package querynode

import (
	"errors"

	"github.com/zilliztech/milvus-distributed/internal/msgstream"
	"github.com/zilliztech/milvus-distributed/internal/proto/commonpb"
	queryPb "github.com/zilliztech/milvus-distributed/internal/proto/querypb"
)

func (node *QueryNode) AddQueryChannel(in *queryPb.AddQueryChannelsRequest) (*commonpb.Status, error) {
	if node.searchService == nil || node.searchService.searchMsgStream == nil {
		errMsg := "null search service or null search message stream"
		status := &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
			Reason:    errMsg,
		}

		return status, errors.New(errMsg)
	}

	searchStream, ok := node.searchService.searchMsgStream.(*msgstream.PulsarMsgStream)
	if !ok {
		errMsg := "type assertion failed for search message stream"
		status := &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
			Reason:    errMsg,
		}

		return status, errors.New(errMsg)
	}

	resultStream, ok := node.searchService.searchResultMsgStream.(*msgstream.PulsarMsgStream)
	if !ok {
		errMsg := "type assertion failed for search result message stream"
		status := &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
			Reason:    errMsg,
		}

		return status, errors.New(errMsg)
	}

	// add request channel
	pulsarBufSize := Params.SearchPulsarBufSize
	consumeChannels := []string{in.RequestChannelID}
	consumeSubName := Params.MsgChannelSubName
	unmarshalDispatcher := msgstream.NewUnmarshalDispatcher()
	searchStream.CreatePulsarConsumers(consumeChannels, consumeSubName, unmarshalDispatcher, pulsarBufSize)

	// add result channel
	producerChannels := []string{in.ResultChannelID}
	resultStream.CreatePulsarProducers(producerChannels)

	status := &commonpb.Status{
		ErrorCode: commonpb.ErrorCode_SUCCESS,
	}
	return status, nil
}

func (node *QueryNode) RemoveQueryChannel(in *queryPb.RemoveQueryChannelsRequest) (*commonpb.Status, error) {
	if node.searchService == nil || node.searchService.searchMsgStream == nil {
		errMsg := "null search service or null search result message stream"
		status := &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
			Reason:    errMsg,
		}

		return status, errors.New(errMsg)
	}

	searchStream, ok := node.searchService.searchMsgStream.(*msgstream.PulsarMsgStream)
	if !ok {
		errMsg := "type assertion failed for search message stream"
		status := &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
			Reason:    errMsg,
		}

		return status, errors.New(errMsg)
	}

	resultStream, ok := node.searchService.searchResultMsgStream.(*msgstream.PulsarMsgStream)
	if !ok {
		errMsg := "type assertion failed for search result message stream"
		status := &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
			Reason:    errMsg,
		}

		return status, errors.New(errMsg)
	}

	// remove request channel
	pulsarBufSize := Params.SearchPulsarBufSize
	consumeChannels := []string{in.RequestChannelID}
	consumeSubName := Params.MsgChannelSubName
	unmarshalDispatcher := msgstream.NewUnmarshalDispatcher()
	// TODO: searchStream.RemovePulsarConsumers(producerChannels)
	searchStream.CreatePulsarConsumers(consumeChannels, consumeSubName, unmarshalDispatcher, pulsarBufSize)

	// remove result channel
	producerChannels := []string{in.ResultChannelID}
	// TODO: resultStream.RemovePulsarProducer(producerChannels)
	resultStream.CreatePulsarProducers(producerChannels)

	status := &commonpb.Status{
		ErrorCode: commonpb.ErrorCode_SUCCESS,
	}
	return status, nil
}

func (node *QueryNode) WatchDmChannels(in *queryPb.WatchDmChannelsRequest) (*commonpb.Status, error) {
	if node.dataSyncService == nil || node.dataSyncService.dmStream == nil {
		errMsg := "null data sync service or null data manipulation stream"
		status := &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
			Reason:    errMsg,
		}

		return status, errors.New(errMsg)
	}

	fgDMMsgStream, ok := node.dataSyncService.dmStream.(*msgstream.PulsarMsgStream)
	if !ok {
		errMsg := "type assertion failed for dm message stream"
		status := &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
			Reason:    errMsg,
		}

		return status, errors.New(errMsg)
	}

	// add request channel
	pulsarBufSize := Params.SearchPulsarBufSize
	consumeChannels := in.ChannelIDs
	consumeSubName := Params.MsgChannelSubName
	unmarshalDispatcher := msgstream.NewUnmarshalDispatcher()
	fgDMMsgStream.CreatePulsarConsumers(consumeChannels, consumeSubName, unmarshalDispatcher, pulsarBufSize)

	status := &commonpb.Status{
		ErrorCode: commonpb.ErrorCode_SUCCESS,
	}
	return status, nil
}

func (node *QueryNode) LoadSegments(in *queryPb.LoadSegmentRequest) (*commonpb.Status, error) {
	// TODO: support db
	fieldIDs := in.FieldIDs
	for _, segmentID := range in.SegmentIDs {
		indexID := UniqueID(0) // TODO: ???
		err := node.segManager.loadSegment(segmentID, &fieldIDs)
		if err != nil {
			// TODO: return or continue?
			status := &commonpb.Status{
				ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
				Reason:    err.Error(),
			}
			return status, err
		}
		err = node.segManager.loadIndex(segmentID, indexID)
		if err != nil {
			// TODO: return or continue?
			status := &commonpb.Status{
				ErrorCode: commonpb.ErrorCode_UNEXPECTED_ERROR,
				Reason:    err.Error(),
			}
			return status, err
		}
	}

	return nil, nil
}

func (node *QueryNode) ReleaseSegments(in *queryPb.ReleaseSegmentRequest) (*commonpb.Status, error) {
	// TODO: implement
	return nil, nil
}

func (node *QueryNode) GetPartitionState(in *queryPb.PartitionStatesRequest) (*queryPb.PartitionStatesResponse, error) {
	// TODO: implement
	return nil, nil
}