package utils

import (
	"encoding/json"
	"fmt"
	"net"
	"os"
	"server/dao"
	"time"
)

const connDataFilePath = "static/devicePath.json"
const dataFilePath = "static/data.json"

// LoadData 从文件读取数据
func LoadData() (regions []dao.Region, err error) {
	data, err := os.ReadFile(dataFilePath)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, nil
		}
		return nil, err
	}
	err = json.Unmarshal(data, &regions)
	if err != nil {
		return nil, err

	}
	return regions, nil
}

func GetOnlineDevices() (devices []dao.Device, err error) {
	regions, err := LoadData()
	if err != nil {
		return nil, err
	}

	for _, region := range regions {
		for _, device := range region.Devices {
			//if device.State == 0 {
			//	continue
			//}
			devices = append(devices, device)
		}
	}

	return devices, err
}

func GetAllDevices() (devices []dao.Device, err error) {
	regions, err := LoadData()
	if err != nil {
		return nil, err
	}

	for _, region := range regions {
		for _, device := range region.Devices {
			devices = append(devices, device)
		}
	}

	return devices, err
}

// GetDataByDeviceId 按设备id获取信息 地区+设备
func GetDataByDeviceId(deviceId string) (reg dao.Region, dev dao.Device, err error) {
	regions, err := LoadData()
	if err != nil {
		return reg, dev, err
	}

	for _, region := range regions {
		for _, device := range region.Devices {
			if device.Sn == deviceId {
				return region, device, nil
			}
		}
	}

	return reg, dev, fmt.Errorf("设备%s未找到", deviceId)
}

func SaveRegionOnData(data dao.Region) ([]dao.Region, error) {
	regions, err := LoadData()
	if err != nil {
		return regions, err
	}
	for i, region := range regions {
		if region.Name == data.Name {
			regions[i] = data
		}
	}
	return regions, nil
}

// SaveData 保存数据到文件
func SaveData(path string, parameter interface{}) error {
	data, err := json.MarshalIndent(parameter, "", "  ")
	if err != nil {
		return err
	}
	return os.WriteFile(path, data, 0644)
}

// CalculateCircuitSum 计算给定回路数量的总和
func CalculateCircuitSum(circuits int) (int, error) {
	if circuits <= 0 {
		return 0, fmt.Errorf("回路数量必须大于0")
	}

	// 计算结果
	result := (1 << circuits) - 1

	return result, nil
}

// WriteDevice 纯写
func WriteDevice(frame []byte, conn net.Conn) error {
	_, err := conn.Write(frame)
	if err != nil {
		fmt.Println("Error writing to connection:", err)
		return err
	}
	return nil
}

// ReadDevice 纯读
func ReadDevice(conn net.Conn) (data []byte) {
	buffer := make([]byte, 1024)
	n, err := conn.Read(buffer)
	if err != nil {
		fmt.Println("Error reading from connection:", err)
		return
	}
	fmt.Printf("Received %d bytes: %X\n", n, buffer[6:n])
	return buffer
}

func WriteAndReadDevice(frame []byte, conn net.Conn, former, after int) (data []byte, err error) {
	// 发送 Modbus RTU 帧
	n, err := conn.Write(frame)
	if err != nil {
		fmt.Println("Error writing to connection:", err)
		return
	}

	// 等待一段时间以接收响应
	time.Sleep(1000 * time.Millisecond)

	// 读取响应
	buffer := make([]byte, 1024)
	n, err = conn.Read(buffer)
	if err != nil {
		fmt.Println("Error reading from connection:", err)
		return
	}

	// 检查读取的字节数是否足够
	if n < former+after {
		err = fmt.Errorf("not enough bytes read to satisfy the slice range")
		return
	}

	// 返回子切片
	return buffer[former : n-after], err
}