package redis

import (
	"context"
	"fmt"
	"kpt-pasture/config"
	"math/rand"
	"time"

	"gitee.com/xuyiping_admin/pkg/xerr"
	"github.com/eko/gocache/cache"
	"github.com/eko/gocache/marshaler"
	"github.com/eko/gocache/metrics"
	"github.com/eko/gocache/store"
	redisv7 "github.com/go-redis/redis/v7"
)

func init() {
	rand.Seed(time.Now().UnixNano())
}

// Options redis 使用约束
type Options = store.Options

// TTL redis key TTL
func TTL(duration time.Duration) *Options {
	return &store.Options{
		// 避免集中过期
		Expiration: duration + time.Duration(rand.Int31n(100))*time.Second,
	}
}

// CacheObject 缓存对象
type CacheObject interface {
	CacheKey() string
}

// CacheStoreRedis Redis 缓存实例
//
//go:generate mockgen -destination mock/redismock.go -package redismock kpt_event/service/redis CacheStoreRedis
type CacheStoreRedis interface {
	Namespace() string
	SetNamespace(string)
	// FullKey 返回带命名空间的完整key
	FullKey(key string) string
	Client() *redisv7.Client

	Get(ctx context.Context, Obj CacheObject) (interface{}, error)
	BatchGet(ctx context.Context, objects []CacheObject) (map[string]interface{}, error)
	Set(ctx context.Context, Obj CacheObject, options *store.Options) error
	TTL(ctx context.Context, obj CacheObject) (time.Duration, error)
	Delete(ctx context.Context, keys ...interface{}) error
}

func NewCacheStoreRedis(cfg *config.AppConfig) CacheStoreRedis {
	return NewCacheStoreRedisEntry(cfg)
}

func NewCacheStoreRedisEntry(cfg *config.AppConfig) *CacheStoreRedisEntry {
	client := NewClientLatest(cfg)
	redisStore := store.NewRedis(client, nil)
	promMetrics := metrics.NewPrometheus(cfg.Name())
	cacheManager := cache.NewMetric(promMetrics, cache.New(redisStore))
	marshal := marshaler.New(cacheManager)
	return &CacheStoreRedisEntry{
		client:         client,
		cacheNamespace: config.Options().CacheNameSpace(),
		cacheMarshal:   marshal,
	}
}

type CacheStoreRedisEntry struct {
	client         *redisv7.Client
	cacheNamespace string
	cacheMarshal   *marshaler.Marshaler
}

func (entry *CacheStoreRedisEntry) fullKey(key string) string {
	return fmt.Sprintf("%s:%s", entry.cacheNamespace, key)
}

func (entry *CacheStoreRedisEntry) FullKey(key string) string {
	return fmt.Sprintf("%s:%s", entry.cacheNamespace, key)
}

func (entry *CacheStoreRedisEntry) pureKey(key string) string {
	return key[len(entry.cacheNamespace):]
}

func (entry *CacheStoreRedisEntry) Namespace() string {
	return entry.cacheNamespace
}

func (entry *CacheStoreRedisEntry) SetNamespace(ns string) {
	entry.cacheNamespace = ns
}

func (entry *CacheStoreRedisEntry) Client() *redisv7.Client {
	return entry.client
}

func (entry *CacheStoreRedisEntry) BatchGet(ctx context.Context, objects []CacheObject) (map[string]interface{}, error) {

	result := make(map[string]interface{})
	for _, obj := range objects {
		got, err := entry.Get(ctx, obj)
		if err != nil {
			return nil, xerr.WithMessage(err, obj.CacheKey())
		}

		if got != nil {
			result[obj.CacheKey()] = got
		}
	}

	return result, nil
}

func (entry *CacheStoreRedisEntry) Get(ctx context.Context, obj CacheObject) (interface{}, error) {
	got, err := entry.cacheMarshal.Get(entry.fullKey(obj.CacheKey()), obj)
	if err != nil {
		if err == redisv7.Nil {
			return nil, nil
		}

		return nil, xerr.WithStack(err)
	}

	return got, nil
}

func (entry *CacheStoreRedisEntry) Set(ctx context.Context, obj CacheObject, options *store.Options) error {
	return entry.cacheMarshal.Set(entry.fullKey(obj.CacheKey()), obj, options)
}

func (entry *CacheStoreRedisEntry) TTL(ctx context.Context, obj CacheObject) (time.Duration, error) {
	return entry.client.TTL(entry.fullKey(obj.CacheKey())).Result()
}

func (entry *CacheStoreRedisEntry) Delete(ctx context.Context, keys ...interface{}) error {
	for _, key := range keys {
		switch keyItem := key.(type) {
		case string:
			if err := entry.cacheMarshal.Delete(entry.fullKey(keyItem)); err != nil {
				return xerr.WithStack(err)
			}
		case CacheObject:
			if err := entry.cacheMarshal.Delete(entry.fullKey(keyItem.CacheKey())); err != nil {
				return xerr.WithStack(err)
			}
		default:
			return xerr.New("invalid redis key type")
		}
	}

	return nil
}