package date

// Copyright 2017 Microsoft Corporation

//

//  Licensed under the Apache License, Version 2.0 (the "License");

//  you may not use this file except in compliance with the License.

//  You may obtain a copy of the License at

//

//      http://www.apache.org/licenses/LICENSE-2.0

//

//  Unless required by applicable law or agreed to in writing, software

//  distributed under the License is distributed on an "AS IS" BASIS,

//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

//  See the License for the specific language governing permissions and

//  limitations under the License.

import (

	"errors"

	"time"

)

const (

	rfc1123JSON = `"` + time.RFC1123 + `"`

	rfc1123     = time.RFC1123

)

// TimeRFC1123 defines a type similar to time.Time but assumes a layout of RFC1123 date-time (i.e.,

// Mon, 02 Jan 2006 15:04:05 MST).

type TimeRFC1123 struct {

	time.Time

}

// UnmarshalJSON reconstitutes the Time from a JSON string conforming to RFC1123 date-time

// (i.e., Mon, 02 Jan 2006 15:04:05 MST).

func (t *TimeRFC1123) UnmarshalJSON(data []byte) (err error) {

	t.Time, err = ParseTime(rfc1123JSON, string(data))

	if err != nil {

		return err

	}

	return nil

}

// MarshalJSON preserves the Time as a JSON string conforming to RFC1123 date-time (i.e.,

// Mon, 02 Jan 2006 15:04:05 MST).

func (t TimeRFC1123) MarshalJSON() ([]byte, error) {

	if y := t.Year(); y < 0 || y >= 10000 {

		return nil, errors.New("Time.MarshalJSON: year outside of range [0,9999]")

	}

	b := []byte(t.Format(rfc1123JSON))

	return b, nil

}

// MarshalText preserves the Time as a byte array conforming to RFC1123 date-time (i.e.,

// Mon, 02 Jan 2006 15:04:05 MST).

func (t TimeRFC1123) MarshalText() ([]byte, error) {

	if y := t.Year(); y < 0 || y >= 10000 {

		return nil, errors.New("Time.MarshalText: year outside of range [0,9999]")

	}

	b := []byte(t.Format(rfc1123))

	return b, nil

}

// UnmarshalText reconstitutes a Time saved as a byte array conforming to RFC1123 date-time

// (i.e., Mon, 02 Jan 2006 15:04:05 MST).

func (t *TimeRFC1123) UnmarshalText(data []byte) (err error) {

	t.Time, err = ParseTime(rfc1123, string(data))

	if err != nil {

		return err

	}

	return nil

}

// MarshalBinary preserves the Time as a byte array conforming to RFC1123 date-time (i.e.,

// Mon, 02 Jan 2006 15:04:05 MST).

func (t TimeRFC1123) MarshalBinary() ([]byte, error) {

	return t.MarshalText()

}

// UnmarshalBinary reconstitutes a Time saved as a byte array conforming to RFC1123 date-time

// (i.e., Mon, 02 Jan 2006 15:04:05 MST).

func (t *TimeRFC1123) UnmarshalBinary(data []byte) error {

	return t.UnmarshalText(data)

}

// ToTime returns a Time as a time.Time

func (t TimeRFC1123) ToTime() time.Time {

	return t.Time

}

// String returns the Time formatted as an RFC1123 date-time string (i.e.,

// Mon, 02 Jan 2006 15:04:05 MST).

func (t TimeRFC1123) String() string {

	// Note: time.Time.String does not return an RFC1123 compliant string, time.Time.MarshalText does.

	b, err := t.MarshalText()

	if err != nil {

		return ""

	}

	return string(b)

}