package main

import (
	crypto_tls "crypto/tls"
	"embed"
	"fmt"
	"io/fs"
	"log/slog"
	"os"
	"os/signal"
	"syscall"

	"github.com/imbytecat/voicepaste/internal/asr"
	"github.com/imbytecat/voicepaste/internal/config"
	"github.com/imbytecat/voicepaste/internal/paste"
	"github.com/imbytecat/voicepaste/internal/server"
	vpTLS "github.com/imbytecat/voicepaste/internal/tls"
	"github.com/imbytecat/voicepaste/internal/ws"
)

//go:embed all:web/dist
var webFS embed.FS
var version = "dev"

func main() {
	initLogger()
	slog.Info("VoicePaste", "version", version)
	cfg := mustLoadConfig()
	stopWatch := config.WatchAndReload("")
	defer func() {
		if stopWatch != nil {
			stopWatch()
		}
	}()
	initClipboard()
	lanIPs := mustDetectLANIPs()
	lanIP := lanIPs[0]
	tlsResult := mustSetupTLS(lanIP)
	printBanner(cfg, tlsResult, lanIPs)
	srv := createServer(cfg, lanIP, tlsResult)
	runWithGracefulShutdown(srv)
}

func initLogger() {
	slog.SetDefault(slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
		Level: slog.LevelInfo,
	})))
}

func mustLoadConfig() config.Config {
	cfg, err := config.Load("")
	if err != nil {
		slog.Error("failed to load config", "error", err)
		os.Exit(1)
	}
	return cfg
}

func initClipboard() {
	if err := paste.Init(); err != nil {
		slog.Warn("clipboard init failed, paste will be unavailable", "err", err)
	}
}

func mustDetectLANIPs() []string {
	lanIPs, err := server.GetLANIPs()
	if err != nil {
		slog.Error("failed to detect LAN IP", "error", err)
		os.Exit(1)
	}
	return lanIPs
}

func mustSetupTLS(lanIP string) *vpTLS.Result {
	tlsResult, err := vpTLS.GetTLSConfig(lanIP)
	if err != nil {
		slog.Error("TLS setup failed", "error", err)
		os.Exit(1)
	}
	return tlsResult
}

func printBanner(cfg config.Config, tlsResult *vpTLS.Result, lanIPs []string) {
	fmt.Println()
	fmt.Println("╔══════════════════════════════════════╗")
	fmt.Println("║          VoicePaste 就绪             ║")
	fmt.Println("╚══════════════════════════════════════╝")
	fmt.Println()
	printAddresses(cfg, tlsResult, lanIPs)
	printCertInfo(tlsResult)
	printAuthInfo(cfg.Server.Token)
	fmt.Println()
	fmt.Println("  在手机浏览器中打开上方地址")
	fmt.Println("  按 Ctrl+C 停止服务")
	fmt.Println()
}

func printAddresses(cfg config.Config, tlsResult *vpTLS.Result, lanIPs []string) {
	token := cfg.Server.Token
	if len(lanIPs) == 1 {
		host := lanIPHost(tlsResult, lanIPs[0])
		fmt.Printf("  地址: %s\n", buildURL(host, cfg.Server.Port, token))
		return
	}
	fmt.Println("  地址:")
	for _, ip := range lanIPs {
		host := lanIPHost(tlsResult, ip)
		fmt.Printf("    - %s\n", buildURL(host, cfg.Server.Port, token))
	}
}

func lanIPHost(tlsResult *vpTLS.Result, ip string) string {
	if tlsResult != nil {
		return vpTLS.AnyIPHost(ip)
	}
	return ip
}

func printCertInfo(tlsResult *vpTLS.Result) {
	if tlsResult != nil {
		fmt.Println("  证书: AnyIP（浏览器信任）")
	} else {
		fmt.Println("  证书: 获取失败")
	}
}

func printAuthInfo(token string) {
	if token != "" {
		fmt.Println("  认证: 已启用")
	} else {
		fmt.Println("  认证: 未启用（无需 token）")
	}
}

func createServer(cfg config.Config, lanIP string, tlsResult *vpTLS.Result) *server.Server {
	webContent, _ := fs.Sub(webFS, "web/dist")
	var tlsConfig *crypto_tls.Config
	if tlsResult != nil {
		tlsConfig = tlsResult.Config
	}
	srv := server.New(cfg.Server.Token, lanIP, webContent, tlsConfig)
	asrFactory := buildASRFactory()
	wsHandler := ws.NewHandler(cfg.Server.Token, paste.Paste, asrFactory)
	wsHandler.Register(srv.App())
	return srv
}

func buildASRFactory() func(chan<- ws.ServerMsg) (func([]byte), func(), error) {
	return func(resultCh chan<- ws.ServerMsg) (func([]byte), func(), error) {
		cfg := config.Get()
		asrCfg := asr.Config{
			AppID:       cfg.Doubao.AppID,
			AccessToken: cfg.Doubao.AccessToken,
			ResourceID:  cfg.Doubao.ResourceID,
			Hotwords:    cfg.ASR.Hotwords,
		}
		client, err := asr.Dial(asrCfg, resultCh)
		if err != nil {
			return nil, nil, err
		}
		sendAudio := func(pcm []byte) {
			if err := client.SendAudio(pcm, false); err != nil {
				slog.Warn("send audio to asr", "err", err)
			}
		}
		cleanup := func() {
			client.Finish()
		}
		return sendAudio, cleanup, nil
	}
}

func runWithGracefulShutdown(srv *server.Server) {
	go func() {
		sigCh := make(chan os.Signal, 1)
		signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
		<-sigCh
		slog.Info("shutting down...")
		srv.Shutdown()
	}()
	if err := srv.Start(); err != nil {
		slog.Error("server error", "error", err)
		os.Exit(1)
	}
}

func buildURL(host string, port int, token string) string {
	if token != "" {
		return fmt.Sprintf("https://%s:%d/?token=%s", host, port, token)
	}
	return fmt.Sprintf("https://%s:%d/", host, port)
}