/**
 * angular-relative-date
 * @version v0.1.0 - 2014-07-31
 * @link https://github.com/ariesjia/angular-relative-date
 * @author Chenjia <ariesjia00@hotmail.com>
 * @license MIT License, http://www.opensource.org/licenses/MIT
 */
'use strict';
angular.module('quark.relativeDate', []).provider('relativeDateFilter', [function () {
    var self = this;
    self.conversions = {
      now: 1,
      second: 1000,
      minute: 60,
      hour: 60,
      day: 24
    };
    self.labelText = {
      now: 'now',
      before_second: {
        'one': '%n second ago',
        'more': '%n seconds ago'
      },
      before_minute: {
        'one': '%n minute ago',
        'more': '%n minutes ago'
      },
      before_hour: {
        'one': '%n hour ago',
        'more': '%n hours ago'
      },
      before_day: {
        'one': '%n day ago',
        'more': '%n days ago'
      },
      after_second: {
        'one': '%n second left',
        'more': '%n seconds left'
      },
      after_minute: {
        'one': '%n minute left',
        'more': '%n minutes left'
      },
      after_hour: {
        'one': '%n hour left',
        'more': '%n hours left'
      },
      after_day: {
        'one': '%n day left',
        'more': '%n days left'
      }
    };
    self.datePattern = 'yyyy-MM-dd';
    self.defaultFormat = function (unit_key, delta, relativeTime) {
      return unit_key === 'day' && delta > 0;
    };
    var getText = function (key) {
        var labelKey = key;
        return self.labelText[labelKey];
      }, localize = function (delta, unit_key) {
        if (unit_key !== 'now') {
          var prefix = 'before_';
          if (delta < 0) {
            prefix = 'after_';
          }
          unit_key = prefix + unit_key;
        }
        var label = getText(unit_key), unit = angular.isString(label) ? label : delta == 1 ? label.one : label.more;
        return unit.replace('%n', Math.abs(delta));
      };
    this.$get = [
      'dateFilter',
      function (dateFilter) {
        return function (date) {
          var now = new Date(), relativeTime = new Date(date), delta = now - relativeTime, unit_key = 'now', key;
          var conversions = self.conversions;
          for (key in conversions) {
            if (Math.abs(delta) < conversions[key]) {
              break;
            }
            unit_key = key;
            delta = delta / conversions[key];
          }
          if (self.defaultFormat(unit_key, delta, relativeTime)) {
            return dateFilter(relativeTime, self.datePattern);
          }
          return localize(Math.floor(delta), unit_key);
        };
      }
    ];
  }]);