package entity

import (
	"context"
	"fmt"
	"grpccanary/examples/grpcentity/protoapi"
	"io"
	"math/rand"
	"net"
	"time"

	"google.golang.org/grpc"
	"google.golang.org/grpc/reflection"
)

var min = 0
var max = 100
var port = ":8080"

func random(min, max int, src rand.Source) int {
	return rand.New(src).Intn(max-min) + min
}

// Extra function for creating secure random numbers
//
// func randomSecure(min, max int) int {
// 	v, err := rand.Int(rand.Reader, big.NewInt(int64(max)))
// 	if err != nil {
// 		fmt.Println(err)
// 		return min
// 	}
// 	fmt.Println("**", v, min, max)

// 	return min + int(v.Uint64())
// }

func getString(len int64, src rand.Source) string {
	temp := ""
	startChar := "!"
	var i int64 = 1
	for {
		// For getting valid ASCII characters
		myRand := random(0, 94, src)
		newChar := string(startChar[0] + byte(myRand))
		temp = temp + newChar
		if i == len {
			break
		}
		i++
	}
	return temp
}

type IoTServer struct {
	protoapi.UnimplementedIoTServiceServer
}

func (IoTServer) GetDate(ctx context.Context, r *protoapi.RequestDateTime) (*protoapi.DateTime, error) {
	currentTime := time.Now()
	response := &protoapi.DateTime{
		Value: currentTime.String(),
	}

	return response, nil
}

func (IoTServer) UpdateSensingData(ctx context.Context, r *protoapi.SensingData) (*protoapi.SensingResponse, error) {
	fmt.Printf("Received sensing data - Device: %s, Temp: %.2f°C, Humid: %.2f%%\n", r.GetDeviceId(), r.GetTemperature(), r.GetHumidity())

	response := &protoapi.SensingResponse{
		Success: true,
		Message: fmt.Sprintf("Sensing data updated successfully for device %s", r.GetDeviceId()),
	}

	return response, nil
}

func (IoTServer) GetRandomPass(ctx context.Context, r *protoapi.RequestPass) (*protoapi.RandomPass, error) {
	src := rand.NewSource(r.GetSeed())
	temp := getString(r.GetLength(), src)

	response := &protoapi.RandomPass{
		Password: temp,
	}

	return response, nil
}

func (IoTServer) UploadFile(stream protoapi.IoTService_UploadFileServer) error {
	var totalBytes int64
	var fileName string

	for {
		chunk, err := stream.Recv()
		if err == io.EOF {
			fmt.Printf("File upload completed. Received %d bytes for file '%s'\n", totalBytes, fileName)
			return stream.SendAndClose(&protoapi.UploadStatus{
				Success:       true,
				Message:       fmt.Sprintf("File '%s' uploaded successfully.", fileName),
				BytesUploaded: totalBytes,
			})
		}
		if err != nil {
			fmt.Println("File upload error:", err)
			return err
		}

		if fileName == "" {
			fileName = chunk.GetFileName()
		}
		totalBytes += int64(len(chunk.GetContent()))
	}
}

func ServerRun(addr string) {
	server := grpc.NewServer()
	var iotServer IoTServer
	protoapi.RegisterIoTServiceServer(server, iotServer)

	reflection.Register(server)

	listen, err := net.Listen("tcp", addr)
	if err != nil {
		fmt.Println(err)
		return
	}

	fmt.Println("Serving requests...")
	server.Serve(listen)
}