package abciclient

import (
	"context"
	"errors"
	"fmt"
	"net"
	"sync"
	"time"

	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"

	"github.com/tendermint/tendermint/abci/types"
	"github.com/tendermint/tendermint/libs/log"
	tmnet "github.com/tendermint/tendermint/libs/net"
	"github.com/tendermint/tendermint/libs/service"
)

// A gRPC client.
type grpcClient struct {
	service.BaseService
	logger log.Logger

	mustConnect bool

	client types.ABCIApplicationClient
	conn   *grpc.ClientConn

	mtx  sync.Mutex
	addr string
	err  error
}

var _ Client = (*grpcClient)(nil)

// NewGRPCClient creates a gRPC client, which will connect to addr upon the
// start. Note Client#Start returns an error if connection is unsuccessful and
// mustConnect is true.
func NewGRPCClient(logger log.Logger, addr string, mustConnect bool) Client {
	cli := &grpcClient{
		logger:      logger,
		addr:        addr,
		mustConnect: mustConnect,
	}
	cli.BaseService = *service.NewBaseService(logger, "grpcClient", cli)
	return cli
}

func dialerFunc(ctx context.Context, addr string) (net.Conn, error) {
	return tmnet.Connect(addr)
}

func (cli *grpcClient) OnStart(ctx context.Context) error {
RETRY_LOOP:
	for {
		conn, err := grpc.Dial(cli.addr,
			grpc.WithTransportCredentials(insecure.NewCredentials()),
			grpc.WithContextDialer(dialerFunc),
		)
		if err != nil {
			if cli.mustConnect {
				return err
			}
			cli.logger.Error(fmt.Sprintf("abci.grpcClient failed to connect to %v.  Retrying...\n", cli.addr), "err", err)
			time.Sleep(time.Second * dialRetryIntervalSeconds)
			continue RETRY_LOOP
		}

		cli.logger.Info("Dialed server. Waiting for echo.", "addr", cli.addr)
		client := types.NewABCIApplicationClient(conn)
		cli.conn = conn

	ENSURE_CONNECTED:
		for {
			_, err := client.Echo(ctx, &types.RequestEcho{Message: "hello"}, grpc.WaitForReady(true))
			if err == nil {
				break ENSURE_CONNECTED
			}
			if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) {
				return err
			}

			cli.logger.Error("Echo failed", "err", err)
			time.Sleep(time.Second * echoRetryIntervalSeconds)
		}

		cli.client = client
		return nil
	}
}

func (cli *grpcClient) OnStop() {
	cli.mtx.Lock()
	defer cli.mtx.Unlock()

	if cli.conn != nil {
		cli.err = cli.conn.Close()
	}
}

func (cli *grpcClient) Error() error {
	cli.mtx.Lock()
	defer cli.mtx.Unlock()

	return cli.err
}

//----------------------------------------

func (cli *grpcClient) Flush(ctx context.Context) error { return nil }

func (cli *grpcClient) Echo(ctx context.Context, msg string) (*types.ResponseEcho, error) {
	return cli.client.Echo(ctx, types.ToRequestEcho(msg).GetEcho(), grpc.WaitForReady(true))
}

func (cli *grpcClient) Info(ctx context.Context, params types.RequestInfo) (*types.ResponseInfo, error) {
	return cli.client.Info(ctx, types.ToRequestInfo(params).GetInfo(), grpc.WaitForReady(true))
}

func (cli *grpcClient) CheckTx(ctx context.Context, params types.RequestCheckTx) (*types.ResponseCheckTx, error) {
	return cli.client.CheckTx(ctx, types.ToRequestCheckTx(params).GetCheckTx(), grpc.WaitForReady(true))
}

func (cli *grpcClient) Query(ctx context.Context, params types.RequestQuery) (*types.ResponseQuery, error) {
	return cli.client.Query(ctx, types.ToRequestQuery(params).GetQuery(), grpc.WaitForReady(true))
}

func (cli *grpcClient) Commit(ctx context.Context) (*types.ResponseCommit, error) {
	return cli.client.Commit(ctx, types.ToRequestCommit().GetCommit(), grpc.WaitForReady(true))
}

func (cli *grpcClient) InitChain(ctx context.Context, params types.RequestInitChain) (*types.ResponseInitChain, error) {
	return cli.client.InitChain(ctx, types.ToRequestInitChain(params).GetInitChain(), grpc.WaitForReady(true))
}

func (cli *grpcClient) ListSnapshots(ctx context.Context, params types.RequestListSnapshots) (*types.ResponseListSnapshots, error) {
	return cli.client.ListSnapshots(ctx, types.ToRequestListSnapshots(params).GetListSnapshots(), grpc.WaitForReady(true))
}

func (cli *grpcClient) OfferSnapshot(ctx context.Context, params types.RequestOfferSnapshot) (*types.ResponseOfferSnapshot, error) {
	return cli.client.OfferSnapshot(ctx, types.ToRequestOfferSnapshot(params).GetOfferSnapshot(), grpc.WaitForReady(true))
}

func (cli *grpcClient) LoadSnapshotChunk(ctx context.Context, params types.RequestLoadSnapshotChunk) (*types.ResponseLoadSnapshotChunk, error) {
	return cli.client.LoadSnapshotChunk(ctx, types.ToRequestLoadSnapshotChunk(params).GetLoadSnapshotChunk(), grpc.WaitForReady(true))
}

func (cli *grpcClient) ApplySnapshotChunk(ctx context.Context, params types.RequestApplySnapshotChunk) (*types.ResponseApplySnapshotChunk, error) {
	return cli.client.ApplySnapshotChunk(ctx, types.ToRequestApplySnapshotChunk(params).GetApplySnapshotChunk(), grpc.WaitForReady(true))
}

func (cli *grpcClient) PrepareProposal(ctx context.Context, params types.RequestPrepareProposal) (*types.ResponsePrepareProposal, error) {
	return cli.client.PrepareProposal(ctx, types.ToRequestPrepareProposal(params).GetPrepareProposal(), grpc.WaitForReady(true))
}

func (cli *grpcClient) ProcessProposal(ctx context.Context, params types.RequestProcessProposal) (*types.ResponseProcessProposal, error) {
	return cli.client.ProcessProposal(ctx, types.ToRequestProcessProposal(params).GetProcessProposal(), grpc.WaitForReady(true))
}

func (cli *grpcClient) ExtendVote(ctx context.Context, params types.RequestExtendVote) (*types.ResponseExtendVote, error) {
	return cli.client.ExtendVote(ctx, types.ToRequestExtendVote(params).GetExtendVote(), grpc.WaitForReady(true))
}

func (cli *grpcClient) VerifyVoteExtension(ctx context.Context, params types.RequestVerifyVoteExtension) (*types.ResponseVerifyVoteExtension, error) {
	return cli.client.VerifyVoteExtension(ctx, types.ToRequestVerifyVoteExtension(params).GetVerifyVoteExtension(), grpc.WaitForReady(true))
}

func (cli *grpcClient) FinalizeBlock(ctx context.Context, params types.RequestFinalizeBlock) (*types.ResponseFinalizeBlock, error) {
	return cli.client.FinalizeBlock(ctx, types.ToRequestFinalizeBlock(params).GetFinalizeBlock(), grpc.WaitForReady(true))
}