// Package cache ...
//
// Description : cache ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 2024-06-14 16:50
package cache

import (
	"context"
	"errors"
	cacheAbstract "git.zhangdeman.cn/zhangdeman/cache/abstract"
	gocache "github.com/patrickmn/go-cache"
	"sync"
	"time"
)

var (
	GocacheClient = &Gocache{}
)

// Gocache 基于gocache的内存缓存
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 16:51 2024/6/14
type Gocache struct{}

func (g *Gocache) Exist(ctx context.Context, cacheInstanceFlag string, key string) (bool, error) {
	_, exist := GocacheStorageClient.Get(cacheInstanceFlag).Get(key)
	return exist, nil
}

func (g *Gocache) TTL(ctx context.Context, cacheInstanceFlag string, key string) (int64, error) {
	var (
		exist    bool
		expireAt time.Time
	)

	_, expireAt, exist = GocacheStorageClient.Get(cacheInstanceFlag).GetWithExpiration(key)
	if !exist {
		// 和redis key不存在返回值一致
		return -2, nil
	}
	if expireAt.Unix() == 0 {
		// 存在并且未设置过期时间, 和redis key返回值一致
		return -1, nil
	}
	return expireAt.Unix() - time.Now().Unix(), nil
}

func (g *Gocache) Set(ctx context.Context, cacheInstanceFlag string, key string, value string, ttl int64) error {
	now := time.Now()
	if now.Unix() < ttl {
		ttl = ttl - now.Unix()
	}
	GocacheStorageClient.Get(cacheInstanceFlag).Set(key, value, time.Duration(ttl)*time.Second)
	return nil
}

func (g *Gocache) Get(ctx context.Context, cacheInstanceFlag string, key string) (string, error) {
	val, exist := GocacheStorageClient.Get(cacheInstanceFlag).Get(key)
	if !exist {
		return "", errors.New(key + " : not found")
	}
	return val.(string), nil
}

func (g *Gocache) GetWithParse(ctx context.Context, cacheInstanceFlag string, key string, parseFunc cacheAbstract.ResultParseFunc) (string, error) {
	val, err := g.Get(ctx, cacheInstanceFlag, key)
	if nil != err {
		return "", err
	}
	if nil == parseFunc {
		return val, nil
	}
	return val, parseFunc(val)
}

func (g *Gocache) Delete(ctx context.Context, cacheInstanceFlag string, key string) error {
	GocacheStorageClient.Get(cacheInstanceFlag).Delete(key)
	return nil
}

var GocacheStorageClient = &GocacheStorage{
	lock:        &sync.RWMutex{},
	clientTable: make(map[string]*gocache.Cache),
}

type GocacheStorage struct {
	lock        *sync.RWMutex
	clientTable map[string]*gocache.Cache
}

func (g *GocacheStorage) Add(cacheInstanceFlag string) {
	_ = g.Get(cacheInstanceFlag)
}

func (g *GocacheStorage) Del(cacheInstanceFlag string) {
	g.lock.Lock()
	defer g.lock.Unlock()
	delete(g.clientTable, cacheInstanceFlag)
}

func (g *GocacheStorage) Get(cacheInstanceFlag string) *gocache.Cache {
	g.lock.Lock()
	defer g.lock.Unlock()
	if _, exist := g.clientTable[cacheInstanceFlag]; !exist {
		g.clientTable[cacheInstanceFlag] = gocache.New(0, 0)
	}
	return g.clientTable[cacheInstanceFlag]
}