// Licensed to the LF AI & Data foundation under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package msgstream

import (
	"github.com/cockroachdb/errors"

	"github.com/milvus-io/milvus-proto/go-api/v2/commonpb"
)

// UnmarshalFunc is an interface that has been implemented by each Msg
type UnmarshalFunc func(interface{}) (TsMsg, error)

// UnmarshalDispatcher is an interface contains method Unmarshal
type UnmarshalDispatcher interface {
	Unmarshal(input interface{}, msgType commonpb.MsgType) (TsMsg, error)
}

// UnmarshalDispatcherFactory is a factory to generate an object which implement interface UnmarshalDispatcher
type UnmarshalDispatcherFactory interface {
	NewUnmarshalDispatcher() *UnmarshalDispatcher
}

// ProtoUnmarshalDispatcher is Unmarshal Dispatcher which used for data of proto type
type ProtoUnmarshalDispatcher struct {
	TempMap map[commonpb.MsgType]UnmarshalFunc
}

// Unmarshal will forward unmarshal request to msg type specified unmarshal function
func (p *ProtoUnmarshalDispatcher) Unmarshal(input interface{}, msgType commonpb.MsgType) (TsMsg, error) {
	unmarshalFunc, ok := p.TempMap[msgType]
	if !ok {
		return nil, errors.New("not set unmarshalFunc for this messageType")
	}
	return unmarshalFunc(input)
}

// ProtoUDFactory is a factory to generate ProtoUnmarshalDispatcher object
type ProtoUDFactory struct{}

// NewUnmarshalDispatcher returns a new UnmarshalDispatcher
func (pudf *ProtoUDFactory) NewUnmarshalDispatcher() *ProtoUnmarshalDispatcher {
	insertMsg := InsertMsg{}
	deleteMsg := DeleteMsg{}
	timeTickMsg := TimeTickMsg{}
	createCollectionMsg := CreateCollectionMsg{}
	dropCollectionMsg := DropCollectionMsg{}
	createPartitionMsg := CreatePartitionMsg{}
	dropPartitionMsg := DropPartitionMsg{}
	dataNodeTtMsg := DataNodeTtMsg{}

	createIndexMsg := CreateIndexMsg{}
	dropIndexMsg := DropIndexMsg{}

	loadCollectionMsg := LoadCollectionMsg{}
	releaseCollectionMsg := ReleaseCollectionMsg{}
	flushMsg := FlushMsg{}
	loadPartitionsMsg := LoadPartitionsMsg{}
	releasePartitionsMsg := ReleasePartitionsMsg{}

	createDatabaseMsg := CreateDatabaseMsg{}
	dropDatabaseMsg := DropDatabaseMsg{}

	p := &ProtoUnmarshalDispatcher{}
	p.TempMap = make(map[commonpb.MsgType]UnmarshalFunc)
	p.TempMap[commonpb.MsgType_Insert] = insertMsg.Unmarshal
	p.TempMap[commonpb.MsgType_Delete] = deleteMsg.Unmarshal
	p.TempMap[commonpb.MsgType_TimeTick] = timeTickMsg.Unmarshal
	p.TempMap[commonpb.MsgType_CreateCollection] = createCollectionMsg.Unmarshal
	p.TempMap[commonpb.MsgType_DropCollection] = dropCollectionMsg.Unmarshal
	p.TempMap[commonpb.MsgType_CreatePartition] = createPartitionMsg.Unmarshal
	p.TempMap[commonpb.MsgType_DropPartition] = dropPartitionMsg.Unmarshal
	p.TempMap[commonpb.MsgType_DataNodeTt] = dataNodeTtMsg.Unmarshal
	p.TempMap[commonpb.MsgType_CreateIndex] = createIndexMsg.Unmarshal
	p.TempMap[commonpb.MsgType_DropIndex] = dropIndexMsg.Unmarshal
	p.TempMap[commonpb.MsgType_LoadCollection] = loadCollectionMsg.Unmarshal
	p.TempMap[commonpb.MsgType_ReleaseCollection] = releaseCollectionMsg.Unmarshal
	p.TempMap[commonpb.MsgType_LoadPartitions] = loadPartitionsMsg.Unmarshal
	p.TempMap[commonpb.MsgType_ReleasePartitions] = releasePartitionsMsg.Unmarshal
	p.TempMap[commonpb.MsgType_Flush] = flushMsg.Unmarshal
	p.TempMap[commonpb.MsgType_CreateDatabase] = createDatabaseMsg.Unmarshal
	p.TempMap[commonpb.MsgType_DropDatabase] = dropDatabaseMsg.Unmarshal

	return p
}

// MemUnmarshalDispatcher ant its factory

//type MemUDFactory struct {
//
//}
//func (mudf *MemUDFactory) NewUnmarshalDispatcher() *UnmarshalDispatcher {
//
//}