// $Id: board.js,v 1.4 2009/02/26 17:59:18 kramos Exp $

function getObject(obj) {
  if (document.getElementById) {  // Mozilla, FireFox, Explorer 5+, Opera 5+, Konqueror, Safari, iCab, Ice, OmniWeb 4.5
    if (typeof obj == "string") {
      if(document.getElementById(obj)) {
        return document.getElementById(obj);
      } else {
        return document.getElementsByName(obj)[0];
      }
    } else {
      return obj.style;
    }
  }
  if (document.all) {        // Explorer 4+, Opera 6+, iCab, Ice, Omniweb 4.2-
    if (typeof obj == "string") {
      return document.all(obj);
    } else {
      return obj.style;
    }
  }
  if (document.layers) {      // Netscape 4, Ice, Escape, Omniweb 4.2-
    if (typeof obj == "string") {
      return document.layers(obj);
    } else {
      return obj.style;
    }
  }
  alert('Object not found: ' + obj);
}

function isGameDrawn()
{
  // Stalemate?
  if(isKingInCheck != '1')
  {  // Not in check
    var myColor = WHITE;
    if(numMoves >= 0 && chessHistory[numMoves][CURCOLOR] == 'white')
       myColor = BLACK;
    if(countMoves(myColor) == 0)
    {
      alert('Stalemate - You should offer your opponent a draw');
    }
  }

  // Is the game drawn due to insufficient material to checkmate?
  var count = 0;
  var canCheckmate = false;
  for (var i = 0; i < 8; i++)
  {
    for (var j = 0; j < 8; j++)
      if(board[i][j] != 0 && (board[i][j] & COLOR_MASK) != KING)
      {
        if((board[i][j] & COLOR_MASK) != KNIGHT && (board[i][j] & COLOR_MASK) != BISHOP)
          canCheckmate = true;
        else
          count++;
      }
  }
  if(count < 2 && !canCheckmate)
  {
    alert('Insufficient material to checkmate - You should offer your opponent a draw');
  }

  // Is the game drawn because this is the third time that the exact same position arises?
  if(numMoves >= 0 && isThirdTimePosDraw(theFEN))
  {
    alert('Draw (this position has occurred three times) - You should offer your opponent a draw')
  }

  // Draw because of no capture of pawn move for the last 50 moves?
  if(numMoves >= 0 && isFiftyMoveDraw(theFEN[theFEN.length-1]))
  {
    alert('Draw (50 move rule) - You should offer your opponent a draw');
  }
}

function displayCaptPieces() {
  var color = 'white';
  var html = '<div>';
  var piece = '';
  for(var i=0; i < captPieces.length; i++)
  {
    for(var j=0; j < captPieces[i].length; j++)
    {
      piece = color + '_' + captPieces[i][j];
      html += '<img src="' + Drupal.settings.chess.base_path + 'images/' + CURRENTTHEME + '/' + piece + '.gif" width="';
      html += parseInt(squareSize * 3 / 5) + '" height="' + parseInt(squareSize * 3 / 5) + '" alt="' + piece + '" />';
    }
    html += "</div>\n<div>";
    color = 'black';
  }
  html += '</div>';
  getObject('captures').innerHTML = html;
}

function unhighlightCurMove()
{
  var square = chessHistory[numMoves][FROMROW] * 8 + chessHistory[numMoves][FROMCOL];
  var bgCol = '';
  if(square % 8 < 6)
    bgCol = getObject('tsq' + (square + 2) + '').style.backgroundColor;
  else
    bgCol = getObject('tsq' + (square - 2) + '').style.backgroundColor;

  getObject('tsq' + square + '').style.backgroundColor = bgCol;
  unhighlight(chessHistory[numMoves][TOROW], chessHistory[numMoves][TOCOL]);
}

function highlightCurMove()
{
  getObject('tsq' + (chessHistory[numMoves][FROMROW] * 8 + chessHistory[numMoves][FROMCOL]) + '').style.backgroundColor = '#FF0';
  setTimeout('highlight(chessHistory[numMoves][TOROW], chessHistory[numMoves][TOCOL])', 200);
  setTimeout('unhighlightCurMove()', 750);
}

function drawCoordinates(invertBoard) {
  var i, j;
  for(i = 1; i < 9; i++) {
    if(!invertBoard) {
      j = i;
    } else {
      j = 9 - i;
    }
    getObject('rank'+i).innerHTML = j;
    getObject('file'+(i-1)).innerHTML = Files[j-1];
  }
}

function moveTo(objMoveId)
{
  if(currMoveIdx > 0)
  {
    getObject('m' + currMoveIdx + '').style.backgroundColor = '#F5F5DC';
  }
  currMoveIdx = objMoveId.id.slice(1);
  currMoveIdx = parseInt(currMoveIdx);
  FENToBoard(theFEN[currMoveIdx]);
  var theBoard = htmlBoard();
  getObject('chessboard').innerHTML = theBoard;
  drawCoordinates(perspective == 'black');
  getObject('m' + currMoveIdx + '').style.backgroundColor = '#3C86F6';
}

function moveJmp(moveDelta)
{
  var moveIdx = currMoveIdx;
  if(moveIdx + moveDelta > theFEN.length - 1)
  {
    moveIdx = theFEN.length - 1;
  }
  else if(moveIdx + moveDelta < 0)
  {
    moveIdx = 0;
  }
  else
  {
    moveIdx += moveDelta;
  }
  moveTo(getObject('m' + moveIdx + ''));
}

// kj changes - auto scroll both PGN and messages to bottom
function scrollToBottom(elm_id)
	{
	var elm = document.getElementById(elm_id);
	try
		{
		elm.scrollTop = elm.scrollHeight;
		}
	catch(e)
		{
		var f = document.createElement("input");
		if (f.setAttribute) f.setAttribute("type","text")
		if (elm.appendChild) elm.appendChild(f);
		f.style.width = "0px";
		f.style.height = "0px";
		if (f.focus) f.focus();
		if (elm.removeChild) elm.removeChild(f);
		}
	}

function displayMovesColumns() {
  var objGamebody = getObject('gamebody');
  var theMoves = '<span id="m0"></span>';
  var moveId = 1;
  theMoves += '<div align="center" style="padding-top:5px; padding-bottom:5px;"><table cellpadding="0" cellspacing="0" style="padding:0; border-collapse: collapse;border-spacing:0;">';
  for(var i = 0; i < moves.length; i++)
  {
    if(isGameOver == '1')
    {
      theMoves += '<tr><td class="mn" style="padding-left:15px; padding-right:10px; border:1px solid #888; text-align:right;">' + (i+1) + '. </td>';
      theMoves += '<td id="m' + (moveId) + '" class="wm" ' + 'onclick="moveTo(this);" style="padding-right:10px;border:1px solid #888;">' + moves[i][0] + '</td>';
      theMoves += '<td id="m' + (moveId+1) + '" class="bm" ' + 'onclick="moveTo(this);" style="padding-right:10px;text-indent:5px; border:1px solid #888;"> ' + moves[i][1] + '</td></tr>';
      moveId = moveId + 2;
    }
    else
    {
      theMoves += '<tr><td class="mn" style="padding-left:15px; padding-right:10px; border:1px solid #888; text-align:right;">' + (i+1) + '.</td> <td class="wm" style="padding-right:10px;border:1px solid #888;">';
      theMoves += moves[i][0] + '</td><td style="padding-right:10px;text-indent:5px; border:1px solid #888;"> ' + moves[i][1] + '</td></tr>';
    }
  }
  theMoves += '</table></div>';
  objGamebody.innerHTML = theMoves;
// kj changes - auto scroll both PGN and messages to bottom
  scrollToBottom("gamebody");
  scrollToBottom("block-chess_messages-0");
}

function displayMovesParagraph() {
  var objGamebody = getObject('gamebody');
  var theMoves = '<span id="m0"></span>';
  var moveId = 1;
  for(var i = 0; i < moves.length; i++)
  {
    if(isGameOver == '1')
    {
      theMoves += '<span id="m' + moveId++ + '" class="wm" ' + 'onclick="moveTo(this);"><span class="mn">' + (i+1) + '.</span> ' + moves[i][0] + '</span>';
      theMoves += '<span id="m' + moveId++ + '" class="bm" ' + 'onclick="moveTo(this);"> ' + moves[i][1] + '</span> ';
    }
    else
    {
      theMoves += '<span class="wm"><span class="mn">' + (i+1) + '.</span> ' + moves[i][0] + '</span> ' + moves[i][1] + ' ';
    }
  }
  objGamebody.innerHTML = theMoves;
}

function displayMoves() {
  if(historyLayout == 'columns')
    displayMovesColumns();
  else
    displayMovesParagraph();
}

function htmlBoard()
{  // Returns the HTML-code for an empty chessboard (Note: Fixed square size and theme)
  if(isBoardDisabled == '')
  {
    var classWSquare = 'light_enabled';
    var classBSquare = 'dark_enabled';
    var classHeader = 'header_enabled';
  }
  else
  {
    var classWSquare = 'light_disabled';
    var classBSquare = 'dark_disabled';
    var classHeader = 'header_disabled';
  }
  var sqBackground = [classWSquare, classBSquare];
  var invertBoard = (perspective == 'black');
  var borderWidth = squareSize / 2;
  var rank = 8;
  var rankLabel = rank;
  if(invertBoard)
  {
    rankLabel = 1
  }
  var j = 1;

  theBoard = '<table id="theBoard" cellpadding="0" style="border:1px solid #888; padding:0; border-collapse: collapse;border-spacing:0; margin-bottom:5px;">';
  theBoard += '<tr id="bordertop" style="height:' + borderWidth + 'px;"><td colspan="10" class="' + classHeader + '">&nbsp;</td></tr>';
  theBoard += '<tr><td id="rank' + rank-- + '" class="' + classHeader + '" width="' + borderWidth + '">' + rankLabel + '</td>';
  var row = 0;
  var col = 0;
  for(var k = 63; k >= 0; k--)
  {
    if((k+1) % 8 == 0)
    {
      var i = k - 7;
      if(invertBoard)
        i = 63 - i;
    }
    else
    {
      if(invertBoard)
        i--;
      else
        i++;
    }
    //theBoard += '<td id="tsq' + i + '" class="' + sqBackground[j] + '" width="' + squareSize + '" height="' + squareSize + '">';
    // kj changes	
    // hard code the size due to issue with format.  cell is badly sized when there are no pieces	
    // -nevermind... using squareSize variable now
    theBoard += '<td id="tsq' + i + '" class="' + sqBackground[j] + '" width="' + squareSize + '" height="' + squareSize + '">';
    var piece = '';
    var source = '';
    row = parseInt(i / 8);
    col = i % 8;
    
    if(board[row][col] != 0)
    {
      piece = getPieceColor(board[row][col]) + '_' + getPieceName(board[row][col]);
      source = Drupal.settings.chess.base_path + 'images/' + CURRENTTHEME + '/' + piece + '.gif';  // Update the square
      theBoard += '<img alt="' + piece + '" id="sq' + i + '" ';
      theBoard += 'src="' + source + '" width="' + squareSize + '" height="' + squareSize + '">';
    }
    else
    {
    // kj changes	
    // better way to control board cell size
      theBoard += '<img src="' + Drupal.settings.chess.base_path + 'images/spacer.gif" width="' + squareSize + '" height="' + squareSize + '">';
    }
    theBoard += '<\/td>';
    if((k % 8) === 0) {
      theBoard += '<td id="rbrd' + (rank+1) + '" class="' + classHeader + '" width=' + borderWidth + '">&nbsp;<\/td><\/tr>';
      if(k != 0) {
        if(invertBoard)
        {
          rankLabel = 9 - rank;
        }
        else
        {
          rankLabel = rank;
        }
        theBoard += '<tr><td id="rank' + rank-- + '" class="' + classHeader + '" width="' + borderWidth + '">' + rankLabel + '</td>';
      }
    }
    else
    {
      j = 1 - j;
    }
  }
  theBoard += '<tr id="borderbottom" class="' + classHeader + '" height="' + borderWidth + '"><td width="' + borderWidth + '">&nbsp;<\/td>';
  var fileLabel;
  for(i = 0; i < 8; i++) {
    if(invertBoard) {
      fileLabel = Files[7-i];
    }
    else
    {
      fileLabel = Files[i];
    }
    theBoard += '<td id="file' + i + '" class="' + classHeader + '">' + fileLabel + '<\/td>';
  }
  theBoard += '<td id="rbrd0" class="' + classHeader + '">&nbsp;<\/td><\/tr><\/table>';
  return theBoard;
}

var theBoard = htmlBoard();  // The HTML code for the board
var theFEN = new Array();
var currMoveIdx = 0;

function chessboard_populate()
{
  var invertBoard = (perspective == 'black');
  getObject('chessboard').innerHTML = theBoard;
//  drawCoordinates(invertBoard);
/*
  var tblBoard = document.createElement('table');
  var tbody = document.createElement('tbody');
  tblBoard.appendChild(tbody);
  var row = document.createElement('tr');
  var col1 = document.createElement('td');
  col1.appendChild(document.createTextNode('Prufutexti'));
  row.appendChild(col1);
  tbody.appendChild(row);
  getObject('chessboard').appendChild(tblBoard);
*/

  // Show/Hide the promoteForm
  //var isPromoting;
  //alert(isPromoting);
  //if(isPromoting == 1) {
  //  $('#promoteForm').hide();
  //} else {
  //  $('#promoteForm').show('slow');
  //}
  // Display the current move below the chessboard
  if(moves.length > 0)
  {
    var lastMove = moves.length + '.';
    if(moves[moves.length-1][1] != '')
    {
      getObject('curmove').innerHTML = lastMove + '..' + moves[moves.length-1][1];
    }
    else
    {
      getObject('curmove').innerHTML = lastMove + ' ' + moves[moves.length-1][0];
    }
    if(isGameOver != '1')
      getObject("curmove").onclick = function(){highlightCurMove();};
  }
  getObject('gameid').innerHTML = 'Game #' + gameId;
  getObject('players').innerHTML = players;
  getObject('whosmove').innerHTML = whosMove;
  getObject('checkmsg').innerHTML = checkMsg;
  getObject('statusmsg').innerHTML = statusMessage;
  displayMoves();
  displayCaptPieces();

  theFEN = historyToFEN();

  getObject("btnReload").disabled = false;
  getObject("btnPGN").disabled = false;

  getObject("btnReload").onclick = function(){reloadPage(this);};
  getObject("btnPGN").onclick = function(){downloadPGN();};

  getObject("btnUndo").onclick = function(){undo();};
  getObject("btnDraw").onclick = function(){draw();};
  getObject("btnResign").onclick = function(){resigngame();};

  if(isBoardDisabled != '1')
  {
    getObject("btnUndo").disabled = false;
    getObject("btnDraw").disabled = false;
    getObject("btnResign").disabled = false;
  }
  if(isGameOver == '1')
  { // Allow game replay
    getObject('gamebuttons').style.display = 'none';
    currMoveIdx = theFEN.length - 1;
    var navButtons = '<form id="navigation" action="">';
    navButtons += '<span id="navbuttons">';
    navButtons += '<input id="start" title="Start of game" type="button" value="Start" />';
    navButtons += '<input id="jmpback" title="Go back five halfmoves" type="button" value="&nbsp;&lt;&lt;&nbsp;" />';
    navButtons += '<input id="prev" title="Go back one halfmove" type="button" value="&nbsp;&lt;&nbsp;" />';
    navButtons += '<input id="next" title="Go forward one halfmove" type="button" value="&nbsp;&gt;&nbsp;" />';
    navButtons += '<input id="jmpfwd" title="Go forward five halfmoves" type="button" value="&nbsp;&gt;&gt;&nbsp;" />';
    navButtons += '<input id="end" title="End of game" type="button" value="End" />';
    navButtons += '</span>';
    navButtons += '</form>';
    getObject('gamenav').innerHTML = navButtons;
    getObject("start").onclick = function(){moveJmp(-10000);};
    getObject("jmpback").onclick = function(){moveJmp(-5);};
    getObject("prev").onclick = function(){moveJmp(-1);};
    getObject("next").onclick = function(){moveJmp(1);};
    getObject("jmpfwd").onclick = function(){moveJmp(5);};
    getObject("end").onclick = function(){moveJmp(10000);};
  }
  else
  { // Alert the players it's stalemate, 50 move draw or the same position has occurred three times
    isGameDrawn();
  }

  if(isPlayersTurn == '1')
  { // No need to set event handlers unless it's the player's move
    for(var i=0; i < 64; i++) {
      getObject("tsq" + i).onclick = function(){squareClicked(this);};
    }
  }
  $('.left-corner > h2' ).text('WebChess -' + whosMove);
  document.title = 'WebChess -' + whosMove; 

  if(autoreload > 0)
      var intervalId = setInterval("window.location.replace('" + Drupal.settings.chess.game_url + "')", autoreload * 1000);
}

$(document).ready(function ()
  {
    chessboard_populate();
  }
  );