package modular

import (
	"context"
	"fmt"
	"io"
	"math/rand"
	"time"

	"grpccanary/lib/grpc/modular/protoapi"

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

func AskingDateTime(ctx context.Context, m protoapi.CoreServiceClient) (*protoapi.DateTime, error) {
	request := &protoapi.RequestDateTime{
		Value: "Please send me the date and time",
	}
	return m.GetDate(ctx, request)
}

func AskPass(ctx context.Context, m protoapi.CoreServiceClient, seed int64, length int64) (*protoapi.RandomPass, error) {
	request := &protoapi.RequestPass{
		Seed:   seed,
		Length: length,
	}
	return m.GetRandomPass(ctx, request)
}

func AskUpdateSensingData(ctx context.Context, m protoapi.CoreServiceClient, deviceId string, temp float64, humid float64) (*protoapi.SensingResponse, error) {
	request := &protoapi.SensingData{
		DeviceId:    deviceId,
		Temperature: temp,
		Humidity:    humid,
	}
	return m.UpdateSensingData(ctx, request)
}

func AskUploadFile(ctx context.Context, m protoapi.FileTransferServiceClient, fileName string, fileData []byte) (*protoapi.UploadStatus, error) {
	stream, err := m.UploadFile(ctx)
	if err != nil {
		return nil, err
	}

	chunkSize := 1024
	totalBytes := len(fileData)

	for i := 0; i < totalBytes; i += chunkSize {
		end := i + chunkSize
		if end > totalBytes {
			end = totalBytes
		}

		err := stream.Send(&protoapi.FileChunk{
			FileName: fileName,
			Content:  fileData[i:end],
		})
		if err != nil {
			return nil, err
		}
	}

	return stream.CloseAndRecv()
}

func AskListFiles(ctx context.Context, m protoapi.FileTransferServiceClient) (*protoapi.FileList, error) {
	return m.ListFiles(ctx, &protoapi.EmptyRequest{})
}

func AskDownloadFile(ctx context.Context, m protoapi.FileTransferServiceClient, fileName string) ([]byte, error) {
	stream, err := m.DownloadFile(ctx, &protoapi.DownloadRequest{FileName: fileName})
	if err != nil {
		return nil, err
	}

	var buffer []byte
	for {
		chunk, err := stream.Recv()
		if err == io.EOF {
			break
		}
		if err != nil {
			return nil, err
		}
		buffer = append(buffer, chunk.GetContent()...)
	}

	return buffer, nil
}

func AskSubscribeAlerts(ctx context.Context, m protoapi.AlertServiceClient, clientId string, topic string) {
	stream, err := m.SubscribeAlerts(ctx, &protoapi.AlertSubscription{
		ClientId: clientId,
		Topic:    topic,
	})
	if err != nil {
		fmt.Println("[Modular Client] Failed to subscribe alerts:", err)
		return
	}

	for {
		alert, err := stream.Recv()
		if err == io.EOF {
			fmt.Println("[Modular Client] Alert subscription stream closed by server.")
			break
		}
		if err != nil {
			break
		}
		fmt.Printf("\n🔔 [Modular ALERT RECEIVED] ID: %s | Device: %s | Msg: %s | Time: %s\n\n",
			alert.GetAlertId(), alert.GetDeviceId(), alert.GetMessage(),
			time.Unix(alert.GetTimestamp(), 0).Format("15:04:05"))
	}
}

func ClientRun(addr string) {
	conn, err := grpc.NewClient(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		fmt.Println("[Modular Client] NewClient error:", err)
		return
	}
	defer conn.Close()

	coreClient := protoapi.NewCoreServiceClient(conn)
	fileClient := protoapi.NewFileTransferServiceClient(conn)
	alertClient := protoapi.NewAlertServiceClient(conn)

	// Background Subscription
	alertCtx, alertCancel := context.WithCancel(context.Background())
	defer alertCancel()
	go AskSubscribeAlerts(alertCtx, alertClient, "modular-client-01", "temperature_warnings")
	time.Sleep(50 * time.Millisecond)

	r, err := AskingDateTime(context.Background(), coreClient)
	if err != nil {
		fmt.Println("[Modular Client] GetDate error:", err)
		return
	}
	fmt.Println("[Modular Client] Server Date and Time:", r.Value)

	length := int64(rand.Intn(20))
	p, err := AskPass(context.Background(), coreClient, 100, length+1)
	if err != nil {
		fmt.Println("[Modular Client] GetRandomPass error:", err)
		return
	}
	fmt.Println("[Modular Client] Random Password:", p.Password)

	res, err := AskUpdateSensingData(context.Background(), coreClient, "modular-sensor-01", 24.5, 52.3)
	if err != nil {
		fmt.Println("[Modular Client] UpdateSensingData error:", err)
		return
	}
	fmt.Println("[Modular Client] Sensing Update Success:", res.Success)

	// File Upload
	dummyData := make([]byte, 10240)
	for i := range dummyData {
		dummyData[i] = byte(rand.Intn(256))
	}
	fmt.Println("[Modular Client] Uploading dummy file...")
	status, err := AskUploadFile(context.Background(), fileClient, "firmware_modular.bin", dummyData)
	if err != nil {
		fmt.Println("[Modular Client] File upload failed:", err)
		return
	}
	fmt.Println("[Modular Client] Upload Success:", status.Success)

	// File List
	list, err := AskListFiles(context.Background(), fileClient)
	if err != nil {
		fmt.Println("[Modular Client] ListFiles failed:", err)
		return
	}
	for i, f := range list.GetFiles() {
		fmt.Printf("[Modular Client] File [%d]: %s, size: %d\n", i+1, f.GetFileName(), f.GetFileSize())
	}

	// File Download & Verification
	downloadedData, err := AskDownloadFile(context.Background(), fileClient, "firmware_modular.bin")
	if err != nil {
		fmt.Println("[Modular Client] Download failed:", err)
		return
	}
	fmt.Printf("[Modular Client] Downloaded %d bytes.\n", len(downloadedData))

	isMatch := true
	if len(dummyData) != len(downloadedData) {
		isMatch = false
	} else {
		for i := range dummyData {
			if dummyData[i] != downloadedData[i] {
				isMatch = false
				break
			}
		}
	}
	fmt.Printf("[Modular Client] Data Integrity Checked: %t\n", isMatch)

	// Trigger alert
	fmt.Println("[Modular Client] Triggering abnormal high-temperature...")
	_, err = AskUpdateSensingData(context.Background(), coreClient, "modular-sensor-01", 45.8, 60.1)
	if err != nil {
		fmt.Println("[Modular Client] UpdateSensingData (abnormal) error:", err)
		return
	}

	time.Sleep(100 * time.Millisecond)
}