
			name[1] == 's' && (
				( elements[i].type == 'checkbox' && elements[i].checked ) ||
				( elements[i].type == 'hidden' && elements[i].value == '1' )
			)
		) {
			if( namespaces != '' ) {
				namespaces += '|';
			}
			namespaces += name.substring( 2 );
		}
	}
	if( namespaces == '' ) {
		namespaces = mw.config.get( 'wgSearchNamespaces' ).join('|');
	}
	return namespaces;
};

/** Update results if user hasn't already typed something else */
window.os_updateIfRelevant = function( r, query, text, cacheKey ) {
	var t = document.getElementById( r.searchbox );
	if( t != null && t.value == query ) { // check if response is still relevant
		os_updateResults( r, query, text, cacheKey );
	}
	r.query = query;
};

/** Fetch results after some timeout */
window.os_delayedFetch = function() {
	if( os_timer == null ) {
		return;
	}
	var r = os_timer.r;
	var query = os_timer.query;
	os_timer = null;
	var path = mw.config.get( 'wgMWSuggestTemplate' ).replace( "{namespaces}", os_getNamespaces( r ) )
									.replace( "{dbname}", mw.config.get( 'wgDBname' ) )
									.replace( "{searchTerms}", os_encodeQuery( query ) );

	// try to get from cache, if not fetch using ajax
	var cached = os_cache[path];
	if( cached != null && cached != undefined ) {
		os_updateIfRelevant( r, query, cached, path );
	} else {
		var xmlhttp = sajax_init_object();
		if( xmlhttp ) {
			try {
				xmlhttp.open( 'GET', path, true );
				xmlhttp.onreadystatechange = function() {
					if ( xmlhttp.readyState == 4 && typeof os_updateIfRelevant == 'function' ) {
						os_updateIfRelevant( r, query, xmlhttp.responseText, path );
					}
				};
				xmlhttp.send( null );
			} catch ( e ) {
				if ( window.location.hostname == 'localhost' ) {
					alert( "Your browser blocks XMLHttpRequest to 'localhost', try using a real hostname for development/testing." );
				}
				throw e;
			}
		}
	}
};

/** Init timed update via os_delayedUpdate() */
window.os_fetchResults = function( r, query, timeout ) {
	if( query == '' ) {
		r.query = '';
		os_hideResults( r );
		return;
	} else if( query == r.query ) {
		return; // no change
	}

	os_is_stopped = false; // make sure we're running

	// cancel any pending fetches
	if( os_timer != null && os_timer.id != null ) {
		clearTimeout( os_timer.id );
	}
	// schedule delayed fetching of results
	if( timeout != 0 ) {
		os_timer = new os_Timer( setTimeout( "os_delayedFetch()", timeout ), r, query );
	} else {
		os_timer = new os_Timer( null, r, query );
		os_delayedFetch(); // do it now!
	}
};

/** Find event target */
window.os_getTarget = function( e ) {
	if ( !e ) {
		e = window.event;
	}
	if ( e.target ) {
		return e.target;
	} else if ( e.srcElement ) {
		return e.srcElement;
	} else {
		return null;
	}
};

/** Check if x is a valid integer */
window.os_isNumber = function( x ) {
	if( x == '' || isNaN( x ) ) {
		return false;
	}
	for( var i = 0; i < x.length; i++ ) {
		var c = x.charAt( i );
		if( !( c >= '0' && c <= '9' ) ) {
			return false;
		}
	}
	return true;
};

/** Call this to enable suggestions on input (id=inputId), on a form (name=formName) */
window.os_enableSuggestionsOn = function( inputId, formName ) {
	os_initHandlers( inputId, formName, document.getElementById( inputId ) );
};

/** Call this to disable suggestios on input box (id=inputId) */
window.os_disableSuggestionsOn = function( inputId ) {
	r = os_map[inputId];
	if( r != null ) {
		// cancel/hide results
		os_timer = null;
		os_hideResults( r );
		// turn autocomplete on !
		document.getElementById( inputId ).setAttribute( 'autocomplete', 'on' );
		// remove descriptor
		os_map[inputId] = null;
	}

	// Remove the element from the os_autoload_* arrays
	var index = os_autoload_inputs.indexOf( inputId );
	if ( index >= 0 ) {
		os_autoload_inputs[index] = os_autoload_forms[index] = '';
	}
};

/************************************************
 * Div-only functions (irrelevant for datalist)
 ************************************************/

/** Event: loss of focus of input box */
window.os_eventBlur = function( e ) {
	var targ = os_getTarget( e );
	var r = os_map[targ.id];
	if( r == null ) {
		return; // not our event
	}
	if( !os_mouse_pressed ) {
		os_hideResults( r );
		// force canvas to stay hidden
		r.stayHidden = true;
		// cancel any pending fetches
		if( os_timer != null && os_timer.id != null ) {
			clearTimeout( os_timer.id );
		}
		os_timer = null;
	}
};

/** Event: focus (catch only when stopped) */
window.os_eventFocus = function( e ) {
	var targ = os_getTarget( e );
	var r = os_map[targ.id];
	if( r == null ) {
		return; // not our event
	}
	r.stayHidden = false;
};

/**
 * Create and populate a <div>, for non-<datalist>-supporting browsers.
 *
 * @param r       os_Result object
 * @param results Array of the new results to replace existing ones
 */
window.os_setupDiv = function( r, results ) {
	var c = document.getElementById( r.container );
	if ( c == null ) {
		c = os_createContainer( r );
	}
	c.innerHTML = os_createResultTable( r, results );
	// init container table sizes
	var t = document.getElementById( r.resultTable );
	r.containerTotal = t.offsetHeight;
	r.containerRow = t.offsetHeight / r.resultCount;
	os_fitContainer( r );
	os_trimResultText( r );
	os_showResults( r );
};

/** Create the result table to be placed in the container div */
window.os_createResultTable = function( r, results ) {
	var c = document.getElementById( r.container );
	var width = c.offsetWidth - os_operaWidthFix( c.offsetWidth );
	var html = '<table class="os-suggest-results" id="' + r.resultTable + '" style="width: ' + width + 'px;">';
	r.results = [];
	r.resultCount = results.length;
	for( i = 0; i < results.length; i++ ) {
		var title = os_decodeValue( results[i] );
		r.results[i] = title;
		html += '<tr><td class="os-suggest-result" id="' + r.resultTable + i + '"><span id="' + r.resultText + i + '">' + title + '</span></td></tr>';
	}
	html += '</table>';
	return html;
};

/** Show results div */
window.os_showResults = function( r ) {
	if( os_is_stopped ) {
		return;
	}
	if( r.stayHidden ) {
		return;
	}
	os_fitContainer( r );
	var c = document.getElementById( r.container );
	r.selected = -1;
	if( c != null ) {
		c.scrollTop = 0;
		c.style.visibility = 'visible';
		r.visible = true;
	}
};

window.os_operaWidthFix = function( x ) {
	// For browsers that don't understand overflow-x, estimate scrollbar width
	if( typeof document.body.style.overflowX != 'string' ) {
		return 30;
	}
	return 0;
};

/** Brower-dependent functions to find window inner size, and scroll status */
window.f_clientWidth = function() {
	return f_filterResults(
		window.innerWidth ? window.innerWidth : 0,
		document.documentElement ? document.documentElement.clientWidth : 0,
		document.body ? document.body.clientWidth : 0
	);
};

window.f_clientHeight = function() {
	return f_filterResults(
		window.innerHeight ? window.innerHeight : 0,
		document.documentElement ? document.documentElement.clientHeight : 0,
		document.body ? document.body.clientHeight : 0
	);
};

window.f_scrollLeft = function() {
	return f_filterResults(
		window.pageXOffset ? window.pageXOffset : 0,
		document.documentElement ? document.documentElement.scrollLeft : 0,
		document.body ? document.body.scrollLeft : 0
	);
};

window.f_scrollTop = function() {
	return f_filterResults(
		window.pageYOffset ? window.pageYOffset : 0,
		document.documentElement ? document.documentElement.scrollTop : 0,
		document.body ? document.body.scrollTop : 0
	);
};

window.f_filterResults = function( n_win, n_docel, n_body ) {
	var n_result = n_win ? n_win : 0;
	if ( n_docel && ( !n_result || ( n_result > n_docel ) ) ) {
		n_result = n_docel;
	}
	return n_body && ( !n_result || ( n_result > n_body ) ) ? n_body : n_result;
};

/** Get the height available for the results container */
window.os_availableHeight = function( r ) {
	var absTop = document.getElementById( r.container ).style.top;
	var px = absTop.lastIndexOf( 'px' );
	if( px > 0 ) {
		absTop = absTop.substring( 0, px );
	}
	return f_clientHeight() - ( absTop - f_scrollTop() );
};

/** Get element absolute position {left,top} */
window.os_getElementPosition = function( elemID ) {
	var offsetTrail = document.getElementById( elemID );
	var offsetLeft = 0;
	var offsetTop = 0;
	while ( offsetTrail ) {
		offsetLeft += offsetTrail.offsetLeft;
		offsetTop += offsetTrail.offsetTop;
		offsetTrail = offsetTrail.offsetParent;
	}
	if ( navigator.userAgent.indexOf('Mac') != -1 && typeof document.body.leftMargin != 'undefined' ) {
		offsetLeft += document.body.leftMargin;
		offsetTop += document.body.topMargin;
	}
	return { left:offsetLeft, top:offsetTop };
};

/** Create the container div that will hold the suggested titles */
window.os_createContainer = function( r ) {
	var c = document.createElement( 'div' );
	var s = document.getElementById( r.searchbox );
	var pos = os_getElementPosition( r.searchbox );
	var left = pos.left;
	var top = pos.top + s.offsetHeight;
	c.className = 'os-suggest';
	c.setAttribute( 'id', r.container );
	document.body.appendChild( c );

	// dynamically generated style params
	// IE workaround, cannot explicitely set "style" attribute
	c = document.getElementById( r.container );
	c.style.top = top + 'px';
	c.style.left = left + 'px';
	c.style.width = s.offsetWidth + 'px';

	// mouse event handlers
	c.onmouseover = function( event ) { os_eventMouseover( r.searchbox, event ); };
	c.onmousemove = function( event ) { os_eventMousemove( r.searchbox, event ); };
	c.onmousedown = function( event ) { return os_eventMousedown( r.searchbox, event ); };
	c.onmouseup = function( event ) { os_eventMouseup( r.searchbox, event ); };
	return c;
};

/** change container height to fit to screen */
window.os_fitContainer = function( r ) {
	var c = document.getElementById( r.container );
	var h = os_availableHeight( r ) - 20;
	var inc = r.containerRow;
	h = parseInt( h / inc ) * inc;
	if( h < ( 2 * inc ) && r.resultCount > 1 ) { // min: two results
		h = 2 * inc;
	}
	if( ( h / inc ) > os_max_lines_per_suggest ) {
		h = inc * os_max_lines_per_suggest;
	}
	if( h < r.containerTotal ) {
		c.style.height = h + 'px';
		r.containerCount = parseInt( Math.round( h / inc ) );
	} else {
		c.style.height = r.containerTotal + 'px';
		r.containerCount = r.resultCount;
	}
};

/** If some entries are longer than the box, replace text with "..." */
window.os_trimResultText = function( r ) {
	// find max width, first see if we could expand the container to fit it
	var maxW = 0;
	for( var i = 0; i < r.resultCount; i++ ) {
		var e = document.getElementById( r.resultText + i );
		if( e.offsetWidth > maxW ) {
			maxW = e.offsetWidth;
		}
	}
	var w = document.getElementById( r.container ).offsetWidth;
	var fix = 0;
	if( r.containerCount < r.resultCount ) {
		fix = 20; // give 20px for scrollbar
	} else {
		fix = os_operaWidthFix( w );
	}
	if( fix < 4 ) {
		fix = 4; // basic padding
	}
	maxW += fix;

	// resize container to fit more data if permitted
	var normW = document.getElementById( r.searchbox ).offsetWidth;
	var prop = maxW / normW;
	if( prop > os_container_max_width ) {
		prop = os_container_max_width;
	} else if( prop < 1 ) {
		prop = 1;
	}
	var newW = Math.round( normW * prop );
	if( w != newW ) {
		w = newW;
		if( os_animation_timer != null ) {
			clearInterval( os_animation_timer.id );
		}
		os_animation_timer = new os_AnimationTimer( r, w );
		os_animation_timer.id = setInterval( "os_animateChangeWidth()", os_animation_delay );
		w -= fix; // this much is reserved
	}

	// trim results
	if( w < 10 ) {
		return;
	}
	for( var i = 0; i < r.resultCount; i++ ) {
		var e = document.getElementById( r.resultText + i );
		var replace = 1;
		var lastW = e.offsetWidth + 1;
		var iteration = 0;
		var changedText = false;
		while( e.offsetWidth > w && ( e.offsetWidth < lastW || iteration < 2 ) ) {
			changedText = true;
			lastW = e.offsetWidth;
			var l = e.innerHTML;
			e.innerHTML = l.substring( 0, l.length - replace ) + '...';
			iteration++;
			replace = 4; // how many chars to replace
		}
		if( changedText ) {
			// show hint for trimmed titles
			document.getElementById( r.resultTable + i ).setAttribute( 'title', r.results[i] );
		}
	}
};

/** Invoked on timer to animate change in container width */
window.os_animateChangeWidth = function() {
	var r = os_animation_timer.r;
	var c = document.getElementById( r.container );
	var w = c.offsetWidth;
	var normW = document.getElementById( r.searchbox ).offsetWidth;
	var normL = os_getElementPosition( r.searchbox ).left;
	var inc = os_animation_timer.inc;
	var target = os_animation_timer.target;
	var nw = w + inc;
	if( ( inc > 0 && nw >= target ) || ( inc <= 0 && nw <= target ) ) {
		// finished !
		c.style.width = target + 'px';
		clearInterval( os_animation_timer.id );
		os_animation_timer = null;
	} else {
		// in-progress
		c.style.width = nw + 'px';
		if( document.documentElement.dir == 'rtl' ) {
			c.style.left = ( normL + normW + ( target - nw ) - os_animation_timer.target - 1 ) + 'px';
		}
	}
};

/** Change the highlighted row (i.e. suggestion), from position cur to next */
window.os_changeHighlight = function( r, cur, next, updateSearchBox ) {
	if ( next >= r.resultCount ) {
		next = r.resultCount - 1;
	}
	if ( next < -1 ) {
		next = -1;
	}
	r.selected = next;
	if ( cur == next ) {
		return; // nothing to do.
	}

	if( cur >= 0 ) {
		var curRow = document.getElementById( r.resultTable + cur );
		if( curRow != null ) {
			curRow.className = 'os-suggest-result';
		}
	}
	var newText;
	if( next >= 0 ) {
		var nextRow = document.getElementById( r.resultTable + next );
		if( nextRow != null ) {
			nextRow.className = os_HighlightClass();
		}
		newText = r.results[next];
	} else {
		newText = r.original;
	}

	// adjust the scrollbar if any
	if( r.containerCount < r.resultCount ) {
		var c = document.getElementById( r.container );
		var vStart = c.scrollTop / r.containerRow;
		var vEnd = vStart + r.containerCount;
		if( next < vStart ) {
			c.scrollTop = next * r.containerRow;
		} else if( next >= vEnd ) {
			c.scrollTop = ( next - r.containerCount + 1 ) * r.containerRow;
		}
	}

	// update the contents of the search box
	if( updateSearchBox ) {
		os_updateSearchQuery( r, newText );
	}
};

window.os_HighlightClass = function() {
	var match = navigator.userAgent.match(/AppleWebKit\/(\d+)/);
	if ( match ) {
		var webKitVersion = parseInt( match[1] );
		if ( webKitVersion < 523 ) {
			// CSS system highlight colors broken on old Safari
			// https://bugs.webkit.org/show_bug.cgi?id=6129
			// Safari 3.0.4, 3.1 known ok
			return 'os-suggest-result-hl-webkit';
		}
	}
	return 'os-suggest-result-hl';
};

window.os_updateSearchQuery = function( r, newText ) {
	document.getElementById( r.searchbox ).value = newText;
	r.query = newText;
};


/********************
 *  Mouse events
 ********************/

/** Mouse over the container */
window.os_eventMouseover = function( srcId, e ) {
	var targ = os_getTarget( e );
	var r = os_map[srcId];
	if( r == null || !os_mouse_moved ) {
		return; // not our event
	}
	var num = os_getNumberSuffix( targ.id );
	if( num >= 0 ) {
		os_changeHighlight( r, r.selected, num, false );
	}
};

/* Get row where the event occured (from its id) */
window.os_getNumberSuffix = function( id ) {
	var num = id.substring( id.length - 2 );
	if( !( num.charAt( 0 ) >= '0' && num.charAt( 0 ) <= '9' ) ) {
		num = num.substring( 1 );
	}
	if( os_isNumber( num ) ) {
		return parseInt( num );
	} else {
		return -1;
	}
};

/** Save mouse move as last action */
window.os_eventMousemove = function( srcId, e ) {
	os_mouse_moved = true;
};

/** Mouse button held down, register possible click */
window.os_eventMousedown = function( srcId, e ) {
	var targ = os_getTarget( e );
	var r = os_map[srcId];
	if( r == null ) {
		return; // not our event
	}
	var num = os_getNumberSuffix( targ.id );

	os_mouse_pressed = true;
	if( num >= 0 ) {
		os_mouse_num = num;
		// os_updateSearchQuery( r, r.results[num] );
	}
	// keep the focus on the search field
	document.getElementById( r.searchbox ).focus();

	return false; // prevents selection
};

/** Mouse button released, check for click on some row */
window.os_eventMouseup = function( srcId, e ) {
	var targ = os_getTarget( e );
	var r = os_map[srcId];
	if( r == null ) {
		return; // not our event
	}
	var num = os_getNumberSuffix( targ.id );

	if( num >= 0 && os_mouse_num == num ) {
		os_updateSearchQuery( r, r.results[num] );
		os_hideResults( r );
		document.getElementById( r.searchform ).submit();
	}
	os_mouse_pressed = false;
	// keep the focus on the search field
	document.getElementById( r.searchbox ).focus();
};

/** Toggle stuff seems to be dead code? */

/** Return the span element that contains the toggle link */
window.os_createToggle = function( r, className ) {
	var t = document.createElement( 'span' );
	t.className = className;
	t.setAttribute( 'id', r.toggle );
	var link = document.createElement( 'a' );
	link.setAttribute( 'href', 'javascript:void(0);' );
	link.onclick = function() { os_toggle( r.searchbox, r.searchform ); };
	var msg = document.createTextNode( wgMWSuggestMessages[0] );
	link.appendChild( msg );
	t.appendChild( link );
	return t;
};

/** Call when user clicks on some of the toggle links */
window.os_toggle = function( inputId, formName ) {
	r = os_map[inputId];
	var msg = '';
	if( r == null ) {
		os_enableSuggestionsOn( inputId, formName );
		r = os_map[inputId];
		msg = wgMWSuggestMessages[0];
	} else{
		os_disableSuggestionsOn( inputId, formName );
		msg = wgMWSuggestMessages[1];
	}
	// change message
	var link = document.getElementById( r.toggle ).firstChild;
	link.replaceChild( document.createTextNode( msg ), link.firstChild );
};

hookEvent( 'load', os_MWSuggestInit );
