var dateInputBinding = new Shiny.InputBinding();
$.extend(dateInputBinding, {
  _newDate: function(date) {
    if (date instanceof Date)
      return date;
    var d = Date.parse(date);
    if (isNaN(d))
      return null;
    return new Date(d);
  },
  _setMin: function(el, date) {
    if (date == null) {
      $(el).bsDatepicker('setStartDate', null);
      return;
    }
    var parsedDate = this._newDate(date);
    if (parsedDate === null)
      return;
    var curValue = $(el).bsDatepicker('getUTCDate');
    $(el).bsDatepicker('setStartDate', this._utcDateAsLocal(parsedDate));
    if (parsedDate && curValue && parsedDate.getTime() > curValue.getTime()) {
      $(el).bsDatepicker('clearDates');
    } else {
      $(el).bsDatepicker('setUTCDate', curValue);
    }
  },
  _setMax: function(el, date) {
    if (date == null) {
      $(el).bsDatepicker('setEndDate', null);
      return;
    }
    var parsedDate = this._newDate(date);
    if (parsedDate === null)
      return;
    var curValue = $(el).bsDatepicker('getUTCDate');
    $(el).bsDatepicker('setEndDate', this._utcDateAsLocal(parsedDate));
    if (parsedDate && curValue && parsedDate.getTime() < curValue.getTime()) {
      $(el).bsDatepicker('clearDates');
    } else {
      $(el).bsDatepicker('setUTCDate', curValue);
    }
  },
  _dateAsUTC: function(date) {
    return new Date(date.getTime() - date.getTimezoneOffset() * 6e4);
  },
  _utcDateAsLocal: function(date) {
    return new Date(date.getTime() + date.getTimezoneOffset() * 6e4);
  },
  _padZeros: function(n, digits) {
    var str = n.toString();
    while (str.length < digits) {
      str = "0" + str;
    }
    return str;
  },
  _formatDateUTC: function(date) {
    if (date instanceof Date) {
      return date.getUTCFullYear() + "-" + this._padZeros(date.getUTCMonth() + 1, 2) + "-" + this._padZeros(date.getUTCDate(), 2);
    } else {
      return null;
    }
  },


  find: function(scope) {
    return $(scope).find('.shiny-betterDate-input');
  },
  getId: function(el) {
    return $(el).attr('id');
  },
  getValue: function(el) {
    var $el = $(el);
    var $input = $el.find('input').eq(0);

    var value = null;
    if ($input.data('date-multidate') == true) {
      value = $input.bsDatepicker('getUTCDates');
      if (value.length > 0) {
        value = value.map(this._formatDateUTC.bind(this));
      }
    } else {
      value = $input.bsDatepicker('getUTCDate');
      value = this._formatDateUTC(value);
    }

    return value;
  },
  setValue: function(el, value) {
    var $el = $(el);
    var $input = $el.find('input').eq(0);

    if (value !== void 0) {
      if (value === null || (Array.isArray(value) && value.length == 0)) {
        $input.val('').bsDatepicker('update');
      } else {
        if ($input.data('date-multidate') == true && Array.isArray(value) && value.length > 1) {
          var newValues = value.map(this._newDate.bind(this));
          $input.bsDatepicker('setUTCDates', newValues);
        } else {
          var newValue = this._newDate(value);
          $input.bsDatepicker('setUTCDate', newValue);
        }
      }
    }
  },
  setView: function(el, view) {
    var $el = $(el);
    var $input = $el.find('input').eq(0);

    if (view !== void 0) {
      if (view === null || (Array.isArray(view) && view.length == 0)) {
        $input.data().datepicker.o.defaultViewDate = new Date();
      } else {
        $input.data().datepicker.o.defaultViewDate = new Date(view);
      }
      $input.bsDatepicker('update');
    }
  },
  subscribe: function(el, callback) {
    $(el).on('change', function(event) {
      callback();
    });
  },
  unsubscribe: function(el) {
    $(el).off('change');
  },
  getState: function(el) {
    return {
      value: this.getValue(el)
    };
  },
  receiveMessage: function(el, data) {
    var $el = $(el);
    var $input = $el.find('input').eq(0);

    if (data.hasOwnProperty('label')) {
      $(el).find('label[for="' + el.id + 'Text"]').text(data.label);
    }

    if (data.hasOwnProperty('min')) {
      this._setMin($input[0], data.min);
    }

    if (data.hasOwnProperty('max')) {
      this._setMax($input[0], data.max);
    }

    if (data.hasOwnProperty('value')) {
      this.setValue(el, data.value);
    }

    if (data.hasOwnProperty('view')) {
      this.setView(el, data.view);
    }

    // if (data.hasOwnProperty('disabled')) {
    // }

    $el.trigger('change');
  },
  initialize: function initialize(el) {
    var $el = $(el);
    var $mainInput = $el.find('.input-betterDate').eq(0);
    var $input = $el.find('input').eq(0)

    $input.bsDatepicker();

    var value = $mainInput.data('initial-date');
    this.setValue(el, value);

    this._setMin($input[0], $mainInput.data('min-date'));
    this._setMax($input[0], $mainInput.data('max-date'));

    $input.bsDatepicker().on('changeDate', function(event) {
      $el.trigger('change');
    })
  }
});

Shiny.inputBindings.register(dateInputBinding, 'shinyExtra.dateInputBinding');