// Copyright (C) 2019-2020 Zilliz. All rights reserved.
//
// Licensed 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 querycoord

import (
	"context"
	"errors"
	"fmt"
	"math/rand"
	"path"
	"strconv"
	"sync"

	"github.com/milvus-io/milvus/internal/common"
	"github.com/milvus-io/milvus/internal/kv"
	minioKV "github.com/milvus-io/milvus/internal/kv/minio"
	"github.com/milvus-io/milvus/internal/log"
	"github.com/milvus-io/milvus/internal/proto/commonpb"
	"github.com/milvus-io/milvus/internal/proto/datapb"
	"github.com/milvus-io/milvus/internal/proto/etcdpb"
	"github.com/milvus-io/milvus/internal/proto/indexpb"
	"github.com/milvus-io/milvus/internal/proto/internalpb"
	"github.com/milvus-io/milvus/internal/proto/milvuspb"
	"github.com/milvus-io/milvus/internal/proto/proxypb"
	"github.com/milvus-io/milvus/internal/proto/schemapb"
	"github.com/milvus-io/milvus/internal/storage"
	"github.com/milvus-io/milvus/internal/types"
	"github.com/milvus-io/milvus/internal/util/funcutil"
)

const (
	defaultCollectionID = UniqueID(2021)
	defaultPartitionID  = UniqueID(2021)
	defaultSegmentID    = UniqueID(2021)
	defaultQueryNodeID  = int64(100)
	defaultChannelNum   = 2
)

func genCollectionSchema(collectionID UniqueID, isBinary bool) *schemapb.CollectionSchema {
	var fieldVec schemapb.FieldSchema
	if isBinary {
		fieldVec = schemapb.FieldSchema{
			FieldID:      UniqueID(101),
			Name:         "vec",
			IsPrimaryKey: false,
			DataType:     schemapb.DataType_BinaryVector,
			TypeParams: []*commonpb.KeyValuePair{
				{
					Key:   "dim",
					Value: "128",
				},
			},
			IndexParams: []*commonpb.KeyValuePair{
				{
					Key:   "metric_type",
					Value: "JACCARD",
				},
			},
		}
	} else {
		fieldVec = schemapb.FieldSchema{
			FieldID:      UniqueID(101),
			Name:         "vec",
			IsPrimaryKey: false,
			DataType:     schemapb.DataType_FloatVector,
			TypeParams: []*commonpb.KeyValuePair{
				{
					Key:   "dim",
					Value: "16",
				},
			},
			IndexParams: []*commonpb.KeyValuePair{
				{
					Key:   "metric_type",
					Value: "L2",
				},
			},
		}
	}

	return &schemapb.CollectionSchema{
		AutoID: true,
		Fields: []*schemapb.FieldSchema{
			{FieldID: 0, Name: "row_id", IsPrimaryKey: false, Description: "row_id", DataType: schemapb.DataType_Int64},
			{FieldID: 1, Name: "Ts", IsPrimaryKey: false, Description: "Ts", DataType: schemapb.DataType_Int64},
			{FieldID: 100, Name: "field_age", IsPrimaryKey: false, Description: "int64", DataType: schemapb.DataType_Int64},
			&fieldVec,
		},
	}
}

func genETCDCollectionMeta(collectionID UniqueID, isBinary bool) *etcdpb.CollectionMeta {
	schema := genCollectionSchema(collectionID, isBinary)
	collectionMeta := etcdpb.CollectionMeta{
		ID:           collectionID,
		Schema:       schema,
		CreateTime:   Timestamp(0),
		PartitionIDs: []UniqueID{defaultPartitionID},
	}

	return &collectionMeta
}

func generateInsertBinLog(collectionID UniqueID, partitionID UniqueID, segmentID UniqueID, keyPrefix string, kv kv.BaseKV) (map[int64]string, error) {
	const (
		msgLength = 1000
		DIM       = 16
	)

	idData := make([]int64, 0)
	for n := 0; n < msgLength; n++ {
		idData = append(idData, int64(n))
	}

	var timestamps []int64
	for n := 0; n < msgLength; n++ {
		timestamps = append(timestamps, int64(n+1))
	}

	var fieldAgeData []int64
	for n := 0; n < msgLength; n++ {
		fieldAgeData = append(fieldAgeData, int64(n))
	}

	fieldVecData := make([]float32, 0)
	for n := 0; n < msgLength; n++ {
		for i := 0; i < DIM; i++ {
			fieldVecData = append(fieldVecData, float32(n*i)*0.1)
		}
	}

	insertData := &storage.InsertData{
		Data: map[int64]storage.FieldData{
			0: &storage.Int64FieldData{
				NumRows: []int64{msgLength},
				Data:    idData,
			},
			1: &storage.Int64FieldData{
				NumRows: []int64{msgLength},
				Data:    timestamps,
			},
			100: &storage.Int64FieldData{
				NumRows: []int64{msgLength},
				Data:    fieldAgeData,
			},
			101: &storage.FloatVectorFieldData{
				NumRows: []int64{msgLength},
				Data:    fieldVecData,
				Dim:     DIM,
			},
		},
	}

	// buffer data to binLogs
	collMeta := genETCDCollectionMeta(collectionID, false)
	inCodec := storage.NewInsertCodec(collMeta)
	binLogs, _, err := inCodec.Serialize(partitionID, segmentID, insertData)

	if err != nil {
		log.Debug("insert data serialize error")
		return nil, err
	}

	// binLogs -> minIO/S3
	segIDStr := strconv.FormatInt(segmentID, 10)
	keyPrefix = path.Join(keyPrefix, segIDStr)

	fieldID2Paths := make(map[int64]string)
	for _, blob := range binLogs {
		uid := rand.Int63n(100000000)
		path := path.Join(keyPrefix, blob.Key, strconv.FormatInt(uid, 10))
		err = kv.Save(path, string(blob.Value[:]))
		if err != nil {
			return nil, err
		}
		fieldID, err := strconv.Atoi(blob.Key)
		if err != nil {
			return nil, err
		}
		fieldID2Paths[int64(fieldID)] = path
	}

	return fieldID2Paths, nil
}

type rootCoordMock struct {
	types.RootCoord
	CollectionIDs []UniqueID
	Col2partition map[UniqueID][]UniqueID
	sync.RWMutex
}

func newRootCoordMock() *rootCoordMock {
	collectionIDs := make([]UniqueID, 0)
	col2partition := make(map[UniqueID][]UniqueID)

	return &rootCoordMock{
		CollectionIDs: collectionIDs,
		Col2partition: col2partition,
	}
}

func (rc *rootCoordMock) createCollection(collectionID UniqueID) {
	rc.Lock()
	defer rc.Unlock()

	if _, ok := rc.Col2partition[collectionID]; !ok {
		rc.CollectionIDs = append(rc.CollectionIDs, collectionID)
		partitionIDs := make([]UniqueID, 0)
		partitionIDs = append(partitionIDs, defaultPartitionID+1)
		rc.Col2partition[collectionID] = partitionIDs
	}
}

func (rc *rootCoordMock) createPartition(collectionID UniqueID, partitionID UniqueID) error {
	rc.Lock()
	defer rc.Unlock()

	if partitionIDs, ok := rc.Col2partition[collectionID]; ok {
		partitionExist := false
		for _, id := range partitionIDs {
			if id == partitionID {
				partitionExist = true
				break
			}
		}
		if !partitionExist {
			rc.Col2partition[collectionID] = append(rc.Col2partition[collectionID], partitionID)
		}
		return nil
	}

	return errors.New("collection not exist")
}

func (rc *rootCoordMock) CreatePartition(ctx context.Context, req *milvuspb.CreatePartitionRequest) (*commonpb.Status, error) {
	rc.createPartition(defaultCollectionID, defaultPartitionID)
	return &commonpb.Status{
		ErrorCode: commonpb.ErrorCode_Success,
	}, nil
}

func (rc *rootCoordMock) ShowPartitions(ctx context.Context, in *milvuspb.ShowPartitionsRequest) (*milvuspb.ShowPartitionsResponse, error) {
	collectionID := in.CollectionID
	status := &commonpb.Status{
		ErrorCode: commonpb.ErrorCode_Success,
	}
	if partitionIDs, ok := rc.Col2partition[collectionID]; ok {
		response := &milvuspb.ShowPartitionsResponse{
			Status:       status,
			PartitionIDs: partitionIDs,
		}

		return response, nil
	}

	rc.createCollection(collectionID)

	return &milvuspb.ShowPartitionsResponse{
		Status:       status,
		PartitionIDs: rc.Col2partition[collectionID],
	}, nil
}

func (rc *rootCoordMock) ReleaseDQLMessageStream(ctx context.Context, in *proxypb.ReleaseDQLMessageStreamRequest) (*commonpb.Status, error) {
	return &commonpb.Status{
		ErrorCode: commonpb.ErrorCode_Success,
	}, nil
}

func (rc *rootCoordMock) DescribeSegment(ctx context.Context, req *milvuspb.DescribeSegmentRequest) (*milvuspb.DescribeSegmentResponse, error) {
	return nil, errors.New("describeSegment fail")
}

type dataCoordMock struct {
	types.DataCoord
	minioKV             kv.BaseKV
	collections         []UniqueID
	col2DmChannels      map[UniqueID][]*datapb.VchannelInfo
	partitionID2Segment map[UniqueID][]UniqueID
	Segment2Binlog      map[UniqueID]*datapb.SegmentBinlogs
	baseSegmentID       UniqueID
	channelNumPerCol    int
}

func newDataCoordMock(ctx context.Context) (*dataCoordMock, error) {
	collectionIDs := make([]UniqueID, 0)
	col2DmChannels := make(map[UniqueID][]*datapb.VchannelInfo)
	partitionID2Segments := make(map[UniqueID][]UniqueID)
	segment2Binglog := make(map[UniqueID]*datapb.SegmentBinlogs)

	// create minio client
	option := &minioKV.Option{
		Address:           Params.MinioEndPoint,
		AccessKeyID:       Params.MinioAccessKeyID,
		SecretAccessKeyID: Params.MinioSecretAccessKey,
		UseSSL:            Params.MinioUseSSLStr,
		BucketName:        Params.MinioBucketName,
		CreateBucket:      true,
	}
	kv, err := minioKV.NewMinIOKV(ctx, option)
	if err != nil {
		return nil, err
	}

	return &dataCoordMock{
		minioKV:             kv,
		collections:         collectionIDs,
		col2DmChannels:      col2DmChannels,
		partitionID2Segment: partitionID2Segments,
		Segment2Binlog:      segment2Binglog,
		baseSegmentID:       defaultSegmentID,
		channelNumPerCol:    defaultChannelNum,
	}, nil
}

func (data *dataCoordMock) GetRecoveryInfo(ctx context.Context, req *datapb.GetRecoveryInfoRequest) (*datapb.GetRecoveryInfoResponse, error) {
	collectionID := req.CollectionID
	partitionID := req.PartitionID

	if _, ok := data.partitionID2Segment[partitionID]; !ok {
		segmentIDs := make([]UniqueID, 0)
		for i := 0; i < data.channelNumPerCol; i++ {
			segmentID := data.baseSegmentID
			if _, ok := data.Segment2Binlog[segmentID]; !ok {
				fieldID2Paths, err := generateInsertBinLog(collectionID, partitionID, segmentID, "queryCoorf-mockDataCoord", data.minioKV)
				if err != nil {
					return nil, err
				}
				fieldBinlogs := make([]*datapb.FieldBinlog, 0)
				for fieldID, path := range fieldID2Paths {
					fieldBinlog := &datapb.FieldBinlog{
						FieldID: fieldID,
						Binlogs: []string{path},
					}
					fieldBinlogs = append(fieldBinlogs, fieldBinlog)
				}
				segmentBinlog := &datapb.SegmentBinlogs{
					SegmentID:    segmentID,
					FieldBinlogs: fieldBinlogs,
				}
				data.Segment2Binlog[segmentID] = segmentBinlog
			}
			segmentIDs = append(segmentIDs, segmentID)
			data.baseSegmentID++
		}
		data.partitionID2Segment[partitionID] = segmentIDs
	}

	if _, ok := data.col2DmChannels[collectionID]; !ok {
		channelInfos := make([]*datapb.VchannelInfo, 0)
		data.collections = append(data.collections, collectionID)
		collectionName := funcutil.RandomString(8)
		for i := int32(0); i < common.DefaultShardsNum; i++ {
			vChannel := fmt.Sprintf("%s_%d_%d_v", collectionName, collectionID, i)
			channelInfo := &datapb.VchannelInfo{
				CollectionID: collectionID,
				ChannelName:  vChannel,
				SeekPosition: &internalpb.MsgPosition{
					ChannelName: vChannel,
				},
			}
			channelInfos = append(channelInfos, channelInfo)
		}
		data.col2DmChannels[collectionID] = channelInfos
	}

	binlogs := make([]*datapb.SegmentBinlogs, 0)
	for _, segmentID := range data.partitionID2Segment[partitionID] {
		if _, ok := data.Segment2Binlog[segmentID]; ok {
			binlogs = append(binlogs, data.Segment2Binlog[segmentID])
		}
	}
	return &datapb.GetRecoveryInfoResponse{
		Status: &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_Success,
		},
		Channels: data.col2DmChannels[collectionID],
		Binlogs:  binlogs,
	}, nil
}

type indexCoordMock struct {
	types.IndexCoord
}

func newIndexCoordMock() *indexCoordMock {
	return &indexCoordMock{}
}

func (c *indexCoordMock) GetIndexFilePaths(ctx context.Context, req *indexpb.GetIndexFilePathsRequest) (*indexpb.GetIndexFilePathsResponse, error) {
	return nil, errors.New("get index file path fail")
}