package main

import (
	"context"
	"errors"
	"fmt"
	"log/slog"
	"net"
	"net/http"
	"os"
	"os/signal"
	"path/filepath"
	"strings"
	"syscall"
	"time"

	"git.asio.asia/nixevol/NixMsg/internal/config"
	"git.asio.asia/nixevol/NixMsg/internal/store"
	"git.asio.asia/nixevol/NixMsg/web"
)

func cmdServe(_ []string) error {
	cfgPath := config.PathFromEnv()
	cfg, err := config.Load(cfgPath)
	if err != nil {
		return err
	}
	// P-WIRE-BEGIN
	if err := cfg.Validate(); err != nil {
		return err
	}
	setupJSONLogger(cfg.Log)
	// P-WIRE-END
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()
	return runServe(ctx, cfg)
}

func runServe(ctx context.Context, cfg config.Config) error {
	deps := wire()

	if err := os.MkdirAll(cfg.DataDir, 0o755); err != nil {
		return fmt.Errorf("mkdir data_dir: %w", err)
	}

	db, err := store.Open(cfg.DataDir, cfg.SQLiteSynchronous)
	if err != nil {
		return err
	}
	defer func() { _ = db.Close() }()

	// P-WIRE-BEGIN
	ok, err := store.HasAdminPassword(ctx, db.Write)
	if err != nil {
		return err
	}
	if !ok {
		return errors.New("admin password not initialized; run: nixmsg admin init")
	}
	// P-WIRE-END

	// 启动恢复入口已挂上（假实现为空操作）；M 线替换 message.Service 后生效。
	if recoverErr := deps.Messages.RecoverOnStart(ctx); recoverErr != nil {
		return fmt.Errorf("message recover: %w", recoverErr)
	}
	// 其余 deps 供后续 admin / broker / httpx 接线；此处显式引用避免未使用告警。
	_ = deps.Identity
	_ = deps.Groups
	_ = deps.Presence
	_ = deps.Downlink
	_ = deps.Conns
	_ = deps.Uplink
	_ = deps.HashPool
	_ = deps.SessionTokens
	_ = deps.APITokens
	_ = deps.LoginLocks

	mux := http.NewServeMux()
	mux.HandleFunc("GET /healthz", func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte("ok"))
	})
	// P-WIRE-BEGIN
	mux.HandleFunc("GET /readyz", func(w http.ResponseWriter, r *http.Request) {
		if readyErr := db.Ready(r.Context()); readyErr != nil {
			slog.Error("readyz failed", "err", readyErr)
			http.Error(w, "not ready", http.StatusServiceUnavailable)
			return
		}
		w.WriteHeader(http.StatusOK)
		_, _ = w.Write([]byte("ok"))
	})
	// P-WIRE-END
	// 确保前端资源被链接进二进制；完整静态托管由后续任务完善。
	_ = web.Dist()

	ln, err := net.Listen("tcp", cfg.Listen)
	if err != nil {
		return fmt.Errorf("listen %s: %w", cfg.Listen, err)
	}

	if err := writeListenAddr(cfg.DataDir, ln.Addr().String()); err != nil {
		_ = ln.Close()
		return err
	}

	srv := &http.Server{
		Handler:           mux,
		ReadHeaderTimeout: 10 * time.Second,
	}

	errCh := make(chan error, 1)
	go func() {
		errCh <- srv.Serve(ln)
	}()

	select {
	case <-ctx.Done():
		// P-WIRE-BEGIN
		// 先停止接受新连接，再等写队列最多 10 秒，然后断开并退出。
		shutdownCtx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
		defer cancel()
		_ = srv.Shutdown(shutdownCtx)
		drainCtx, drainCancel := context.WithTimeout(context.Background(), 10*time.Second)
		defer drainCancel()
		if drainErr := db.Queue.Drain(drainCtx); drainErr != nil && !errors.Is(drainErr, context.DeadlineExceeded) {
			slog.Error("write queue drain", "err", drainErr)
		}
		// P-WIRE-END
		serveErr := <-errCh
		if serveErr != nil && !errors.Is(serveErr, http.ErrServerClosed) {
			return serveErr
		}
		return nil
	case serveErr := <-errCh:
		if errors.Is(serveErr, http.ErrServerClosed) {
			return nil
		}
		return serveErr
	}
}

func writeListenAddr(dataDir, addr string) error {
	path := filepath.Join(dataDir, "listen.addr")
	return os.WriteFile(path, []byte(addr+"\n"), 0o644)
}

// P-WIRE-BEGIN
func setupJSONLogger(cfg config.LogConfig) {
	level := slog.LevelInfo
	switch strings.ToLower(strings.TrimSpace(cfg.Level)) {
	case "debug":
		level = slog.LevelDebug
	case "warn", "warning":
		level = slog.LevelWarn
	case "error":
		level = slog.LevelError
	}
	h := slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: level})
	slog.SetDefault(slog.New(h))
}

// P-WIRE-END