var timerModule = angular.module('timer', [])
  .directive('timer', ['$compile', function ($compile) {
    return  {
      restrict: 'EA',
      replace: false,
      scope: {
        interval: '=interval',
        startTimeAttr: '=startTime',
        endTimeAttr: '=endTime',
        countdownattr: '=countdown',
        finishCallback: '&finishCallback',
        autoStart: '&autoStart',
        maxTimeUnit: '='
      },
      controller: ['$scope', '$element', '$attrs', '$timeout', function ($scope, $element, $attrs, $timeout) {

        // Checking for trim function since IE8 doesn't have it
        // If not a function, create tirm with RegEx to mimic native trim
        if (typeof String.prototype.trim !== 'function') {
          String.prototype.trim = function () {
            return this.replace(/^\s+|\s+$/g, '');
          };
        }

        //angular 1.2 doesn't support attributes ending in "-start", so we're
        //supporting both "autostart" and "auto-start" as a solution for
        //backward and forward compatibility.
        $scope.autoStart = $attrs.autoStart || $attrs.autostart;

        if ($element.html().trim().length === 0) {
          $element.append($compile('<span>{{millis}}</span>')($scope));
        } else {
          $element.append($compile($element.contents())($scope));
        }

        $scope.startTime = null;
        $scope.endTime = null;
        $scope.timeoutId = null;
        $scope.countdown = $scope.countdownattr && parseInt($scope.countdownattr, 10) >= 0 ? parseInt($scope.countdownattr, 10) : undefined;
        $scope.isRunning = false;

        $scope.$on('timer-start', function () {
          $scope.start();
        });

        $scope.$on('timer-resume', function () {
          $scope.resume();
        });

        $scope.$on('timer-stop', function () {
          $scope.stop();
        });

        $scope.$on('timer-clear', function () {
          $scope.clear();
        });

        $scope.$on('timer-set-countdown', function (e, countdown) {
          $scope.countdown = countdown;
        });

        function resetTimeout() {
          if ($scope.timeoutId) {
            clearTimeout($scope.timeoutId);
          }
        }

        $scope.start = $element[0].start = function () {
          $scope.startTime = $scope.startTimeAttr ? new Date($scope.startTimeAttr) : new Date();
          $scope.endTime = $scope.endTimeAttr ? new Date($scope.endTimeAttr) : null;
          if (!$scope.countdown) {
            $scope.countdown = $scope.countdownattr && parseInt($scope.countdownattr, 10) > 0 ? parseInt($scope.countdownattr, 10) : undefined;
          }
          resetTimeout();
          tick();
          $scope.isRunning = true;
        };

        $scope.resume = $element[0].resume = function () {
          resetTimeout();
          if ($scope.countdownattr) {
            $scope.countdown += 1;
          }
          $scope.startTime = new Date() - ($scope.stoppedTime - $scope.startTime);
          tick();
          $scope.isRunning = true;
        };

        $scope.stop = $scope.pause = $element[0].stop = $element[0].pause = function () {
          var timeoutId = $scope.timeoutId;
          $scope.clear();
          $scope.$emit('timer-stopped', {timeoutId: timeoutId, millis: $scope.millis, seconds: $scope.seconds, minutes: $scope.minutes, hours: $scope.hours, days: $scope.days});
        };

        $scope.clear = $element[0].clear = function () {
          // same as stop but without the event being triggered
          $scope.stoppedTime = new Date();
          resetTimeout();
          $scope.timeoutId = null;
          $scope.isRunning = false;
        };

        $element.bind('$destroy', function () {
          resetTimeout();
          $scope.isRunning = false;
        });

        function calculateTimeUnits() {
          if ($attrs.startTime !== undefined){
            $scope.millis = new Date() - new Date($scope.startTimeAttr);
          }
          // compute time values based on maxTimeUnit specification
          if (!$scope.maxTimeUnit || $scope.maxTimeUnit === 'day') {
            $scope.seconds = Math.floor(($scope.millis / 1000) % 60);
            $scope.minutes = Math.floor((($scope.millis / (60000)) % 60));
            $scope.hours = Math.floor((($scope.millis / (3600000)) % 24));
            $scope.days = Math.floor((($scope.millis / (3600000)) / 24));
            $scope.months = 0;
            $scope.years = 0;
          } else if ($scope.maxTimeUnit === 'second') {
            $scope.seconds = Math.floor($scope.millis / 1000);
            $scope.minutes = 0;
            $scope.hours = 0;
            $scope.days = 0;
            $scope.months = 0;
            $scope.years = 0;
          } else if ($scope.maxTimeUnit === 'minute') {
            $scope.seconds = Math.floor(($scope.millis / 1000) % 60);
            $scope.minutes = Math.floor($scope.millis / 60000);
            $scope.hours = 0;
            $scope.days = 0;
            $scope.months = 0;
            $scope.years = 0;
          } else if ($scope.maxTimeUnit === 'hour') {
            $scope.seconds = Math.floor(($scope.millis / 1000) % 60);
            $scope.minutes = Math.floor((($scope.millis / (60000)) % 60));
            $scope.hours = Math.floor($scope.millis / 3600000);
            $scope.days = 0;
            $scope.months = 0;
            $scope.years = 0;
          } else if ($scope.maxTimeUnit === 'month') {
            $scope.seconds = Math.floor(($scope.millis / 1000) % 60);
            $scope.minutes = Math.floor((($scope.millis / (60000)) % 60));
            $scope.hours = Math.floor((($scope.millis / (3600000)) % 24));
            $scope.days = Math.floor((($scope.millis / (3600000)) / 24) % 30);
            $scope.months = Math.floor((($scope.millis / (3600000)) / 24) / 30);
            $scope.years = 0;
          } else if ($scope.maxTimeUnit === 'year') {
            $scope.seconds = Math.floor(($scope.millis / 1000) % 60);
            $scope.minutes = Math.floor((($scope.millis / (60000)) % 60));
            $scope.hours = Math.floor((($scope.millis / (3600000)) % 24));
            $scope.days = Math.floor((($scope.millis / (3600000)) / 24) % 30);
            $scope.months = Math.floor((($scope.millis / (3600000)) / 24 / 30) % 12);
            $scope.years = Math.floor(($scope.millis / (3600000)) / 24 / 365);
          }
          // plural - singular unit decision
          $scope.secondsS = ($scope.seconds === 1 || $scope.seconds === 0) ? '' : 's';
          $scope.minutesS = ($scope.minutes === 1 || $scope.minutes === 0) ? '' : 's';
          $scope.hoursS = ($scope.hours === 1 || $scope.hours === 0) ? '' : 's';
          $scope.daysS = ($scope.days === 1 || $scope.days === 0)? '' : 's';
          $scope.monthsS = ($scope.months === 1 || $scope.months === 0)? '' : 's';
          $scope.yearsS = ($scope.years === 1 || $scope.years === 0)? '' : 's';
          //add leading zero if number is smaller than 10
          $scope.sseconds = $scope.seconds < 10 ? '0' + $scope.seconds : $scope.seconds;
          $scope.mminutes = $scope.minutes < 10 ? '0' + $scope.minutes : $scope.minutes;
          $scope.hhours = $scope.hours < 10 ? '0' + $scope.hours : $scope.hours;
          $scope.ddays = $scope.days < 10 ? '0' + $scope.days : $scope.days;
          $scope.mmonths = $scope.months < 10 ? '0' + $scope.months : $scope.months;
          $scope.yyears = $scope.years < 10 ? '0' + $scope.years : $scope.years;

        }

        //determine initial values of time units and add AddSeconds functionality
        if ($scope.countdownattr) {
          $scope.millis = $scope.countdownattr * 1000;

          $scope.addCDSeconds = $element[0].addCDSeconds = function (extraSeconds) {
            $scope.countdown += extraSeconds;
            $scope.$digest();
            if (!$scope.isRunning) {
              $scope.start();
            }
          };

          $scope.$on('timer-add-cd-seconds', function (e, extraSeconds) {
            $timeout(function () {
              $scope.addCDSeconds(extraSeconds);
            });
          });

          $scope.$on('timer-set-countdown-seconds', function (e, countdownSeconds) {
            if (!$scope.isRunning) {
              $scope.clear();
            }

            $scope.countdown = countdownSeconds;
            $scope.millis = countdownSeconds * 1000;
            calculateTimeUnits();
          });
        } else {
          $scope.millis = 0;
        }
        calculateTimeUnits();

        var tick = function () {

          $scope.millis = new Date() - $scope.startTime;
          var adjustment = $scope.millis % 1000;

          if ($scope.endTimeAttr) {
            $scope.millis = $scope.endTime - new Date();
            adjustment = $scope.interval - $scope.millis % 1000;
          }


          if ($scope.countdownattr) {
            $scope.millis = $scope.countdown * 1000;
          }

          if ($scope.millis < 0) {
            $scope.stop();
            $scope.millis = 0;
            calculateTimeUnits();
            if($scope.finishCallback) {
              $scope.$eval($scope.finishCallback);
            }
            return;
          }
          calculateTimeUnits();

          //We are not using $timeout for a reason. Please read here - https://github.com/siddii/angular-timer/pull/5
          $scope.timeoutId = setTimeout(function () {
            tick();
            $scope.$digest();
          }, $scope.interval - adjustment);

          $scope.$emit('timer-tick', {timeoutId: $scope.timeoutId, millis: $scope.millis});

          if ($scope.countdown > 0) {
            $scope.countdown--;
          }
          else if ($scope.countdown <= 0) {
            $scope.stop();
            if($scope.finishCallback) {
              $scope.$eval($scope.finishCallback);
            }
          }
        };

        if ($scope.autoStart === undefined || $scope.autoStart === true) {
          $scope.start();
        }
      }]
    };
  }]);

/* commonjs package manager support (eg componentjs) */
if (typeof module !== "undefined" && typeof exports !== "undefined" && module.exports === exports){
  module.exports = timerModule;
}
