var dateRangeInputBinding = new Shiny.InputBinding();
$.extend(dateRangeInputBinding, {
  _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) {
    var $el = $(el);
    var $mainInput = $el.closest('.input-daterange').eq(0);

    var autonext = false;
    if ($mainInput.data('autonext') == true) {
      $mainInput.data('autonext', false);
      autonext = true;
    }

    if (date == null) {
      $el.bsDatepicker('setStartDate', null);
      $mainInput.data('autonext', autonext);
      return;
    }
    
    var parsedDate = this._newDate(date);
    if (parsedDate === null) {
      $mainInput.data('autonext', autonext);
      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);
    }

    $mainInput.data('autonext', autonext);
  },
  _setMax: function(el, date) {
    var $el = $(el);
    var $mainInput = $el.closest('.input-daterange').eq(0);

    var autonext = false;
    if ($mainInput.data('autonext') == true) {
      $mainInput.data('autonext', false);
      autonext = true;
    }

    if (date == null) {
      $el.bsDatepicker('setEndDate', null);
      $mainInput.data('autonext', autonext);
      return;
    }

    var parsedDate = this._newDate(date);
    if (parsedDate === null) {
      $mainInput.data('autonext', autonext);
      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);
    }

    $mainInput.data('autonext', autonext);
  },
  _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-dateRange-input');
  },
  getId: function(el) {
    return $(el).attr('id');
  },
  getValue: function(el) {
    var $inputs = $(el).find('input');
    var start = $inputs.eq(0).bsDatepicker('getUTCDate');
    var end = $inputs.eq(1).bsDatepicker('getUTCDate');
    return {
      start: this._formatDateUTC(start),
      end: this._formatDateUTC(end)
    };
  },
  setValue: function(el, value) {
    if (!(value instanceof Object)) {
      return;
    }

    var $el = $(el);
    var $mainInput = $el.find('.input-daterange').eq(0);

    var autonext = false;
    if ($mainInput.data('autonext') == true) {
      $mainInput.data('autonext', false);
      autonext = true;
    }

    var $inputs = $el.find('input');
    if (value.start !== void 0) {
      if (value.start === null || value.start.length == 0) {
        $inputs.eq(0).val('').bsDatepicker('clearDates');
      } else {
        var start = this._newDate(value.start);
        $inputs.eq(0).bsDatepicker('setUTCDate', start);
      }
    }
    if (value.end !== void 0) {
      if (value.end === null || value.end.length == 0) {
        $inputs.eq(1).val('').bsDatepicker('clearDates');
      } else {
        var end = this._newDate(value.end);
        $inputs.eq(1).bsDatepicker('setUTCDate', end);
      }
    }

    $mainInput.data('autonext', autonext);
  },
  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 $inputs = $el.find('input');
    var $startinput = $inputs.eq(0);
    var $endinput = $inputs.eq(1);

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

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

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

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

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

    $(el).trigger('change');
  },
  initialize: function initialize(el) {
    var $el = $(el);
    var $mainInput = $el.find('.input-daterange').eq(0);
    var $inputs = $el.find('input');
    var $startinput = $inputs.eq(0);
    var $endinput = $inputs.eq(1);

    var start = $mainInput.data('initial-start-date');
    var end = $mainInput.data('initial-end-date');

    $el.find('.input-daterange').eq(0).bsDatepicker();

    this.setValue(el, {
      start: start,
      end: end
    });

    this._setMin($startinput[0], $mainInput.data('min-date'));
    this._setMin($endinput[0], $mainInput.data('min-date'));

    this._setMax($startinput[0], $mainInput.data('max-date'));
    this._setMax($endinput[0], $mainInput.data('max-date'));

    $startinput.on('focus', function(event) {
       $(this).select();
    });
    $endinput.on('focus', function(event) {
       $(this).select();
    });

    $startinput.bsDatepicker().on('changeDate', function(event) {
      if ($mainInput.data('autonext') == true && $startinput.bsDatepicker('getUTCDate')) {
        $startinput.bsDatepicker('hide');
        $endinput.focus();
        $endinput.select();
        $endinput.bsDatepicker('show');
      }
      $el.trigger('change');
    })
    $endinput.bsDatepicker().on('changeDate', function(event) {
      $el.trigger('change');
    })
  }
});

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