// Command scoreboard 是赛事积分榜系统的服务端。
package main

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

	_ "modernc.org/sqlite"

	"git.yeij.top/AskaEth/Scoreboard/server/internal/auth"
	"git.yeij.top/AskaEth/Scoreboard/server/internal/config"
	"git.yeij.top/AskaEth/Scoreboard/server/internal/export"
	"git.yeij.top/AskaEth/Scoreboard/server/internal/httpapi"
	"git.yeij.top/AskaEth/Scoreboard/server/internal/middleware"
	"git.yeij.top/AskaEth/Scoreboard/server/internal/realtime"
	"git.yeij.top/AskaEth/Scoreboard/server/internal/store"
)

// version 由构建时注入：-ldflags "-X main.version=..."
var version = "dev_0.1.0"

func main() {
	if len(os.Args) > 1 && os.Args[1] == "backup" {
		if err := runBackup(os.Args[2:]); err != nil {
			fmt.Fprintf(os.Stderr, "备份失败: %v\n", err)
			os.Exit(1)
		}
		return
	}
	if len(os.Args) > 1 && os.Args[1] == "passwd" {
		if err := runPasswd(os.Args[2:]); err != nil {
			fmt.Fprintf(os.Stderr, "重置密码失败: %v\n", err)
			os.Exit(1)
		}
		return
	}

	configPath := flag.String("config", "config.yaml", "配置文件路径")
	project := flag.String("project", "default", "赛事项目名（data/event_projs/<项目名>/event.db）")
	flag.Parse()

	cfg, err := config.Load(*configPath)
	if err != nil {
		fmt.Fprintf(os.Stderr, "加载配置失败: %v\n", err)
		os.Exit(1)
	}

	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: cfg.Log.SlogLevel()}))
	slog.SetDefault(logger)

	st, err := store.Open(cfg.DataDir)
	if err != nil {
		logger.Error("打开系统库失败", "err", err)
		os.Exit(1)
	}
	defer func() { _ = st.Close() }()

	if err := st.Migrate(); err != nil {
		logger.Error("系统库迁移失败", "err", err)
		os.Exit(1)
	}

	eventDB, err := openEventDB(cfg.DataDir, *project)
	if err != nil {
		logger.Error("打开赛事库失败", "err", err)
		os.Exit(1)
	}
	defer func() { _ = eventDB.Close() }()
	if err := store.MigrateEvent(eventDB); err != nil {
		logger.Error("赛事库迁移失败", "err", err)
		os.Exit(1)
	}
	logger.Info("数据库就绪", "dataDir", cfg.DataDir, "project", *project)

	authSvc := auth.New(st.DB(), auth.Options{Logger: logger})
	hub := realtime.NewHub(eventDB, logger)
	hub.SetAllowedOrigins(cfg.Server.AllowedOrigins)
	defer func() { _ = hub.Close() }()

	// 可信代理：默认空，表示不采信任何代理头（见 devdocs/08 第 1 节）。
	// 反向代理部署时用 SCOREBOARD_TRUSTED_PROXIES 指定代理 IP/CIDR，逗号分隔。
	if raw := strings.TrimSpace(os.Getenv("SCOREBOARD_TRUSTED_PROXIES")); raw != "" {
		if err := middleware.SetTrustedProxies(strings.Split(raw, ",")); err != nil {
			logger.Error("可信代理配置非法", "err", err)
			os.Exit(1)
		}
	}

	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()

	if username, password, created, err := authSvc.EnsureDefaultAdmin(ctx); err != nil {
		logger.Error("初始化默认管理员失败", "err", err)
		os.Exit(1)
	} else if created {
		fmt.Print(initialAdminBanner(username, password))
		logger.Warn("已创建默认管理员，初始密码仅在上方一次性输出，不写入日志", "username", username)
	}

	backupSvc := export.NewService(st.DB(), eventDB, filepath.Join(cfg.DataDir, "backups"), cfg.Backup.Keep, logger)

	srv := &http.Server{
		Addr: cfg.Server.Addr(),
		Handler: httpapi.New(httpapi.Options{
			Logger:  logger,
			Version: version,
			System:  st.DB(),
			Event:   eventDB,
			Auth:    authSvc,
			DataDir: cfg.DataDir,
			Backup:  backupSvc,
			// POST /api/shutdown 复用同一个关闭信号：取消 ctx 后走下面的 Shutdown + 关库。
			Shutdown:   stop,
			ProjectDir: filepath.Join(cfg.DataDir, "event_projs", *project),
			Display:    displaySender{hub: hub},
			Realtime:   hub,
			WS:         hub.Handler(),
		}),
		ReadHeaderTimeout: 10 * time.Second,
	}

	// 定时备份跟随服务端生命周期：收到退出信号（ctx 取消）即停止。
	backupSvc.StartAuto(ctx, time.Duration(cfg.Backup.IntervalMinutes)*time.Minute)

	go func() {
		logger.Info("服务启动", "addr", srv.Addr, "version", version)
		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			logger.Error("服务异常退出", "err", err)
			os.Exit(1)
		}
	}()

	<-ctx.Done()

	logger.Info("正在关闭…")
	// Console 的关闭握手要求 3 秒内完成，超时后仍会关库并退出（defer 顺序保证）。
	shutdownCtx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
	defer cancel()
	if err := srv.Shutdown(shutdownCtx); err != nil {
		logger.Error("关闭超时", "err", err)
	}
}

// initialAdminBanner 组装初始管理员提示块：初始密码只在这里一次性输出，不写入结构化日志。
// 末尾的纯 ASCII 锚供现场在 logs\console.log 里检索——中文 findstr 在 chcp 936/65001 下不可靠。
func initialAdminBanner(username, password string) string {
	return fmt.Sprintf("\n========================================\n"+
		" 已创建默认管理员\n 用户名: %s\n 初始密码: %s\n 首次登录后请立即修改密码\n"+
		"=== INITIAL ADMIN CREATED (password above) ===\n"+
		"========================================\n\n", username, password)
}

// displaySender 把 httpapi 的大屏命令接口适配到实时层。
type displaySender struct{ hub *realtime.Hub }

func (d displaySender) SendDisplayCommand(action string, payload any) error {
	cmd, err := realtime.NewDisplayCommand(action, payload)
	if err != nil {
		return err
	}
	d.hub.SendCommand(cmd)
	return nil
}

// runBackup 实现 `scoreboard backup` 子命令：内置 VACUUM INTO，不依赖外部 sqlite3.exe。
func runBackup(args []string) error {
	fs := flag.NewFlagSet("backup", flag.ExitOnError)
	configPath := fs.String("config", "config.yaml", "配置文件路径")
	project := fs.String("project", "default", "赛事项目名")
	reason := fs.String("reason", "manual", "备份原因：manual / publish / auto")
	if err := fs.Parse(args); err != nil {
		return err
	}

	cfg, err := config.Load(*configPath)
	if err != nil {
		return err
	}
	dir := filepath.Join(cfg.DataDir, "backups")
	if err := os.MkdirAll(dir, 0o755); err != nil {
		return err
	}

	sysDB, err := openSQLite(filepath.Join(cfg.DataDir, "system.db"))
	if err != nil {
		return err
	}
	defer func() { _ = sysDB.Close() }()
	if _, err := export.Backup(sysDB, export.BackupOptions{Dir: dir, Prefix: "system", Reason: *reason}); err != nil {
		return err
	}

	evPath := filepath.Join(cfg.DataDir, "event_projs", *project, "event.db")
	if _, err := os.Stat(evPath); err == nil {
		evDB, err := openSQLite(evPath)
		if err != nil {
			return err
		}
		defer func() { _ = evDB.Close() }()
		// 前缀必须与 Service 一致：PruneBackups 只清理 <prefix>-*，用项目名会让 CLI 备份只增不减。
		if _, err := export.Backup(evDB, export.BackupOptions{Dir: dir, Prefix: "event", Reason: *reason}); err != nil {
			return err
		}
	}

	items, err := export.ListBackups(dir, "")
	if err != nil {
		return err
	}
	fmt.Printf("备份完成：%s（现有 %d 份）\n", dir, len(items))
	return nil
}

// openEventDB 打开（必要时创建）赛事库；store 包不持有赛事库连接，
// 由 main 负责生命周期，再交给 httpapi 与实时层使用。
func openEventDB(dataDir, project string) (*sql.DB, error) {
	dir := filepath.Join(dataDir, "event_projs", project)
	if err := os.MkdirAll(dir, 0o755); err != nil {
		return nil, fmt.Errorf("创建赛事目录 %s: %w", dir, err)
	}
	return openSQLite(filepath.Join(dir, "event.db"))
}

func openSQLite(path string) (*sql.DB, error) {
	dsn := "file:" + path +
		"?_pragma=journal_mode(WAL)" +
		"&_pragma=foreign_keys(1)" +
		"&_pragma=busy_timeout(5000)"

	db, err := sql.Open("sqlite", dsn)
	if err != nil {
		return nil, fmt.Errorf("打开数据库 %s: %w", path, err)
	}
	db.SetMaxOpenConns(1)
	if err := db.Ping(); err != nil {
		_ = db.Close()
		return nil, fmt.Errorf("连接数据库 %s: %w", path, err)
	}
	return db, nil
}