package main

import (
	"log"
	"net"
	"os"
	"sync"
	"time"
)

var (
	logger         *log.Logger
	logFile        *os.File
	activeConn     net.Conn
	activeSensor   *SensorComm
	activeConnMutex sync.Mutex
	clientAddress  string
)

func main() {
	setupLogging()
	defer logFile.Close()

	initDB()
	defer db.Close()

	go startWebServer()

	addr := "0.0.0.0:10004"
	listener, err := net.Listen("tcp", addr)
	if err != nil {
		logger.Fatalf("监听端口错误: %v", err)
	}
	defer listener.Close()

	logger.Printf("服务器已启动: %s", addr)

	for {
		conn, err := listener.Accept()
		if err != nil {
			logger.Printf("接受连接错误: %v", err)
			continue
		}

		activeConnMutex.Lock()
		// 关闭旧连接
		if activeConn != nil {
			oldConn := activeConn
			oldSensor := activeSensor
			activeConn = nil
			activeSensor = nil
			activeConnMutex.Unlock()
			
			if oldSensor != nil {
				oldSensor.close()
			} else if oldConn != nil {
				oldConn.Close()
			}
			
			logger.Printf("关闭旧连接，接入新连接: %s", conn.RemoteAddr().String())
		} else {
			activeConnMutex.Unlock()
			logger.Printf("新连接: %s", conn.RemoteAddr().String())
		}
		
		sensorComm := newSensorComm(conn)
		
		activeConnMutex.Lock()
		activeConn = conn
		activeSensor = sensorComm
		clientAddress = conn.RemoteAddr().String()
		activeConnMutex.Unlock()

		go handleConnection(sensorComm)
	}
}

func handleConnection(sensor *SensorComm) {
	defer func() {
		activeConnMutex.Lock()
		if activeConn == sensor.conn {
			activeConn = nil
			activeSensor = nil
			clientAddress = ""
		}
		activeConnMutex.Unlock()
		
		sensor.close()
	}()

	logger.Printf("处理连接: %s", sensor.address)

	nextQuery := getNextQueryTime()
	nextReset := getNextHourTime()
	
	var nextEvent time.Time
	isQueryEvent := true
	
	if nextQuery.Before(nextReset) {
		nextEvent = nextQuery
		isQueryEvent = true
	} else {
		nextEvent = nextReset
		isQueryEvent = false
	}
	
	timer := time.NewTimer(time.Until(nextEvent))
	sensor.sendQuery()

	buffer := make([]byte, 1024)
	done := make(chan bool)

	go func() {
		for {
			n, err := sensor.conn.Read(buffer)
			if err != nil {
				logger.Printf("客户端断开: %v", err)
				done <- true
				return
			}

			if n >= 37 {
				sensorData := sensor.handleData(buffer[:n])
				if sensorData != nil {
					saveSensorData(*sensorData)
					logSensorData(*sensorData)
				}
			}

			logger.Printf("接收数据长度: %d", n)
			logger.Printf("Raw Data: %x\n",buffer[:n])
		}
	}()
	
	for {
		select {
		case <-timer.C:
			if isQueryEvent {
				sensor.sendQuery()
				nextQuery = getNextQueryTime()
			} else {
				sensor.resetHourly()
				nextReset = getNextHourTime()
			}
			
			if nextQuery.Before(nextReset) {
				nextEvent = nextQuery
				isQueryEvent = true
			} else {
				nextEvent = nextReset
				isQueryEvent = false
			}
			
			timer.Reset(time.Until(nextEvent))
			
		case <-done:
			return
		}
	}
}

func setupLogging() {
	if err := os.MkdirAll("logs", 0755); err != nil {
		log.Fatalf("创建日志目录失败: %v", err)
	}

	logFileName := "logs/sensor_" + time.Now().Format("2006-01-02") + ".log"
	var err error
	logFile, err = os.OpenFile(logFileName, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		log.Fatalf("打开日志文件失败: %v", err)
	}

	logger = log.New(logFile, "", log.LstdFlags)
}