From 2e2326843fe515a30deeec1117273cadd6df0d5d Mon Sep 17 00:00:00 2001
From: eikendev <raphael@eiken.dev>
Date: Tue, 9 Feb 2021 00:05:16 +0100
Subject: [PATCH] Repair channels if necessary

---
 cmd/pushbits/main.go                        | 13 ++++--
 internal/api/application.go                 | 21 ++++------
 internal/api/interfaces.go                  |  2 +-
 internal/api/notification.go                |  2 +-
 internal/api/user.go                        |  6 +--
 internal/authentication/credentials/hibp.go |  2 +-
 internal/database/database.go               | 45 ++++++++++++++++++++-
 internal/database/interfaces.go             | 13 ++++++
 internal/dispatcher/application.go          | 33 +++++++++++++--
 internal/dispatcher/dispatcher.go           |  4 +-
 internal/dispatcher/notification.go         |  2 +-
 internal/model/user.go                      |  2 +-
 12 files changed, 114 insertions(+), 31 deletions(-)
 create mode 100644 internal/database/interfaces.go

diff --git a/cmd/pushbits/main.go b/cmd/pushbits/main.go
index 84a5a5d..66bcaae 100644
--- a/cmd/pushbits/main.go
+++ b/cmd/pushbits/main.go
@@ -32,29 +32,34 @@ func main() {
 	c := configuration.Get()
 
 	if c.Debug {
-		log.Printf("%+v\n", c)
+		log.Printf("%+v", c)
 	}
 
 	cm := credentials.CreateManager(c.Security.CheckHIBP, c.Crypto)
 
 	db, err := database.Create(cm, c.Database.Dialect, c.Database.Connection)
 	if err != nil {
-		panic(err)
+		log.Fatal(err)
 	}
 	defer db.Close()
 
 	if err := db.Populate(c.Admin.Name, c.Admin.Password, c.Admin.MatrixID); err != nil {
-		panic(err)
+		log.Fatal(err)
 	}
 
 	dp, err := dispatcher.Create(db, c.Matrix.Homeserver, c.Matrix.Username, c.Matrix.Password)
 	if err != nil {
-		panic(err)
+		log.Fatal(err)
 	}
 	defer dp.Close()
 
 	setupCleanup(db, dp)
 
+	err = db.RepairChannels(dp)
+	if err != nil {
+		log.Fatal(err)
+	}
+
 	engine := router.Create(c.Debug, cm, db, dp)
 
 	runner.Run(engine, c.HTTP.ListenAddress, c.HTTP.Port)
diff --git a/internal/api/application.go b/internal/api/application.go
index 1ee56a7..c598414 100644
--- a/internal/api/application.go
+++ b/internal/api/application.go
@@ -27,7 +27,7 @@ func (h *ApplicationHandler) generateToken(compat bool) string {
 }
 
 func (h *ApplicationHandler) registerApplication(ctx *gin.Context, a *model.Application, u *model.User) error {
-	log.Printf("Registering application %s.\n", a.Name)
+	log.Printf("Registering application %s.", a.Name)
 
 	channelID, err := h.DP.RegisterApplication(a.ID, a.Name, a.Token, u.MatrixID)
 	if success := successOrAbort(ctx, http.StatusInternalServerError, err); !success {
@@ -41,7 +41,7 @@ func (h *ApplicationHandler) registerApplication(ctx *gin.Context, a *model.Appl
 }
 
 func (h *ApplicationHandler) createApplication(ctx *gin.Context, u *model.User, name string, compat bool) (*model.Application, error) {
-	log.Printf("Creating application %s.\n", name)
+	log.Printf("Creating application %s.", name)
 
 	application := model.Application{}
 	application.Name = name
@@ -57,7 +57,7 @@ func (h *ApplicationHandler) createApplication(ctx *gin.Context, u *model.User,
 		err := h.DB.DeleteApplication(&application)
 
 		if success := successOrAbort(ctx, http.StatusInternalServerError, err); !success {
-			log.Printf("Cannot delete application with ID %d.\n", application.ID)
+			log.Printf("Cannot delete application with ID %d.", application.ID)
 		}
 
 		return nil, err
@@ -67,7 +67,7 @@ func (h *ApplicationHandler) createApplication(ctx *gin.Context, u *model.User,
 }
 
 func (h *ApplicationHandler) deleteApplication(ctx *gin.Context, a *model.Application, u *model.User) error {
-	log.Printf("Deleting application %s (ID %d).\n", a.Name, a.ID)
+	log.Printf("Deleting application %s (ID %d).", a.Name, a.ID)
 
 	err := h.DP.DeregisterApplication(a, u)
 	if success := successOrAbort(ctx, http.StatusInternalServerError, err); !success {
@@ -82,8 +82,8 @@ func (h *ApplicationHandler) deleteApplication(ctx *gin.Context, a *model.Applic
 	return nil
 }
 
-func (h *ApplicationHandler) updateApplication(ctx *gin.Context, a *model.Application, u *model.User, updateApplication *model.UpdateApplication) error {
-	log.Printf("Updating application %s (ID %d).\n", a.Name, a.ID)
+func (h *ApplicationHandler) updateApplication(ctx *gin.Context, a *model.Application, updateApplication *model.UpdateApplication) error {
+	log.Printf("Updating application %s (ID %d).", a.Name, a.ID)
 
 	if updateApplication.Name != nil {
 		log.Printf("Updating application name to '%s'.", *updateApplication.Name)
@@ -101,7 +101,7 @@ func (h *ApplicationHandler) updateApplication(ctx *gin.Context, a *model.Applic
 		return err
 	}
 
-	err = h.DP.UpdateApplication(a, u)
+	err = h.DP.UpdateApplication(a)
 	if success := successOrAbort(ctx, http.StatusInternalServerError, err); !success {
 		return err
 	}
@@ -200,12 +200,7 @@ func (h *ApplicationHandler) UpdateApplication(ctx *gin.Context) {
 		return
 	}
 
-	user := authentication.GetUser(ctx)
-	if user == nil {
-		return
-	}
-
-	if err := h.updateApplication(ctx, application, user, &updateApplication); err != nil {
+	if err := h.updateApplication(ctx, application, &updateApplication); err != nil {
 		return
 	}
 
diff --git a/internal/api/interfaces.go b/internal/api/interfaces.go
index 73486c0..4bc72b1 100644
--- a/internal/api/interfaces.go
+++ b/internal/api/interfaces.go
@@ -28,7 +28,7 @@ type Database interface {
 type Dispatcher interface {
 	RegisterApplication(id uint, name, token, user string) (string, error)
 	DeregisterApplication(a *model.Application, u *model.User) error
-	UpdateApplication(a *model.Application, u *model.User) error
+	UpdateApplication(a *model.Application) error
 }
 
 // The CredentialsManager interface for updating credentials.
diff --git a/internal/api/notification.go b/internal/api/notification.go
index 553bf1c..bfb8af0 100644
--- a/internal/api/notification.go
+++ b/internal/api/notification.go
@@ -36,7 +36,7 @@ func (h *NotificationHandler) CreateNotification(ctx *gin.Context) {
 	}
 
 	application := authentication.GetApplication(ctx)
-	log.Printf("Sending notification for application %s.\n", application.Name)
+	log.Printf("Sending notification for application %s.", application.Name)
 
 	notification.ID = 0
 	notification.ApplicationID = application.ID
diff --git a/internal/api/user.go b/internal/api/user.go
index ea06ff2..65e5159 100644
--- a/internal/api/user.go
+++ b/internal/api/user.go
@@ -84,7 +84,7 @@ func (h *UserHandler) updateUser(ctx *gin.Context, u *model.User, updateUser mod
 		}
 	}
 
-	log.Printf("Updating user %s.\n", u.Name)
+	log.Printf("Updating user %s.", u.Name)
 
 	if updateUser.Name != nil {
 		u.Name = *updateUser.Name
@@ -126,7 +126,7 @@ func (h *UserHandler) CreateUser(ctx *gin.Context) {
 		return
 	}
 
-	log.Printf("Creating user %s.\n", createUser.Name)
+	log.Printf("Creating user %s.", createUser.Name)
 
 	user, err := h.DB.CreateUser(createUser)
 
@@ -181,7 +181,7 @@ func (h *UserHandler) DeleteUser(ctx *gin.Context) {
 		}
 	}
 
-	log.Printf("Deleting user %s.\n", user.Name)
+	log.Printf("Deleting user %s.", user.Name)
 
 	if err := h.deleteApplications(ctx, user); err != nil {
 		return
diff --git a/internal/authentication/credentials/hibp.go b/internal/authentication/credentials/hibp.go
index 5836126..81680a8 100644
--- a/internal/authentication/credentials/hibp.go
+++ b/internal/authentication/credentials/hibp.go
@@ -26,7 +26,7 @@ func IsPasswordPwned(password string) (bool, error) {
 	lookup := hashStr[0:5]
 	match := hashStr[5:]
 
-	log.Printf("Checking HIBP for hashes starting with '%s'.\n", lookup)
+	log.Printf("Checking HIBP for hashes starting with '%s'.", lookup)
 
 	resp, err := http.Get(pwnedHashesURL + lookup)
 	if err != nil {
diff --git a/internal/database/database.go b/internal/database/database.go
index b4bc3d8..c7f52ff 100644
--- a/internal/database/database.go
+++ b/internal/database/database.go
@@ -79,6 +79,8 @@ func (d *Database) Close() {
 
 // Populate fills the database with initial information like the admin user.
 func (d *Database) Populate(name, password, matrixID string) error {
+	log.Print("Populating database.")
+
 	var user model.User
 
 	query := d.gormdb.Where("name = ?", name).First(&user)
@@ -86,14 +88,53 @@ func (d *Database) Populate(name, password, matrixID string) error {
 	if errors.Is(query.Error, gorm.ErrRecordNotFound) {
 		user, err := model.NewUser(d.credentialsManager, name, password, true, matrixID)
 		if err != nil {
-			log.Fatal(err)
+			return err
 		}
 
 		if err := d.gormdb.Create(&user).Error; err != nil {
 			return errors.New("user cannot be created")
 		}
 	} else {
-		log.Printf("Admin user %s already exists.\n", name)
+		log.Printf("Priviledged user %s already exists.", name)
+	}
+
+	return nil
+}
+
+// RepairChannels resets channels that have been modified by a user.
+func (d *Database) RepairChannels(dp Dispatcher) error {
+	log.Print("Repairing application channels.")
+
+	users, err := d.GetUsers()
+	if err != nil {
+		return err
+	}
+
+	for _, user := range users {
+		applications, err := d.GetApplications(&user)
+		if err != nil {
+			return err
+		}
+
+		for _, application := range applications {
+			if err := dp.UpdateApplication(&application); err != nil {
+				return err
+			}
+
+			orphan, err := dp.IsOrphan(&application, &user)
+			if err != nil {
+				return err
+			}
+
+			if orphan {
+				log.Printf("Found orphan channel for application %s (ID %d)", application.Name, application.ID)
+
+				if err = dp.RepairApplication(&application, &user); err != nil {
+					log.Printf("Unable to repair application %s (ID %d).", application.Name, application.ID)
+					log.Println(err)
+				}
+			}
+		}
 	}
 
 	return nil
diff --git a/internal/database/interfaces.go b/internal/database/interfaces.go
new file mode 100644
index 0000000..7d4a70c
--- /dev/null
+++ b/internal/database/interfaces.go
@@ -0,0 +1,13 @@
+package database
+
+import (
+	"github.com/pushbits/server/internal/model"
+)
+
+// The Dispatcher interface for constructing and destructing channels.
+type Dispatcher interface {
+	DeregisterApplication(a *model.Application, u *model.User) error
+	UpdateApplication(a *model.Application) error
+	IsOrphan(a *model.Application, u *model.User) (bool, error)
+	RepairApplication(a *model.Application, u *model.User) error
+}
diff --git a/internal/dispatcher/application.go b/internal/dispatcher/application.go
index d6a49da..8728a7d 100644
--- a/internal/dispatcher/application.go
+++ b/internal/dispatcher/application.go
@@ -25,7 +25,6 @@ func (d *Dispatcher) RegisterApplication(id uint, name, token, user string) (str
 		Topic:      buildRoomTopic(id),
 		Visibility: "private",
 	})
-
 	if err != nil {
 		log.Print(err)
 		return "", err
@@ -45,9 +44,9 @@ func (d *Dispatcher) DeregisterApplication(a *model.Application, u *model.User)
 		UserID: u.MatrixID,
 	}
 
+	// The user might have left the channel, but we can still try to remove them.
 	if _, err := d.client.KickUser(a.MatrixID, kickUser); err != nil {
 		log.Print(err)
-		return err
 	}
 
 	if _, err := d.client.LeaveRoom(a.MatrixID); err != nil {
@@ -73,7 +72,7 @@ func (d *Dispatcher) sendRoomEvent(roomID, eventType string, content interface{}
 }
 
 // UpdateApplication updates a channel for an application.
-func (d *Dispatcher) UpdateApplication(a *model.Application, u *model.User) error {
+func (d *Dispatcher) UpdateApplication(a *model.Application) error {
 	log.Printf("Updating application %s (ID %d) with Matrix ID %s.\n", a.Name, a.ID, a.MatrixID)
 
 	content := map[string]interface{}{
@@ -94,3 +93,31 @@ func (d *Dispatcher) UpdateApplication(a *model.Application, u *model.User) erro
 
 	return nil
 }
+
+// IsOrphan checks if the user is still connected to the channel.
+func (d *Dispatcher) IsOrphan(a *model.Application, u *model.User) (bool, error) {
+	resp, err := d.client.JoinedMembers(a.MatrixID)
+	if err != nil {
+		return false, err
+	}
+
+	found := false
+
+	for userID := range resp.Joined {
+		found = found || (userID == u.MatrixID)
+	}
+
+	return !found, nil
+}
+
+// RepairApplication re-invites the user to the channel.
+func (d *Dispatcher) RepairApplication(a *model.Application, u *model.User) error {
+	_, err := d.client.InviteUser(a.MatrixID, &gomatrix.ReqInviteUser{
+		UserID: u.MatrixID,
+	})
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
diff --git a/internal/dispatcher/dispatcher.go b/internal/dispatcher/dispatcher.go
index baf324e..631a5f6 100644
--- a/internal/dispatcher/dispatcher.go
+++ b/internal/dispatcher/dispatcher.go
@@ -45,8 +45,10 @@ func Create(db Database, homeserver, username, password string) (*Dispatcher, er
 
 // Close closes the dispatcher connection.
 func (d *Dispatcher) Close() {
-	log.Printf("Logging out.\n")
+	log.Printf("Logging out.")
 
 	d.client.Logout()
 	d.client.ClearCredentials()
+
+	log.Printf("Successfully logged out.")
 }
diff --git a/internal/dispatcher/notification.go b/internal/dispatcher/notification.go
index 63f8b04..fd26991 100644
--- a/internal/dispatcher/notification.go
+++ b/internal/dispatcher/notification.go
@@ -11,7 +11,7 @@ import (
 
 // SendNotification sends a notification to the specified user.
 func (d *Dispatcher) SendNotification(a *model.Application, n *model.Notification) error {
-	log.Printf("Sending notification to room %s.\n", a.MatrixID)
+	log.Printf("Sending notification to room %s.", a.MatrixID)
 
 	plainTitle := strings.TrimSpace(n.Title)
 	plainMessage := strings.TrimSpace(n.Message)
diff --git a/internal/model/user.go b/internal/model/user.go
index 7c7cbfc..16d6a08 100644
--- a/internal/model/user.go
+++ b/internal/model/user.go
@@ -37,7 +37,7 @@ type CreateUser struct {
 
 // NewUser creates a new user.
 func NewUser(cm *credentials.Manager, name, password string, isAdmin bool, matrixID string) (*User, error) {
-	log.Printf("Creating user %s.\n", name)
+	log.Printf("Creating user %s.", name)
 
 	passwordHash, err := cm.CreatePasswordHash(password)
 	if err != nil {