feat: long poller error backoff

README.md

@@ -1 +1,13 @@
-**gomax** is a framework for MAX BotAPI, originating from [github.com/abelith/etu-bot/pkg/maxlib](https://github.com/abelith/etu-bot/tree/main/pkg/maxlib)
+**gomax** is a framework for [MAX BotAPI](https://dev.max.ru/docs-api), originating from [github.com/abelith/etu-bot/pkg/maxlib](https://github.com/abelith/etu-bot/tree/main/pkg/maxlib)
+
+The project is inspired by [aiogram](https://aiogram.dev)
+
+The project is in active development, so things may change quickly
+
+# Table of Contents
+- [General](#general)
+- [Future plans](#future-plans)
+
+# General
+
+# Future plans

core/dispatcher.go

@@ -1,118 +0,0 @@
-package core
-
-import (
-	"context"
-	"errors"
-	mcontext "github.com/abelith/gomax/context"
-	"github.com/abelith/gomax/state"
-	maxbot "github.com/max-messenger/max-bot-api-client-go/v2"
-	"github.com/max-messenger/max-bot-api-client-go/v2/model"
-	"github.com/rs/zerolog/log"
-	"time"
-)
-
-type FSMStorage interface {
-	Get(ctx context.Context, userID int) (state.Snapshot, error)
-	Put(ctx context.Context, state state.Snapshot) error
-	Delete(ctx context.Context, userID int) error
-}
-
-type UpdateHandler interface {
-	HandleUpdate(c *mcontext.Context) error
-	Use(mw ...Middleware)
-}
-
-type Dispatcher struct {
-	PollInterval time.Duration
-	Api          *maxbot.Api
-	Handler      UpdateHandler
-	FSMStorage   FSMStorage
-}
-
-func (d *Dispatcher) getUpdates(ctx context.Context) <-chan model.Update {
-	var updates []model.Update
-	var marker int64
-	var err error
-
-	ch := make(chan model.Update)
-
-	go func() {
-		defer close(ch)
-
-		for {
-			select {
-			case <-ctx.Done():
-				return
-			case <-time.Tick(d.PollInterval):
-				start := time.Now()
-				updates, marker, err = d.Api.Subscriptions.GetUpdates(ctx, marker)
-				latency := time.Since(start)
-				if err != nil && !errors.Is(err, context.Canceled) {
-					log.Error().Err(err).Send()
-				}
-				log.Ctx(ctx).Debug().
-					Int("received", len(updates)).
-					Dur("latency", latency).
-					Msg("received updates")
-
-				for _, update := range updates {
-					select {
-					case <-ctx.Done():
-						return
-					case ch <- update:
-					}
-				}
-			}
-		}
-	}()
-
-	return ch
-}
-
-func (d *Dispatcher) handleUpdates(ch <-chan model.Update) {
-	for update := range ch {
-		go d.handleUpdate(update)
-	}
-}
-
-func (d *Dispatcher) StartPolling(ctx context.Context) {
-	d.handleUpdates(d.getUpdates(ctx))
-	<-ctx.Done()
-}
-
-func (d *Dispatcher) handleUpdate(upd model.Update) {
-	ctx := context.Background()
-	var st *state.Context
-
-	snapshot, err := d.FSMStorage.Get(ctx, int(upd.UserID))
-	if err != nil && !errors.Is(err, state.ErrStateNotFound) {
-		log.Error().Err(err).Send()
-		return
-	}
-	if errors.Is(err, state.ErrStateNotFound) {
-		st = state.New(int(upd.UserID))
-	} else {
-		st = state.Restore(snapshot)
-	}
-
-	c := mcontext.New(ctx, upd, st, d.Api)
-
-	if err := d.Handler.HandleUpdate(c); err != nil {
-		log.Error().Err(err).Send()
-		return
-	}
-
-	st = c.State()
-	if st.State() == state.ClearState {
-		if err := d.FSMStorage.Delete(ctx, int(upd.UserID)); err != nil {
-			log.Error().Err(err).Send()
-			return
-		}
-	}
-	if st.State() != "" {
-		if err := d.FSMStorage.Put(ctx, st.Snapshot()); err != nil {
-			log.Error().Err(err).Send()
-			return
-		}
-	}
-}

go.mod

@@ -8,6 +8,7 @@ require (
 )
 
 require (
+	github.com/google/uuid v1.6.0 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	golang.org/x/sys v0.29.0 // indirect

go.sum

@@ -1,3 +1,5 @@
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=
 github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=

gomax.go

@@ -1 +0,0 @@
-package gomax

middleware/middleware.go

@@ -1,59 +0,0 @@
-package middleware
-
-import (
-	"errors"
-	mcontext "github.com/abelith/gomax/context"
-	"github.com/abelith/gomax/core"
-	merrors "github.com/abelith/gomax/errors"
-	"github.com/rs/zerolog/log"
-)
-
-func MwErrorResponder(defaultMsg string) core.Middleware {
-	return func(next core.HandlerFunc) core.HandlerFunc {
-		return func(c *mcontext.Context) error {
-			err := next.HandleUpdate(c)
-			var maxErr *merrors.GomaxError
-
-			if errors.As(err, &maxErr) {
-				return c.Respond(maxErr.Message)
-			}
-
-			if err != nil {
-				return c.Respond(defaultMsg)
-			}
-			return nil
-		}
-	}
-}
-
-func MwLoggerInjector() core.Middleware {
-	return func(next core.HandlerFunc) core.HandlerFunc {
-		return func(c *mcontext.Context) error {
-			ctx := log.Logger.With().Int64("user_id", c.Update().UserID).
-				Logger().WithContext(c.Context())
-			c.SetContext(ctx)
-			return next.HandleUpdate(c)
-		}
-	}
-}
-
-func MwDebugState() core.Middleware {
-	return func(next core.HandlerFunc) core.HandlerFunc {
-		return func(c *mcontext.Context) error {
-			log.Debug().Any("state", c.State()).Any("update", c.Update()).Send()
-			return next.HandleUpdate(c)
-		}
-	}
-}
-
-func MwErrorLogger() core.Middleware {
-	return func(next core.HandlerFunc) core.HandlerFunc {
-		return func(c *mcontext.Context) error {
-			if err := next.HandleUpdate(c); err != nil {
-				log.Ctx(c).Err(err).Send()
-				return err
-			}
-			return nil
-		}
-	}
-}

state/memory/memory.go

@@ -1,34 +0,0 @@
-package memory
-
-import (
-	"context"
-	"github.com/abelith/gomax/state"
-	"sync"
-)
-
-type FSMStorage struct {
-	m sync.Map
-}
-
-func NewMemoryFSMStorage() *FSMStorage {
-	return &FSMStorage{}
-}
-
-func (f *FSMStorage) Get(_ context.Context, userID int) (*state.Snapshot, error) {
-	st, ok := f.m.Load(userID)
-	if !ok {
-		return nil, state.ErrStateNotFound
-	}
-
-	return st.(*state.Snapshot), nil
-}
-
-func (f *FSMStorage) Put(_ context.Context, snapshot *state.Snapshot) error {
-	f.m.Store(snapshot.ID, snapshot)
-	return nil
-}
-
-func (f *FSMStorage) Delete(_ context.Context, snapshot *state.Snapshot) error {
-	f.m.Delete(snapshot.ID)
-	return nil
-}

v1/context/context.go

@@ -2,7 +2,7 @@ package context
 
 import (
 	"context"
-	"github.com/abelith/gomax/state"
+	"github.com/abelith/gomax/v1/fsm/state"
 	maxbot "github.com/max-messenger/max-bot-api-client-go/v2"
 	"github.com/max-messenger/max-bot-api-client-go/v2/model"
 	"time"

v1/core/dispatcher.go

@@ -0,0 +1,275 @@
+package core
+
+import (
+	"context"
+	"errors"
+	mcontext "github.com/abelith/gomax/v1/context"
+	"github.com/abelith/gomax/v1/core/pollers"
+	"github.com/abelith/gomax/v1/fsm/memory"
+	"github.com/abelith/gomax/v1/fsm/state"
+	"github.com/abelith/gomax/v1/isolation"
+	"github.com/google/uuid"
+	maxbot "github.com/max-messenger/max-bot-api-client-go/v2"
+	"github.com/max-messenger/max-bot-api-client-go/v2/model"
+	"github.com/rs/zerolog"
+	"sync"
+	"time"
+)
+
+const (
+	defaultTTL            = 30 * time.Second
+	defaultLockTimeout    = 10 * time.Second
+	defaultHandlerTimeout = 10 * time.Second
+)
+
+type EventIsolation interface {
+	Lock(ctx context.Context, key isolation.Key) error
+	Unlock(ctx context.Context, key isolation.Key) error
+}
+
+type FSMStorage interface {
+	Get(ctx context.Context, scope isolation.Scope) (state.Snapshot, error)
+	Put(ctx context.Context, state state.Snapshot) error
+	Delete(ctx context.Context, scope isolation.Scope) error
+}
+
+type UpdateHandler interface {
+	HandleUpdate(c *mcontext.Context) error
+	Use(mw ...Middleware)
+}
+
+type Poller interface {
+	Start(ctx context.Context) (<-chan model.Update, error)
+	Stop(ctx context.Context) error
+}
+
+type DispatcherOption interface {
+	apply(d *dispatcherOptions)
+}
+
+type Dispatcher struct {
+	api            *maxbot.Api
+	poller         Poller
+	fsmStorage     FSMStorage
+	eventIsolation EventIsolation
+	onStart        func(ctx context.Context) error
+	onStop         func(ctx context.Context) error
+	rt             *Router
+	logger         zerolog.Logger
+	wg             sync.WaitGroup
+}
+
+type dispatcherOptions struct {
+	poller         Poller
+	fsmStorage     FSMStorage
+	eventIsolation EventIsolation
+	logger         zerolog.Logger
+}
+
+type dispatcherOptionWrapper struct {
+	fn func(options *dispatcherOptions)
+}
+
+func NewDispatcher(api *maxbot.Api, options ...DispatcherOption) *Dispatcher {
+	d := &Dispatcher{
+		api: api,
+		rt:  &Router{},
+	}
+
+	opts := newDispatcherOptions(api)
+	for _, opt := range options {
+		opt.apply(opts)
+	}
+
+	d.poller = opts.poller
+	d.fsmStorage = opts.fsmStorage
+	d.eventIsolation = opts.eventIsolation
+	d.logger = opts.logger
+
+	return d
+}
+
+func (d *Dispatcher) Handle(handler UpdateHandler, filters ...func(c *mcontext.Context) bool) {
+	d.rt.Handle(handler, filters...)
+}
+
+func (d *Dispatcher) HandleFunc(handler func(c *mcontext.Context) error, filters ...func(c *mcontext.Context) bool) {
+	d.rt.HandleFunc(handler, filters...)
+}
+
+func (d *Dispatcher) HandleUpdate(c *mcontext.Context) error {
+	return d.rt.HandleUpdate(c)
+}
+
+func (d *Dispatcher) Use(mw ...Middleware) {
+	d.rt.Use(mw...)
+}
+
+func (d *Dispatcher) Start(ctx context.Context) error {
+	ch, err := d.poller.Start(ctx)
+	if err != nil {
+		return err
+	}
+
+	if d.onStart != nil {
+		if err := d.onStart(ctx); err != nil {
+			return err
+		}
+	}
+
+	d.handleUpdates(ch)
+	return nil
+}
+
+func (d *Dispatcher) Stop(ctx context.Context) error {
+	if err := d.poller.Stop(ctx); err != nil {
+		return err
+	}
+
+	done := make(chan struct{})
+
+	go func() {
+		d.wg.Wait()
+		done <- struct{}{}
+	}()
+
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-done:
+	}
+
+	if d.onStop != nil {
+		return d.onStop(ctx)
+	}
+
+	return nil
+}
+
+func (d *Dispatcher) OnStart(f func(ctx context.Context) error) {
+	d.onStart = f
+}
+
+func (d *Dispatcher) OnStop(f func(ctx context.Context) error) {
+	d.onStop = f
+}
+
+func (d *Dispatcher) handleUpdates(ch <-chan model.Update) {
+	for upd := range ch {
+		d.wg.Go(func() {
+			key := isolation.Key{
+				UpdateID: uuid.New(),
+				UserID:   upd.UserID,
+				ChatID:   upd.ChatID,
+			}
+			l := d.logger.With().
+				Str("update_id", key.UpdateID.String()).
+				Int64("user_id", key.UserID).
+				Int64("chat_id", key.ChatID).
+				Logger()
+
+			lockCtx, cancel := context.WithTimeout(context.Background(), defaultLockTimeout)
+			defer cancel()
+
+			if err := d.eventIsolation.Lock(lockCtx, key); err != nil {
+				d.logger.Error().
+					Err(err).
+					Int64("user_id", key.UserID).
+					Int64("chat_id", key.ChatID).
+					Msg("failed to lock on update")
+				return
+			}
+			defer func() {
+				unlockCtx, unlockCancel := context.WithTimeout(context.Background(), defaultLockTimeout)
+				defer unlockCancel()
+
+				err := d.eventIsolation.Unlock(unlockCtx, key)
+				switch {
+				case errors.Is(err, isolation.ErrNotOwner):
+					l.Warn().Msg("lock expired before handler finished")
+				case err != nil:
+					l.Warn().Err(err).Msg("failed to unlock on update")
+				}
+			}()
+
+			handleCtx, cancel := context.WithTimeout(context.Background(), defaultHandlerTimeout)
+			defer cancel()
+			d.handleUpdate(handleCtx, upd)
+		})
+	}
+}
+
+func (d *Dispatcher) handleUpdate(ctx context.Context, upd model.Update) {
+	var st *state.Context
+
+	snapshot, err := d.fsmStorage.Get(ctx, isolation.Scope{UserID: upd.UserID, ChatID: upd.ChatID})
+	if err != nil && !errors.Is(err, state.ErrStateNotFound) {
+		d.logger.Error().Err(err).Send()
+		return
+	}
+	if errors.Is(err, state.ErrStateNotFound) {
+		st = state.New(isolation.Scope{UserID: upd.UserID, ChatID: upd.ChatID})
+	} else {
+		st = state.Restore(snapshot)
+	}
+
+	c := mcontext.New(ctx, upd, st, d.api)
+
+	if err := d.rt.HandleUpdate(c); err != nil {
+		d.logger.Error().Err(err).Send()
+		return
+	}
+
+	st = c.State()
+	if st.IsEmpty() {
+		if err := d.fsmStorage.Delete(ctx, isolation.Scope{UserID: upd.UserID, ChatID: upd.ChatID}); err != nil {
+			d.logger.Error().Err(err).Send()
+		}
+		return
+	}
+
+	if err := d.fsmStorage.Put(ctx, st.Snapshot()); err != nil {
+		d.logger.Error().Err(err).Send()
+	}
+}
+
+func WithPoller(poller Poller) DispatcherOption {
+	return newOption(func(opts *dispatcherOptions) {
+		opts.poller = poller
+	})
+}
+
+func WithFSMStorage(storage FSMStorage) DispatcherOption {
+	return newOption(func(opts *dispatcherOptions) {
+		opts.fsmStorage = storage
+	})
+}
+
+func WithEventIsolation(eventIsolation EventIsolation) DispatcherOption {
+	return newOption(func(opts *dispatcherOptions) {
+		opts.eventIsolation = eventIsolation
+	})
+}
+
+func WithZerolog(logger zerolog.Logger) DispatcherOption {
+	return newOption(func(options *dispatcherOptions) {
+		options.logger = logger
+	})
+}
+
+func newDispatcherOptions(api *maxbot.Api) *dispatcherOptions {
+	return &dispatcherOptions{
+		poller:         pollers.NewLongPoller(api),
+		fsmStorage:     memory.NewFSMStorage(),
+		eventIsolation: memory.NewEventIsolation(defaultTTL),
+		logger:         zerolog.Nop(),
+	}
+}
+
+func newOption(fn func(options *dispatcherOptions)) DispatcherOption {
+	return dispatcherOptionWrapper{fn: fn}
+}
+
+func (dow dispatcherOptionWrapper) apply(opts *dispatcherOptions) {
+	dow.fn(opts)
+}

v1/core/handler.go

@@ -1,6 +1,6 @@
 package core
 
-import mcontext "github.com/abelith/gomax/context"
+import mcontext "github.com/abelith/gomax/v1/context"
 
 type HandlerFunc func(c *mcontext.Context) error
 

v1/core/pollers/pollers.go

@@ -0,0 +1,432 @@
+package pollers
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	maxbot "github.com/max-messenger/max-bot-api-client-go/v2"
+	"github.com/max-messenger/max-bot-api-client-go/v2/model"
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
+	"net"
+	"net/http"
+	"sync"
+	"time"
+)
+
+const (
+	defaultInterval       = 200 * time.Millisecond
+	defaultWhStartTimeout = 10 * time.Second
+)
+
+type WebhookOption interface {
+	apply(opts *webhookOptions)
+}
+
+type LongPollerOption interface {
+	apply(opts *longPollerOptions)
+}
+
+type Webhook struct {
+	srv *http.Server
+	ch  chan model.Update
+	wg  *sync.WaitGroup
+}
+
+type LongPoller struct {
+	api          *maxbot.Api
+	pollInterval time.Duration
+	logger       zerolog.Logger
+	wg           sync.WaitGroup
+}
+
+type TestPoller struct {
+	ch chan model.Update
+	mu sync.Mutex
+}
+
+type backoff struct {
+	base time.Duration
+	max  time.Duration
+
+	window []bool
+	pos    int
+	count  int
+	errors int
+
+	sinceAdjust int
+	interval    time.Duration
+}
+
+type webhookOptions struct {
+	addr              string
+	tlsConfig         *tls.Config
+	readTimeout       time.Duration
+	readHeaderTimeout time.Duration
+	writeTimeout      time.Duration
+	idleTimeout       time.Duration
+	maxHeaderBytes    int
+	baseContext       func(l net.Listener) context.Context
+	connContext       func(ctx context.Context, conn net.Conn) context.Context
+}
+
+type longPollerOptions struct {
+	pollInterval time.Duration
+	logger       zerolog.Logger
+}
+
+type longPollerOptionWrapper struct {
+	fn func(opts *longPollerOptions)
+}
+
+type webhookOptionWrapper struct {
+	fn func(opts *webhookOptions)
+}
+
+func NewWebhookPoller(api *maxbot.Api, secret string, options ...WebhookOption) *Webhook {
+	ch := make(chan model.Update, 1)
+
+	handler := api.GetHandler(func(ctx context.Context, update model.Update) {
+		select {
+		case ch <- update:
+		case <-ctx.Done():
+		}
+	}, secret)
+
+	srv := &http.Server{
+		Handler: handler,
+	}
+
+	wh := &Webhook{
+		srv: srv,
+		ch:  ch,
+	}
+
+	opts := newWebhookOptions()
+	for _, opt := range options {
+		opt.apply(opts)
+	}
+
+	wh.srv.Addr = opts.addr
+	wh.srv.TLSConfig = opts.tlsConfig
+	wh.srv.ReadTimeout = opts.readTimeout
+	wh.srv.ReadHeaderTimeout = opts.readHeaderTimeout
+	wh.srv.WriteTimeout = opts.writeTimeout
+	wh.srv.IdleTimeout = opts.idleTimeout
+	wh.srv.MaxHeaderBytes = opts.maxHeaderBytes
+	wh.srv.BaseContext = opts.baseContext
+	wh.srv.ConnContext = opts.connContext
+
+	return wh
+}
+
+func (w *Webhook) Start(ctx context.Context) (<-chan model.Update, error) {
+	l, err := net.Listen("tcp", w.srv.Addr)
+	if err != nil {
+		return nil, err
+	}
+
+	go func() {
+		var err error
+
+		if w.srv.TLSConfig == nil {
+			err = w.srv.Serve(l)
+		} else {
+			err = w.srv.ServeTLS(l, "", "")
+		}
+
+		if err != nil && !errors.Is(err, http.ErrServerClosed) {
+			log.Ctx(ctx).Error().Err(err).Msg("failed to start webhook server")
+		}
+	}()
+
+	return w.ch, nil
+}
+
+func (w *Webhook) Stop(ctx context.Context) error {
+	defer close(w.ch)
+
+	if err := w.srv.Shutdown(ctx); err != nil {
+		return err
+	}
+	return nil
+}
+
+func NewLongPoller(api *maxbot.Api, options ...LongPollerOption) *LongPoller {
+	lp := &LongPoller{
+		api: api,
+	}
+
+	opts := newLongPollerOptions()
+	for _, opt := range options {
+		opt.apply(opts)
+	}
+
+	lp.pollInterval = opts.pollInterval
+	lp.logger = opts.logger
+
+	return lp
+}
+
+func (lp *LongPoller) Start(ctx context.Context) (<-chan model.Update, error) {
+	ch := make(chan model.Update)
+
+	lp.wg.Go(func() {
+		defer close(ch)
+		lp.poll(ctx, ch)
+	})
+
+	return ch, nil
+}
+
+func (lp *LongPoller) Stop(ctx context.Context) error {
+	done := make(chan struct{})
+
+	go func() {
+		lp.wg.Wait()
+		done <- struct{}{}
+	}()
+
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-done:
+		return nil
+	}
+}
+
+func (tp *TestPoller) Inject(ctx context.Context, updates []model.Update) {
+	ch := make(chan model.Update, 1)
+
+	go func() {
+		defer close(ch)
+
+		for _, upd := range updates {
+			select {
+			case <-ctx.Done():
+			case ch <- upd:
+			}
+		}
+	}()
+
+	tp.mu.Lock()
+	tp.ch = ch
+	defer tp.mu.Unlock()
+}
+
+func (tp *TestPoller) Start(_ context.Context) (<-chan model.Update, error) {
+	return tp.ch, nil
+}
+
+func (tp *TestPoller) Stop(_ context.Context) error {
+	return nil
+}
+
+func WithPollInterval(interval time.Duration) LongPollerOption {
+	return newLpOption(func(opts *longPollerOptions) {
+		opts.pollInterval = interval
+	})
+}
+
+func WithZerolog(logger zerolog.Logger) LongPollerOption {
+	return newLpOption(func(opts *longPollerOptions) {
+		opts.logger = logger
+	})
+}
+
+func WithAddress(addr string) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.addr = addr
+	})
+}
+
+func WithTLSConfig(cfg *tls.Config) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.tlsConfig = cfg
+	})
+}
+
+func WithReadTimeout(timeout time.Duration) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.readTimeout = timeout
+	})
+}
+
+func WithReadHeaderTimeout(timeout time.Duration) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.readHeaderTimeout = timeout
+	})
+}
+
+func WithWriteTimeout(timeout time.Duration) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.writeTimeout = timeout
+	})
+}
+
+func WithIdleTimeout(timeout time.Duration) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.idleTimeout = timeout
+	})
+}
+
+func WithMaxHeaderBytes(bytes int) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.maxHeaderBytes = bytes
+	})
+}
+
+func WithBaseContext(fn func(l net.Listener) context.Context) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.baseContext = fn
+	})
+}
+
+func WithConnContext(fn func(ctx context.Context, c net.Conn) context.Context) WebhookOption {
+	return newWhOption(func(opts *webhookOptions) {
+		opts.connContext = fn
+	})
+}
+
+func newBackoff(
+	base, max time.Duration,
+	windowSize int,
+) *backoff {
+	if base <= 0 || max < base || windowSize <= 0 {
+		panic("backoff: invalid configuration")
+	}
+
+	return &backoff{
+		base:     base,
+		max:      max,
+		window:   make([]bool, windowSize),
+		interval: base,
+	}
+}
+
+func (b *backoff) observe(err error) time.Duration {
+	failed := err != nil
+
+	if b.count == len(b.window) && b.window[b.pos] {
+		b.errors--
+	} else {
+		b.count++
+	}
+
+	b.window[b.pos] = failed
+	if failed {
+		b.errors++
+	}
+
+	b.pos = (b.pos + 1) % len(b.window)
+	b.sinceAdjust++
+
+	if b.count < len(b.window) ||
+		b.sinceAdjust < len(b.window) {
+		return b.interval
+	}
+
+	b.sinceAdjust = 0
+	errorRate := float64(b.errors) / float64(b.count)
+
+	switch {
+	case errorRate >= 0.3:
+		b.interval = min(b.interval*2, b.max)
+	case errorRate <= 0.1:
+		b.interval = max(b.interval/2, b.base)
+	}
+
+	return b.interval
+}
+
+func (lp *LongPoller) poll(ctx context.Context, ch chan model.Update) {
+	b := newBackoff(
+		lp.pollInterval,
+		30*time.Second,
+		20,
+	)
+
+	var marker int64
+
+	for {
+		if err := wait(ctx, b.interval); err != nil {
+			return
+		}
+
+		start := time.Now()
+		updates, nextMarker, err := lp.api.Subscriptions.GetUpdates(ctx, marker)
+		latency := time.Since(start)
+
+		if err != nil {
+			if errors.Is(err, context.Canceled) ||
+				ctx.Err() != nil {
+				return
+			}
+
+			delay := b.observe(err)
+
+			lp.logger.Error().
+				Err(err).
+				Dur("latency", latency).
+				Dur("next_interval", delay).
+				Msg("failed to receive updates")
+
+			continue
+		}
+
+		b.observe(nil)
+		marker = nextMarker
+
+		lp.logger.Debug().
+			Int("received", len(updates)).
+			Dur("latency", latency).
+			Msg("received updates")
+
+		for _, update := range updates {
+			select {
+			case ch <- update:
+			}
+		}
+	}
+}
+
+func newLongPollerOptions() *longPollerOptions {
+	return &longPollerOptions{
+		pollInterval: defaultInterval,
+		logger:       zerolog.Nop(),
+	}
+}
+
+func newWebhookOptions() *webhookOptions {
+	return &webhookOptions{
+		addr: ":8080",
+	}
+}
+
+func newLpOption(fn func(opts *longPollerOptions)) LongPollerOption {
+	return longPollerOptionWrapper{fn: fn}
+}
+
+func newWhOption(fn func(options *webhookOptions)) WebhookOption {
+	return webhookOptionWrapper{fn: fn}
+}
+
+func (low longPollerOptionWrapper) apply(opts *longPollerOptions) {
+	low.fn(opts)
+}
+
+func (wow webhookOptionWrapper) apply(opts *webhookOptions) {
+	wow.fn(opts)
+}
+
+func wait(ctx context.Context, delay time.Duration) error {
+	timer := time.NewTimer(delay)
+	defer timer.Stop()
+
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-timer.C:
+		return nil
+	}
+}

v1/core/router.go

@@ -2,13 +2,11 @@ package core
 
 import (
 	"errors"
-	mcontext "github.com/abelith/gomax/context"
+	mcontext "github.com/abelith/gomax/v1/context"
 )
 
 type Middleware func(next HandlerFunc) HandlerFunc
 
-type Filter func(c *mcontext.Context) bool
-
 type route struct {
 	h       UpdateHandler
 	filters []func(c *mcontext.Context) bool

v1/errors/errors.go

@@ -1,16 +1,20 @@
 package errors
 
-type GomaxError struct {
+type GoMaxError struct {
 	Message string
 	Err     error
 }
 
-func (ge *GomaxError) Error() string {
+func (ge *GoMaxError) Error() string {
 	return ge.Err.Error()
 }
 
+func (ge *GoMaxError) Unwrap() error {
+	return ge.Err
+}
+
 func New(parent error, text string) error {
-	return &GomaxError{
+	return &GoMaxError{
 		Message: text,
 		Err:     parent,
 	}

v1/filters/filters.go

@@ -1,17 +1,44 @@
 package filters
 
 import (
-	mcontext "github.com/abelith/gomax/context"
-	"github.com/abelith/gomax/core"
-	"github.com/abelith/gomax/state"
+	mcontext "github.com/abelith/gomax/v1/context"
+	"github.com/abelith/gomax/v1/fsm/state"
 	"github.com/max-messenger/max-bot-api-client-go/v2/model"
 	"regexp"
 	"strings"
 )
 
-type CallbackFilter core.Filter
+type Filter func(c *mcontext.Context) bool
 
-func StartCommand() core.Filter {
+type CallbackFilter Filter
+
+type MessageFilter Filter
+
+func And(filters ...func(c *mcontext.Context) bool) func(c *mcontext.Context) bool {
+	return func(c *mcontext.Context) bool {
+		for _, filter := range filters {
+			if !filter(c) {
+				return false
+			}
+		}
+
+		return true
+	}
+}
+
+func Or(filters ...func(c *mcontext.Context) bool) func(c *mcontext.Context) bool {
+	return func(c *mcontext.Context) bool {
+		for _, filter := range filters {
+			if filter(c) {
+				return true
+			}
+		}
+
+		return false
+	}
+}
+
+func StartCommand() Filter {
 	return func(c *mcontext.Context) bool {
 		upd := c.Update()
 		if upd.UpdateType == model.UpdateBotStarted {
@@ -22,41 +49,54 @@ func StartCommand() core.Filter {
 	}
 }
 
-func Command(cmd string) core.Filter {
+func Command(cmd string) Filter {
 	return func(c *mcontext.Context) bool {
 		upd := c.Update()
 		return upd.UpdateType == model.UpdateMessageCreated && strings.HasPrefix(upd.GetCommand().Command, cmd)
 	}
 }
 
-func State(state state.State) core.Filter {
+func State(state state.State) Filter {
 	return func(c *mcontext.Context) bool {
 		return c.State().State() == state
 	}
 }
 
-func MessageText(s string) core.Filter {
+func BotStopped() Filter {
 	return func(c *mcontext.Context) bool {
-		if msg := c.Update().Message; msg != nil {
-			return s == msg.Body.Text
-		}
-		return false
+		return c.Update().UpdateType == model.UpdateBotStopped
 	}
 }
 
-func MessageTextRe(re *regexp.Regexp) core.Filter {
+func Message() MessageFilter {
 	return func(c *mcontext.Context) bool {
-		if msg := c.Update().Message; msg != nil {
-			s := strings.TrimSpace(msg.Body.Text)
-			return re.MatchString(s)
-		}
-		return false
+		return c.Update().UpdateType == model.UpdateMessageCreated && c.Update().Message != nil
 	}
 }
 
-func MessageGeo() core.Filter {
+func (mf MessageFilter) Text(s string) MessageFilter {
 	return func(c *mcontext.Context) bool {
-		if c.Update().Message == nil {
+		if !mf(c) {
+			return false
+		}
+
+		return c.Update().Message.Body.Text == s
+	}
+}
+
+func (mf MessageFilter) Regex(re *regexp.Regexp) MessageFilter {
+	return func(c *mcontext.Context) bool {
+		if !mf(c) {
+			return false
+		}
+
+		return re.MatchString(c.Update().Message.Body.Text)
+	}
+}
+
+func (mf MessageFilter) Geo() MessageFilter {
+	return func(c *mcontext.Context) bool {
+		if !mf(c) {
 			return false
 		}
 
@@ -70,29 +110,6 @@ func MessageGeo() core.Filter {
 	}
 }
 
-func BotStopped() core.Filter {
-	return func(c *mcontext.Context) bool {
-		return c.Update().UpdateType == model.UpdateBotStopped
-	}
-}
-
-func Or(filters ...core.Filter) core.Filter {
-	return func(c *mcontext.Context) bool {
-		for _, filter := range filters {
-			if filter(c) {
-				return true
-			}
-		}
-		return false
-	}
-}
-
-func Message() core.Filter {
-	return func(c *mcontext.Context) bool {
-		return c.Update().UpdateType == model.UpdateMessageCreated && c.Update().Message != nil
-	}
-}
-
 func Callback() CallbackFilter {
 	return func(c *mcontext.Context) bool {
 		return c.Update().UpdateType == model.UpdateMessageCallback
@@ -104,15 +121,12 @@ func (cf CallbackFilter) StartsWith(prefix string) CallbackFilter {
 		if !cf(c) {
 			return false
 		}
-		payload, ok := getCallbackPayload(c)
-		return ok && strings.HasPrefix(payload, prefix)
-	}
+
+		upd := c.Update().Callback
+		if upd == nil {
+			return false
 		}
 
-func getCallbackPayload(c *mcontext.Context) (string, bool) {
-	upd := c.Update()
-	if upd.Callback == nil {
-		return "", false
+		return strings.HasPrefix(upd.Payload, prefix)
 	}
-	return upd.Callback.Payload, true
 }

v1/fsm/memory/memory.go

@@ -0,0 +1,129 @@
+package memory
+
+import (
+	"context"
+	"github.com/abelith/gomax/v1/fsm/state"
+	"github.com/abelith/gomax/v1/isolation"
+	"github.com/google/uuid"
+	"sync"
+	"time"
+)
+
+type FSMStorage struct {
+	m sync.Map
+}
+
+type EventIsolation struct {
+	mu    sync.Mutex
+	locks map[isolation.Scope]*lockEntry
+	ttl   time.Duration
+}
+
+type fsmKey struct {
+	userID int64
+	chatID int64
+}
+
+type eventIsolationKey struct {
+	userID int
+	chatID int
+}
+
+type lockEntry struct {
+	owner uuid.UUID
+	timer *time.Timer
+	done  chan struct{}
+}
+
+func NewFSMStorage() *FSMStorage {
+	return &FSMStorage{}
+}
+
+func (f *FSMStorage) Get(_ context.Context, scope isolation.Scope) (state.Snapshot, error) {
+	st, ok := f.m.Load(fsmKey{
+		userID: scope.UserID,
+		chatID: scope.ChatID,
+	})
+	if !ok {
+		return state.Snapshot{}, state.ErrStateNotFound
+	}
+
+	return st.(state.Snapshot), nil
+}
+
+func (f *FSMStorage) Put(_ context.Context, snapshot state.Snapshot) error {
+	f.m.Store(fsmKey{
+		userID: snapshot.Scope.UserID,
+		chatID: snapshot.Scope.ChatID,
+	}, snapshot)
+	return nil
+}
+
+func (f *FSMStorage) Delete(_ context.Context, scope isolation.Scope) error {
+	f.m.Delete(fsmKey{
+		userID: scope.UserID,
+		chatID: scope.ChatID,
+	})
+	return nil
+}
+
+func NewEventIsolation(ttl time.Duration) *EventIsolation {
+	return &EventIsolation{
+		locks: make(map[isolation.Scope]*lockEntry),
+		ttl:   ttl,
+	}
+}
+
+func (ei *EventIsolation) Lock(ctx context.Context, key isolation.Key) error {
+	scope := key.Scope()
+
+	for {
+		ei.mu.Lock()
+		entry, busy := ei.locks[scope]
+		if !busy {
+			ei.acquireLocked(scope, key.UpdateID)
+			ei.mu.Unlock()
+			return nil
+		}
+		done := entry.done
+		ei.mu.Unlock()
+
+		select {
+		case <-done:
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+}
+
+func (ei *EventIsolation) Unlock(_ context.Context, key isolation.Key) error {
+	scope := key.Scope()
+
+	ei.mu.Lock()
+	defer ei.mu.Unlock()
+
+	entry, ok := ei.locks[scope]
+	if !ok || entry.owner != key.UpdateID {
+		return isolation.ErrNotOwner
+	}
+	ei.releaseLocked(scope, entry)
+	return nil
+}
+
+func (ei *EventIsolation) acquireLocked(scope isolation.Scope, owner uuid.UUID) {
+	entry := &lockEntry{owner: owner, done: make(chan struct{})}
+	entry.timer = time.AfterFunc(ei.ttl, func() {
+		ei.mu.Lock()
+		defer ei.mu.Unlock()
+		if cur, ok := ei.locks[scope]; ok && cur == entry {
+			ei.releaseLocked(scope, entry)
+		}
+	})
+	ei.locks[scope] = entry
+}
+
+func (ei *EventIsolation) releaseLocked(scope isolation.Scope, entry *lockEntry) {
+	entry.timer.Stop()
+	delete(ei.locks, scope)
+	close(entry.done)
+}

v1/fsm/state/state.go

@@ -3,8 +3,8 @@ package state
 import (
 	"encoding/json"
 	"fmt"
-
-	"github.com/rs/zerolog/log"
+	"github.com/abelith/gomax/v1/isolation"
+	"strings"
 )
 
 var (
@@ -12,9 +12,15 @@ var (
 	ErrKeyNotFound   = fmt.Errorf("state: key not found")
 )
 
-const ClearState State = "clear"
+type State struct {
+	group string
+	name  string
+}
 
-type State string
+type Group struct {
+	name   string
+	states map[string]*State
+}
 
 type Codec interface {
 	Marshal(v any) ([]byte, error)
@@ -32,25 +38,69 @@ func (JSONCodec) Unmarshal(d []byte, v any) error {
 }
 
 type Snapshot struct {
-	ID    int               `json:"id"`
-	State State             `json:"state"`
+	Scope isolation.Scope   `json:"id"`
+	State string            `json:"state"`
 	Data  map[string][]byte `json:"data"`
 }
 
 type Context struct {
-	id    int
+	scope isolation.Scope
 	state State
 	data  map[string][]byte
 	codec Codec
+	clear bool
 }
 
 type Option func(*Context)
 
+func NewStateGroup(name string) *Group {
+	return &Group{
+		name:   name,
+		states: make(map[string]*State),
+	}
+}
+
+func (g *Group) State(name string) State {
+	state := g.states[name]
+
+	if state != nil {
+		return *state
+	}
+
+	if state = g.states[name]; state != nil {
+		return *state
+	}
+
+	state = &State{
+		group: g.name,
+		name:  name,
+	}
+
+	g.states[name] = state
+	return *state
+}
+
+func (s *State) String() string {
+	return fmt.Sprintf("%s:%s", s.group, s.name)
+}
+
+func fromString(s string) State {
+	pieces := strings.Split(s, ":")
+	if len(pieces) < 2 {
+		return State{}
+	}
+
+	return State{
+		group: pieces[0],
+		name:  pieces[1],
+	}
+}
+
 func WithCodec(c Codec) Option { return func(sc *Context) { sc.codec = c } }
 
-func New(id int, opts ...Option) *Context {
+func New(scope isolation.Scope, opts ...Option) *Context {
 	sc := &Context{
-		id:    id,
+		scope: scope,
 		data:  make(map[string][]byte),
 		codec: JSONCodec{},
 	}
@@ -61,8 +111,8 @@ func New(id int, opts ...Option) *Context {
 }
 
 func Restore(s Snapshot, opts ...Option) *Context {
-	sc := New(s.ID, opts...)
-	sc.state = s.State
+	sc := New(s.Scope, opts...)
+	sc.state = fromString(s.State)
 	for k, v := range s.Data {
 		sc.data[k] = v
 	}
@@ -74,25 +124,25 @@ func (sc *Context) Snapshot() Snapshot {
 	for k, v := range sc.data {
 		data[k] = v
 	}
-	return Snapshot{ID: sc.id, State: sc.state, Data: data}
+	return Snapshot{Scope: sc.scope, State: sc.state.String(), Data: data}
 }
 
 func (sc *Context) Set(state State) {
-	log.Debug().
-		Int("user_id", sc.id).
-		Str("from", string(sc.state)).
-		Str("to", string(state)).
-		Msg("fsm state transition")
 	sc.state = state
 }
 
 func (sc *Context) State() State { return sc.state }
 
 func (sc *Context) Clear() {
-	sc.state = ClearState
+	sc.state = State{}
+	sc.clear = true
 	sc.data = make(map[string][]byte)
 }
 
+func (sc *Context) IsEmpty() bool {
+	return sc.state == State{} && sc.clear
+}
+
 func (sc *Context) Store(key string, val any) error {
 	b, err := sc.codec.Marshal(val)
 	if err != nil {

v1/gomax.go

@@ -0,0 +1 @@
+package v1

v1/isolation/isolation.go

@@ -0,0 +1,22 @@
+package isolation
+
+import (
+	"errors"
+
+	"github.com/google/uuid"
+)
+
+var ErrNotOwner = errors.New("isolation: lock is not held by this owner")
+
+type Key struct {
+	UpdateID uuid.UUID // владелец
+	UserID   int64
+	ChatID   int64
+}
+
+type Scope struct {
+	UserID int64
+	ChatID int64
+}
+
+func (k Key) Scope() Scope { return Scope{UserID: k.UserID, ChatID: k.ChatID} }

v1/middleware/middleware.go

@@ -0,0 +1,63 @@
+package middleware
+
+import (
+	"errors"
+	"fmt"
+	mcontext "github.com/abelith/gomax/v1/context"
+	"github.com/abelith/gomax/v1/core"
+	merrors "github.com/abelith/gomax/v1/errors"
+)
+
+func MwPanicHandler(onPanic func()) core.Middleware {
+	return func(next core.HandlerFunc) core.HandlerFunc {
+		return func(c *mcontext.Context) (err error) {
+			defer func() {
+				p := recover()
+				if p != nil {
+					onPanic()
+					err = fmt.Errorf("panic: %v", p)
+				}
+			}()
+			return next(c)
+		}
+	}
+}
+
+func MwErrorResponder(defaultMsg string) core.Middleware {
+	return func(next core.HandlerFunc) core.HandlerFunc {
+		return func(c *mcontext.Context) error {
+			err := next(c)
+			var maxErr *merrors.GoMaxError
+
+			if errors.As(err, &maxErr) {
+				return errors.Join(c.Respond(maxErr.Message), maxErr)
+			}
+
+			if err != nil {
+				return errors.Join(c.Respond(defaultMsg), err)
+			}
+			return nil
+		}
+	}
+}
+
+func MwCallback(callback func(c *mcontext.Context)) core.Middleware {
+	return func(next core.HandlerFunc) core.HandlerFunc {
+		return func(c *mcontext.Context) error {
+			callback(c)
+			return next(c)
+		}
+	}
+}
+
+func MwErrorHandler(onError func(err error)) core.Middleware {
+	return func(next core.HandlerFunc) core.HandlerFunc {
+		return func(c *mcontext.Context) error {
+			var err error
+			if err = next(c); err != nil {
+				onError(err)
+			}
+			return err
+		}
+	}
+}