package etcd

import (
	"context"
	"encoding/json"
	"reflect"

	"go.etcd.io/etcd/client/v3"
	"mongo.games.com/goserver/core"
	"mongo.games.com/goserver/core/basic"
	"mongo.games.com/goserver/core/etcd"
	"mongo.games.com/goserver/core/logger"

	"mongo.games.com/game/proto"
)

// Register 注册etcd监听方法
// key:监听的key
// msgType:数据类型
// f:数据变更回调方法, completeKey:完整键, isInit:第一次主动拉取数据,event:事件类型, data:已经反序列化的数据，类型为msgType,是指针类型
// **isInit** 为true时，表示是第一次主动拉取数据，此时允许耗时操作。为false时，表示是监听到数据变更，此时不允许耗时操作。
func Register(key string, msgType interface{}, f func(ctx context.Context, completeKey string, isInit bool, event *clientv3.Event, data interface{})) {
	createFunc := func() interface{} {
		tp := reflect.TypeOf(msgType)
		if tp.Kind() == reflect.Ptr {
			tp = tp.Elem()
		}
		return reflect.New(tp).Interface()
	}

	initFunc := func(ctx context.Context, res *clientv3.GetResponse) {
		if res == nil {
			return
		}
		f := func() {
			for i := int64(0); i < res.Count; i++ {
				data := createFunc()
				switch d := data.(type) {
				case proto.Message:
					err := proto.Unmarshal(res.Kvs[i].Value, d)
					if err != nil {
						logger.Logger.Errorf("ETCD %v proto.Unmarshal error:%v", key, err)
						continue
					}
					logger.Logger.Debugf("ETCD 拉取成功 %v ==> %v", string(res.Kvs[i].Key), d)
					event := &clientv3.Event{
						Type: 0,
					}
					f(context.TODO(), string(res.Kvs[i].Key), true, event, d)
				default:
					err := json.Unmarshal(res.Kvs[i].Value, d)
					if err != nil {
						logger.Logger.Errorf("ETCD %v josn.Unmarshal error:%v", key, err)
						continue
					}
					logger.Logger.Debugf("ETCD 拉取成功 %v ==> %v", string(res.Kvs[i].Key), d)
					event := &clientv3.Event{
						Type: 0,
					}
					f(context.TODO(), string(res.Kvs[i].Key), true, event, d)
				}
			}
		}
		obj := core.CoreObject()
		if obj == nil {
			f()
			return
		}
		obj.SendCommand(basic.CommandWrapper(func(*basic.Object) error {
			f()
			return nil
		}), true)
	}

	// 监控数据变动
	watchFunc := func(ctx context.Context, res *clientv3.WatchResponse) {
		if res == nil {
			return
		}
		f := func() {
			for _, ev := range res.Events {
				switch ev.Type {
				case clientv3.EventTypePut:
					data := createFunc()
					switch d := data.(type) {
					case proto.Message:
						err := proto.Unmarshal(ev.Kv.Value, d)
						if err != nil {
							logger.Logger.Errorf("ETCD %v proto.Unmarshal error:%v", key, err)
							continue
						}
						logger.Logger.Tracef("ETCD 更新事件 %v ==> %v", string(ev.Kv.Key), d)
						f(ctx, string(ev.Kv.Key), false, ev, d)
					default:
						err := json.Unmarshal(ev.Kv.Value, d)
						if err != nil {
							logger.Logger.Errorf("ETCD %v josn.Unmarshal error:%v", key, err)
							continue
						}
						logger.Logger.Tracef("ETCD 更新事件 %v ==> %v", string(ev.Kv.Key), d)
						f(ctx, string(ev.Kv.Key), false, ev, d)
					}
				case clientv3.EventTypeDelete:
					logger.Logger.Tracef("ETCD 删除事件 %v", string(ev.Kv.Key))
					f(ctx, string(ev.Kv.Key), false, ev, nil)
				}
			}
		}
		obj := core.CoreObject()
		if obj == nil {
			f()
			return
		}
		obj.SendCommand(basic.CommandWrapper(func(*basic.Object) error {
			f()
			return nil
		}), true)
	}

	etcd.AddFunc(key, initFunc, watchFunc)
}