feat(db/notifications): simplify notifications scheme

Signed-off-by: brookjeynes <[e-mail]>

internal/db/db.go

···
 				actor_did text not null,
 				subject_uri text not null,
 
-				state text not null default 'unread' check(state in ('unread', 'read')),
-				type text not null check(type in ('follow', 'reaction', 'comment')),
+				state integer not null default 0,
+				type text not null,
 
 				created_at text not null default (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
 
···
 				is_deleted boolean not null default false,
 				created_at text not null default (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
 
-				foreign key (did) references profiles(did) on delete cascade
+				foreign key (did) references profiles(did) on delete cascade,
 				unique (did, rkey)
 			);
 
···
 	if err != nil {
 		return nil, fmt.Errorf("failed to execute db create statement: %w", err)
 	}
+
+	// This migration removes the type constraint on the notification type as
+	// it was painful to add new types. It also changes state to an integer
+	// check instead of text.
+	runMigration(conn, logger, "simplify-notification-constraints", func(tx *sql.Tx) error {
+		// Create new table with state as integer and no type constraint
+		_, err := tx.Exec(`
+			create table if not exists notifications_new (
+				id integer primary key autoincrement,
+
+				recipient_did text not null,
+				actor_did text not null,
+				subject_uri text not null,
+
+				state integer not null default 0,
+				type text not null,
+
+				created_at text not null default (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
+
+				foreign key (recipient_did) references profiles(did) on delete cascade,
+				foreign key (actor_did) references profiles(did) on delete cascade
+			);
+		`)
+		if err != nil {
+			return err
+		}
+
+		// Copy data, converting state from text to integer
+		_, err = tx.Exec(`
+			insert into notifications_new (id, recipient_did, actor_did, subject_uri, state, type, created_at)
+			select 
+				id, 
+				recipient_did, 
+				actor_did, 
+				subject_uri, 
+				case state
+					when 'unread' then 0
+					when 'read' then 1
+					else 0
+				end,
+				type, 
+				created_at
+			from notifications;
+		`)
+		if err != nil {
+			return err
+		}
+
+		// Drop old table
+		_, err = tx.Exec(`drop table notifications`)
+		if err != nil {
+			return err
+		}
+
+		// Rename new table
+		_, err = tx.Exec(`alter table notifications_new rename to notifications`)
+		return err
+	})
 
 	return &DB{
 		db,

internal/db/notification.go

···
 	NotificationTypeReply    NotificationType = "reply"
 )
 
-type NotificationState string
+type NotificationState int
 
 const (
-	NotificationStateUnread NotificationState = "unread"
-	NotificationStateRead   NotificationState = "read"
+	NotificationStateUnread NotificationState = 0
+	NotificationStateRead   NotificationState = 1
 )
 
 type NotificationWithBskyHandle struct {
···
 }
 
 func GetUnreadNotificationCount(e Execer, recipientDid string) (int, error) {
-	query := `select count(*) from notifications where recipient_did = ? and state = 'unread';`
+	query := `select count(*) from notifications where recipient_did = ? and state = 0;`
 
 	var count int
 	row := e.QueryRow(query, recipientDid)
···
 func MarkAllNotificationsAsRead(e Execer, did string) error {
 	query := `
 		update notifications
-		set state = 'read'
-		where recipient_did = ? and state = 'unread';
+		set state = 1
+		where recipient_did = ? and state = 0;
 	`
 
 	_, err := e.Exec(query, did)

migrations/update_notification_type.sql

···
--- This script should be used and updated whenever a new notification type
--- constraint needs to be added.
-
-BEGIN TRANSACTION;
-
-ALTER TABLE notifications RENAME TO notifications_old;
-
-CREATE TABLE notifications (
-    id INTEGER PRIMARY KEY AUTOINCREMENT,
-    recipient_did TEXT NOT NULL,
-    actor_did TEXT NOT NULL,
-    subject_uri TEXT NOT NULL,
-    state TEXT NOT NULL DEFAULT 'unread' CHECK(state IN ('unread', 'read')),
-    type TEXT NOT NULL CHECK(type IN ('follow', 'reaction', 'comment', 'reply')),
-    created_at TEXT NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
-    FOREIGN KEY (recipient_did) REFERENCES profiles(did) ON DELETE CASCADE,
-    FOREIGN KEY (actor_did) REFERENCES profiles(did) ON DELETE CASCADE
-);
-
-INSERT INTO notifications (id, recipient_did, actor_did, subject_uri, state, type, created_at)
-SELECT id, recipient_did, actor_did, subject_uri, state, type, created_at
-FROM notifications_old;
-
-DROP TABLE notifications_old;
-
-COMMIT;