package app

import (
	"context"
	"fmt"
	"net/http"
	"time"

	"mengstack/internal/app/cache"
	"mengstack/internal/app/database"
	"mengstack/internal/app/health"
	"mengstack/internal/app/middleware"
	appmigrate "mengstack/internal/app/migrate"
	"mengstack/internal/app/upgrade"
	"mengstack/internal/config"
	"mengstack/internal/kernel/i18n"
	"mengstack/internal/kernel/plugin"
	"mengstack/internal/kernel/jobs"
	"mengstack/internal/kernel/tenant"
	kws "mengstack/internal/kernel/websocket"
	"mengstack/internal/logger"
	"mengstack/migrations"
	authinterfaces "mengstack/internal/modules/auth/interfaces"
	rbacinterfaces "mengstack/internal/modules/rbac/interfaces"
	orginterfaces "mengstack/internal/modules/org/interfaces"
	auditinterfaces "mengstack/internal/modules/audit/interfaces"
	settingsinterfaces "mengstack/internal/modules/settings/interfaces"
	notificationinterfaces "mengstack/internal/modules/notification/interfaces"
	dashboardinterfaces "mengstack/internal/modules/dashboard/interfaces"
	exampleinterfaces "mengstack/internal/modules/example/interfaces"

	"github.com/gin-gonic/gin"
	"github.com/redis/go-redis/v9"
	"go.uber.org/fx"
	"go.uber.org/zap"
	"gorm.io/gorm"
)

var Module = fx.Module("app",
	fx.Provide(
		newEngine,
		newServer,
		func(log *zap.Logger) *kws.Hub {
			return kws.NewHub(log)
		},
		func(hub *kws.Hub, log *zap.Logger) *kws.Handler {
			return kws.NewHandler(hub, log)
		},
		func(log *zap.Logger) (*jobs.Scheduler, error) {
			return jobs.NewScheduler(log)
		},
	),
	fx.Invoke(registerLifecycle),
)

func newEngine(
	cfg *config.Config,
	log *zap.Logger,
	db *gorm.DB,
	rdb *redis.Client,
	authHandler *authinterfaces.Handler,
	authMW gin.HandlerFunc,
	rbacHandler *rbacinterfaces.Handler,
	orgHandler *orginterfaces.Handler,
	auditHandler *auditinterfaces.Handler,
	settingsHandler *settingsinterfaces.Handler,
	notificationHandler *notificationinterfaces.Handler,
	dashboardHandler *dashboardinterfaces.Handler,
	examplePlugin *exampleinterfaces.ExamplePlugin,
	wsHandler *kws.Handler,
) *gin.Engine {
	ginMode := "release"
	if cfg.Server.Mode == "debug" || cfg.Server.Mode == "dev" {
		ginMode = "debug"
	}
	gin.SetMode(ginMode)
	r := gin.New()

	r.Use(middleware.RequestID())
	r.Use(middleware.RequestLogger(log))
	r.Use(middleware.SecurityHeaders())
	r.Use(middleware.CORS())
	r.Use(middleware.AcceptLanguage())
	r.Use(middleware.RateLimitRedis(rdb))
	r.Use(middleware.BodyLimit(10 << 20))
	r.Use(middleware.Recovery(log))

	healthHandler := health.NewHandler(db, rdb, log)
	r.GET("/health", healthHandler.Handle)
	r.GET("/healthz", healthHandler.Healthz)
	r.GET("/readyz", healthHandler.Readyz)
	r.GET("/api/version", healthHandler.Version)

	upgradeHandler := upgrade.NewHandler()
	r.GET("/api/upgrade/check", upgradeHandler.Check)

	r.GET("/swagger/*any", middleware.SwaggerHandler())

	tenantResolver := tenant.NewResolver(cfg.Tenant)

	authinterfaces.SetupRoutes(r, authHandler, authMW, tenantResolver)
	rbacinterfaces.SetupRoutes(r, rbacHandler, authMW, tenantResolver)
	orginterfaces.SetupRoutes(r, orgHandler, authMW, tenantResolver)
	auditinterfaces.SetupRoutes(r, auditHandler, authMW, tenantResolver)
	settingsinterfaces.SetupRoutes(r, settingsHandler, authMW, tenantResolver)
	notificationinterfaces.SetupRoutes(r, notificationHandler, authMW, tenantResolver)
	dashboardinterfaces.SetupRoutes(r, dashboardHandler, authMW, tenantResolver)

	r.GET("/api/v1/ws", authMW, wsHandler.ServeWS)

	examplePlugin.SetupRoutes(r, authMW, tenantResolver)

	return r
}

func newServer(cfg *config.Config, engine *gin.Engine) *http.Server {
	return &http.Server{
		Addr:         fmt.Sprintf(":%d", cfg.Server.Port),
		Handler:      engine,
		ReadTimeout:  15 * time.Second,
		WriteTimeout: 15 * time.Second,
		IdleTimeout:  60 * time.Second,
	}
}

func registerLifecycle(lc fx.Lifecycle, srv *http.Server, db *gorm.DB, sched *jobs.Scheduler, log *zap.Logger) {
	lc.Append(fx.Hook{
		OnStart: func(ctx context.Context) error {
			if err := i18n.Init(i18n.Files, "zh"); err != nil {
				return fmt.Errorf("init i18n: %w", err)
			}
			log.Info("i18n initialized")

			if err := appmigrate.Run(db, migrations.Files); err != nil {
				return fmt.Errorf("run migrations: %w", err)
			}
			log.Info("database migrations applied")

			for _, p := range plugin.All() {
				meta := p.Metadata()
				pfs := p.MigrationsFS()
				if pfs == nil {
					continue
				}
				if err := appmigrate.RunPlugin(db, meta.Name, pfs); err != nil {
					return fmt.Errorf("plugin %s migrations: %w", meta.Name, err)
				}
				log.Info("plugin migrations applied", zap.String("plugin", meta.Name))
			}

			sandbox := plugin.NewSandbox(log)
			if err := plugin.InitAll(log, sandbox); err != nil {
				return err
			}

			sched.Start()

			log.Info("server starting", zap.String("addr", srv.Addr))
			go func() {
				if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
					log.Error("server error", zap.Error(err))
				}
			}()
			return nil
		},
		OnStop: func(ctx context.Context) error {
			shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
			defer cancel()
			log.Info("server shutting down")
			if err := sched.Stop(); err != nil {
				log.Error("scheduler stop error", zap.Error(err))
			}
			return srv.Shutdown(shutdownCtx)
		},
	})
}

func NewApp() *fx.App {
	return fx.New(
		fx.Provide(
			func() (*config.Config, error) { return config.Load() },
			func(cfg *config.Config) (*zap.Logger, error) { return logger.New(cfg.Log) },
		),
		database.Module,
		cache.Module,
		authinterfaces.Module,
		rbacinterfaces.Module,
		orginterfaces.Module,
		auditinterfaces.Module,
		settingsinterfaces.Module,
		notificationinterfaces.Module,
		dashboardinterfaces.Module,
		exampleinterfaces.Module,
		Module,
	)
}