package cache

import (
	"context"
	"git.nspix.com/golang/kos/util/env"
	"github.com/patrickmn/go-cache"
	"os"
	"time"
)

var (
	memCacheDefaultExpired  time.Duration
	memCacheCleanupInterval time.Duration
)

func init() {
	memCacheDefaultExpired, _ = time.ParseDuration(env.Get("MEMCACHE_DEFAULT_EXPIRED", "1h"))
	memCacheCleanupInterval, _ = time.ParseDuration(env.Get("MEMCACHE_CLEANUP_INTERVAL", "10m"))

	if memCacheDefaultExpired < time.Second*5 {
		memCacheDefaultExpired = time.Second * 5
	}

	if memCacheCleanupInterval < time.Minute {
		memCacheCleanupInterval = time.Minute
	}
}

type MemCache struct {
	engine *cache.Cache
}

func (cache *MemCache) Try(ctx context.Context, key string, cb LoadFunc) (buf []byte, err error) {
	var (
		ok bool
	)
	if buf, ok = cache.Get(ctx, key); ok {
		return buf, nil
	}
	if cb == nil {
		return nil, os.ErrNotExist
	}
	if buf, err = cb(ctx); err == nil {
		cache.Set(ctx, key, buf)
	}
	return
}

func (cache *MemCache) Set(ctx context.Context, key string, buf []byte) {
	cache.engine.Set(key, buf, 0)
}

func (cache *MemCache) SetEx(ctx context.Context, key string, buf []byte, expire time.Duration) {
	cache.engine.Set(key, buf, expire)
}

func (cache *MemCache) Get(ctx context.Context, key string) (buf []byte, ok bool) {
	var (
		val any
	)
	if val, ok = cache.engine.Get(key); ok {
		buf, ok = val.([]byte)
	}
	return
}

func (cache *MemCache) Del(ctx context.Context, key string) {
	cache.engine.Delete(key)
}

func NewMemCache() *MemCache {
	return &MemCache{
		engine: cache.New(memCacheDefaultExpired, memCacheCleanupInterval),
	}
}