package main

import (
	"bufio"
	"encoding/hex"
	"fmt"
	"io"
	"log"
	"net"
	"os"
	"path/filepath"
	"strings"
	"time"
	"unicode/utf8"

	"weatherstation/config"
	"weatherstation/model"

	"github.com/gin-gonic/gin"
)

type UTF8Writer struct {
	w io.Writer
}

func NewUTF8Writer(w io.Writer) *UTF8Writer {
	return &UTF8Writer{w: w}
}

func (w *UTF8Writer) Write(p []byte) (n int, err error) {
	if utf8.Valid(p) {
		return w.w.Write(p)
	}
	s := string(p)
	s = strings.ToValidUTF8(s, "")
	return w.w.Write([]byte(s))
}

func setupLogger() {
	logDir := "log"
	if _, err := os.Stat(logDir); os.IsNotExist(err) {
		os.MkdirAll(logDir, 0755)
	}
	currentTime := time.Now()
	logFileName := filepath.Join(logDir, fmt.Sprintf("%s.log", currentTime.Format("2006-01-02")))
	logFile, err := os.OpenFile(logFileName, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
	if err != nil {
		log.Fatalf("无法创建日志文件: %v", err)
	}
	bufferedWriter := bufio.NewWriter(logFile)
	utf8Writer := NewUTF8Writer(bufferedWriter)
	go func() {
		for {
			time.Sleep(1 * time.Second)
			bufferedWriter.Flush()
		}
	}()
	multiWriter := io.MultiWriter(os.Stdout, utf8Writer)
	log.SetOutput(multiWriter)
	log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
}

func startUDP() {
	cfg := config.GetConfig()
	err := model.InitDB()
	if err != nil {
		log.Fatalf("初始化数据库失败: %v", err)
	}
	defer model.CloseDB()
	addr := fmt.Sprintf(":%d", cfg.Server.UDPPort)
	conn, err := net.ListenPacket("udp", addr)
	if err != nil {
		log.Fatalf("无法监听UDP端口 %d: %v", cfg.Server.UDPPort, err)
	}
	defer conn.Close()
	log.Printf("UDP服务器已启动，监听端口 %d...", cfg.Server.UDPPort)
	buffer := make([]byte, 2048)
	for {
		n, addr, err := conn.ReadFrom(buffer)
		if err != nil {
			log.Printf("读取数据错误: %v", err)
			continue
		}
		rawData := buffer[:n]
		data := string(rawData)
		log.Printf("从 %s 接收到 %d 字节数据", addr.String(), n)
		weatherData, err := model.ParseWeatherData(data)
		if err != nil {
			log.Printf("解析数据失败: %v", err)
			hexDump := hexDump(rawData)
			log.Printf("原始码流(十六进制):\n%s", hexDump)
			asciiDump := asciiDump(rawData)
			log.Printf("ASCII码:\n%s", asciiDump)
			continue
		}
		log.Println("成功解析气象站数据:")
		log.Println(weatherData)

		// 注册设备
		model.RegisterDevice(weatherData.StationID, addr)

		err = model.SaveWeatherData(weatherData, data)
		if err != nil {
			log.Printf("保存数据到数据库失败: %v", err)
		} else {
			log.Printf("数据已成功保存到数据库")
		}
	}
}

func startDeviceCheck() {
	cfg := config.GetConfig()
	ticker := time.NewTicker(time.Duration(cfg.DeviceCheck.Interval) * time.Minute)
	defer ticker.Stop()

	for range ticker.C {
		devices := model.GetOnlineDevices()
		log.Printf("当前在线设备数: %d", len(devices))

		for _, device := range devices {
			sendUDPMessage(device.IP, cfg.DeviceCheck.Message)
		}
	}
}

func sendUDPMessage(ip string, message string) {
	addr, err := net.ResolveUDPAddr("udp", ip+":10006")
	if err != nil {
		log.Printf("解析UDP地址失败: %v", err)
		return
	}

	conn, err := net.DialUDP("udp", nil, addr)
	if err != nil {
		log.Printf("连接UDP失败: %v", err)
		return
	}
	defer conn.Close()

	_, err = conn.Write([]byte(message))
	if err != nil {
		log.Printf("发送UDP消息失败: %v", err)
		return
	}

	log.Printf("成功向 %s 发送消息: %s", ip, message)
}

func main() {
	setupLogger()
	go startUDP()
	go startDeviceCheck()

	r := gin.Default()
	r.LoadHTMLGlob("templates/*")
	r.Static("/static", "static")
	r.GET("/", func(c *gin.Context) {
		c.HTML(200, "index.html", gin.H{})
	})
	r.Run(":10007")
}

func hexDump(data []byte) string {
	var result strings.Builder
	for i := 0; i < len(data); i += 16 {
		end := i + 16
		if end > len(data) {
			end = len(data)
		}
		chunk := data[i:end]
		hexStr := hex.EncodeToString(chunk)
		for j := 0; j < len(hexStr); j += 2 {
			if j+2 <= len(hexStr) {
				result.WriteString(strings.ToUpper(hexStr[j : j+2]))
				result.WriteString(" ")
			}
		}
		result.WriteString("\n")
	}
	return result.String()
}

func asciiDump(data []byte) string {
	var result strings.Builder
	for i := 0; i < len(data); i += 64 {
		end := i + 64
		if end > len(data) {
			end = len(data)
		}
		chunk := data[i:end]
		for _, b := range chunk {
			if b >= 32 && b <= 126 {
				result.WriteByte(b)
			} else {
				result.WriteString(".")
			}
		}
		result.WriteString("\n")
	}
	return result.String()
}