package main

import (
	"bytes"
	"fmt"
	"github.com/caarlos0/env/v6"
	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/websocket/v2"
	"l_szr_go/pkg"
	"os/signal"
	"syscall"
	"time"

	"l_szr_go/entity"
	"log"
	"os"
	"sync"
)

var (
	config            entity.Config
	activeConnections sync.WaitGroup
)

func Server() *fiber.App {
	app := fiber.New()

	// 健康检查
	app.Get("/health", func(c *fiber.Ctx) error {
		return c.SendStatus(fiber.StatusOK)
	})

	// WebSocket 路由
	app.Use("/ws", func(c *fiber.Ctx) error {
		if websocket.IsWebSocketUpgrade(c) {
			c.Locals("allowed", true)
			return c.Next()
		}
		return fiber.ErrUpgradeRequired
	})

	app.Get("/ws", websocket.New(HandleWebSocket))
	return app
}

func HandleWebSocket(c *websocket.Conn) {
	activeConnections.Add(1)
	defer activeConnections.Done()

	var audioBuffer bytes.Buffer
	fileName := fmt.Sprintf("output_%s.wav",
		time.Now().Format("20060102_150405.000"))

	log.Printf("客户端连接: %s", c.RemoteAddr())

	defer func() {
		if audioBuffer.Len() == 0 {
			log.Println("未接收到音频数据，跳过保存")
			return
		}

		if err := pkg.SaveAsWav(&audioBuffer, fileName, config); err != nil {
			log.Printf("保存文件失败: %v", err)
		} else {
			log.Printf("音频已保存为 %s (%d字节)", fileName, audioBuffer.Len())
		}
	}()

	for {
		_, message, err := c.ReadMessage()
		if err != nil {
			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
				log.Printf("客户端异常断开: %v", err)
			} else {
				log.Println("客户端主动断开")
			}
			break
		}

		// 检查缓冲区大小
		if audioBuffer.Len()+len(message) > config.MaxBufferSize {
			log.Println("达到最大缓冲区大小，断开连接")
			break
		}

		// 验证PCM数据 (基本验证)
		if config.BitDepth == 16 && len(message)%2 != 0 {
			log.Println("接收到无效的16位PCM数据，长度不是2的倍数")
			continue
		}

		if _, err := audioBuffer.Write(message); err != nil {
			log.Printf("写入缓冲区失败: %v", err)
			break
		}

		log.Printf("接收到 %d 字节音频数据 (总大小: %d字节)",
			len(message), audioBuffer.Len())
	}
}

func main() {
	if err := env.Parse(&config); err != nil {
		log.Fatalf("加载配置失败: %v", err)
	}
	fmt.Print(config.SampleRate)
	app := Server()
	// 启动服务器
	go func() {
		log.Printf("服务器启动，监听端口 %s", config.Port)
		log.Printf("音频配置: %dHz, %d通道, %d位深",
			config.SampleRate, config.Channels, config.BitDepth)
		if err := app.Listen(":" + config.Port); err != nil {
			log.Fatalf("服务器启动失败: %v", err)
		}
	}()

	// 优雅关闭
	quit := make(chan os.Signal, 1)
	signal.Notify(quit, os.Interrupt, syscall.SIGTERM)
	<-quit
	log.Println("正在关闭服务器...")

	// 等待所有连接完成
	activeConnections.Wait()
	log.Println("所有连接已关闭")
	os.Exit(0)
}