// Copyright 2018 gf Author(https://github.com/gogf/gf). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.

package gtype

import (
	"bytes"
	"github.com/gogf/gf/util/gconv"
	"sync/atomic"
)

// String is a struct for concurrent-safe operation for type string.
type String struct {
	value atomic.Value
}

// NewString creates and returns a concurrent-safe object for string type,
// with given initial value <value>.
func NewString(value ...string) *String {
	t := &String{}
	if len(value) > 0 {
		t.value.Store(value[0])
	}
	return t
}

// Clone clones and returns a new concurrent-safe object for string type.
func (v *String) Clone() *String {
	return NewString(v.Val())
}

// Set atomically stores <value> into t.value and returns the previous value of t.value.
func (v *String) Set(value string) (old string) {
	old = v.Val()
	v.value.Store(value)
	return
}

// Val atomically loads and returns t.value.
func (v *String) Val() string {
	s := v.value.Load()
	if s != nil {
		return s.(string)
	}
	return ""
}

// String implements String interface for string printing.
func (v *String) String() string {
	return v.Val()
}

// MarshalJSON implements the interface MarshalJSON for json.Marshal.
func (v *String) MarshalJSON() ([]byte, error) {
	return gconv.UnsafeStrToBytes(`"` + v.Val() + `"`), nil
}

// UnmarshalJSON implements the interface UnmarshalJSON for json.Unmarshal.
func (v *String) UnmarshalJSON(b []byte) error {
	v.Set(gconv.UnsafeBytesToStr(bytes.Trim(b, `"`)))
	return nil
}

// UnmarshalValue is an interface implement which sets any type of value for <v>.
func (v *String) UnmarshalValue(value interface{}) error {
	v.Set(gconv.String(value))
	return nil
}