package grpc

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

	pb "github.com/mudler/LocalAI/pkg/grpc/proto"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
)

const maxGRPCMessageSize = 50 * 1024 * 1024 // 50MB

// bearerToken implements credentials.PerRPCCredentials to inject a bearer token
// into every gRPC call.
type bearerToken struct {
	token string
}

func (b bearerToken) GetRequestMetadata(ctx context.Context, uri ...string) (map[string]string, error) {
	return map[string]string{"authorization": "Bearer " + b.token}, nil
}

func (b bearerToken) RequireTransportSecurity() bool { return false }

type Client struct {
	address  string
	busy     bool
	parallel bool
	token    string
	sync.Mutex
	opMutex sync.Mutex
	wd      WatchDog
}

type WatchDog interface {
	Mark(address string)
	UnMark(address string)
}

func (c *Client) IsBusy() bool {
	c.Lock()
	defer c.Unlock()
	return c.busy
}

func (c *Client) setBusy(v bool) {
	c.Lock()
	c.busy = v
	c.Unlock()
}

func (c *Client) wdMark() {
	if c.wd != nil {
		c.wd.Mark(c.address)
	}
}

func (c *Client) wdUnMark() {
	if c.wd != nil {
		c.wd.UnMark(c.address)
	}
}

// dial creates a gRPC client connection with common options.
// If c.token is set, bearer token credentials are included.
func (c *Client) dial() (*grpc.ClientConn, error) {
	opts := []grpc.DialOption{
		grpc.WithTransportCredentials(insecure.NewCredentials()),
		grpc.WithDefaultCallOptions(
			grpc.MaxCallRecvMsgSize(maxGRPCMessageSize),
			grpc.MaxCallSendMsgSize(maxGRPCMessageSize),
		),
	}
	if c.token != "" {
		opts = append(opts, grpc.WithPerRPCCredentials(bearerToken{token: c.token}))
	}
	return grpc.NewClient(c.address, opts...)
}

func (c *Client) HealthCheck(ctx context.Context) (bool, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	conn, err := c.dial()
	if err != nil {
		return false, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)

	// The healthcheck call shouldn't take long time
	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
	defer cancel()

	res, err := client.Health(ctx, &pb.HealthMessage{})
	if err != nil {
		return false, err
	}

	if string(res.Message) == "OK" {
		return true, nil
	}

	return false, fmt.Errorf("health check failed: %s", res.Message)
}

func (c *Client) Embeddings(ctx context.Context, in *pb.PredictOptions, opts ...grpc.CallOption) (*pb.EmbeddingResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)

	return client.Embedding(ctx, in, opts...)
}

func (c *Client) Predict(ctx context.Context, in *pb.PredictOptions, opts ...grpc.CallOption) (*pb.Reply, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)

	return client.Predict(ctx, in, opts...)
}

func (c *Client) LoadModel(ctx context.Context, in *pb.ModelOptions, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.LoadModel(ctx, in, opts...)
}

func (c *Client) PredictStream(ctx context.Context, in *pb.PredictOptions, f func(reply *pb.Reply), opts ...grpc.CallOption) error {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)

	stream, err := client.PredictStream(ctx, in, opts...)
	if err != nil {
		return err
	}

	for {
		// Check if context is cancelled before receiving
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		reply, err := stream.Recv()
		if errors.Is(err, io.EOF) {
			break
		}
		if err != nil {
			// Check if error is due to context cancellation
			if ctx.Err() != nil {
				return ctx.Err()
			}
			fmt.Println("Error", err)

			return err
		}
		f(reply)
	}

	return nil
}

func (c *Client) GenerateImage(ctx context.Context, in *pb.GenerateImageRequest, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.GenerateImage(ctx, in, opts...)
}

func (c *Client) GenerateVideo(ctx context.Context, in *pb.GenerateVideoRequest, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.GenerateVideo(ctx, in, opts...)
}

func (c *Client) TTS(ctx context.Context, in *pb.TTSRequest, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.TTS(ctx, in, opts...)
}

func (c *Client) TTSStream(ctx context.Context, in *pb.TTSRequest, f func(reply *pb.Reply), opts ...grpc.CallOption) error {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)

	stream, err := client.TTSStream(ctx, in, opts...)
	if err != nil {
		return err
	}

	for {
		// Check if context is cancelled before receiving
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		reply, err := stream.Recv()
		if errors.Is(err, io.EOF) {
			break
		}
		if err != nil {
			// Check if error is due to context cancellation
			if ctx.Err() != nil {
				return ctx.Err()
			}
			return err
		}
		f(reply)
	}

	return nil
}

func (c *Client) SoundGeneration(ctx context.Context, in *pb.SoundGenerationRequest, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.SoundGeneration(ctx, in, opts...)
}

func (c *Client) AudioTranscription(ctx context.Context, in *pb.TranscriptRequest, opts ...grpc.CallOption) (*pb.TranscriptResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.AudioTranscription(ctx, in, opts...)
}

func (c *Client) TokenizeString(ctx context.Context, in *pb.PredictOptions, opts ...grpc.CallOption) (*pb.TokenizationResponse, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)

	res, err := client.TokenizeString(ctx, in, opts...)

	if err != nil {
		return nil, err
	}
	return res, nil
}

func (c *Client) Status(ctx context.Context) (*pb.StatusResponse, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.Status(ctx, &pb.HealthMessage{})
}

func (c *Client) StoresSet(ctx context.Context, in *pb.StoresSetOptions, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.StoresSet(ctx, in, opts...)
}

func (c *Client) StoresDelete(ctx context.Context, in *pb.StoresDeleteOptions, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.wdMark()
	defer c.wdUnMark()
	c.setBusy(true)
	defer c.setBusy(false)
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.StoresDelete(ctx, in, opts...)
}

func (c *Client) StoresGet(ctx context.Context, in *pb.StoresGetOptions, opts ...grpc.CallOption) (*pb.StoresGetResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.StoresGet(ctx, in, opts...)
}

func (c *Client) StoresFind(ctx context.Context, in *pb.StoresFindOptions, opts ...grpc.CallOption) (*pb.StoresFindResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.StoresFind(ctx, in, opts...)
}

func (c *Client) Rerank(ctx context.Context, in *pb.RerankRequest, opts ...grpc.CallOption) (*pb.RerankResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.Rerank(ctx, in, opts...)
}

func (c *Client) GetTokenMetrics(ctx context.Context, in *pb.MetricsRequest, opts ...grpc.CallOption) (*pb.MetricsResponse, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.GetMetrics(ctx, in, opts...)
}

func (c *Client) VAD(ctx context.Context, in *pb.VADRequest, opts ...grpc.CallOption) (*pb.VADResponse, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.VAD(ctx, in, opts...)
}

func (c *Client) Detect(ctx context.Context, in *pb.DetectOptions, opts ...grpc.CallOption) (*pb.DetectResponse, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.Detect(ctx, in, opts...)
}

func (c *Client) AudioEncode(ctx context.Context, in *pb.AudioEncodeRequest, opts ...grpc.CallOption) (*pb.AudioEncodeResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.AudioEncode(ctx, in, opts...)
}

func (c *Client) AudioDecode(ctx context.Context, in *pb.AudioDecodeRequest, opts ...grpc.CallOption) (*pb.AudioDecodeResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.AudioDecode(ctx, in, opts...)
}

func (c *Client) StartFineTune(ctx context.Context, in *pb.FineTuneRequest, opts ...grpc.CallOption) (*pb.FineTuneJobResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.StartFineTune(ctx, in, opts...)
}

func (c *Client) FineTuneProgress(ctx context.Context, in *pb.FineTuneProgressRequest, f func(update *pb.FineTuneProgressUpdate), opts ...grpc.CallOption) error {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)

	stream, err := client.FineTuneProgress(ctx, in, opts...)
	if err != nil {
		return err
	}

	for {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		update, err := stream.Recv()
		if errors.Is(err, io.EOF) {
			break
		}
		if err != nil {
			if ctx.Err() != nil {
				return ctx.Err()
			}
			return err
		}
		f(update)
	}

	return nil
}

func (c *Client) StopFineTune(ctx context.Context, in *pb.FineTuneStopRequest, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.StopFineTune(ctx, in, opts...)
}

func (c *Client) ListCheckpoints(ctx context.Context, in *pb.ListCheckpointsRequest, opts ...grpc.CallOption) (*pb.ListCheckpointsResponse, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.ListCheckpoints(ctx, in, opts...)
}

func (c *Client) ExportModel(ctx context.Context, in *pb.ExportModelRequest, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.ExportModel(ctx, in, opts...)
}

func (c *Client) StartQuantization(ctx context.Context, in *pb.QuantizationRequest, opts ...grpc.CallOption) (*pb.QuantizationJobResult, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.StartQuantization(ctx, in, opts...)
}

func (c *Client) QuantizationProgress(ctx context.Context, in *pb.QuantizationProgressRequest, f func(update *pb.QuantizationProgressUpdate), opts ...grpc.CallOption) error {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)

	stream, err := client.QuantizationProgress(ctx, in, opts...)
	if err != nil {
		return err
	}

	for {
		select {
		case <-ctx.Done():
			return ctx.Err()
		default:
		}

		update, err := stream.Recv()
		if errors.Is(err, io.EOF) {
			break
		}
		if err != nil {
			if ctx.Err() != nil {
				return ctx.Err()
			}
			return err
		}
		f(update)
	}

	return nil
}

func (c *Client) StopQuantization(ctx context.Context, in *pb.QuantizationStopRequest, opts ...grpc.CallOption) (*pb.Result, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.StopQuantization(ctx, in, opts...)
}

func (c *Client) Free(ctx context.Context) error {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()

	conn, err := c.dial()
	if err != nil {
		return err
	}
	defer conn.Close()

	client := pb.NewBackendClient(conn)
	_, err = client.Free(ctx, &pb.HealthMessage{})
	return err
}

func (c *Client) ModelMetadata(ctx context.Context, in *pb.ModelOptions, opts ...grpc.CallOption) (*pb.ModelMetadataResponse, error) {
	if !c.parallel {
		c.opMutex.Lock()
		defer c.opMutex.Unlock()
	}
	c.setBusy(true)
	defer c.setBusy(false)
	c.wdMark()
	defer c.wdUnMark()
	conn, err := c.dial()
	if err != nil {
		return nil, err
	}
	defer conn.Close()
	client := pb.NewBackendClient(conn)
	return client.ModelMetadata(ctx, in, opts...)
}