/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
// size and spacing variables
var dotSpacing = 10; // spacing between centers of dots (radius)
var dotPadding = 0.5; // dot padding
var minDotRadius = 3; // min dot radius
var maxDotRadius = dotSpacing - dotPadding;

// arrays of information about each dot
var stats = {'servers': []};
var dots = new Array(0); // current sizes and change directions
var mousedDot = -1; // the dot currently under the mouse

var colorPalette = ['#0000CC', '#0014B8', '#0029A3', '#003D8F', '#00527A', '#006666', '#007A52', '#008F3D', '#00A329', '#00B814', '#00CC00', '#14D100', '#29D600', '#3DDB00', '#52E000', '#66E600', '#7AEB00', '#8FF000', '#A3F500', '#B8FA00', '#CCFF00', '#CCFF00', '#CCF200', '#CCE600', '#CCD900', '#CCCC00', '#CCBF00', '#CCB200', '#CCA600', '#CC9900', '#CC8C00', '#CC8000', '#CC7300', '#CC6600', '#CC5900', '#CC4C00', '#CC4000', '#CC3300', '#CC2600', '#CC1A00', '#CC0D00', '#CC0000'];

var nullColor = '#F5F8FA';
var deadColor = '#B000CC';

// animation variables
var drawing = false;
var canvas = document.getElementById('visCanvas');
var context = canvas.getContext('2d');

// mouse handling for server information display
document.getElementById('hoverable').addEventListener('mouseover', showId, false);
document.getElementById('hoverable').addEventListener('mousemove', showId, false);
document.getElementById('hoverable').addEventListener('mouseout', hideId, false);
document.getElementById('vishoverinfo').addEventListener('click', goToServer, false);
canvas.addEventListener('click', goToServer, false);

// initialize settings based on request parameters
var main = document.getElementById('main');
var speedStatType;
var colorStatType;
var speedDisabled = true;
var useCircles = true;
setShape(document.getElementById('shape'));
setSize(document.getElementById('size'));
setMotion(document.getElementById('motion'));
setColor(document.getElementById('color'));

// xml loading variables
var xmlReturned = true;
var xmlhttp=new XMLHttpRequest(); // don't bother allowing for IE 5 or 6 since canvas won't work
xmlhttp.onreadystatechange=function() {
  handleNewData();
}
self.setInterval("getXML()",5000);
//self.setInterval("drawDots()",20);

window.requestAnimFrame = (function(callback){
  return window.requestAnimationFrame ||
  window.webkitRequestAnimationFrame ||
  window.mozRequestAnimationFrame ||
  window.oRequestAnimationFrame ||
  window.msRequestAnimationFrame ||
  function(callback){
    window.setTimeout(callback, 1000 / 60);
  };
})();

function handleNewData() {
  if (xmlhttp.readyState!=4) {
    return;
  }
  if (xmlhttp.status!=200 || xmlhttp.responseText==null) {
    xmlReturned = true;
    return;
  }
  var newstats = JSON.parse(xmlhttp.responseText);
  for (var i in newstats.servers) {
    for (var s in statNames) {
      if (statNames[s])
        continue;
      newstats.servers[i][s] = Math.max(0,Math.floor(significance[s]*newstats.servers[i][s])/significance[s]);
      if (adjustMax[s])
        maxStatValues[s] = Math.max(newstats.servers[i][s],maxStatValues[s]);
    }
  }
  
  initDerivedInfo(newstats);
  var oldstats = stats;
  while(drawing) {}
  stats = newstats;
  delete oldstats;
  xmlReturned = true;
}

// set max and average
function setDerivedStats(serverStats) {
  var avgStat = 0;
  var maxStat = 0;
  var maxIndex = 0;
  for (var s in statNames) {
    if (statNames[s])
      continue;
    normStat = serverStats[s]/maxStatValues[s];
    if (normStat > 0)
      avgStat += normStat;
    if (maxStat < normStat) {
      maxStat = normStat;
      maxIndex = s;
    }
  }
  serverStats.allmax = Math.floor(significance.allmax*Math.min(1,maxStat))/significance.allmax;
  serverStats.allavg = Math.floor(significance.allavg*avgStat/numNormalStats)/significance.allavg;
  serverStats.maxStat = maxIndex;
}

function initDerivedInfo(newstats) {
  for (var i in newstats.servers) {
    if ('dead' in newstats.servers[i] || 'bad' in newstats.servers[i]) {
      continue;
    }
    if (i >= dots.length) {
      dots.push({'size': maxDotRadius, 'growing': false});
    }
    setDerivedStats(newstats.servers[i]);
  }
}

// construct server info for hover
function getInfo(serverStats) {
  var extra = '<strong>' + serverStats.ip + '</strong>';
  if ('dead' in serverStats || 'bad' in serverStats)
    return extra;
  extra = extra + ' (' + serverStats.hostname + ')';
  var j = 0;
  for (var s in statNames) {
    if (j % 4 == 0)
      extra = extra + '<br>\n';
    extra = extra + '&nbsp;&nbsp;' + s + ': <strong>' + serverStats[s] + '</strong>';
    j++;
  }
  extra = extra + ' (' + serverStats.maxStat + ')';
  return extra;
}

// reload xml
function getXML() {
  if (xmlReturned == true) {
    xmlReturned = false;
    xmlhttp.open('POST',jsonurl,true);
    xmlhttp.send();
  }
}

// redraw
function drawDots() {
  requestAnimFrame(drawDots);
  
  var width = Math.ceil(Math.sqrt(stats.servers.length));
  var height = Math.ceil(stats.servers.length/width);
  var x;
  var y;
  var server
  var sizeChange;
  drawing = true;
  for (var i in stats.servers) {
    server = stats.servers[i];
    x = i % width;
    y = Math.floor(i / width);
    if ('bad' in server || 'dead' in server) {
      strokeDot(x,y,maxDotRadius-1,deadColor);
      continue;
    }
    if (speedDisabled || Math.floor(dots[i].size) > maxDotRadius) {
      // check for resize by the user
      dots[i].size = maxDotRadius;
    } else if (server[speedStatType]<=0) {
      // if not changing size, increase to max radius
      if (dots[i].size < maxDotRadius)
        dots[i].size = dots[i].size + 1;
      if (dots[i].size > maxDotRadius)
        dots[i].size = maxDotRadius;
    } else {
      sizeChange = getStat(i,speedStatType);
      if (dots[i].growing) {
        dots[i].size = dots[i].size + sizeChange;
        if (dots[i].size + sizeChange > maxDotRadius) {
          dots[i].growing = false;
        }
      }
      else {
        dots[i].size = dots[i].size - sizeChange;
        if (dots[i].size - sizeChange < minDotRadius) {
          dots[i].growing = true;
        }
      }
    }
    drawDot(x,y,Math.floor(dots[i].size),getColor(getStat(i,colorStatType)));
  }
  // mousedDot shouldn't be set to an invalid dot, but stats might have changed since then
  if (mousedDot >= 0 && mousedDot < stats.servers.length)
    document.getElementById('vishoverinfo').innerHTML=getInfo(stats.servers[mousedDot]);
  drawing = false;
}

// fill in a few grey dots
function drawGrid() {
  context.clearRect(0, 0, canvas.width, canvas.height);
  for (var i=0, k=0; i < canvas.width; i+=dotSpacing*2,k++) {
    for (var j=0, l=0; j < canvas.height; j+=dotSpacing*2,l++) {
      drawDot(k,l,maxDotRadius,nullColor);
    }
  }
}

// fill a dot specified by indices into dot grid
function drawDot(i,j,r,c) {
  var x = i*dotSpacing*2 + dotSpacing;
  var y = j*dotSpacing*2 + dotSpacing;
  context.clearRect(x-dotSpacing, y-dotSpacing, dotSpacing*2, dotSpacing*2);
  if (useCircles)
    fillCircle(x,y,r-dotPadding,c);
  else
    fillSquare(x-r,y-r,(r-dotPadding)*2,c);
}

// stroke a dot specified by indices into dot grid
function strokeDot(i,j,r,c) {
  var x = i*dotSpacing*2 + dotSpacing;
  var y = j*dotSpacing*2 + dotSpacing;
  context.clearRect(x-dotSpacing, y-dotSpacing, dotSpacing*2, dotSpacing*2);
  if (useCircles)
    strokeCircle(x,y,r-dotPadding,c);
  else
    strokeSquare(x-r,y-r,(r-dotPadding)*2,c);
}

function getStat(dotIndex,statIndex) {
  return Math.min(1,stats.servers[dotIndex][statIndex]/maxStatValues[statIndex]);
}

// translate color between 0 and maxObservedColor into an html color code
function getColor(normColor) {
  return colorPalette[Math.round((colorPalette.length-1)*normColor)];
}

function strokeCircle(x,y,r,c) {
  context.strokeStyle = c;
  context.lineWidth = 2;
  context.beginPath();
  context.arc(x,y,r,0,Math.PI*2,true);
  context.closePath();
  context.stroke();
}

function fillCircle(x,y,r,c) {
  context.fillStyle = c;
  context.beginPath();
  context.arc(x,y,r,0,Math.PI*2,true);
  context.closePath();
  context.fill();
}

function strokeSquare(x,y,d,c) {
  context.strokeStyle = c;
  context.lineWidth = 2;
  context.strokeRect(x,y,d,d);
}

function fillSquare(x,y,d,c) {
  context.fillStyle = c;
  context.fillRect(x,y,d,d);
}

// callback for shape selection
function setShape(obj) {
  switch (obj.selectedIndex) {
    case 0:
      useCircles = true;
      break;
    case 1:
      useCircles = false;
      break;
    default:
      useCircles = true;
  }
  drawGrid();
  setState();
}

// callback for size selection
function setSize(obj) {
  switch (obj.selectedIndex) {
    case 0:
      dotSpacing = 5;
      minDotRadius = 1;
      break;
    case 1:
      dotSpacing = 10;
      minDotRadius = 3;
      break;
    case 2:
      dotSpacing = 20;
      minDotRadius = 5;
      break;
    case 3:
      dotSpacing = 40;
      minDotRadius = 7;
      break;
    default:
      dotSpacing = 10;
      minDotRadius = 3;
  }
  maxDotRadius = dotSpacing - dotPadding;
  drawGrid();
  setState();
}

// callback for motion selection
function setMotion(obj) {
  if (obj.selectedIndex==0) {
    speedDisabled = true;
    setState();
    return;
  }
  var i = 1;
  for (var s in statNames) {
    if (i==obj.selectedIndex) {
      speedStatType = s;
      break;
    }
    i++;
  }
  speedDisabled = false;
  setState();
}

// callback for color selection
function setColor(obj) {
  var i = 0;
  for (var s in statNames) {
    if (i==obj.selectedIndex) {
      colorStatType = s;
      break;
    }
    i++;
  }
  setState();
}

// hide server info on mouseout
function hideId(e) {
  document.getElementById('vishoverinfo').style.visibility='hidden';
}

// display server info on mouseover
function showId(e) {
  var x;
  var y;
  if (e.pageX || e.pageY) {
    x = e.pageX + main.scrollLeft;
    y = e.pageY + main.scrollTop;
  }
  else {
    // clientX and clientY unimplemented
    return;
  }
  var relx = x - canvas.offsetLeft - main.offsetLeft;
  var rely = y - canvas.offsetTop - main.offsetTop;
  var width = Math.ceil(Math.sqrt(stats.servers.length));
  gotDot = Math.floor(relx/(dotSpacing*2)) + width*Math.floor(rely/(dotSpacing*2));
  mousedDot = -1;
  if (relx < (width*dotSpacing*2) && gotDot >= 0 && gotDot < stats.servers.length) {
    mousedDot = gotDot;
    document.getElementById('vishoverinfo').style.left=relx+canvas.offsetLeft;
    document.getElementById('vishoverinfo').style.top=Math.max(0,rely+canvas.offsetTop-70);
    document.getElementById('vishoverinfo').style.visibility='visible';
  }
  else {
    document.getElementById('vishoverinfo').style.visibility='hidden';
  }
}

function setState() {
  var url = visurl+'?shape='+(useCircles?'circles':'squares')+'&size='+(dotSpacing*2)+(speedDisabled ? '' : '&motion='+speedStatType)+'&color='+colorStatType;
  window.history.replaceState(window.history.state,'Server Activity',url);
}

// go to server page on click
function goToServer(e) {
  // mousedDot shouldn't be set to an invalid dot, but stats might have changed since then
  if (mousedDot >= 0 && mousedDot < stats.servers.length)
    window.location = serverurl + stats.servers[mousedDot].ip;
}

window.onload = function() {
  drawGrid();
  drawDots();
  getXML();
}