// 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 grpcquerycoord

import (
	"context"
	"io"
	"math"
	"net"
	"strconv"
	"sync"
	"time"

	grpc_opentracing "github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing"
	dsc "github.com/milvus-io/milvus/internal/distributed/datacoord/client"
	rcc "github.com/milvus-io/milvus/internal/distributed/rootcoord/client"
	"github.com/milvus-io/milvus/internal/log"
	"github.com/milvus-io/milvus/internal/msgstream"
	qc "github.com/milvus-io/milvus/internal/querycoord"
	"github.com/milvus-io/milvus/internal/types"
	"github.com/milvus-io/milvus/internal/util/funcutil"
	"github.com/milvus-io/milvus/internal/util/trace"
	"go.uber.org/zap"
	"google.golang.org/grpc"

	"github.com/milvus-io/milvus/internal/proto/commonpb"
	"github.com/milvus-io/milvus/internal/proto/internalpb"
	"github.com/milvus-io/milvus/internal/proto/milvuspb"
	"github.com/milvus-io/milvus/internal/proto/querypb"
)

type Server struct {
	wg         sync.WaitGroup
	loopCtx    context.Context
	loopCancel context.CancelFunc
	grpcServer *grpc.Server

	grpcErrChan chan error

	queryCoord *qc.QueryCoord

	msFactory msgstream.Factory

	dataCoord *dsc.Client
	rootCoord *rcc.GrpcClient

	closer io.Closer
}

func NewServer(ctx context.Context, factory msgstream.Factory) (*Server, error) {
	ctx1, cancel := context.WithCancel(ctx)
	svr, err := qc.NewQueryCoord(ctx1, factory)
	if err != nil {
		cancel()
		return nil, err
	}

	return &Server{
		queryCoord:  svr,
		loopCtx:     ctx1,
		loopCancel:  cancel,
		msFactory:   factory,
		grpcErrChan: make(chan error),
	}, nil
}

func (s *Server) Run() error {

	if err := s.init(); err != nil {
		return err
	}
	log.Debug("QueryCoord init done ...")

	if err := s.start(); err != nil {
		return err
	}
	return nil
}

func (s *Server) init() error {
	Params.Init()
	qc.Params.Init()
	qc.Params.Port = Params.Port

	closer := trace.InitTracing("querycoord")
	s.closer = closer

	if err := s.queryCoord.Register(); err != nil {
		return err
	}

	s.wg.Add(1)
	go s.startGrpcLoop(Params.Port)
	// wait for grpc server loop start
	if err := <-s.grpcErrChan; err != nil {
		return err
	}

	// --- Master Server Client ---
	log.Debug("QueryCoord try to new RootCoord client", zap.Any("RootCoordAddress", Params.RootCoordAddress))
	rootCoord, err := rcc.NewClient(s.loopCtx, qc.Params.MetaRootPath, qc.Params.EtcdEndpoints)
	if err != nil {
		log.Debug("QueryCoord try to new RootCoord client failed", zap.Error(err))
		panic(err)
	}

	if err = rootCoord.Init(); err != nil {
		log.Debug("QueryCoord RootCoordClient Init failed", zap.Error(err))
		panic(err)
	}

	if err = rootCoord.Start(); err != nil {
		log.Debug("QueryCoord RootCoordClient Start failed", zap.Error(err))
		panic(err)
	}
	// wait for master init or healthy
	log.Debug("QueryCoord try to wait for RootCoord ready")
	err = funcutil.WaitForComponentInitOrHealthy(s.loopCtx, rootCoord, "RootCoord", 1000000, time.Millisecond*200)
	if err != nil {
		log.Debug("QueryCoord wait for RootCoord ready failed", zap.Error(err))
		panic(err)
	}

	if err := s.SetRootCoord(rootCoord); err != nil {
		panic(err)
	}
	log.Debug("QueryCoord report RootCoord ready")

	// --- Data service client ---
	log.Debug("QueryCoord try to new DataCoord client", zap.Any("DataCoordAddress", Params.DataCoordAddress))

	dataCoord, err := dsc.NewClient(s.loopCtx, qc.Params.MetaRootPath, qc.Params.EtcdEndpoints)
	if err != nil {
		log.Debug("QueryCoord try to new DataCoord client failed", zap.Error(err))
		panic(err)
	}
	if err = dataCoord.Init(); err != nil {
		log.Debug("QueryCoord DataCoordClient Init failed", zap.Error(err))
		panic(err)
	}
	if err = dataCoord.Start(); err != nil {
		log.Debug("QueryCoord DataCoordClient Start failed", zap.Error(err))
		panic(err)
	}
	log.Debug("QueryCoord try to wait for DataCoord ready")
	err = funcutil.WaitForComponentInitOrHealthy(s.loopCtx, dataCoord, "DataCoord", 1000000, time.Millisecond*200)
	if err != nil {
		log.Debug("QueryCoord wait for DataCoord ready failed", zap.Error(err))
		panic(err)
	}
	if err := s.SetDataCoord(dataCoord); err != nil {
		panic(err)
	}
	log.Debug("QueryCoord report DataCoord ready")

	s.queryCoord.UpdateStateCode(internalpb.StateCode_Initializing)
	log.Debug("QueryCoord", zap.Any("State", internalpb.StateCode_Initializing))
	if err := s.queryCoord.Init(); err != nil {
		return err
	}
	return nil
}

func (s *Server) startGrpcLoop(grpcPort int) {

	defer s.wg.Done()

	log.Debug("network", zap.String("port", strconv.Itoa(grpcPort)))
	lis, err := net.Listen("tcp", ":"+strconv.Itoa(grpcPort))
	if err != nil {
		log.Debug("GrpcServer:failed to listen:", zap.String("error", err.Error()))
		s.grpcErrChan <- err
		return
	}

	ctx, cancel := context.WithCancel(s.loopCtx)
	defer cancel()

	opts := trace.GetInterceptorOpts()
	s.grpcServer = grpc.NewServer(
		grpc.MaxRecvMsgSize(math.MaxInt32),
		grpc.MaxSendMsgSize(math.MaxInt32),
		grpc.UnaryInterceptor(
			grpc_opentracing.UnaryServerInterceptor(opts...)),
		grpc.StreamInterceptor(
			grpc_opentracing.StreamServerInterceptor(opts...)))
	querypb.RegisterQueryCoordServer(s.grpcServer, s)

	go funcutil.CheckGrpcReady(ctx, s.grpcErrChan)
	if err := s.grpcServer.Serve(lis); err != nil {
		s.grpcErrChan <- err
	}
}

func (s *Server) start() error {
	return s.queryCoord.Start()
}

func (s *Server) Stop() error {
	if s.closer != nil {
		if err := s.closer.Close(); err != nil {
			return err
		}
	}
	err := s.queryCoord.Stop()
	s.loopCancel()
	if s.grpcServer != nil {
		s.grpcServer.GracefulStop()
	}
	return err
}

func (s *Server) SetRootCoord(m types.RootCoord) error {
	s.queryCoord.SetRootCoord(m)
	return nil
}

func (s *Server) SetDataCoord(d types.DataCoord) error {
	s.queryCoord.SetDataCoord(d)
	return nil
}

func (s *Server) GetComponentStates(ctx context.Context, req *internalpb.GetComponentStatesRequest) (*internalpb.ComponentStates, error) {
	return s.queryCoord.GetComponentStates(ctx)
}

func (s *Server) GetTimeTickChannel(ctx context.Context, req *internalpb.GetTimeTickChannelRequest) (*milvuspb.StringResponse, error) {
	return s.queryCoord.GetTimeTickChannel(ctx)
}

func (s *Server) GetStatisticsChannel(ctx context.Context, req *internalpb.GetStatisticsChannelRequest) (*milvuspb.StringResponse, error) {
	return s.queryCoord.GetStatisticsChannel(ctx)
}

func (s *Server) ShowCollections(ctx context.Context, req *querypb.ShowCollectionsRequest) (*querypb.ShowCollectionsResponse, error) {
	return s.queryCoord.ShowCollections(ctx, req)
}

func (s *Server) LoadCollection(ctx context.Context, req *querypb.LoadCollectionRequest) (*commonpb.Status, error) {
	return s.queryCoord.LoadCollection(ctx, req)
}

func (s *Server) ReleaseCollection(ctx context.Context, req *querypb.ReleaseCollectionRequest) (*commonpb.Status, error) {
	return s.queryCoord.ReleaseCollection(ctx, req)
}

func (s *Server) ShowPartitions(ctx context.Context, req *querypb.ShowPartitionsRequest) (*querypb.ShowPartitionsResponse, error) {
	return s.queryCoord.ShowPartitions(ctx, req)
}

func (s *Server) GetPartitionStates(ctx context.Context, req *querypb.GetPartitionStatesRequest) (*querypb.GetPartitionStatesResponse, error) {
	return s.queryCoord.GetPartitionStates(ctx, req)
}

func (s *Server) LoadPartitions(ctx context.Context, req *querypb.LoadPartitionsRequest) (*commonpb.Status, error) {
	return s.queryCoord.LoadPartitions(ctx, req)
}

func (s *Server) ReleasePartitions(ctx context.Context, req *querypb.ReleasePartitionsRequest) (*commonpb.Status, error) {
	return s.queryCoord.ReleasePartitions(ctx, req)
}

func (s *Server) CreateQueryChannel(ctx context.Context, req *querypb.CreateQueryChannelRequest) (*querypb.CreateQueryChannelResponse, error) {
	return s.queryCoord.CreateQueryChannel(ctx, req)
}

func (s *Server) GetSegmentInfo(ctx context.Context, req *querypb.GetSegmentInfoRequest) (*querypb.GetSegmentInfoResponse, error) {
	return s.queryCoord.GetSegmentInfo(ctx, req)
}