Gateway: Split GuildCreateEvent (#116)

* Session: fix event handler loop not getting properly closed

* Implement #113

* Session: move guild events to state

* Session: close hStop

handler/handler.go

@@ -75,6 +75,34 @@ func (h *Handler) Call(ev interface{}) {
 	}
 }
 
+// CallDirect is the same as Call, but only calls those event handlers that
+// listen for this specific event, i.e. that aren't interface handlers.
+func (h *Handler) CallDirect(ev interface{}) {
+	var evV = reflect.ValueOf(ev)
+	var evT = evV.Type()
+
+	h.hmutex.RLock()
+	defer h.hmutex.RUnlock()
+
+	for _, order := range h.horders {
+		handler, ok := h.handlers[order]
+		if !ok {
+			// This shouldn't ever happen, but we're adding this just in case.
+			continue
+		}
+
+		if evT != handler.event {
+			continue
+		}
+
+		if h.Synchronous {
+			handler.call(evV)
+		} else {
+			go handler.call(evV)
+		}
+	}
+}
+
 // WaitFor blocks until there's an event. It's advised to use ChanFor instead,
 // as WaitFor may skip some events if it's not ran fast enough after the event
 // arrived.
@@ -127,6 +155,14 @@ func (h *Handler) ChanFor(fn func(interface{}) bool) (out <-chan interface{}, ca
 
 // AddHandler adds the handler, returning a function that would remove this
 // handler when called.
+//
+// GuildCreateEvents and GuildDeleteEvents will not be called on interface{}
+// events. Instead their situation-specific version will be fired, as they
+// provides more information about the context of the event:
+// GuildReadyEvent, GuildAvailableEvent, GuildJoinEvent, GuildUnavailableEvent
+// or GuildLeaveEvent
+// Listening to directly to GuildCreateEvent or GuildDeleteEvent will still
+// work, however.
 func (h *Handler) AddHandler(handler interface{}) (rm func()) {
 	rm, err := h.addHandler(handler)
 	if err != nil {
@@ -137,6 +173,14 @@ func (h *Handler) AddHandler(handler interface{}) (rm func()) {
 
 // AddHandlerCheck adds the handler, but safe-guards reflect panics with a
 // recoverer, returning the error.
+//
+// GuildCreateEvents and GuildDeleteEvents will not be called on interface{}
+// events. Instead their situation-specific version will be fired, as they
+// provides more information about the context of the event:
+// GuildReadyEvent, GuildAvailableEvent, GuildJoinEvent, GuildUnavailableEvent
+// or GuildLeaveEvent
+// Listening to directly to GuildCreateEvent or GuildDeleteEvent will still
+// work, however.
 func (h *Handler) AddHandlerCheck(handler interface{}) (rm func(), err error) {
 	// Reflect would actually panic if anything goes wrong, so this is just in
 	// case.

handler/handler_test.go

@@ -35,7 +35,7 @@ func TestCall(t *testing.T) {
 		t.Fatal("Returned results is wrong:", r)
 	}
 
-	// Remove handler test
+	// Delete handler test
 	rm()
 
 	go h.Call(newMessage("astolfo"))

session/session.go

@@ -4,14 +4,17 @@
 package session
 
 import (
+	"github.com/pkg/errors"
+
 	"github.com/diamondburned/arikawa/api"
 	"github.com/diamondburned/arikawa/gateway"
 	"github.com/diamondburned/arikawa/handler"
-	"github.com/pkg/errors"
 )
 
+var ErrMFA = errors.New("account has 2FA enabled")
+
 // Closed is an event that's sent to Session's command handler. This works by
-// using (*Gateway).AfterError. If the user sets this callback, no Closed events
+// using (*Gateway).AfterClose. If the user sets this callback, no Closed events
 // would be sent.
 //
 // Usage
@@ -22,8 +25,6 @@ type Closed struct {
 	Error error
 }
 
-var ErrMFA = errors.New("account has 2FA enabled")
-
 // Session manages both the API and Gateway. As such, Session inherits all of
 // API's methods, as well has the Handler used for Gateway.
 type Session struct {
@@ -41,19 +42,13 @@ type Session struct {
 }
 
 func New(token string) (*Session, error) {
-	// Initialize the session and the API interface
-	s := &Session{}
-	s.Handler = handler.New()
-	s.Client = api.NewClient(token)
-
 	// Create a gateway
 	g, err := gateway.NewGateway(token)
 	if err != nil {
-		return nil, errors.Wrap(err, "failed to connect to Gateway")
+		err = errors.Wrap(err, "failed to connect to Gateway")
 	}
-	s.Gateway = g
 
-	return s, nil
+	return NewWithGateway(g), err
 }
 
 // Login tries to log in as a normal user account; MFA is optional.
@@ -121,7 +116,7 @@ func (s *Session) startHandler(stop <-chan struct{}) {
 		case <-stop:
 			return
 		case ev := <-s.Gateway.Events:
-			s.Handler.Call(ev)
+			s.Call(ev)
 		}
 	}
 }

state/event_dispatcher.go

@@ -0,0 +1,75 @@
+package state
+
+import (
+	"github.com/diamondburned/arikawa/gateway"
+)
+
+func (s *State) handleEvent(ev interface{}) {
+	if s.PreHandler != nil {
+		s.PreHandler.Call(ev)
+	}
+	s.Handler.Call(ev)
+}
+
+func (s *State) handleReady(ev *gateway.ReadyEvent) {
+	s.handleEvent(ev)
+
+	for _, g := range ev.Guilds {
+		// store this so we know when we need to dispatch a belated
+		// GuildReadyEvent
+		if g.Unavailable {
+			s.unreadyGuilds.Add(g.ID)
+		} else {
+			s.handleEvent(&GuildReadyEvent{
+				GuildCreateEvent: &g,
+			})
+		}
+	}
+}
+
+func (s *State) handleGuildCreate(ev *gateway.GuildCreateEvent) {
+	// before we dispatch the specific events, we can already call the handlers
+	// that subscribed to the generic version
+	s.handleEvent(ev)
+
+	// this guild was unavailable, but has come back online
+	if s.unavailableGuilds.Delete(ev.ID) {
+		s.handleEvent(&GuildAvailableEvent{
+			GuildCreateEvent: ev,
+		})
+
+		// the guild was already unavailable when connecting to the gateway
+		// we can dispatch a belated GuildReadyEvent
+	} else if s.unreadyGuilds.Delete(ev.ID) {
+		s.handleEvent(&GuildReadyEvent{
+			GuildCreateEvent: ev,
+		})
+	} else { // we don't know this guild, hence we just joined it
+		s.handleEvent(&GuildJoinEvent{
+			GuildCreateEvent: ev,
+		})
+	}
+}
+
+func (s *State) handleGuildDelete(ev *gateway.GuildDeleteEvent) {
+	// before we dispatch the specific events, we can already call the handlers
+	// that subscribed to the generic version
+	s.handleEvent(ev)
+
+	// store this so we can later dispatch a GuildAvailableEvent, once the
+	// guild becomes available again.
+	if ev.Unavailable {
+		s.unavailableGuilds.Add(ev.ID)
+
+		s.handleEvent(&GuildUnavailableEvent{
+			GuildDeleteEvent: ev,
+		})
+	} else {
+		// it might have been unavailable before we left
+		s.unavailableGuilds.Delete(ev.ID)
+
+		s.handleEvent(&GuildLeaveEvent{
+			GuildDeleteEvent: ev,
+		})
+	}
+}

state/events.go

@@ -0,0 +1,42 @@
+package state
+
+import "github.com/diamondburned/arikawa/gateway"
+
+// events that originated from GuildCreate:
+type (
+	// GuildReady gets fired for every guild the bot/user is in, as found in
+	// the Ready event.
+	//
+	// Guilds that are unavailable when connecting, will not trigger a
+	// GuildReadyEvent, until they become available again.
+	GuildReadyEvent struct {
+		*gateway.GuildCreateEvent
+	}
+
+	// GuildAvailableEvent gets fired when a guild becomes available again,
+	// after being previously declared unavailable through a
+	// GuildUnavailableEvent. This event will not be fired for guilds that
+	// were already unavailable when connecting to the gateway.
+	GuildAvailableEvent struct {
+		*gateway.GuildCreateEvent
+	}
+
+	// GuildJoinEvent gets fired if the bot/user joins a guild.
+	GuildJoinEvent struct {
+		*gateway.GuildCreateEvent
+	}
+)
+
+// events that originated from GuildDelete:
+type (
+	// GuildLeaveEvent gets fired if the bot/user left a guild, was removed
+	// or the owner deleted the guild.
+	GuildLeaveEvent struct {
+		*gateway.GuildDeleteEvent
+	}
+
+	// GuildUnavailableEvent gets fired if a guild becomes unavailable.
+	GuildUnavailableEvent struct {
+		*gateway.GuildDeleteEvent
+	}
+)

state/state.go

@@ -10,6 +10,8 @@ import (
 	"github.com/diamondburned/arikawa/gateway"
 	"github.com/diamondburned/arikawa/handler"
 	"github.com/diamondburned/arikawa/session"
+	"github.com/diamondburned/arikawa/utils/moreatomic"
+
 	"github.com/pkg/errors"
 )
 
@@ -48,6 +50,15 @@ type State struct {
 	// again.
 	fewMessages map[discord.Snowflake]struct{}
 	fewMutex    *sync.Mutex
+
+	// unavailableGuilds is a set of discord.Snowflakes of guilds that became
+	// unavailable when already connected to the gateway, i.e. sent in a
+	// GuildUnavailableEvent.
+	unavailableGuilds *moreatomic.SnowflakeSet
+	// unreadyGuilds is a set of discord.Snowflakes of guilds that were
+	// unavailable when connecting to the gateway, i.e. they had Unavailable
+	// set to true during Ready.
+	unreadyGuilds *moreatomic.SnowflakeSet
 }
 
 func New(token string) (*State, error) {
@@ -65,12 +76,14 @@ func NewWithStore(token string, store Store) (*State, error) {
 
 func NewFromSession(s *session.Session, store Store) (*State, error) {
 	state := &State{
-		Session:     s,
-		Store:       store,
-		Handler:     handler.New(),
-		StateLog:    func(err error) {},
-		fewMessages: map[discord.Snowflake]struct{}{},
-		fewMutex:    new(sync.Mutex),
+		Session:           s,
+		Store:             store,
+		Handler:           handler.New(),
+		StateLog:          func(err error) {},
+		fewMessages:       map[discord.Snowflake]struct{}{},
+		fewMutex:          new(sync.Mutex),
+		unavailableGuilds: moreatomic.NewSnowflakeSet(),
+		unreadyGuilds:     moreatomic.NewSnowflakeSet(),
 	}
 
 	return state, state.hookSession()

state/state_events.go

@@ -1,18 +1,26 @@
 package state
 
 import (
+	"github.com/pkg/errors"
+
 	"github.com/diamondburned/arikawa/discord"
 	"github.com/diamondburned/arikawa/gateway"
-	"github.com/pkg/errors"
 )
 
 func (s *State) hookSession() error {
 	s.unhooker = s.Session.AddHandler(func(iface interface{}) {
-		if s.PreHandler != nil {
-			s.PreHandler.Call(iface)
-		}
 		s.onEvent(iface)
-		s.Handler.Call(iface)
+
+		switch e := iface.(type) {
+		case *gateway.ReadyEvent:
+			s.handleReady(e)
+		case *gateway.GuildCreateEvent:
+			s.handleGuildCreate(e)
+		case *gateway.GuildDeleteEvent:
+			s.handleGuildDelete(e)
+		default:
+			s.handleEvent(iface)
+		}
 	})
 
 	return nil
@@ -35,7 +43,7 @@ func (s *State) onEvent(iface interface{}) {
 
 		// Handle guilds
 		for i := range ev.Guilds {
-			s.batchLog(handleGuildCreate(s.Store, &ev.Guilds[i])...)
+			s.batchLog(storeGuildCreate(s.Store, &ev.Guilds[i])...)
 		}
 
 		// Handle private channels
@@ -50,16 +58,13 @@ func (s *State) onEvent(iface interface{}) {
 			s.stateErr(err, "failed to set self in state")
 		}
 
-	case *gateway.GuildCreateEvent:
-		s.batchLog(handleGuildCreate(s.Store, ev)...)
-
 	case *gateway.GuildUpdateEvent:
 		if err := s.Store.GuildSet((*discord.Guild)(ev)); err != nil {
 			s.stateErr(err, "failed to update guild in state")
 		}
 
 	case *gateway.GuildDeleteEvent:
-		if err := s.Store.GuildRemove(ev.ID); err != nil {
+		if err := s.Store.GuildRemove(ev.ID); err != nil && !ev.Unavailable {
 			s.stateErr(err, "failed to delete guild in state")
 		}
 
@@ -304,30 +309,28 @@ func findReaction(rs []discord.Reaction, emoji discord.Emoji) int {
 	return -1
 }
 
-func handleGuildCreate(store Store, guild *gateway.GuildCreateEvent) []error {
-	// If a guild is unavailable, don't populate it in the state, as the guild
-	// data is very incomplete.
+func storeGuildCreate(store Store, guild *gateway.GuildCreateEvent) []error {
 	if guild.Unavailable {
 		return nil
 	}
 
-	stack, error := newErrorStack()
+	stack, errs := newErrorStack()
 
 	if err := store.GuildSet(&guild.Guild); err != nil {
-		error(err, "failed to set guild in Ready")
+		errs(err, "failed to set guild in Ready")
 	}
 
 	// Handle guild emojis
 	if guild.Emojis != nil {
 		if err := store.EmojiSet(guild.ID, guild.Emojis); err != nil {
-			error(err, "failed to set guild emojis")
+			errs(err, "failed to set guild emojis")
 		}
 	}
 
 	// Handle guild member
 	for i := range guild.Members {
 		if err := store.MemberSet(guild.ID, &guild.Members[i]); err != nil {
-			error(err, "failed to set guild member in Ready")
+			errs(err, "failed to set guild member in Ready")
 		}
 	}
 
@@ -338,21 +341,21 @@ func handleGuildCreate(store Store, guild *gateway.GuildCreateEvent) []error {
 		ch.GuildID = guild.ID
 
 		if err := store.ChannelSet(&ch); err != nil {
-			error(err, "failed to set guild channel in Ready")
+			errs(err, "failed to set guild channel in Ready")
 		}
 	}
 
 	// Handle guild presences
 	for i := range guild.Presences {
 		if err := store.PresenceSet(guild.ID, &guild.Presences[i]); err != nil {
-			error(err, "failed to set guild presence in Ready")
+			errs(err, "failed to set guild presence in Ready")
 		}
 	}
 
 	// Handle guild voice states
 	for i := range guild.VoiceStates {
 		if err := store.VoiceStateSet(guild.ID, &guild.VoiceStates[i]); err != nil {
-			error(err, "failed to set guild voice state in Ready")
+			errs(err, "failed to set guild voice state in Ready")
 		}
 	}
 

utils/moreatomic/snowflake_set.go

@@ -0,0 +1,51 @@
+package moreatomic
+
+import (
+	"sync"
+
+	"github.com/diamondburned/arikawa/discord"
+)
+
+type SnowflakeSet struct {
+	set map[discord.Snowflake]struct{}
+	mut sync.Mutex
+}
+
+// NewSnowflakeSet creates a new SnowflakeSet.
+func NewSnowflakeSet() *SnowflakeSet {
+	return &SnowflakeSet{
+		set: make(map[discord.Snowflake]struct{}),
+	}
+}
+
+// Add adds the passed discord.Snowflake to the set.
+func (s *SnowflakeSet) Add(flake discord.Snowflake) {
+	s.mut.Lock()
+
+	s.set[flake] = struct{}{}
+
+	s.mut.Unlock()
+}
+
+// Contains checks whether the passed discord.Snowflake is present in the set.
+func (s *SnowflakeSet) Contains(flake discord.Snowflake) (ok bool) {
+	s.mut.Lock()
+	defer s.mut.Unlock()
+
+	_, ok = s.set[flake]
+	return
+}
+
+// Delete deletes the passed discord.Snowflake from the set and returns true if
+// the element is present. If not, Delete is a no-op and returns false.
+func (s *SnowflakeSet) Delete(flake discord.Snowflake) bool {
+	s.mut.Lock()
+	defer s.mut.Unlock()
+
+	if _, ok := s.set[flake]; ok {
+		delete(s.set, flake)
+		return true
+	}
+
+	return false
+}