switch mentions from _inbox tags to mentions relation

db/node.go

@@ -67,6 +67,18 @@ func (db *DB) resolveUserRef(tx *sql.Tx, ref string) (string, error) {
 	return db.ensureUser(tx, ref)
 }
 
+func (db *DB) GetUserByUsername(username string) (string, error) {
+	var id string
+	err := db.QueryRow(`
+		SELECT n.id FROM nodes n
+		JOIN tags t ON n.id = t.node_id
+		WHERE n.title = ? AND t.tag = '_type::user'`, username).Scan(&id)
+	if err == sql.ErrNoRows {
+		return "", nil
+	}
+	return id, err
+}
+
 func (db *DB) ensureNamespace(tx *sql.Tx, name string) (string, error) {
 	var existingID string
 	err := tx.QueryRow(`
@@ -123,8 +135,9 @@ type UpdateParams struct {
 	AddRels, RemoveRels     map[models.RelType][]string
 }
 type ListFilter struct {
-	TagPrefixes []string
-	Assignee    string
+	TagPrefixes  []string
+	Assignee     string
+	MentionsUser string
 }
 
 func (db *DB) CreateNode(p CreateParams) (*models.Node, error) {
@@ -142,17 +155,17 @@ func (db *DB) CreateNode(p CreateParams) (*models.Node, error) {
 	}
 
 	for _, m := range parse.Mentions(p.Title + " " + p.Content) {
-		if _, err := db.ensureUser(tx, m); err != nil {
+		userID, err := db.resolveUserRef(tx, m)
+		if err != nil {
+			return nil, err
+		}
+		if _, err := tx.Exec("INSERT INTO rels (from_id, to_id, rel_type) VALUES (?, ?, ?)", id, userID, models.RelMentions); err != nil {
 			return nil, err
 		}
 	}
 
-	for _, t := range append(p.Tags, parse.Mentions(p.Title+" "+p.Content)...) {
-		if !strings.HasPrefix(t, "_") && strings.HasPrefix(t, "@") {
-			if _, err = tx.Exec("INSERT INTO tags (node_id, tag) VALUES (?, ?)", id, "_inbox::"+t[1:]); err != nil {
-				return nil, err
-			}
-		} else if _, err := tx.Exec("INSERT INTO tags (node_id, tag) VALUES (?, ?)", id, t); err != nil {
+	for _, t := range p.Tags {
+		if _, err := tx.Exec("INSERT INTO tags (node_id, tag) VALUES (?, ?)", id, t); err != nil {
 			return nil, err
 		}
 	}
@@ -188,24 +201,28 @@ func (db *DB) UpdateNode(id string, p UpdateParams) error {
 	}
 	defer tx.Rollback()
 
+	var currentTitle, currentContent string
+	err = tx.QueryRow("SELECT title, COALESCE(content, '') FROM nodes WHERE id = ?", id).Scan(&currentTitle, &currentContent)
+	if err != nil {
+		return err
+	}
+
 	upd := func(col, val string) error {
 		_, err := tx.Exec("UPDATE nodes SET "+col+" = ? WHERE id = ?", val, id)
 		return err
 	}
+	newTitle, newContent := currentTitle, currentContent
 	if p.Title != nil {
 		if err := upd("title", *p.Title); err != nil {
 			return err
 		}
+		newTitle = *p.Title
 	}
 	if p.Content != nil {
 		if err := upd("content", *p.Content); err != nil {
 			return err
 		}
-		for _, m := range parse.Mentions(*p.Content) {
-			if _, err := db.ensureUser(tx, m); err != nil {
-				return err
-			}
-		}
+		newContent = *p.Content
 	}
 	if p.DueDate != nil {
 		if err := upd("due_date", *p.DueDate); err != nil {
@@ -218,6 +235,46 @@ func (db *DB) UpdateNode(id string, p UpdateParams) error {
 		}
 	}
 
+	if p.Title != nil || p.Content != nil {
+		newMentions := parse.Mentions(newTitle + " " + newContent)
+		rows, err := tx.Query("SELECT to_id FROM rels WHERE from_id = ? AND rel_type = ?", id, models.RelMentions)
+		if err != nil {
+			return err
+		}
+		existingMentionIDs := make(map[string]bool)
+		for rows.Next() {
+			var uid string
+			if err := rows.Scan(&uid); err != nil {
+				rows.Close()
+				return err
+			}
+			existingMentionIDs[uid] = true
+		}
+		rows.Close()
+
+		mentionedUserIDs := make(map[string]bool)
+		for _, m := range newMentions {
+			userID, err := db.resolveUserRef(tx, m)
+			if err != nil {
+				return err
+			}
+			mentionedUserIDs[userID] = true
+			if !existingMentionIDs[userID] {
+				if _, err := tx.Exec("INSERT INTO rels (from_id, to_id, rel_type) VALUES (?, ?, ?)", id, userID, models.RelMentions); err != nil {
+					return err
+				}
+			}
+		}
+
+		for uid := range existingMentionIDs {
+			if !mentionedUserIDs[uid] {
+				if _, err := tx.Exec("DELETE FROM rels WHERE from_id = ? AND to_id = ? AND rel_type = ?", id, uid, models.RelMentions); err != nil {
+					return err
+				}
+			}
+		}
+	}
+
 	for _, t := range p.RemoveTags {
 		tx.Exec("DELETE FROM tags WHERE node_id = ? AND tag = ?", id, t)
 	}
@@ -315,6 +372,11 @@ func (db *DB) ListNodes(f ListFilter) ([]*models.Node, error) {
 		conds = append(conds, "r_assign.to_id = ? AND r_assign.rel_type = ?")
 		args = append(args, f.Assignee, models.RelAssignee)
 	}
+	if f.MentionsUser != "" {
+		joins = append(joins, "JOIN rels r_mentions ON n.id = r_mentions.from_id")
+		conds = append(conds, "r_mentions.to_id = ? AND r_mentions.rel_type = ?")
+		args = append(args, f.MentionsUser, models.RelMentions)
+	}
 
 	if len(joins) > 0 {
 		q += " " + strings.Join(joins, " ") + " "