// Copyright 2007 by Lindsay Wright, Technology Solutions Ltd, Rangiora, New Zealand.
// All rights reserved.  No unauthorised copying permitted.
// <script> 


var MSIE = navigator.appName.indexOf('Microsoft') >= 0;

var Tides = null;

var TideDataDays = 82;  // Days of data we get from server.
var StartMonth;
var DateTitle = "";
var DebugGrid = "";
var PlacePop = null;

var OneDay = 24 * 60 * 60 * 1000;  // Dates; 1 day in mSec.
var Mos  = ["January","February","March","April","May","June","July","August","September","October","November","December"];
var Dayz = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"];


function HandleError (msg, url, line)
{
   var errorText = msg + ", " + url + ", line " + line;
   
   if (Tides != null)
   {
      if (Tides.Place)
      {
         errorText += ", T.P=" + Tides.Place;
      }
      if (Tides.Start)
      {
         errorText += ", T.S=" + Tides.Start.getUTCFullYear() + "-" + Tides.Start.getUTCMonth() + "-" + Tides.Start.getUTCDate();
      }
      if (DateTitle && DateTitle.length > 5)
      {
         errorText += ", DaTtl=" + DateTitle;
      }
      if (DebugGrid && DebugGrid.length > 5)
      {
         errorText += ", Grid=" + DebugGrid;
      }
   }
   else
   {
      errorText += ", Tides=null";
   }
   
   var msgText = "Error: " + msg + "\nUrl: " + url + "\nLine: " + line;
  
   if (!GetCookie("CrashReported"))
   {
      alert ("An error has occurred while running the TideFlash graph on your computer\n\n" +
             "Press OK to report this error to OceanFun Publishing Ltd.\n\n" + msgText);
         
      SetCookie ("CrashReported", "yes", 1);
   
      conf = false;
   }
   else
   {
      var conf = window.confirm (
         "An error has occurred while running the TideFlash graph on your computer\n\n" +
         "Press Cancel to report this error to OceanFun Publishing Ltd, or\n" +
         "Press OK to ignore the error and continue.\n\n" + msgText);
    }
   
    if (conf)
    {
      return true;
    }
    else
    {
      location.href = "http://ofu.co.nz" +        // "http://ofu.co.nz/" +
                      location.pathname.split("/")[1] +
                      "/graphError.php?e=" + encodeURIComponent(errorText);
    }
}


function SetErrorHandler()
{
   onerror = HandleError;
}


function getElemById(aID)
{ 
  return (document.getElementById) ? document.getElementById(aID)
                                   : document.all[aID];
} 


function ShowGridDebug()
{
   PlsCrash();
}


// We use UTC coz JS local dates screw everything up for us.
// This function returns the local date/time stuffed into a UTC date.
function MakeUTCDate(utc)
{
  return new Date (Date.UTC (utc.getFullYear(), utc.getMonth(), utc.getDate(), 
                             utc.getHours(), utc.getMinutes(), utc.getSeconds()));
}


// Given a standard time, returns true if Daylight saving applies.
function IsDLS(date)
{
  var DLSstart = new Date (Date.UTC(date.getUTCFullYear(), 9, 7, 2, 0, 0));
  DLSstart.setUTCDate ( - DLSstart.getUTCDay()); // Last Sunday of Sept

  var DLSend = new Date (Date.UTC(date.getUTCFullYear(), 3, 1, 2, 0, 0));            // Yes, 3 is April.
  var dwe = 8 - DLSend.getUTCDay();
  if (dwe == 8) dwe = 1;
  DLSend.setUTCDate (dwe);   // First Sunday in April at 2am
 
  return date < DLSend || date > DLSstart;
}


// Construct two and a half months' data.
function TideData(place,minHeight,maxHeight,year,month,day,tabs)
{
  this.Place = place;
  this.Start = new Date (Date.UTC (year,month-1,day));
  this.Heights = new Array(96 * TideDataDays);
  this.MinHeight = minHeight;  // These seem to be wrong (come from SQL DB)
  this.MaxHeight = maxHeight;
  this.Tips = new Array(TideDataDays * 8);
  
  if (!tabs || tabs.length < 4)  return;
  
  var tablen   = tabs.length;
  var loHeight = 99.0;
  var hiHeight = -99.0;
  
  for (var tabx = 0; tabx < tablen - 4; tabx += 2)
  {
     var tmin = tabs[tabx];
     var tht  = tabs[tabx+1];
     
     if (tht > hiHeight)  hiHeight = tht;
     if (tht < loHeight)  loHeight = tht;
     
     var date = new Date (this.Start);
     date.setUTCMinutes(date.getUTCMinutes() + tmin);
     
     if (IsDLS(date))
     {
        date.setUTCHours(date.getUTCHours() + 1);
        nztstr = ' NZDT';
     }
     else
     {
        nztstr = ' NZST';
     }
     
     if (tht < tabs[tabx+3])
        prefx = 'Low tide at ';
     else
        prefx = 'High tide at ';
        
     var hstr = date.getUTCHours().toFixed(0);  if (hstr.length == 1) hstr = '0' + hstr;
     var mstr = date.getUTCMinutes().toFixed(0);  if (mstr.length == 1) mstr = '0' + mstr;
     
     var tipstr = prefx + hstr + ":" + mstr + "" + nztstr + "  (" + tht.toFixed(1) + "m)" ;
     var tipx   = Math.floor(tmin / 180);
     
     this.Tips[Math.floor(tmin / 180)] = tipstr;
     this.Tips[Math.floor((tmin-96) / 180)] = tipstr; 
     this.Tips[Math.floor((tmin+96) / 180)] = tipstr; 
  }
  
  this.MaxHeight = Math.ceil(hiHeight);
  this.MinHeight = Math.floor(loHeight * 2.0 + 0.01) / 2.0;
  
  if (this.MinHeight > 0) this.MinHeight = 0;
  
  var gridRange = (this.MaxHeight - this.MinHeight);
  
  this.GridHtInc = 0.25;
  
  while (Math.floor (gridRange / this.GridHtInc + 0.01) >= GridRows)
  {
    this.GridHtInc *= 2.0;
  }
  
  if (this.GridHtInc > 1.9)
  {
     this.MinHeight = Math.floor(loHeight);  
     gridRange = (this.MaxHeight - this.MinHeight);
  }
  
  var dbg = "Tide conversion starting " + this.Start.toString() + 
            "<br>MinHt="+this.MinHeight+", MaxHt="+this.MaxHeight+
            ", HtInc="+this.GridHtInc+"<br><br>";
  
  // Now generate the tide curve.
  
  var tx = 0;  // 0 means we're doing the 0,1,2,3 set of 4.
  var t1m = tabs[tx];
  var t1h = tabs[tx+1];
  var t2m = tabs[tx+2];
  var t2h = tabs[tx+3];
  var px  = 0;
  
  while (px < (96 * TideDataDays))
  {
     var pm = px * 15;  // Plot minute
     
     if (pm < t1m)
        this.Heights[px++] = 0.0;
     else if (pm > t2m)
     {
        tx += 2;
        if ((tx+2) >= tablen) break;
        t1m = tabs[tx];
        t1h = tabs[tx+1];
        t2m = tabs[tx+2];
        t2h = tabs[tx+3];
     }
     else
     {
        var ang = ((pm-t1m)/(t2m-t1m)) * Math.PI;
        var ratio = (Math.cos(ang)+1) / 2.0;
        
        var ht = ratio * t1h + (1.0 - ratio) * t2h;
        
        this.Heights[px++] = ht;
           
        // dbg += "pm="+pm+", ang="+ang.toFixed(4)+", ratio="+ratio.toFixed(4)+", ht="+this.Heights[px-1].toFixed(2)+", tx="+tx+", t1m="+t1m+", t1h="+t1h+", t2m="+t2m+", t2h="+t2h+"<br>\n";
     }
  }
  // getElemById('debug').innerHTML = dbg;
}


function LatLongToString(degrees,pos,neg)
{
  var adeg = Math.abs(degrees);
  var str = String(Math.floor(adeg)) + "&deg;" + String(Math.round((adeg - Math.floor(adeg)) * 60)) +"'";
  
  var hemi = (degrees >= 0) ? pos : neg;
  
  return str + hemi;
}


function CurveClick(e, col)
{
  eimg = getElemById('grid');
  
  if (MSIE)
  {
      var mouseX = window.event.offsetX + col * (PixWidth / 8) + 3;  // IE mousepos is relative to <td>
  }
  else
  {
    var totXoff = 0;
    var elem = eimg;
    
    while (elem != null)
    {
        totXoff += elem.offsetLeft;
        elem = elem.offsetParent;
    }
    var mouseX = e.clientX - totXoff + pageXOffset;
  }
  
  mouseAdj = (MSIE) ? -2 : 1;
  
  var spot = new Date (Date.UTC (SelectedDate.getUTCFullYear(), 
                                 SelectedDate.getUTCMonth(), 
                                 SelectedDate.getUTCDate(), 
                                 0, 
                                 ((mouseX + mouseAdj) * 24 * 60) / PixWidth, // Mins
                                 0));
             
  DisplaySpotTideInfo(spot,'');
}


function DisplaySpotTideInfo(spot,prefix)
{          
  if (Tides == null)
  {
     return;
  }
  var ttt  = ' nzst';
  var dls  = 0;
  
  if (IsDLS(spot))
  {
    dls   = 4;       // 4 * 15 mins = 1 hour dls offset.
    ttt   = ' nzdt';
  }

  var foff   = (spot.getTime() - Tides.Start.getTime()) / (1000 * 60 * 15) - dls;
  var offset = Math.floor(foff);
  var delta  = foff - offset;
  var h1 = Tides.Heights[offset];
  var h2 = Tides.Heights[offset+1];
  var height = h1 + ((h2 - h1) * delta);
  
  var tstr = prefix + height.toFixed(2) + "m at ";
  var hrs  = spot.getUTCHours();
  var mins = spot.getUTCMinutes();
  
  if (hrs < 10) tstr += '0';
  tstr +=  hrs;
  
  if (mins < 10)
    tstr += ":0" + mins;
  else
    tstr += ":" + mins;
  
  getElemById("tgr").innerHTML = DateTitle + "<b>" + tstr + ttt + "</b>";
  
  setTimeout ("getElemById('tgr').innerHTML='" + DateTitle + tstr + ttt + "';", 800);
}


var GridRows = 8;   // Max in table

function MakeGridTableHTML()
{
  var MaxHeight = 4.0;  // Default initial grid.
  var MinHeight = 0.0;
  var gridRange = 4.0
  var gridHt    = MaxHeight;
  var gridHtInc = 1;
  var gridLines = 4;
  var cellWid   = ((PixWidth / 8) - 1);
  var cellHeight = Math.ceil(PixHeight / gridLines) - 1;
  var topOff     = (MSIE) ? -3 : -1;
  
  gridHt   -= gridHtInc;
  
  var tstr = "<table id='grid' cellspacing='0' style='margin-top:" + (topOff-PixHeight) + "px; margin-bottom:2px; padding:0;height:227px;'>";
  
  for (var i = 0; i < GridRows; i++)
  {
    if (i >= gridLines)
    {
      cellHeight = 0;
      htLabel    = "";
      emptyCell  = "";
    }
    else
    {
      htLabel = String(gridHt);
      emptyCell = "&nbsp;";
    }
    
    tstr += "<tr id='gridR" + i + "' style='height:" + cellHeight +"px;'>";

    tstr += "<td class='grid1' id='gridC0R" + i + "' style='width:" + cellWid + "' onClick='CurveClick(event,0);'>" + htLabel + "</td>";

    for (var j = 1; j < 8; j++)
    {
       tstr += "<td class='grid' id='gridC" + j + "R" + i + "' style='width:" + cellWid + 
               ";' onClick='CurveClick(event," + j + ");'>" + emptyCell + "</td>";
    }

    tstr += "</tr>";
    
    gridHt -= gridHtInc;
  }

  tstr += "<tr id='gts'>";
  tstr += "<td id='gts' onDblClick='ShowGridDebug();'><span id='gtsl'>Midnt</span>3</td>";
  tstr += "<td id='gts'><span id='gtsl'>am</span>6</td>";
  tstr += "<td id='gts'><span id='gtsl'>am</span>9</td>";
  tstr += "<td id='gts'><span id='gtsl'>am</span>no</td>";
  tstr += "<td id='gts'><span id='gtsl'>on</span>3</td>";
  tstr += "<td id='gts'><span id='gtsl'>pm</span>6</td>";
  tstr += "<td id='gts'><span id='gtsl'>pm</span>9</td>";
  tstr += "<td id='gts'><span id='gtsl'>pm</span>Midnt</td>";
  tstr += "</tr></table>";
  
  return tstr;
}


function AdjustGridHeights(tData, date)
{
  // First empty out all the rows.
  for (var i = 0; i < GridRows; i++)
  {
    var trelem = getElemById('gridR' + i);
    
    if (trelem.style.height != 0)
    {
      for (var j = 0; j < 8; j++)
      {
         getElemById('gridC' + j + 'R' + i).innerHTML = '';
      }
      trelem.style.height = 0;
    }
  }

  var daysOff   = Math.floor((date - tData.Start) / OneDay);
  var tipx      = daysOff * 8;  // Number of grids per day.
  
  var trange    = tData.MaxHeight - tData.MinHeight;
  var pixPerM   = PixHeight / trange;
  var gridLabel = tData.MaxHeight - tData.GridHtInc;
  var cellHeight= tData.GridHtInc * pixPerM;
  var cellWid   = ((PixWidth / 8) - 1) / 12;
  var elemHeight= cellHeight;
  var i         = 0;
  var totht     = 0;
  
  DebugGrid = 'MxH=' + tData.MaxHeight.toFixed(3) + ', MnHt=' + tData.MinHeight.toFixed(3) + 
              ', PixPM=' + pixPerM.toFixed(3) + ', CellHt=' + cellHeight.toFixed(3) + 
              ', GridInc=' + tData.GridHtInc.toFixed(3);
  
  while (PixHeight - totht > 4)
  {
    if (PixHeight - totht - cellHeight < 4)
    {
       gridLabel = Math.round(tData.MinHeight * 20) / 20;
        
       elemHeight = PixHeight - totht;   // The rest of the way to the graph baseline.
    }
    else
    {
       elemHeight = Math.floor(Math.round(cellHeight * (i + 1)) / (i + 1));
    }
    getElemById('gridR' + i).style.visibility = "visible";
    getElemById('gridR' + i).style.height = "" + elemHeight + "px";

    var td0elem = getElemById('gridC0R' + i);
    
    if (elemHeight > 14)
       td0elem.innerHTML = gridLabel.toFixed ( (gridLabel * 10 % 10 == 0) ? 0 : 1);
    else
       td0elem.innerHTML = '';
    
    td0elem.title = Tides.Tips[tipx];
    
    for (var j = 1; j < 8; j++)
    {
       var tdelem = getElemById('gridC' + j + 'R' + i);
       tdelem.innerHTML = "&nbsp;";
       tdelem.title = Tides.Tips[tipx + j];
    }
  
    i++;
    totht += elemHeight;
    gridLabel -= tData.GridHtInc;
  }
  
  while (i < 8)
  {
     getElemById('gridR' + i).style.display = "none";
     getElemById('gridR' + i).style.height = "0px";
     i++;
  }
}


function DrawTideFramework()
{
  var bgImage = 'GraphBg' + (Math.random() * 9).toFixed(0) + '.jpg';
  
  document.write ("<table id='graph_t' style='background: url(\"" + bgImage + "\") no-repeat -1 -1;'>");
  document.write ("<tr height='50'>");
  document.write ("<td id='tgl' colspan='" + (PixWidth/2-1) + "'>&nbsp;</td>"); // Place
  document.write ("<td id='tgr' colspan='" + (PixWidth/2-1) + "'>&nbsp;</td>"); // Date
  document.write ("</tr>");
  document.write ("<tr id='g_row'>");

  for (var i=0; i < PixWidth-1; i++)
  {
    document.write ("<td id='g' style='height:204px'><img src='g.png' id='tg' height='1'></td>");
  }

  document.write ("</tr></table>");
  
  document.write (MakeGridTableHTML());
  
  document.write ("<div style='margin-top:-15px;'><form id='MonthForm'>");
  document.write ("<input type='hidden' name='sdate' id='sdate' value='Apr 01 2007'></form></div>");
}


function DrawTideGraph(tData,date)
{
  if (tData == null)
  {
    return;
  } 
  
  DateTitle = Dayz[date.getUTCDay()] + " " +
              date.getUTCDate().toString() + " " + 
              Mos[date.getUTCMonth()] + " " +
              date.getUTCFullYear() + "<br>&nbsp;";
 
  var date_elem = getElemById("tgr");
  date_elem.innerHTML = DateTitle;
  
  var gridRange = (tData.MaxHeight - tData.MinHeight);
  var pixPerVal = PixWidth / 96.0;
  var daysOff   = Math.floor((date - tData.Start) / OneDay);
  var startX    = daysOff * 96;
  var today     = MakeUTCDate(new Date());
  var nowShown  = today.getUTCDate() != date.getUTCDate() || today.getUTCMonth() != date.getUTCMonth();
  var nowi      = Math.floor (PixWidth / 1440 * (today.getUTCHours() * 60 + today.getUTCMinutes()));
  
  var dls1am = IsDLS(MakeUTCDate(new Date(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(), 1, 0, 0)));
  var dls4am = IsDLS(MakeUTCDate(new Date(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate(), 4, 0, 0)));
  var dlsi   = 99999;
  
  if (dls1am != dls4am)
  {
     dlsi = Math.round (8 * pixPerVal);  // <i> at which dls changes (2am)
  }
  
  if (dls1am)  // DLS state at 1am dictates how we start.
  {
     startX -= 4;
  }
  
  if (!tData.Heights[startX + 95])
  {
     getElemById('tgl').innerHTML = tData.Place + "<br><i>No tide data available</i>";
     
     var trelem = getElemById("g_row");
      
     for (var i = 0; i < trelem.childNodes.length; i++)
     {
       trelem.childNodes[i].firstChild.height = 1;
     }
     return;
  }
  
  AdjustGridHeights (tData, date);
  
  var p = PList[tData.Place];
  
  var lalo = "<br>(" + LatLongToString(p.Lat,'N','S') + ", " + LatLongToString(p.Long,'E','W') + ")";

  getElemById('tgl').innerHTML = tData.Place + " tides" + lalo;
  
  var trelem = getElemById("g_row");
  
  for (var i = 0; i < trelem.childNodes.length; i++)
  {
    if (i >= dlsi)
    {
      dlsi = 99999;
      
      if (!dls1am && dls4am)
      {
        startX -= 4;   // Starts
      }
      else if (dls1am && !dls4am)
      {
        startX += 4;  // Ends
      }
    }
  
    var hx = Math.floor(i / pixPerVal);
    var h1 = tData.Heights[hx+startX];
    var h2 = tData.Heights[hx+1+startX];
    var dh = ((i / pixPerVal) - hx) * (h2 - h1);
    var mh = h1 + dh;
    var height = (mh - tData.MinHeight) * (PixHeight / gridRange);

    if (!nowShown && i >= nowi)
    {
      nowShown = true;
      trelem.childNodes[i].firstChild.height = PixHeight;
      trelem.childNodes[i].firstChild.src = 'black.png';
      
      DisplaySpotTideInfo(today, ' Now: ');
    }
    else
    {
      trelem.childNodes[i].firstChild.src = 'g.png';
      
      if (MSIE && i == 0)               // IE screws up the zeroth
        trelem.childNodes[i].firstChild.height = 0;
      else
        trelem.childNodes[i].firstChild.height = height - 1;
    }
  }
}

function RefreshTideGraph()
{
  DrawTideGraph (Tides, SelectedDate);
}


// ------ Month calendars and events --------

var oldClickTarget = null;
var oldClickTargetCol = "Black";

function DateClick(event,val)
{
  var seldate = new Date(StartMonth);
  seldate.setTime(val);
  
  if (oldClickTarget != null)
  {
    oldClickTarget.style.color = oldClickTargetCol;
    oldClickTarget.style.background = "";
  }
 
  if (event.target)
  {
    oldClickTarget = event.target;
    oldClickTarget.style.background = "Blue";
    oldClickTargetCol = oldClickTarget.style.color;
    oldClickTarget.style.color = "White";
  }
  SelectedDate = seldate;  // Update global.
  RefreshTideGraph();
}


function OnNextMonth(dateInc)
{
   var sdate = getElemById('sdate');
   
   var curr = new Date (StartMonth);
   curr.setUTCMonth(curr.getUTCMonth() + dateInc);
   
   sdate.value = Mos[curr.getUTCMonth()] + ' 1 ' + curr.getUTCFullYear();

   getElemById('MonthForm').submit();
}


function DrawCalendar(calDate,dateInc)
{
  var today = MakeUTCDate(new Date());
  var tdate = today.getUTCDate();
  var tmonth = today.getUTCMonth();
  var cmonth = calDate.getUTCMonth();
  
  var MoYr = Mos[calDate.getUTCMonth()] + " " + calDate.getUTCFullYear();

  var cdate = new Date (calDate);
  cdate.setUTCDate (1);
  cdate.setTime (cdate.getTime() - cdate.getUTCDay() * OneDay);  // Previous Sunday.

  document.write("<table id='cal' cellspacing='5' border='0'>");
  document.write("<tr id='calMo' onDblClick='OnNextMonth(" + dateInc + ");'><td id='calMo' colspan='7'>" + MoYr + "<td></tr>");
  document.write("<tr id='calDow'><td id='calDow'>S</td><td id='calDow'>M</td><td id='calDow'>T</td>");
  document.write("<td id='calDow'>W</td><td id='calDow'>T</td><td id='calDow'>F</td><td id='calDow'>S</td></tr>");

  for (var days=0; days < 42; days++)
  {
    if (cdate.getUTCDay() == 0) document.write("<tr id='cal'>");
    
    var onc = " onClick='DateClick(event," + cdate.valueOf() + ");'";
    var  tdid = "";

    if (cdate.getUTCMonth() == tmonth && cdate.getUTCDate() == tdate)
      tdid = "'calToday'";
    else if (cdate.getUTCMonth() == cmonth)
      tdid = "'cal'";
    else
      tdid = "'calOmo'";
      
    document.write("<td id=" + tdid + onc + ">" + cdate.getUTCDate() + "</td>");
      
    cdate.setUTCDate(cdate.getUTCDate() + 1);
    
    if (cdate.getUTCDay() == 0) document.write("</tr>");
  }
  document.write("</table>");
}

// ------ Place list ------

var PList = new Object;

function Place(lat, longi)
{
   this.Lat = lat;
   this.Long = longi;
}

function PAdd(name,lat,longi)
{
   PList[name] = new Place(lat,longi);
}

function PDel(name)
{
   PList[name] = null;
}

AddAllPlaces();  // In places.js

PAdd("Cape Reinga", -34.43, 172.7);
PAdd("East Cape", -37.7, 178.55);
PAdd("Puysegur Point", -46.17, 166.6); 

function Transform (placeE, pixE, placeW, pixW, placeN, pixN, placeS, pixS)
{
   latN  = PList[placeN].Lat;
   latS  = PList[placeS].Lat;
   longE = PList[placeE].Long;
   longW = PList[placeW].Long;
   this.XScale = (longW - longE) / (pixW - pixE);
   this.YScale = (latN - latS) / (pixN - pixS);
   this.Xoff   = longW - (pixW * this.XScale);
   this.Yoff   = latN  - (pixN * this.YScale);
}

SItrans = new Transform("Picton",193,"Puysegur Point",100,"Picton",24,"Puysegur Point",115);

NItrans = new Transform("Wellington",30,"East Cape",82,"Cape Reinga",1,"Wellington",126);

PDel("Cape Reinga");  // Remove these (no tide data)
PDel("East Cape");
PDel("Puysegur Point");
PDel("Solunar"); 

// ------- NZ Map ------

function DrawNZMap()
{
  document.write("<table id='map' cellpadding='0' cellspacing='0'><tr><td valign='top' align='center'>");
  document.write("<img src='nz.png' usemap='#nzsiMap' id='nzimg' border='0'/>");
  document.write("<div id='placeSelect'>");
  document.write('<select name="placeName" id="placeSel" onchange="OnPlaceListChange(this)">');
  document.write('<option value="0" selected></option>');
  document.write('</select></div>');
  document.write('</td></tr></table>');
  PopulateFullPlaceList();
}

function SdCompare(a,b)
{
  return a.Sd - b.Sd;
}

function SdPlace(name,sd)
{
  this.Name = name;
  this.Sd = sd;
}

function NZClick(e)
{
  eimg = getElemById('nzimg');
  
  if (MSIE)
  {
      var mouseX = window.event.offsetX;
      var mouseY = window.event.offsetY;
  }
  else
  {
    var totXoff = 0;
    var totYoff = 0;
    var elem = eimg;
    
    while (elem != null)
    {
        totXoff += elem.offsetLeft;
        totYoff += elem.offsetTop;
        elem = elem.offsetParent;
    }
    var mouseX = e.clientX - totXoff + pageXOffset;
    var mouseY = e.clientY - totYoff + pageYOffset;
  }
  
  if ((mouseX + mouseY * 0.586) > 144)  // SI
  {
     var lati  = mouseY * SItrans.YScale + SItrans.Yoff;
     var longi = mouseX * SItrans.XScale + SItrans.Xoff;
  }
  else  // NI
  {
     var lati  = mouseY * NItrans.YScale + NItrans.Yoff;
     var longi = mouseX * NItrans.XScale + NItrans.Xoff;
  }
  
  //alert('mouseX:'+mouseX+', Long:'+longi+', mouseY:'+mouseY+', Lat:'+lati);
  
  var places = NearbyPlaces (lati,longi);
  PopulatePlacePopup(places);
  return false;
}

function NearbyPlaces(lati, longi)
{  
  var deltas = new Array(0);
  
  for (p in PList)
  {
     if (PList[p] == null) continue;
     var  dlat = PList[p].Lat - lati;
     var  dlon = PList[p].Long - longi;
     dlat  = dlat / Math.cos ((lati + dlat / 2.0) * Math.PI / 180.0);
     var sd = dlat * dlat + dlon * dlon;

     deltas.push (new SdPlace(p, Math.floor(sd * 1000)));
  }
  return deltas.sort(SdCompare);
}

function  PopulatePlaceList(places)
{
  var placeSel = getElemById('placeSel');
  
  for (sPos in places) 
  {
     if (places[sPos].Sd > 12000 / (sPos * sPos)) break;
     placeSel.options[sPos] = new Option (places[sPos].Name, places[sPos].Name);
  }
  placeSel.length = sPos;
}

function PopulatePlacePopup(places)
{                    
    CancelPlacePopup();
    var menuItems = '';
   
    for (var place in places)
    {
       if (places[place].Sd > 12000 / (place * place)) break;   // Restrict list to closer places only.
       var name = places[place].Name;
       menuItems += '<div class="PlacePopItem" onclick="ChangePlace(\'' + name.replace("'", "`") + '\')">' + name + '</div>';
    }
    
    PlacePop = document.getElementById('PlacePop');
         
    PlacePop.innerHTML = '<div style="position:relative;">' +
                      menuItems +
                      '<div class="PlacePopItemSep"></div>' +
                      '<div class="PlacePopItem" onclick="ChangePlace(\'\')">Cancel</div>' +
                      '</div>'; 
                      
    var left = 576;
    var top  = 400;

    if (top < 0) top = 0;

    PlacePop.style.left = left + "px"
    PlacePop.style.top  = top + "px";
    PlacePop.style.display = "block";
}

function CancelPlacePopup()
{
   if (PlacePop != null)
   {
      PlacePop.innerHTML = '';
      PlacePop.style.display = "none";                            
      PlacePop = null;
   }
}

function PopulateFullPlaceList()
{
  var alpha = new Array(0);
  
  for (p in PList)
  {
     alpha.push (p);
  }
  var Sorted = alpha.sort();
  var placeSel = getElemById('placeSel');
  
  for (sPos in Sorted) 
  {
     placeSel.options[sPos] = new Option (Sorted[sPos], Sorted[sPos]);
  }
}

function DrawNZMapImagemap()
{
  if (!MSIE) 
    ahref = "href='#m'";
  else
    ahref = "";
    
  document.write('<map name="nzsiMap"><area shape="poly" coords="');
  document.write('0,0,21,65,8,89,24,129,36,132,50,132,98,60,'); // West + South NI
  document.write('89,103,99,125,114,139,159,112,199,45,199,9,174,3,161,14,143,49,');       // Whole SI
  document.write('65,56,25,0"');  // East NI
  document.write(' alt="" '); 
  document.write(ahref);
  document.write('onmouseover="getElemById(\'nzimg\').style.cursor=\'pointer\';"');
  document.write('onmouseout="getElemById(\'nzimg\').style.cursor=\'\';"');
  document.write('onMouseUp="javaScript:NZClick(event);"/>');
  document.write('</map>');
}

function OnPlaceListChange(list)
{
  ChangePlace(list.value);
}
  
function ChangePlace(place)
{
  CancelPlacePopup();
  if (place == '') return;
  do
  {
    var place2 = place;
    place = place2.replace("'", '`');
  } while (place2 != place);
  
  LoadTideScript(place2);
  SetCookie ('Place', place2, 100);
  pageTracker._trackEvent("WebGraph", "ChoosePlace", place);
}

function GoButtonClick()
{
   OnPlaceListChange(getElemById('placeSel'));
}

function StartTideGraph (placeOverride)
{
  var place;
  
  if ((placeOverride != null) && PList[placeOverride])
  {
     place = placeOverride;
  }
  else
  {
     place = GetCookie('Place');
  }
  if (place)
  {
    LoadTideScript(place);
    pageTracker._trackEvent("WebGraph", "InitialPlace", place);
  }
  else
  {
    pageTracker._trackEvent("WebGraph", "InitialPlace", "-None-");
  }
}

function LoadTideScript(place)
{
   var base = window.location.href;
   base = base.substr (0, base.lastIndexOf('/'));
   
   var tStart = new Date(StartMonth);
   tStart.setUTCDate(-8);
   uri = base + "/tdata.php?p=NZ." + place.replace("`", "'") + 
         "&y=" + tStart.getUTCFullYear() + "&m=" + (tStart.getUTCMonth()+1) + "&d=" + tStart.getUTCDate() +
         "&s=83";
         
   var head = document.getElementsByTagName("head")[0];
   script = document.createElement('script');
   script.id = 'uploadScript';
   script.type = 'text/javascript';
   script.src = uri;
   head.appendChild(script)
   var pw = getElemById('tgl');
   if (pw) pw.innerHTML = "Please wait...";
}

function SetCookie(name, value, days)
{
   var date = new Date();
   date.setDate (date.getDate() + days);
   var expires = "; expires=" + date.toGMTString();
   document.cookie = name + "=" + value + expires + "; path=/";
}

function GetCookie(name)
{
  var results = document.cookie.match (name + '=(.*?)(;|$)');

  if (results)
    return (unescape (results[1]));
  else
    return null;
}

function InstrOpenClose(id)
{
   elem = getElemById(id);
   img = getElemById(id + "Img");
   if (elem.style.display != "block")
   {
      elem.style.display = "block";
      img.src = "collapse.png";
   }
   else
   {
      elem.style.display = "none";
      img.src = "openclose.png";
   }
}


function DrawInstructions()
{
   document.write('<div class="Instructions">');
   document.write('<span onClick="InstrOpenClose(\'InsBody\');"><img class="OpenClose" src="openclose.png" id="InsBodyImg"> Open for instructions and information</span><br/>');
   document.write('<span class="Instructions" id="InsBody"><p class="instr">This page provides a graph of the tide height over one day for any one of ');
   document.write('about 180 different places around NZ.  Please use <a href="http://tidespy.com">TideSpy</a> for USA and Pacific Islands tides.</p>');
   document.write('<p class="instr">To display a tide graph for your desired location:');
   document.write('<ol><li>Click on the map near the location, and choose from the menu of closest places,<br/>');
   document.write('or choose your location from the alphabetical list at the bottom of the map.</li>');
   document.write('<li>Click a date on the calendar to see tides for any other day.</li>');
   document.write('<li>Hover the mouse over the graph for the time and height of the nearest high or low tide.</li>');
   document.write('<li>Click anywhere on the curve to see the tide height and time displayed in the title bar. ');
   document.write('When the graph is first displayed, the current tide is shown.  A black line on the graph indicates the current time.</li>');
   document.write('<li><b>Important:</b> Double-check that the correct place and date are shown at the top of the graph before relying on the figures obtained.</li>');
   document.write('</ol>');
   document.write('<p class="instr">Any time you return to this page, the last-chosen place will be shown.</p>');
   document.write('<p class="instr">When clicking on the map, the list shows nearby places in order of distance from the place ');
   document.write('that was clicked.</p>');
   document.write('<p class="instr">"Nearby places" means those places that are close in a straight line distance. Tide figures for ');
   document.write('"nearby places" may be quite different.</p>');
   document.write('<p class="instr" style="text-align:center;"><i>Times are corrected for daylight saving where approriate.<br>');
   document.write('This graph is not intended for navigational or engineering purposes.<br>');
   document.write('Heights may be less accurate for places where specific height information is not available.</i></p>');
   document.write('<p class="instr">If you would like more information or are having problems with this page, please visit ');
   document.write('our <a href="../faq">Frequently Asked Questions (FAQ)</a>.</p></span>');
   document.write('<br><center><a href="../termz.php">Click here to see Copyright and Disclaimer notices</a></center></div>');
}

var TgJsFullyLoaded = 1;