// 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 datanode

import (
	"bytes"
	"context"
	"encoding/binary"
	"math"
	"math/rand"
	"path"
	"strconv"
	"sync"
	"time"

	"go.etcd.io/etcd/clientv3"
	"go.uber.org/zap"

	etcdkv "github.com/milvus-io/milvus/internal/kv/etcd"
	"github.com/milvus-io/milvus/internal/log"
	"github.com/milvus-io/milvus/internal/msgstream"
	"github.com/milvus-io/milvus/internal/types"

	"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/internalpb"
	"github.com/milvus-io/milvus/internal/proto/masterpb"
	"github.com/milvus-io/milvus/internal/proto/milvuspb"
	"github.com/milvus-io/milvus/internal/proto/schemapb"
)

const ctxTimeInMillisecond = 5000
const debug = false

func newIDLEDataNodeMock() *DataNode {
	var ctx context.Context

	if debug {
		ctx = context.Background()
	} else {
		var cancel context.CancelFunc
		d := time.Now().Add(ctxTimeInMillisecond * time.Millisecond)
		ctx, cancel = context.WithDeadline(context.Background(), d)
		go func() {
			<-ctx.Done()
			cancel()
		}()
	}

	msFactory := msgstream.NewPmsFactory()
	node := NewDataNode(ctx, msFactory)

	ms := &MasterServiceFactory{
		ID:             0,
		collectionID:   1,
		collectionName: "collection-1",
	}

	node.SetMasterServiceInterface(ms)

	ds := &DataServiceFactory{}
	node.SetDataServiceInterface(ds)

	return node
}

func newHEALTHDataNodeMock(dmChannelName, ddChannelName string) *DataNode {
	var ctx context.Context

	if debug {
		ctx = context.Background()
	} else {
		var cancel context.CancelFunc
		d := time.Now().Add(ctxTimeInMillisecond * time.Millisecond)
		ctx, cancel = context.WithDeadline(context.Background(), d)
		go func() {
			<-ctx.Done()
			cancel()
		}()
	}

	msFactory := msgstream.NewPmsFactory()
	node := NewDataNode(ctx, msFactory)

	ms := &MasterServiceFactory{
		ID:             0,
		collectionID:   1,
		collectionName: "collection-1",
	}

	node.SetMasterServiceInterface(ms)

	ds := &DataServiceFactory{}
	node.SetDataServiceInterface(ds)

	vpair := &datapb.VchannelPair{
		CollectionID:    1,
		DmlVchannelName: dmChannelName,
		DdlVchannelName: ddChannelName,
		DdlPosition:     &datapb.PositionPair{},
		DmlPosition:     &datapb.PositionPair{},
	}

	_ = node.NewDataSyncService(vpair)

	return node
}

func makeNewChannelNames(names []string, suffix string) []string {
	var ret []string
	for _, name := range names {
		ret = append(ret, name+suffix)
	}
	return ret
}

func refreshChannelNames() {
	Params.DDChannelNames = []string{"datanode-test"}
	Params.SegmentStatisticsChannelName = "segment-statistics"
	Params.CompleteFlushChannelName = "flush-completed"
	Params.InsertChannelNames = []string{"intsert-a-1", "insert-b-1"}
	Params.TimeTickChannelName = "hard-timetick"
	suffix := "-test-data-node" + strconv.FormatInt(rand.Int63n(100), 10)
	Params.DDChannelNames = makeNewChannelNames(Params.DDChannelNames, suffix)
	Params.InsertChannelNames = makeNewChannelNames(Params.InsertChannelNames, suffix)
}

func clearEtcd(rootPath string) error {
	etcdAddr := Params.EtcdAddress
	log.Info("etcd tests address", zap.String("address", etcdAddr))
	etcdClient, err := clientv3.New(clientv3.Config{Endpoints: []string{etcdAddr}})
	if err != nil {
		return err
	}
	etcdKV := etcdkv.NewEtcdKV(etcdClient, rootPath)

	err = etcdKV.RemoveWithPrefix("writer/segment")
	if err != nil {
		return err
	}
	_, _, err = etcdKV.LoadWithPrefix("writer/segment")
	if err != nil {
		return err
	}
	log.Debug("Clear ETCD with prefix writer/segment ")

	err = etcdKV.RemoveWithPrefix("writer/ddl")
	if err != nil {
		return err
	}
	_, _, err = etcdKV.LoadWithPrefix("writer/ddl")
	if err != nil {
		return err
	}
	log.Debug("Clear ETCD with prefix writer/ddl")
	return nil

}

type MetaFactory struct {
}

type DataFactory struct {
	rawData []byte
}

type MasterServiceFactory struct {
	types.MasterService
	ID             UniqueID
	collectionName string
	collectionID   UniqueID
}

type DataServiceFactory struct {
	types.DataService
}

func (ds *DataServiceFactory) SaveBinlogPaths(ctx context.Context, req *datapb.SaveBinlogPathsRequest) (*commonpb.Status, error) {
	return &commonpb.Status{ErrorCode: commonpb.ErrorCode_Success}, nil
}

func (ds *DataServiceFactory) RegisterNode(ctx context.Context, req *datapb.RegisterNodeRequest) (*datapb.RegisterNodeResponse, error) {
	ret := &datapb.RegisterNodeResponse{Status: &commonpb.Status{
		ErrorCode: commonpb.ErrorCode_Success}}

	ret.InitParams = &internalpb.InitParams{
		NodeID: Params.NodeID,
		StartParams: []*commonpb.KeyValuePair{
			{Key: "DDChannelName", Value: "fake-dd-channel-name"},
			{Key: "SegmentStatisticsChannelName", Value: "fake-segment-statistics-channel-name"},
			{Key: "TimeTickChannelName", Value: "fake-time-tick-channel-name"},
			{Key: "CompleteFlushChannelName", Value: "fake-complete-flush-name"},
		},
	}

	return ret, nil
}

func (mf *MetaFactory) CollectionMetaFactory(collectionID UniqueID, collectionName string) *etcdpb.CollectionMeta {
	sch := schemapb.CollectionSchema{
		Name:        collectionName,
		Description: "test collection by meta factory",
		AutoID:      true,
		Fields: []*schemapb.FieldSchema{
			{
				FieldID:     0,
				Name:        "RowID",
				Description: "RowID field",
				DataType:    schemapb.DataType_Int64,
				TypeParams: []*commonpb.KeyValuePair{
					{
						Key:   "f0_tk1",
						Value: "f0_tv1",
					},
				},
			},
			{
				FieldID:     1,
				Name:        "Timestamp",
				Description: "Timestamp field",
				DataType:    schemapb.DataType_Int64,
				TypeParams: []*commonpb.KeyValuePair{
					{
						Key:   "f1_tk1",
						Value: "f1_tv1",
					},
				},
			},
			{
				FieldID:     100,
				Name:        "float_vector_field",
				Description: "field 100",
				DataType:    schemapb.DataType_FloatVector,
				TypeParams: []*commonpb.KeyValuePair{
					{
						Key:   "dim",
						Value: "2",
					},
				},
				IndexParams: []*commonpb.KeyValuePair{
					{
						Key:   "indexkey",
						Value: "indexvalue",
					},
				},
			},
			{
				FieldID:     101,
				Name:        "binary_vector_field",
				Description: "field 101",
				DataType:    schemapb.DataType_BinaryVector,
				TypeParams: []*commonpb.KeyValuePair{
					{
						Key:   "dim",
						Value: "32",
					},
				},
				IndexParams: []*commonpb.KeyValuePair{
					{
						Key:   "indexkey",
						Value: "indexvalue",
					},
				},
			},
			{
				FieldID:     102,
				Name:        "bool_field",
				Description: "field 102",
				DataType:    schemapb.DataType_Bool,
				TypeParams:  []*commonpb.KeyValuePair{},
				IndexParams: []*commonpb.KeyValuePair{},
			},
			{
				FieldID:     103,
				Name:        "int8_field",
				Description: "field 103",
				DataType:    schemapb.DataType_Int8,
				TypeParams:  []*commonpb.KeyValuePair{},
				IndexParams: []*commonpb.KeyValuePair{},
			},
			{
				FieldID:     104,
				Name:        "int16_field",
				Description: "field 104",
				DataType:    schemapb.DataType_Int16,
				TypeParams:  []*commonpb.KeyValuePair{},
				IndexParams: []*commonpb.KeyValuePair{},
			},
			{
				FieldID:     105,
				Name:        "int32_field",
				Description: "field 105",
				DataType:    schemapb.DataType_Int32,
				TypeParams:  []*commonpb.KeyValuePair{},
				IndexParams: []*commonpb.KeyValuePair{},
			},
			{
				FieldID:     106,
				Name:        "int64_field",
				Description: "field 106",
				DataType:    schemapb.DataType_Int64,
				TypeParams:  []*commonpb.KeyValuePair{},
				IndexParams: []*commonpb.KeyValuePair{},
			},
			{
				FieldID:     107,
				Name:        "float32_field",
				Description: "field 107",
				DataType:    schemapb.DataType_Float,
				TypeParams:  []*commonpb.KeyValuePair{},
				IndexParams: []*commonpb.KeyValuePair{},
			},
			{
				FieldID:     108,
				Name:        "float64_field",
				Description: "field 108",
				DataType:    schemapb.DataType_Double,
				TypeParams:  []*commonpb.KeyValuePair{},
				IndexParams: []*commonpb.KeyValuePair{},
			},
		},
	}

	collection := etcdpb.CollectionMeta{
		ID:           collectionID,
		Schema:       &sch,
		CreateTime:   Timestamp(1),
		SegmentIDs:   make([]UniqueID, 0),
		PartitionIDs: []UniqueID{0},
	}
	return &collection
}

func NewDataFactory() *DataFactory {
	return &DataFactory{rawData: GenRowData()}
}

func GenRowData() (rawData []byte) {
	const DIM = 2
	const N = 1

	// Float vector
	var fvector = [DIM]float32{1, 2}
	for _, ele := range fvector {
		buf := make([]byte, 4)
		binary.LittleEndian.PutUint32(buf, math.Float32bits(ele))
		rawData = append(rawData, buf...)
	}

	// Binary vector
	// Dimension of binary vector is 32
	// size := 4,  = 32 / 8
	var bvector = []byte{255, 255, 255, 0}
	rawData = append(rawData, bvector...)

	// Bool
	var fieldBool = true
	buf := new(bytes.Buffer)
	if err := binary.Write(buf, binary.LittleEndian, fieldBool); err != nil {
		panic(err)
	}

	rawData = append(rawData, buf.Bytes()...)

	// int8
	var dataInt8 int8 = 100
	bint8 := new(bytes.Buffer)
	if err := binary.Write(bint8, binary.LittleEndian, dataInt8); err != nil {
		panic(err)
	}
	rawData = append(rawData, bint8.Bytes()...)

	// int16
	var dataInt16 int16 = 200
	bint16 := new(bytes.Buffer)
	if err := binary.Write(bint16, binary.LittleEndian, dataInt16); err != nil {
		panic(err)
	}
	rawData = append(rawData, bint16.Bytes()...)

	// int32
	var dataInt32 int32 = 300
	bint32 := new(bytes.Buffer)
	if err := binary.Write(bint32, binary.LittleEndian, dataInt32); err != nil {
		panic(err)
	}
	rawData = append(rawData, bint32.Bytes()...)

	// int64
	var dataInt64 int64 = 400
	bint64 := new(bytes.Buffer)
	if err := binary.Write(bint64, binary.LittleEndian, dataInt64); err != nil {
		panic(err)
	}
	rawData = append(rawData, bint64.Bytes()...)

	// float32
	var datafloat float32 = 1.1
	bfloat32 := new(bytes.Buffer)
	if err := binary.Write(bfloat32, binary.LittleEndian, datafloat); err != nil {
		panic(err)
	}
	rawData = append(rawData, bfloat32.Bytes()...)

	// float64
	var datafloat64 = 2.2
	bfloat64 := new(bytes.Buffer)
	if err := binary.Write(bfloat64, binary.LittleEndian, datafloat64); err != nil {
		panic(err)
	}
	rawData = append(rawData, bfloat64.Bytes()...)
	log.Debug("Rawdata length:", zap.Int("Length of rawData", len(rawData)))
	return
}

func (df *DataFactory) GenMsgStreamInsertMsg(idx int, chanName string) *msgstream.InsertMsg {
	var msg = &msgstream.InsertMsg{
		BaseMsg: msgstream.BaseMsg{
			HashValues: []uint32{uint32(idx)},
		},
		InsertRequest: internalpb.InsertRequest{
			Base: &commonpb.MsgBase{
				MsgType:   commonpb.MsgType_Insert,
				MsgID:     0,
				Timestamp: Timestamp(idx + 1000),
				SourceID:  0,
			},
			CollectionName: "col1",
			PartitionName:  "default",
			SegmentID:      1,
			ChannelID:      chanName,
			Timestamps:     []Timestamp{Timestamp(idx + 1000)},
			RowIDs:         []UniqueID{UniqueID(idx)},
			RowData:        []*commonpb.Blob{{Value: df.rawData}},
		},
	}
	return msg
}

func (df *DataFactory) GetMsgStreamTsInsertMsgs(n int, chanName string) (inMsgs []msgstream.TsMsg) {
	for i := 0; i < n; i++ {
		var msg = df.GenMsgStreamInsertMsg(i, chanName)
		var tsMsg msgstream.TsMsg = msg
		inMsgs = append(inMsgs, tsMsg)
	}
	return
}

func (df *DataFactory) GetMsgStreamInsertMsgs(n int) (inMsgs []*msgstream.InsertMsg) {
	for i := 0; i < n; i++ {
		var msg = df.GenMsgStreamInsertMsg(i, "")
		inMsgs = append(inMsgs, msg)
	}
	return
}

type AllocatorFactory struct {
	sync.Mutex
	r *rand.Rand
}

var _ allocatorInterface = &AllocatorFactory{}

func NewAllocatorFactory(id ...UniqueID) *AllocatorFactory {
	f := &AllocatorFactory{
		r: rand.New(rand.NewSource(time.Now().UnixNano())),
	}

	return f
}

func (alloc *AllocatorFactory) allocID() (UniqueID, error) {
	alloc.Lock()
	defer alloc.Unlock()
	return alloc.r.Int63n(10000), nil
}

func (alloc *AllocatorFactory) genKey(isalloc bool, ids ...UniqueID) (key string, err error) {
	if isalloc {
		idx, err := alloc.allocID()
		if err != nil {
			return "", err
		}
		ids = append(ids, idx)
	}

	idStr := make([]string, len(ids))
	for _, id := range ids {
		idStr = append(idStr, strconv.FormatInt(id, 10))
	}

	key = path.Join(idStr...)
	return
}

func (m *MasterServiceFactory) setID(id UniqueID) {
	m.ID = id // GOOSE TODO: random ID generator
}

func (m *MasterServiceFactory) setCollectionID(id UniqueID) {
	m.collectionID = id
}

func (m *MasterServiceFactory) setCollectionName(name string) {
	m.collectionName = name
}

func (m *MasterServiceFactory) AllocID(ctx context.Context, in *masterpb.AllocIDRequest) (*masterpb.AllocIDResponse, error) {
	resp := &masterpb.AllocIDResponse{
		Status: &commonpb.Status{},
		ID:     m.ID,
	}
	return resp, nil
}

func (m *MasterServiceFactory) ShowCollections(ctx context.Context, in *milvuspb.ShowCollectionsRequest) (*milvuspb.ShowCollectionsResponse, error) {
	resp := &milvuspb.ShowCollectionsResponse{
		Status:          &commonpb.Status{},
		CollectionNames: []string{m.collectionName},
	}
	return resp, nil

}

func (m *MasterServiceFactory) DescribeCollection(ctx context.Context, in *milvuspb.DescribeCollectionRequest) (*milvuspb.DescribeCollectionResponse, error) {
	f := MetaFactory{}
	meta := f.CollectionMetaFactory(m.collectionID, m.collectionName)
	resp := &milvuspb.DescribeCollectionResponse{
		Status:       &commonpb.Status{},
		CollectionID: m.collectionID,
		Schema:       meta.Schema,
	}
	return resp, nil
}

func (m *MasterServiceFactory) GetComponentStates(ctx context.Context) (*internalpb.ComponentStates, error) {
	return &internalpb.ComponentStates{
		State:              &internalpb.ComponentInfo{},
		SubcomponentStates: make([]*internalpb.ComponentInfo, 0),
		Status: &commonpb.Status{
			ErrorCode: commonpb.ErrorCode_Success,
		},
	}, nil
}