Initial bot functionality

* The bot now properly joins the management room
* The management room is persisted in the database
* Welcome/help messages are sent in the management room

bridge/user.go

@@ -0,0 +1,93 @@
+package bridge
+
+import (
+	log "maunium.net/go/maulogger/v2"
+	"maunium.net/go/mautrix/id"
+
+	"gitlab.com/beeper/discord/database"
+)
+
+type User struct {
+	*database.User
+
+	bridge *Bridge
+	log    log.Logger
+}
+
+func (b *Bridge) loadUser(dbUser *database.User, mxid *id.UserID) *User {
+	// If we weren't passed in a user we attempt to create one if we were given
+	// a matrix id.
+	if dbUser == nil {
+		if mxid == nil {
+			return nil
+		}
+
+		dbUser = b.db.User.New()
+		dbUser.MXID = *mxid
+		dbUser.Insert()
+	}
+
+	user := b.NewUser(dbUser)
+
+	// We assume the usersLock was acquired by our caller.
+	b.usersByMXID[user.MXID] = user
+	if user.ID != "" {
+		b.usersByID[user.ID] = user
+	}
+
+	if user.ManagementRoom != "" {
+		// Lock the management rooms for our update
+		b.managementRoomsLock.Lock()
+		b.managementRooms[user.ManagementRoom] = user
+		b.managementRoomsLock.Unlock()
+	}
+
+	return user
+}
+
+func (b *Bridge) GetUserByMXID(userID id.UserID) *User {
+	// TODO: check if puppet
+
+	b.usersLock.Lock()
+	defer b.usersLock.Unlock()
+
+	user, ok := b.usersByMXID[userID]
+	if !ok {
+		return b.loadUser(b.db.User.GetByMXID(userID), &userID)
+	}
+
+	return user
+}
+
+func (b *Bridge) NewUser(dbUser *database.User) *User {
+	user := &User{
+		User:   dbUser,
+		bridge: b,
+		log:    b.log.Sub("User").Sub(string(dbUser.MXID)),
+	}
+
+	return user
+}
+
+func (u *User) SetManagementRoom(roomID id.RoomID) {
+	u.bridge.managementRoomsLock.Lock()
+	defer u.bridge.managementRoomsLock.Unlock()
+
+	existing, ok := u.bridge.managementRooms[roomID]
+	if ok {
+		// If there's a user already assigned to this management room, clear it
+		// out.
+		// I think this is due a name change or something? I dunno, leaving it
+		// for now.
+		existing.ManagementRoom = ""
+		existing.Update()
+	}
+
+	u.ManagementRoom = roomID
+	u.bridge.managementRooms[u.ManagementRoom] = u
+	u.Update()
+}
+
+func (u *User) HasSession() bool {
+	return u.User.Session != nil
+}