package bootstrap

import (
	"context"
	"crypto/tls"
	"errors"
	"fmt"
	"net/http"
	"os"
	"os/signal"
	"sync"
	"sync/atomic"
	"syscall"
	"time"

	"go.uber.org/zap"

	"spark-server/internal/infrastructure/id"
	"spark-server/internal/infrastructure/logger"
	"spark-server/internal/infrastructure/mysql"
	"spark-server/internal/infrastructure/objectstore"
	redisx "spark-server/internal/infrastructure/redis"
	adminlogic "spark-server/internal/module/admin/logic"
	adminmodel "spark-server/internal/module/admin/model"
	authlogic "spark-server/internal/module/auth/logic"
	convlogic "spark-server/internal/module/conversation/logic"
	convmodel "spark-server/internal/module/conversation/model"
	deliverlogic "spark-server/internal/module/deliver/logic"
	delivermodel "spark-server/internal/module/deliver/model"
	favlogic "spark-server/internal/module/favorite/logic"
	favmodel "spark-server/internal/module/favorite/model"
	friendlogic "spark-server/internal/module/friend/logic"
	friendmodel "spark-server/internal/module/friend/model"
	grouplogic "spark-server/internal/module/group/logic"
	groupmodel "spark-server/internal/module/group/model"
	inboxlogic "spark-server/internal/module/inbox/logic"
	inboxmodel "spark-server/internal/module/inbox/model"
	msglogic "spark-server/internal/module/message/logic"
	msgmodel "spark-server/internal/module/message/model"
	momentlogic "spark-server/internal/module/moment/logic"
	momentmodel "spark-server/internal/module/moment/model"
	smslogic "spark-server/internal/module/sms/logic"
	squarelogic "spark-server/internal/module/square/logic"
	squaremodel "spark-server/internal/module/square/model"
	synclogic "spark-server/internal/module/sync/logic"
	syncmodel "spark-server/internal/module/sync/model"
	uploadlogic "spark-server/internal/module/upload/logic"
	userlogic "spark-server/internal/module/user/logic"
	usermodel "spark-server/internal/module/user/model"
	"spark-server/internal/pkg/ratelimit"
	httpx "spark-server/internal/transport/http"
	tcp "spark-server/internal/transport/tcp"
	"spark-server/internal/transport/tcp/session"
)

type App struct {
	cfg          *Config
	log          *zap.Logger
	logClose     func() error
	http         *httpx.Server
	tcp          *tcp.Server
	pool         tcp.TaskPool
	mysql        *mysql.DB
	redis        *redisx.Client
	idgen        *id.Generator
	sessions     session.Manager
	deliver      *deliverlogic.Worker
	accepting    atomic.Bool
	shutdownOnce sync.Once
}

func New(cfg *Config) (*App, error) {
	log, logClose := logger.New(&logger.Options{
		Level:    cfg.Log.Level,
		Encoding: cfg.Log.Encoding,
		Console:  cfg.Log.Console,
		File: logger.FileOptions{
			Path:       cfg.Log.File.Path,
			MaxSizeMB:  cfg.Log.File.MaxSizeMB,
			MaxBackups: cfg.Log.File.MaxBackups,
			MaxAgeDays: cfg.Log.File.MaxAgeDays,
			Compress:   cfg.Log.File.Compress,
		},
	})
	idgen, err := id.New(cfg.ID.SnowflakeWorkerID)
	if err != nil {
		_ = logClose()
		return nil, err
	}
	db, err := mysql.Open(log, &mysql.Options{
		DSN:             cfg.MySQL.DSN,
		SlowThreshold:   cfg.MySQL.SlowThreshold,
		LogLevel:        cfg.MySQL.LogLevel,
		ZapLevel:        cfg.Log.Level,
		MaxOpenConns:    cfg.MySQL.MaxOpenConns,
		MaxIdleConns:    cfg.MySQL.MaxIdleConns,
		ConnMaxLifetime: cfg.MySQL.ConnMaxLifetime,
		ConnMaxIdleTime: cfg.MySQL.ConnMaxIdleTime,
	})
	if err != nil {
		_ = logClose()
		return nil, err
	}
	rdb, err := redisx.Open(&redisx.Options{
		Addr:     cfg.Redis.Addr,
		Username: cfg.Redis.Username,
		Password: cfg.Redis.Password,
		DB:       cfg.Redis.DB,
	})
	if err != nil {
		_ = db.Close()
		_ = logClose()
		return nil, err
	}
	return finishApp(cfg, log, logClose, idgen, db, rdb)
}

func finishApp(cfg *Config, log *zap.Logger, logClose func() error, idgen *id.Generator, db *mysql.DB, rdb *redisx.Client) (*App, error) {
	jwtSvc, err := authlogic.NewJWT(&authlogic.Options{
		Secret:     cfg.JWT.Secret,
		Issuer:     cfg.JWT.Issuer,
		TTL:        cfg.JWT.TTL,
		RefreshTTL: cfg.JWT.RefreshTTL,
		Denylist:   jwtDenylist(rdb, cfg.JWT.DenylistPrefix),
		Pairs:      jwtPairs(rdb, cfg.JWT.RefreshPrefix),
	})
	if err != nil {
		_ = rdb.Close()
		_ = db.Close()
		_ = logClose()
		return nil, err
	}
	pool := tcp.NewTaskPoolRecover(cfg.TaskPool.Size, cfg.TaskPool.Queue, func(rec any) {
		log.Error("taskpool panic", zap.Any("panic", rec))
	})
	sessions := session.NewManager()
	tlsConf, err := loadTLS(cfg.Server.TCP.TLS)
	if err != nil {
		pool.Close()
		_ = rdb.Close()
		_ = db.Close()
		_ = logClose()
		return nil, err
	}
	authLimit := ratelimit.New(cfg.RateLimit.AuthPerSecond)
	objects, err := objectstore.Open(&objectstore.Options{
		Endpoint:       cfg.ObjectStorage.Endpoint,
		PublicEndpoint: cfg.ObjectStorage.PublicEndpoint,
		AccessKey:      cfg.ObjectStorage.AccessKey,
		SecretKey:      cfg.ObjectStorage.SecretKey,
		Bucket:         cfg.ObjectStorage.Bucket,
		Region:         cfg.ObjectStorage.Region,
		UseSSL:         cfg.ObjectStorage.UseSSL,
		ChatExpireDays: cfg.ObjectStorage.ChatExpireDays,
		Log:            log,
	})
	if err != nil {
		pool.Close()
		_ = rdb.Close()
		_ = db.Close()
		_ = logClose()
		return nil, err
	}
	app := &App{cfg: cfg, log: log, logClose: logClose, pool: pool, mysql: db, redis: rdb, idgen: idgen, sessions: sessions}
	probe := &Probe{mysql: db, redis: rdb, objects: objects, pool: pool, accepting: &app.accepting, requireDeps: cfg.Production()}
	userRepo := wireUserRepo(db)
	smsSvc := wireSMS(cfg, rdb, userRepo)
	users := userlogic.NewService(userRepo, smsSvc, idgen, wireUserObjects(objects))
	login := authlogic.NewLoginService(jwtSvc, users)
	login.Sessions = sessions
	var deliverQueue deliverlogic.Queue
	inbox, mailbox := wireInbox(idgen, db, rdb)
	app.deliver, deliverQueue = wireDeliver(cfg, log, rdb, sessions, inbox, mailbox)
	syncSvc := synclogic.NewService(inbox, mailbox)
	chat := wireChat(idgen, db)
	friends := wireFriends(idgen, db, users, deliverQueue, chat)
	groups := wireGroups(idgen, db, users, friends, deliverQueue, objects, chat)
	messages := wireMessages(idgen, friends, groups, deliverQueue, chat)
	files := wireFiles(cfg, objects, groups)
	favorites := wireFavorites(idgen, db, objects, chat)
	moments := wireMoments(idgen, db, objects, friends, users)
	square := wireSquare(idgen, db, objects, friends, users)
	users.BindAccountCleanup(jwtSvc, sessions, accountCleaners(friends, moments, square, groups, favorites, inbox, mailbox, chat)...)
	adminSvc, adminTokens := wireAdmin(cfg, db, groups, idgen)
	app.tcp = tcp.NewServer(log, pool, sessions, &tcp.Options{
		Addr:          cfg.Server.TCP.Addr,
		Multicore:     cfg.Server.TCP.Multicore,
		KeepAlive:     cfg.Server.TCP.KeepAlive,
		RecvBuffer:    cfg.Server.TCP.RecvBuffer,
		SendBuffer:    cfg.Server.TCP.SendBuffer,
		MaxFrameSize:  cfg.Server.TCP.MaxFrameSize,
		TLS:           tlsConf,
		ProxyProtocol: cfg.Server.TCP.ProxyProtocol,
		IdleTimeout:   cfg.Server.TCP.IdleTimeout,
		OutboundSize:  cfg.Session.OutboundQueueSize,
		RatePerSec:    cfg.RateLimit.MessagePerSecond,
		CompressMin:   cfg.Server.TCP.CompressMinSize,
		IDs:           idgen,
		Auth:          jwtSvc,
		AuthLimiter:   authLimit,
		Messages:      messages,
		Sync:          syncSvc,
	})
	app.http = httpx.New(log, cfg.Server.HTTP.Addr, httpEngineDeps(
		jwtSvc, login, smsSvc, users, friends, groups, files, favorites, moments, square, messages, syncSvc, adminSvc, adminTokens, probe, authLimit,
	))
	return app, nil
}

func httpEngineDeps(
	jwtSvc *authlogic.JWT,
	login *authlogic.LoginService,
	sms *smslogic.Service,
	users *userlogic.Service,
	friends *friendlogic.Service,
	groups *grouplogic.Service,
	files *uploadlogic.Service,
	favorites *favlogic.Service,
	moments *momentlogic.Service,
	square *squarelogic.Service,
	messages *msglogic.Service,
	syncSvc *synclogic.Service,
	adminSvc *adminlogic.Service,
	adminTokens *adminlogic.TokenService,
	probe *Probe,
	authLimit *ratelimit.Limiter,
) *httpx.EngineDeps {
	return &httpx.EngineDeps{
		Auth: jwtSvc, Login: login, SMS: sms, Users: users, Friends: friends, Groups: groups,
		Files: files, Favorites: favorites, Moments: moments, Square: square,
		Messages: messages, Sync: syncSvc, Admin: adminSvc, AdminTokens: adminTokens,
		Health: probe, AuthLimiter: authLimit,
	}
}

func wireAdmin(cfg *Config, db *mysql.DB, groups *grouplogic.Service, idgen *id.Generator) (*adminlogic.Service, *adminlogic.TokenService) {
	tokens := adminlogic.NewTokenService(cfg.Admin.JWTSecret)
	var repo *adminmodel.Repo
	if db != nil && db.Ready() {
		repo = adminmodel.NewRepo(db.Gorm())
	}
	return adminlogic.NewService(repo, groups, idgen), tokens
}

func loadTLS(t TLSConfig) (*tls.Config, error) {
	if t.CertFile == "" || t.KeyFile == "" {
		return nil, nil
	}
	cert, err := tls.LoadX509KeyPair(t.CertFile, t.KeyFile)
	if err != nil {
		return nil, fmt.Errorf("tls: %w", err)
	}
	return &tls.Config{MinVersion: tls.VersionTLS12, Certificates: []tls.Certificate{cert}}, nil
}

func wireUserRepo(db *mysql.DB) userlogic.Repository {
	if db != nil && db.Ready() {
		return usermodel.NewRepo(db.Gorm())
	}
	return usermodel.NewMemoryRepo()
}

func wireUserObjects(store *objectstore.Store) userlogic.Objects {
	if store != nil && store.Ready() {
		return store
	}
	return nil
}

type chatStores struct {
	msgs  msglogic.Repository
	chats msglogic.Conversations
	p2p   *convlogic.P2PService
}

func wireChat(idgen *id.Generator, db *mysql.DB) chatStores {
	if idgen == nil {
		return chatStores{}
	}
	if db != nil && db.Ready() {
		convRepo := convmodel.NewRepo(db.Gorm())
		return chatStores{msgs: msgmodel.NewRepo(db.Gorm()), chats: convRepo, p2p: convlogic.NewP2PService(convRepo, idgen)}
	}
	mem := convmodel.NewMemoryP2P()
	return chatStores{msgs: msgmodel.NewMemoryRepo(), chats: mem, p2p: convlogic.NewP2PService(mem, idgen)}
}

func wireFriends(idgen *id.Generator, db *mysql.DB, users *userlogic.Service, q friendlogic.DeliverQueue, chat chatStores) *friendlogic.Service {
	var repo friendlogic.Repository
	if db != nil && db.Ready() {
		repo = friendmodel.NewRepo(db.Gorm())
	} else {
		repo = friendmodel.NewMemoryRepo()
	}
	return friendlogic.NewService(repo, users, idgen, friendlogic.NewGreeter(chat.p2p, chat.msgs, idgen, q))
}

func wireGroups(idgen *id.Generator, db *mysql.DB, users *userlogic.Service, friends *friendlogic.Service, q grouplogic.DeliverQueue, store *objectstore.Store, chat chatStores) *grouplogic.Service {
	var repo grouplogic.Repository
	if db != nil && db.Ready() {
		repo = groupmodel.NewRepo(db.Gorm())
	} else {
		repo = groupmodel.NewMemoryRepo()
	}
	var objects grouplogic.Objects
	if store != nil && store.Ready() {
		objects = store
	}
	return grouplogic.NewService(repo, users, friends, idgen, chat.msgs, q, objects)
}

func wireFiles(cfg *Config, store *objectstore.Store, groups *grouplogic.Service) *uploadlogic.Service {
	if store == nil || !store.Ready() {
		return nil
	}
	return uploadlogic.NewService(store, uploadlogic.Options{
		TTL:    cfg.ObjectStorage.PresignTTL,
		Limit:  ratelimit.New(cfg.RateLimit.UploadPerSecond),
		Groups: groups,
	})
}

func wireFavorites(idgen *id.Generator, db *mysql.DB, store *objectstore.Store, chat chatStores) *favlogic.Service {
	if idgen == nil {
		return nil
	}
	var repo favlogic.Repository
	if db != nil && db.Ready() {
		repo = favmodel.NewRepo(db.Gorm())
	} else {
		repo = favmodel.NewMemoryRepo()
	}
	var objects favlogic.Objects
	if store != nil && store.Ready() {
		objects = store
	}
	return favlogic.NewService(repo, chat.msgs, chat.chats, objects, idgen)
}

func wireSquare(idgen *id.Generator, db *mysql.DB, store *objectstore.Store, friends *friendlogic.Service, users *userlogic.Service) *squarelogic.Service {
	if idgen == nil || friends == nil || users == nil {
		return nil
	}
	var repo squarelogic.Repository
	if db != nil && db.Ready() {
		repo = squaremodel.NewRepo(db.Gorm())
	} else {
		repo = squaremodel.NewMemoryRepo()
	}
	var objects squarelogic.Objects
	if store != nil && store.Ready() {
		objects = store
	}
	return squarelogic.NewService(repo, friends, users, objects, idgen)
}

func wireMoments(idgen *id.Generator, db *mysql.DB, store *objectstore.Store, friends *friendlogic.Service, users *userlogic.Service) *momentlogic.Service {
	if idgen == nil || friends == nil || users == nil {
		return nil
	}
	var repo momentlogic.Repository
	if db != nil && db.Ready() {
		repo = momentmodel.NewRepo(db.Gorm())
	} else {
		repo = momentmodel.NewMemoryRepo()
	}
	var objects momentlogic.Objects
	if store != nil && store.Ready() {
		objects = store
	}
	return momentlogic.NewService(repo, friends, users, objects, idgen)
}

func wireInbox(idgen *id.Generator, db *mysql.DB, rdb *redisx.Client) (inboxlogic.Store, synclogic.Mailbox) {
	var inbox inboxlogic.Store
	if rdb != nil && rdb.Ready() {
		inbox = inboxmodel.NewRedisStore(rdb.RDB())
	} else {
		inbox = inboxmodel.NewMemoryStore()
	}
	var box synclogic.Mailbox
	if db != nil && db.Ready() {
		box = syncmodel.NewStore(db.Gorm(), idgen)
	} else {
		box = syncmodel.NewMemoryStore(idgen)
	}
	return inbox, box
}

func wireDeliver(cfg *Config, log *zap.Logger, rdb *redisx.Client, sessions session.Manager, inbox inboxlogic.Store, mailbox deliverlogic.Mailbox) (*deliverlogic.Worker, deliverlogic.Queue) {
	var q deliverlogic.Queue
	var done deliverlogic.Deduper
	if rdb != nil && rdb.Ready() {
		q = delivermodel.NewRedisQueue(rdb.RDB(), cfg.Redis.DeliverQueueKey, cfg.Redis.DeliverProcessingKey)
		done = delivermodel.NewRedisDone(rdb.RDB(), cfg.Redis.DeliverDonePrefix, cfg.Deliver.DoneTTL)
	} else {
		q = delivermodel.NewMemoryQueue()
		done = delivermodel.NewMemoryDone()
	}
	return deliverlogic.NewWorker(log, q, done, deliverlogic.WorkerOptions{
		Workers:     cfg.Deliver.Workers,
		TakeTimeout: cfg.Deliver.TakeTimeout,
		Handler:     deliverlogic.InboxFanout(sessions, inbox, mailbox),
	}), q
}

func wireMessages(idgen *id.Generator, friends *friendlogic.Service, groups *grouplogic.Service, q msglogic.DeliverQueue, chat chatStores) *msglogic.Service {
	if idgen == nil {
		return nil
	}
	return msglogic.NewService(chat.msgs, chat.chats, chat.p2p, friends, groups, idgen, q)
}

func accountCleaners(
	friends *friendlogic.Service,
	moments *momentlogic.Service,
	square *squarelogic.Service,
	groups *grouplogic.Service,
	favorites *favlogic.Service,
	inbox inboxlogic.Store,
	mailbox synclogic.Mailbox,
	chat chatStores,
) []userlogic.UserDataCleaner {
	out := make([]userlogic.UserDataCleaner, 0, 8)
	if friends != nil {
		out = append(out, friends)
	}
	if moments != nil {
		out = append(out, moments)
	}
	if square != nil {
		out = append(out, square)
	}
	if groups != nil {
		out = append(out, groups)
	}
	if favorites != nil {
		out = append(out, favorites)
	}
	if inbox != nil {
		out = append(out, userlogic.CleanerFunc(inbox.PurgeUser))
	}
	if mailbox != nil {
		out = append(out, userlogic.CleanerFunc(mailbox.PurgeUser))
	}
	if chat.msgs != nil {
		out = append(out, userlogic.CleanerFunc(chat.msgs.PurgeUser))
	}
	if p, ok := chat.chats.(interface {
		PurgeUser(context.Context, int64) error
	}); ok {
		out = append(out, userlogic.CleanerFunc(p.PurgeUser))
	}
	return out
}

func jwtDenylist(rdb *redisx.Client, prefix string) authlogic.Denylist {
	if rdb != nil && rdb.Ready() {
		return authlogic.NewRedisDenylist(rdb.RDB(), prefix)
	}
	return authlogic.NewMemoryDenylist()
}

func jwtPairs(rdb *redisx.Client, prefix string) authlogic.PairStore {
	if rdb != nil && rdb.Ready() {
		return authlogic.NewRedisPairs(rdb.RDB(), prefix)
	}
	return authlogic.NewMemoryPairs()
}

func (a *App) Run() error {
	if a.deliver != nil {
		a.deliver.Start(context.Background())
	}
	errCh := make(chan error, 2)
	go func() { errCh <- a.http.Start() }()
	go func() { errCh <- a.tcp.Start() }()
	if err := a.waitListening(errCh); err != nil {
		return errors.Join(err, a.Shutdown())
	}
	a.accepting.Store(true)
	a.log.Info("ready")
	return a.serve(errCh)
}

func (a *App) waitListening(errCh <-chan error) error {
	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
	defer cancel()
	done := make(chan error, 1)
	go func() {
		done <- errors.Join(a.http.WaitReady(ctx), a.tcp.WaitReady(ctx))
	}()
	select {
	case err := <-errCh:
		if err == nil {
			return ctx.Err()
		}
		return err
	case err := <-done:
		return err
	}
}

func (a *App) serve(errCh <-chan error) error {
	sigCh := make(chan os.Signal, 1)
	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
	defer signal.Stop(sigCh)
	select {
	case err := <-errCh:
		a.log.Error("server exit", zap.Error(err))
		return errors.Join(err, a.Shutdown())
	case sig := <-sigCh:
		a.log.Info("shutdown", zap.String("signal", sig.String()))
		return a.Shutdown()
	}
}

func (a *App) Shutdown() error {
	var err error
	a.shutdownOnce.Do(func() { err = a.doShutdown() })
	return err
}

func (a *App) doShutdown() error {
	a.accepting.Store(false)
	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
	defer cancel()
	var err error
	if e := a.http.Stop(ctx); e != nil && !errors.Is(e, http.ErrServerClosed) {
		err = errors.Join(err, e)
	}
	if e := a.tcp.Stop(ctx); e != nil {
		err = errors.Join(err, e)
	}
	if a.pool != nil {
		a.pool.Close()
	}
	if a.deliver != nil {
		a.deliver.Stop()
	}
	err = errors.Join(err, a.redis.Close(), a.mysql.Close())
	if a.logClose != nil {
		err = errors.Join(err, a.logClose())
	}
	return err
}