/**
 * JavaScript for sortable tables. Based on
 * http://www.kryogenix.org/code/browser/sorttable/
 * 
 * TODO: optimize this file for use with the MW resource loader.
 * * Get rid of addOnloadHook, so wikibits is no longer needed.
 * * Use jQuery to bind behaviour to DOM events.
 * 
 * @file SMW_sorttable.js
 * @ingroup SMW
 *
 * @author Stuart Langridge
 * @licence MIT license
 */

addOnloadHook( smw_sortables_init );

var SORT_COLUMN_INDEX;
var SMW_PATH;

function smw_sortables_init() {
	// The following is a hack to find out the path to our skin directory
	// I am happy to change this into anything else if there is another way ...
// 	if (!document.getElementById) return;
// 	st = document.getElementById("SMW_sorttable_script_inclusion");
// 	SMW_PATH = st.src.substring(0, st.src.length-17);
	SMW_PATH = wgScriptPath + '/extensions/SemanticMediaWiki/skins';
	// Preload images
	smw_preload_images();
	// Now find the tables
	//if (!document.getElementsByTagName) return;
	//tbls = document.getElementsByTagName("SMW_headscript_sorttable");
	// Find all tables with class smwtable and make them sortable
	if ( !document.getElementsByTagName ) {
		return;
	}
	tbls = document.getElementsByTagName( 'table' );
	for ( ti = 0; ti < tbls.length; ti++) {
		thisTbl = tbls[ti];
		if ( ( ( ' ' + thisTbl.className + ' ' ).indexOf( 'smwtable' ) != -1 ) && ( thisTbl.id ) ) {
			//initTable( thisTbl.id );
			smw_makeSortable( thisTbl );
		}
	}
}

function smw_preload_images() {
	// preload icons needed by SMW
	if ( document.images ) {
		pic1 = new Image( 12, 14 );
		pic1.src = SMW_PATH + '/images/sort_up.gif';
		pic2 = new Image( 12, 14 );
		pic2.src = SMW_PATH + '/images/sort_down.gif';
		pic3 = new Image( 16, 16 );
		pic3.src = SMW_PATH + '/images/search_icon.png'; // TODO: move this preload to somewhere else?
	}
}

function smw_makeSortable( table ) {
	if ( table.rows && table.rows.length > 0 ) {
		var firstRow = table.rows[0];
	}
	if ( !firstRow ) {
		return;
	}
	if ( ( firstRow.cells.length == 0 ) || ( firstRow.cells[0].tagName.toLowerCase() != 'th' ) ) {
		return;
	}

	// We have a first row that is a header; make its contents clickable links:
	for ( var i = 0; i < firstRow.cells.length; i++ ) {
		var cell = firstRow.cells[i];
		//var txt = smw_getInnerText( cell ); // unused -- we preserve the inner html
		cell.innerHTML = '<a href="#" class="sortheader" '+
		'onclick="smw_resortTable(this, '+i+');return false;">' +
		'<span class="sortarrow"><img alt="[&lt;&gt;]" src="' + SMW_PATH + '/images/sort_none.gif"/></span></a>&nbsp;<span style="margin-left: 0.3em; margin-right: 1em;">' + cell.innerHTML + '</span>'; // the &nbsp; is for Opera ...
	}

	/**
	 * make sortkeys invisible
	 * for now done in CSS
	 * this code provides the possibility to do it via JS, so that non-JS
	 * clients can see the keys
	 */
/*	for( var ti = 0; ti < table.rows.length; ti++ ) {
		for ( var tj = 0; tj < table.rows[ti].cells.length; tj++ ) {
			var spans = table.rows[ti].cells[tj].getElementsByTagName( 'span' );
			if( spans.length > 0 ) {
				for ( var tk = 0; tk < spans.length; tk++ ) {
					if( spans[tk].className == 'smwsortkey' ) {
						spans[tk].style.display = 'none';
					}
				}
			}
		}
	}*/
}

function smw_getInnerText( el ) {
	var spans = el.getElementsByTagName( 'span' );
	if( spans.length > 0 ) {
		for ( var i = 0; i < spans.length; i++ ) {
			if( spans[i].className == 'smwsortkey' ) {
				return spans[i].innerHTML;
			}
		}
	} else {
		return el.innerHTML;
	}
}

function smw_resortTable( lnk, clid ) {
	// get the span
	var span;
	for ( var ci = 0; ci < lnk.childNodes.length; ci++ ) {
		if ( lnk.childNodes[ci].tagName && lnk.childNodes[ci].tagName.toLowerCase() == 'span' ) {
			span = lnk.childNodes[ci];
		}
	}
	var spantext = smw_getInnerText( span ); // Is this variable unused?
	var td = lnk.parentNode;
	var column = clid || td.cellIndex;
	var table = smw_getParent( td, 'TABLE' );

	if ( table.rows.length <= 1 ) {
		return;
	}

	if ( table.rows[0].cells[column].className == 'numericsort' ) {
		sortfn = smw_sort_numeric; // sorting with keys
	}
	else {
		sortfn = smw_sort_caseinsensitive;
	}

	SORT_COLUMN_INDEX = column;
	var firstRow = new Array();
	var newRows = new Array();
	var footers = new Array();
	for ( i = 0; i < table.rows[0].length; i++ ) {
		firstRow[i] = table.rows[0][i];
	}
	// class "sortbottom" makes rows sort below all others, but they are still sorted
	// class "smwfooter" excludes rows from sorting and appends them below in unchanged order
	for ( j = 1; j < table.rows.length; j++ ) {
		if ( ( !table.rows[j].className || table.rows[j].className.indexOf( 'smwfooter' ) == -1 ) ) {
			newRows.push( table.rows[j] );
		} else {
			footers.push( table.rows[j] );
		}
	}

	newRows.sort( sortfn );

	var ARROW;
	if ( span.getAttribute( 'sortdir' ) == 'down' ) {
		ARROW = '<img alt="[&gt;]" src="' + SMW_PATH + '/images/sort_up.gif"/>';
		newRows.reverse();
		span.setAttribute( 'sortdir', 'up' );
	} else {
		ARROW = '<img alt="[&lt;]" src="' + SMW_PATH + '/images/sort_down.gif"/>';
		span.setAttribute( 'sortdir', 'down' );
	}

	// We appendChild rows that already exist to the tbody, so it moves them rather than creating new ones
	// don't do sortbottom rows
	for ( i = 0; i < newRows.length; i++ ) {
		if ( !newRows[i].className || ( newRows[i].className && ( newRows[i].className.indexOf( 'sortbottom' ) == -1 ) ) ) {
			table.tBodies[0].appendChild( newRows[i] );
		}
	}
	// do sortbottom rows only
	for ( i = 0; i < newRows.length; i++ ) {
		if ( newRows[i].className && ( newRows[i].className.indexOf( 'sortbottom' ) != -1 ) ) {
			table.tBodies[0].appendChild( newRows[i] );
		}
	}
	for ( i = 0; i < footers.length; i++ ) {
		table.tBodies[0].appendChild( footers[i] );
	}

	// Delete any other arrows there may be showing
	var allspans = document.getElementsByTagName( 'span' );
	for ( var ci = 0; ci < allspans.length; ci++ ) {
		if ( allspans[ci].className == 'sortarrow' ) {
			if ( smw_getParent( allspans[ci], 'table' ) == smw_getParent( lnk, 'table' ) ) { // in the same table as us?
				allspans[ci].innerHTML = '<img alt="[&lt;&gt;]" src="' + SMW_PATH + '/images/sort_none.gif"/>';
			}
		}
	}

	span.innerHTML = ARROW;
}
window.smw_resortTable = smw_resortTable;

function smw_getParent( el, pTagName ) {
	if ( el == null ) {
		return null;
	} else if ( el.nodeType == 1 && el.tagName.toLowerCase() == pTagName.toLowerCase() ) { // Gecko bug, supposed to be uppercase
		return el;
	} else {
		return smw_getParent( el.parentNode, pTagName );
	}
}

function smw_sort_caseinsensitive( a, b ) {
	aa = smw_getInnerText( a.cells[SORT_COLUMN_INDEX] ).toLowerCase();
	bb = smw_getInnerText( b.cells[SORT_COLUMN_INDEX] ).toLowerCase();
	if ( aa == bb ) {
		return 0;
	}
	if ( aa < bb ) {
		return -1;
	}
	return 1;
}

function smw_sort_numeric( a, b ) {
	aa = parseFloat( smw_getInnerText( a.cells[SORT_COLUMN_INDEX] ) );
	if ( isNaN( aa ) ) {
		aa = 0;
	}
	bb = parseFloat( smw_getInnerText( b.cells[SORT_COLUMN_INDEX] ) );
	if ( isNaN( bb ) ) {
		bb = 0;
	}
	return aa-bb;
}

function smw_sort_default( a, b ) {
	aa = smw_getInnerText( a.cells[SORT_COLUMN_INDEX] );
	bb = smw_getInnerText( b.cells[SORT_COLUMN_INDEX] );
	if ( aa == bb ) {
		return 0;
	}
	if ( aa < bb ) {
		return -1;
	}
	return 1;
}

// addEvent and removeEvent
// cross-browser event handling for IE5+,  NS6 and Mozilla
// By Scott Andrew
function addEvent( elm, evType, fn, useCapture ) {
	if ( elm.addEventListener ) {
		elm.addEventListener( evType, fn, useCapture );
		return true;
	} else if ( elm.attachEvent ) {
		var r = elm.attachEvent( 'on' + evType, fn );
		return r;
	} else {
		alert( 'Handler could not be removed' );
	}
}