package cmd

import (
	"context"
	"errors"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"otpm/database"
	"otpm/handlers"
	"otpm/utils"
	"syscall"
	"time"

	"github.com/jmoiron/sqlx"
	"github.com/julienschmidt/httprouter"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

var rootCmd = &cobra.Command{
	Use:   "otpm",
	Short: "otp backend for microapp on wechat",
	Run: func(cmd *cobra.Command, args []string) {
		startApp()
	},
}

func Execute() {
	if err := rootCmd.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

func init() {
	cobra.OnInitialize(initConfig)

	rootCmd.PersistentFlags().StringP("config", "c", "", "config file (default is $HOME/config.yaml)")
	rootCmd.PersistentFlags().StringP("driver", "d", "sqlite3", "database driver (sqlite3, postgres, mysql)")
	rootCmd.PersistentFlags().StringP("dsn", "s", "", "database connection string")
	rootCmd.PersistentFlags().StringP("port", "p", "8080", "port to listen on")

	viper.BindPFlag("database.driver", rootCmd.PersistentFlags().Lookup("driver"))
	viper.BindPFlag("database.dsn", rootCmd.PersistentFlags().Lookup("dsn"))
	viper.BindPFlag("port", rootCmd.PersistentFlags().Lookup("port"))
}

func initConfig() {
	if cfgFile := viper.GetString("config"); cfgFile != "" {
		viper.SetConfigFile(cfgFile)
	} else {
		viper.AddConfigPath(".")
		viper.SetConfigName("config")
		viper.SetConfigType("yaml")
	}

	if err := viper.ReadInConfig(); err != nil {
		log.Fatalf("Error reading config file: %v", err)
	}
}

type App struct {
	db     *sqlx.DB
	router http.Handler
	port   int
}

func NewApp() (*App, error) {
	db, err := connectDB()
	if err != nil {
		return nil, err
	}

	if err := runMigrations(db); err != nil {
		return nil, err
	}

	router := setupRouter(db)

	port := viper.GetInt("port")

	return &App{
		db:     db,
		router: router,
		port:   port,
	}, nil
}

func connectDB() (*sqlx.DB, error) {
	db, err := database.InitDB()
	if err != nil {
		return nil, fmt.Errorf("failed to connect to the database: %v", err)
	}
	return db, nil
}

func runMigrations(db *sqlx.DB) error {
	if err := database.MigrateDB(db); err != nil {
		log.Fatalf("Error migrating the database: %v", err)
		return fmt.Errorf("error migrating the database: %w", err)
	}
	return nil
}

func setupRouter(db *sqlx.DB) http.Handler {
	handler := &handlers.Handler{DB: db}

	router := httprouter.New()
	router.POST("/login", utils.AdaptHandler(handler.Login))
	router.POST("/refresh", utils.AdaptHandler(utils.AuthMiddleware(handler.RefreshToken)))
	router.POST("/set", utils.AdaptHandler(utils.AuthMiddleware(handler.UpdateOrCreateOtp)))
	router.GET("/get", utils.AdaptHandler(utils.AuthMiddleware(handler.GetOtp)))

	return router
}

func (a *App) Start() error {
	server := &http.Server{Addr: fmt.Sprintf(":%d", a.port), Handler: a.router}
	go func() {
		if err := server.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			log.Fatalf("Failed to start server: %v", err)
		}
	}()

	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	log.Println("Shutting down server...")

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	return server.Shutdown(ctx)
}

func startApp() {
	app, err := NewApp()
	if err != nil {
		log.Fatalf("Failed to initialize application: %v", err)
	}
	defer func() {
		if err := app.db.Close(); err != nil {
			log.Printf("Failed to close database connection: %v", err)
		}
	}()
	if err := app.Start(); err != nil {
		log.Fatalf("Failed to start application: %v", err)
	}
}