package cache

import (
	"sync"

	"gitee.com/haodreams/golib/logs"
	"gitee.com/haodreams/golib/lz4file"
	"github.com/ugorji/go/codec"
)

// Cache 缓存数据
type Cache struct {
	kv   map[string]string
	lock sync.RWMutex
}

// New 新建一个缓存
func New() *Cache {
	c := new(Cache)
	c.Init()
	return c
}

// Init 初始化
func (m *Cache) Init() {
	m.kv = map[string]string{}
}

// Save 保存
func (m *Cache) Save(path string) {
	m.lock.RLock()
	defer m.lock.RUnlock()

	mh := new(codec.MsgpackHandle)
	var data []byte
	if len(m.kv) > 0 {
		err := codec.NewEncoderBytes(&data, mh).Encode(&m.kv)
		if err != nil {
			logs.Warn("Encode msgpack", err.Error())
			return
		}

		err = lz4file.SaveLz4File(path, data)
		if err != nil {
			logs.Warn("保存Msgpack文件错误", err.Error())
			return
		}
	}
}

// Load 加载缓存
func (m *Cache) Load(path string) (err error) {
	m.lock.Lock()
	defer m.lock.Unlock()

	mh := new(codec.MsgpackHandle)
	//加载风机的中间变量
	data, err := lz4file.LoadLz4File(path)
	if err != nil {
		logs.Error("加载 缓存数据错误", err.Error())
		return
	}

	err = codec.NewDecoderBytes(data, mh).Decode(&m.kv)
	if err != nil {
		logs.Error("lz4 解码失败", err.Error())
		return
	}

	return err
}

// Set 设置值
// force 是否强制设置值
func (m *Cache) Set(key, value string, force ...bool) {
	m.lock.Lock()
	defer m.lock.Unlock()
	if len(force) > 0 && force[0] {
		m.kv[key] = value
		return
	}
	if _, ok := m.kv[key]; ok {
		return
	}
	m.kv[key] = value
}

// Get 获取值
func (m *Cache) Get(key string) (value string, ok bool) {
	m.lock.RLock()
	defer m.lock.RUnlock()

	value, ok = m.kv[key]
	return
}

// Each 遍历每一个元素
func (m *Cache) Each(f func(key, value string) error) (err error) {
	m.lock.RLock()
	defer m.lock.RUnlock()
	for key, value := range m.kv {
		err = f(key, value)
		if err != nil {
			return
		}
	}
	return
}

// Clear 清空
func (m *Cache) Clear() {
	m.lock.Lock()
	defer m.lock.Unlock()
	m.kv = map[string]string{}
}