/*
 * Timer
 *
 */
var Timer = {
  start_t: 0,
  pause_start_t: 0,
  pause_acc_t: 0,
  paused: false,

  start: function() {
    this.start_t = Date.now();
    this.pause_start_t = 0;
    this.pause_acc_t = 0;
    this.paused = false;
  },
  pause: function() {
    this.paused = true;
    this.pause_start_t = Date.now();
  },
  unpause: function() {
    this.paused = false;
    this.pause_acc_t += Date.now()-this.pause_start_t;
    this.pause_start_t = 0;
  },
  get: function() {
    return (Date.now()-this.start_t)-this.pause_acc_t;
  }
}

/*
 * pause/unpause timer
 *
 */
function pause()
{
  var paused          = document.getElementById("paused");
  var button          = document.getElementById("pause_button");
  var next_button     = document.getElementById("next");
  var target_textarea = document.getElementById("target_textarea")
  var initialized     = document.getElementById("init");

  if (paused.value == 0) {
    button.innerHTML = "Unpause";
    paused.value = 1;
    next.setAttribute("disabled", "disabled");
    target_textarea.setAttribute("disabled", "disabled");
    Timer.pause();
  } else {
    button.innerHTML = "Pause";
    paused.value = 0;
    next.removeAttribute("disabled");
    if (initialized.value != "") {
      target_textarea.removeAttribute("disabled");
    }
    Timer.unpause();
  }
}

/*
 * no newline on return in textarea
 *
 */
function catch_return(e)
{
  if (e.keyCode == 13) {
    e.preventDefault();
    Next();
  }

  return false;
}

/*
 *
 *
 */
function working()
{
  // elements
  var button              = document.getElementById("next");
  var pause_button        = document.getElementById("pause_button");
  var target_textarea     = document.getElementById("target_textarea")
  var raw_source_textarea = document.getElementById("raw_source_textarea");
  var current_seg_id      = document.getElementById("current_seg_id");
  var source              = document.getElementById("source");
  var status              = document.getElementById("status");
  var oov_correct         = document.getElementById("oov_correct");
  var last_post_edit      = document.getElementById("last_post_edit");

  // show 'working' message
  status.style.display = "block";

  // disable button and textarea
           button.setAttribute("disabled", "disabled");
     pause_button.setAttribute("disabled", "disabled");
  target_textarea.setAttribute("disabled", "disabled");
}

/*
 *
 *
 */
function not_working()
{
  // elements
  var button              = document.getElementById("next");
  var pause_button        = document.getElementById("pause_button");
  var target_textarea     = document.getElementById("target_textarea")
  var raw_source_textarea = document.getElementById("raw_source_textarea");
  var current_seg_id      = document.getElementById("current_seg_id");
  var source              = document.getElementById("source");
  var status              = document.getElementById("status");
  var oov_correct         = document.getElementById("oov_correct");
  var last_post_edit      = document.getElementById("last_post_edit");

  // hide 'working' message
  status.style.display = "none";

  // enable buttons
          document.getElementById("next").removeAttribute("disabled");
  document.getElementById("pause_button").removeAttribute("disabled");
}

/*
 * next button
 *
 */
function Next()
{
  // elements
  var button              = document.getElementById("next");
  var pause_button        = document.getElementById("pause_button");
  var target_textarea     = document.getElementById("target_textarea")
  var raw_source_textarea = document.getElementById("raw_source_textarea");
  var current_seg_id      = document.getElementById("current_seg_id");
  var source              = document.getElementById("source");
  var status              = document.getElementById("status");
  var oov_correct         = document.getElementById("oov_correct");
  var last_post_edit      = document.getElementById("last_post_edit");

  working();

  // get metadata stored in DOM
  var base_url = "http://coltrane.cl.uni-heidelberg.de";
  var port     = document.getElementById("port").value;
  var key      = document.getElementById("key").value;

  // url
  next_url = base_url+":"+port+"/next?key="+key;

  // post edit
  var post_edit = '';

  // extract data from interfaces
  if (ui_type == 'g') {
    post_edit = JSON.parse(extract_data())["target"].join(" ")
  } else {
    post_edit = trim(target_textarea.value);
  }

  // send data
  // ???
  if (oov_correct.value=="false" && post_edit != "") {
      // compose request
      next_url += "&example="+encodeURIComponent(source.value)+"%20%7C%7C%7C%20"+encodeURIComponent(post_edit)+"&duration="+Timer.get();
      // no change?
      if (post_edit == last_post_edit.value) {
        next_url += "&nochange=1";
      }
      // update document overview
      document.getElementById("seg_"+(current_seg_id.value)+"_t").innerHTML=post_edit;
  // OOV correction mode
  } else if (oov_correct.value=="true") {
     var l = document.getElementById("oov_fields").children.length;
     var src = [];
     var tgt = [];
     for (var i=0; i<l/2; i++) {
       src.push(trim(document.getElementById("oov_src"+i).value));
       tgt.push(trim(document.getElementById("oov_tgt"+i).value));
       if (tgt[tgt.length-1] == "") { // empty correction
         alert("Please provide translations for all OOV words.");
         not_working();

         return;
       }
     }
     var l = document.getElementById("oov_fields").children.length;
     for (var i=0; i<l; i++)
       { document.getElementById("oov_fields").children[0].remove(); }
     $("#oov_form").css("display", "none");
     next_url += "&correct="+encodeURIComponent(src.join("\t"))
                 +"%20%7C%7C%7C%20"+encodeURIComponent(tgt.join("\t"))
  // ???
  } else {
    if (source.value != "") {
      alert("Please provide a post-edit.");
      target_textarea.removeAttribute("disabled", "disabled");
         pause_button.removeAttribute("disabled", "disabled");
               button.removeAttribute("disabled", "disabled");
      return;
    }
  }

  // confirm to server
  if (document.getElementById("init").value != "") {
    var xhr_confirm = CreateCORSRequest('get', base_url+":"+port+"/confirm");
    xhr_confirm.send(); // FIXME: handle errors
  }

  // build request
  var xhr = CreateCORSRequest('get', next_url);
  if (!xhr) {
    alert("Error: 2"); // FIXME: do something reasonable
  }

  // 'next' request's callbacks
  xhr.onload = function() {
    document.getElementById("init").value = 1; // for pause()
     // translation system is currently handling a request
     // FIXME: maybe poll server for result?
     if (xhr.responseText == "locked") {
       alert("Translation system is locked, try again in a moment (reload page and click 'Start/Continue' again).");
       not_working();

       return;
     }

    data = JSON.parse(xhr.responseText)
    document.getElementById("data").value = xhr.responseText;

    // done, disable interface
    if (data["fin"]) {
      raw_source_textarea.setAttribute("disabled", "disabled");
          target_textarea.setAttribute("disabled", "disabled");
      status.style.display              = "none";
      button.innerHTML                  = "Session finished, thank you!";
            button.setAttribute("disabled", "disabled");
      pause_button.setAttribute("disabled", "disabled");
      if (current_seg_id.value)
        removeClass(document.getElementById("seg_"+current_seg_id.value), "bold");

      return;

    // enter OOV correct mode
    } else if (data["oovs"]) {
      var append_to = document.getElementById("oov_fields");
      for (var i=0; i<data["oovs"].length; i++) {
        var node_src = document.createElement("input");
        var node_tgt = document.createElement("input");
        node_src.type = "text";
        node_tgt.type = "text";
        node_src.id = "oov_src"+i;
        node_tgt.id = "oov_tgt"+i;
        node_src.value = data["oovs"][i];
        node_src.setAttribute("disabled", "disabled");
        append_to.appendChild(node_src);
        append_to.appendChild(node_tgt);
      }
      oov_correct.value = true;

      $("#oov_form").css("display", "block");
      not_working();

    // translation mode
    } else {
      var id          = data["progress"];
      var src         = data["source"];
      var translation = data["transl_detok"];
      var raw_source  = data["raw_source"];

      // update interface
      oov_correct.value         = false;
      status.style.display      = "none";
      target_textarea.value     = translation;
      raw_source_textarea.value = raw_source;
      button.innerHTML          = "Next";
               button.removeAttribute("disabled");
      target_textarea.removeAttribute("disabled", "disabled");
         pause_button.removeAttribute("disabled", "disabled");
      document.getElementById("seg_"+id).className += " bold";
      if (id > 0) {
        removeClass(document.getElementById("seg_"+(id-1)), "bold");
      }
      target_textarea.rows     = Math.round(translation.length/80)+1;
      raw_source_textarea.rows = Math.round(raw_source.length/80)+1;
      target_textarea.focus();
      target_textarea.selectionStart = 0;
      target_textarea.selectionEnd   = 0;

      // remember aux data in DOM
      current_seg_id.value = id;
      source.value         = src;
      last_post_edit.value = translation;

      // confirm to server
      var xhr_confirm = CreateCORSRequest('get', base_url+":"+port+"/confirm");
      xhr_confirm.send(); // FIXME: handle errors

      // load data into graphical UI
      if (ui_type == "g") {
        load_data();
      }

      // start timer
      Timer.start();
    }
  };

  xhr.onerror = function() {}; // FIXME: do something reasonable

  xhr.send(); // send 'next' request

  return;
}

/*
 * init text interface
 *
 */
function init_text_editor()
{
  document.getElementById("target_textarea").value     = "";
  document.getElementById("raw_source_textarea").value = "";
  document.getElementById("target_textarea").setAttribute("disabled", "disabled");

  return false;
}

/*
 * init site
 *
 */
window.onload = function ()
{
  // reset vars
  document.getElementById("source").value              = "";
  document.getElementById("current_seg_id").value      = "";
  document.getElementById("paused").value              = "";
  document.getElementById("oov_correct").value         = false;
  document.getElementById("displayed_oov_hint").value  = false;
  document.getElementById("init").value                = "";

  not_working();

  ui_type = document.getElementById("ui_type").value;

  // graphical derivation editor
  if (ui_type == "g") {
    document.getElementById("derivation_editor").style.display = "block";
  // text based editor
  } else {
    init_text_editor();
    document.getElementById("textboxes").style.display = "block";
  }
};