$(function() {
  var info = $('#info');
  var infoAlert = $('#info>div');
  var infoHead = $('#info>h1');
  var main = $('#main');
  var plBody = $('#processList>tbody');
  var plHeader = $('#processList>thead>tr');
  var serverList = $('#serverList>ul');

  var cankill;
  var interval;
  var selected;

  var plCols = plHeader.children().map(function() {
    return $(this).text();
  }).get();


  function commonError(jqXHR, textStatus, errorThrown) {
    plBody.empty();
    main.hide();
    infoHead.text('An error has occurred');
    infoAlert.text((0 == jqXHR.readyState) ? 'Service unavailable' : errorThrown);
    infoAlert.removeClass().addClass('alert alert-danger');
    info.show();
  }

  function switchServer() {
    cankill = undefined;
    clearInterval(interval);
    if ('' !== selected) {
      document.title = selected + ' — ' + 'MyWatch';
      serverList.find('.active').removeClass('active');
      var s = $('a[href="#' + selected + '"]');
      if (s) {
        s.parent().addClass('active');
        getProcessList();
        interval = setInterval(getProcessList, 60 * 1000);
      }
    } else {
      document.title = 'MyWatch';
    }
  }

  function onHash() {
    selected = location.hash.substring(1);
    switchServer();
  };
  window.onhashchange = onHash;

  function kill(id) {
    $.ajax({
      url: 'server/' + selected + '/process/' + id,
      method: 'DELETE',
      success: function() {
        $('#' + id).fadeOut(300, function() {
          $(this).remove();
        });
      }
    });
  }

  function showProcessList(procs) {
    plBody.empty();
    if (cankill) {
      if (!plHeader.children('#kill').length) {
        plHeader.prepend('<th id="kill">');
      }
    } else {
      plHeader.children('#kill').remove();
    }
    procs.map(function(p) {
      var tr = $('<tr id="' + p['id'] + '">');
      if (cankill) {
        var td;
        if (('' != p['host']) && (0 < p['time']) && ('Killed' != p['state'])) {
          td = $('<td role="button" title="KILL" class="btn btn-danger btn-xs">&nbsp;</td>');
          td.on('click', function() {
            kill($(this).parent().attr('id'));
          });
        } else {
          td = $('<td>');
        }
        tr.append(td);
      }
      plCols.map(function(c) {
        var td = $('<td>');
        if ('id' === c) {
          td.addClass('mywatch-number');
        } else if ('info' === c) {
          td.addClass('mywatch-query');
        } else if ('time' === c) {
          td.addClass('mywatch-number');
        }
        td.text(p[c]);
        tr.append(td);
      });
      plBody.append(tr);
    });
    info.hide();
    main.show();
  }

  function getProcessList() {
    function get() {
      $.ajax({
        url: 'server/' + selected + '/processlist.json',
        method: 'GET',
        error: commonError,
        success: showProcessList
      });
    }
    if (typeof cankill === 'undefined') {
      $.ajax({
        url: 'server/' + selected + '/process/0',
        method: 'DELETE',
        complete: function(jqXHR) {
          cankill = (200 === jqXHR.status);
          get();
        }
      });
    } else {
      get();
    }
  };

  function showAvailable(available) {
    available.sort().forEach(function(s) {
      serverList.append('<li><a href="#' + s + '">' + s + '</a></li>');
    });
    serverList.find('a').on('click', function() {
      if ($(this).text() === selected) {
        getProcessList();
      }
    });
    info.hide();
    onHash();
  };

  function getAvailableFallback(servers) {
    var total = servers.length;
    var available = [];
    var checked = 0;
    $.each(servers, function(i, s) {
      $.ajax({
        url: 'server/' + s + '/processlist.json',
        method: 'HEAD',
        success: function() {
          available.push(s);
        },
        complete: function() {
          checked++;
          if (checked === total) {
            showAvailable(available);
          }
        }
      });
    });
  };

  function getAvailable(servers) {
    var total = servers.length;
    var available = [];
    var data = {};
    servers.forEach(function(tag) {
      data[tag] = {
        method: 'GET',
        path: '/server/' + tag + '/processlist.json'
      };
    });

    $.ajax({
      url: '.sproxy/access',
      method: 'POST',
      contentType: 'application/json',
      data: JSON.stringify(data),
      error: function() {
        getAvailableFallback(servers)
      },
      success: showAvailable
    });
  };

  $.ajax({
    url: 'serverlist.json',
    method: 'GET',
    error: commonError,
    success: getAvailable
  });

});