/*

 * A time picker for jQuery

 * Based on original timePicker by Sam Collet (http://www.texotela.co.uk) -

 * copyright (c) 2006 Sam Collett (http://www.texotela.co.uk)

 *

 * Dual licensed under the MIT and GPL licenses.

 * Copyright (c) 2010 Anders Fajerson

 * @name     timePicker

 * @version  0.2

 * @author   Anders Fajerson (http://perifer.se)

 * @example  $("#mytime").timePicker();

 * @example  $("#mytime").timePicker({step:30, startTime:"15:00", endTime:"18:00"});

 */

(function($){

  $.fn.timePicker = function(options) {

    // Build main options before element iteration

    var settings = $.extend({}, $.fn.timePicker.defaults, options);

    return this.each(function() {

      $.timePicker(this, settings);

    });

  };

  $.timePicker = function (elm, settings) {

    var e = $(elm)[0];

    return e.timePicker || (e.timePicker = new jQuery._timePicker(e, settings));

  };

  $._timePicker = function(elm, settings) {

    var tpOver = false;

    var keyDown = false;

    var startTime = timeToDate(settings.startTime, settings);

    var endTime = timeToDate(settings.endTime, settings);

    $(elm).attr('autocomplete', 'OFF'); // Disable browser autocomplete

    var times = [];

    var time = new Date(startTime); // Create a new date object.

    while(time <= endTime) {

      times[times.length] = formatTime(time, settings);

      time = new Date(time.setMinutes(time.getMinutes() + settings.step));

    }

    var $tpDiv = $('<div class="time-picker'+ (settings.show24Hours ? '' : ' time-picker-12hours') +'"></div>');

    var $tpList = $('<ul></ul>');

    // Build the list.

    for(var i = 0; i < times.length; i++) {

      if (times[i] == settings.selectedTime) {

        $tpList.append('<li class="selected">' + times[i] + "</li>");

      } else {

        $tpList.append("<li>" + times[i] + "</li>");

      }

    }

    $tpDiv.append($tpList);

    // Append the timPicker to the body and position it.

    var elmOffset = $(elm).offset();

    $tpDiv.appendTo('body').css({'top':elmOffset.top+20, 'left':elmOffset.left}).hide();

    // Store the mouse state, used by the blur event. Use mouseover instead of

    // mousedown since Opera fires blur before mousedown.

    $tpDiv.mouseover(function() {

      tpOver = true;

    }).mouseout(function() {

      tpOver = false;

    });

    $("li", $tpList).mouseover(function() {

      if (!keyDown) {

        $("li.selected", $tpDiv).removeClass("selected");

        $(this).addClass("selected");

      }

    }).mousedown(function() {

       tpOver = true;

    }).click(function() {

      setTimeVal(elm, this, $tpDiv, settings);

      tpOver = false;

    });

    var showPicker = function() {

      if ($tpDiv.is(":visible")) {

        return false;

      }

      $("li", $tpDiv).removeClass("selected");

      // Show picker. This has to be done before scrollTop is set since that

      // can't be done on hidden elements.

      $tpDiv.show();

      // Try to find a time in the list that matches the entered time.

      var time = elm.value ? timeStringToDate(elm.value, settings) : startTime;

      var startMin = startTime.getHours() * 60 + startTime.getMinutes();

      var min = (time.getHours() * 60 + time.getMinutes()) - startMin;

      var steps = Math.round(min / settings.step);

      var roundTime = normaliseTime(new Date(0, 0, 0, 0, (steps * settings.step + startMin), 0));

      roundTime = (startTime < roundTime && roundTime <= endTime) ? roundTime : startTime;

      var $matchedTime = $("li:contains(" + formatTime(roundTime, settings) + ")", $tpDiv);

      if ($matchedTime.length) {

        $matchedTime.addClass("selected");

        // Scroll to matched time.

        $tpDiv[0].scrollTop = $matchedTime[0].offsetTop;

      }

      return true;

    };

    // Attach to click as well as focus so timePicker can be shown again when

    // clicking on the input when it already has focus.

    $(elm).focus(showPicker).click(showPicker);

    // Hide timepicker on blur

    $(elm).blur(function() {

      if (!tpOver) {

        $tpDiv.hide();

      }

    });

    // Keypress doesn't repeat on Safari for non-text keys.

    // Keydown doesn't repeat on Firefox and Opera on Mac.

    // Using kepress for Opera and Firefox and keydown for the rest seems to

    // work with up/down/enter/esc.

    var event = ($.browser.opera || $.browser.mozilla) ? 'keypress' : 'keydown';

    $(elm)[event](function(e) {

      var $selected;

      keyDown = true;

      var top = $tpDiv[0].scrollTop;

      switch (e.keyCode) {

        case 38: // Up arrow.

          // Just show picker if it's hidden.

          if (showPicker()) {

            return false;

          };

          $selected = $("li.selected", $tpList);

          var prev = $selected.prev().addClass("selected")[0];

          if (prev) {

            $selected.removeClass("selected");

            // Scroll item into view.

            if (prev.offsetTop < top) {

              $tpDiv[0].scrollTop = top - prev.offsetHeight;

            }

          }

          else {

            // Loop to next item.

            $selected.removeClass("selected");

            prev = $("li:last", $tpList).addClass("selected")[0];

            $tpDiv[0].scrollTop = prev.offsetTop - prev.offsetHeight;

          }

          return false;

          break;

        case 40: // Down arrow, similar in behaviour to up arrow.

          if (showPicker()) {

            return false;

          };

          $selected = $("li.selected", $tpList);

          var next = $selected.next().addClass("selected")[0];

          if (next) {

            $selected.removeClass("selected");

            if (next.offsetTop + next.offsetHeight > top + $tpDiv[0].offsetHeight) {

              $tpDiv[0].scrollTop = top + next.offsetHeight;

            }

          }

          else {

            $selected.removeClass("selected");

            next = $("li:first", $tpList).addClass("selected")[0];

            $tpDiv[0].scrollTop = 0;

          }

          return false;

          break;

        case 13: // Enter

          if ($tpDiv.is(":visible")) {

            var sel = $("li.selected", $tpList)[0];

            setTimeVal(elm, sel, $tpDiv, settings);

          }

          return false;

          break;

        case 27: // Esc

          $tpDiv.hide();

          return false;

          break;

      }

      return true;

    });

    $(elm).keyup(function(e) {

      keyDown = false;

    });

    // Helper function to get an inputs current time as Date object.

    // Returns a Date object.

    this.getTime = function() {

      return timeStringToDate(elm.value, settings);

    };

    // Helper function to set a time input.

    // Takes a Date object.

    this.setTime = function(time) {

      elm.value = formatTime(normaliseTime(time), settings);

      // Trigger element's change events.

      $(elm).change();

    };

  }; // End fn;

  // Plugin defaults.

  $.fn.timePicker.defaults = {

    step:30,

    startTime: new Date(0, 0, 0, 0, 0, 0),

    endTime: new Date(0, 0, 0, 23, 30, 0),

    selectedTime: new Date(0, 0, 0, 0, 0, 0),

    separator: ':',

    show24Hours: true

  };

  // Private functions.

  function setTimeVal(elm, sel, $tpDiv, settings) {

    // Update input field

    elm.value = $(sel).text();

    // Trigger element's change events.

    $(elm).change();

    // Keep focus for all but IE (which doesn't like it)

    if (!$.browser.msie) {

      elm.focus();

    }

    // Hide picker

    $tpDiv.hide();

  }

  function formatTime(time, settings) {

    var h = time.getHours();

    var hours = settings.show24Hours ? h : (((h + 11) % 12) + 1);

    var minutes = time.getMinutes();

    return formatNumber(hours) + settings.separator + formatNumber(minutes) + (settings.show24Hours ? '' : ((h < 12) ? ' AM' : ' PM'));

  }

  function formatNumber(value) {

    return (value < 10 ? '0' : '') + value;

  }

  function timeToDate(input, settings) {

    return (typeof input == 'object') ? normaliseTime(input) : timeStringToDate(input, settings);

  }

  function timeStringToDate(input, settings) {

    if (input) {

      var array = input.split(settings.separator);

      var hours = parseFloat(array[0]);

      var minutes = parseFloat(array[1]);

      // Convert AM/PM hour to 24-hour format.

      if (!settings.show24Hours) {

        if (hours === 12 && input.substr('AM') !== -1) {

          hours = 0;

        }

        else if (hours !== 12 && input.indexOf('PM') !== -1) {

          hours += 12;

        }

      }

      var time = new Date(0, 0, 0, hours, minutes, 0);

      return normaliseTime(time);

    }

    return null;

  }

  /* Normalise time object to a common date. */

  function normaliseTime(time) {

    time.setFullYear(2001);

    time.setMonth(0);

    time.setDate(0);

    return time;

  }

})(jQuery);