add termail db functions

internal/db/user.go

@@ -173,6 +173,127 @@ func GetUserByEmail(ctx context.Context, email string) (*User, error) {
 	return &user, nil
 }
 
+type Termail struct {
+	ID         int       `json:"id"`
+	SenderID   int       `json:"sender_id"`
+	ReceiverID int       `json:"receiver_id"`
+	Subject    string    `json:"subject"`
+	Content    string    `json:"content"`
+	IsRead     bool      `json:"is_read"`
+	SentAt     time.Time `json:"sent_at"`
+	Sender     string    `json:"sender,omitempty"`
+	Receiver   string    `json:"receiver,omitempty"`
+}
+
+type SendTermailRequest struct {
+	ReceiverUsername string `json:"receiver_username"`
+	Subject          string `json:"subject"`
+	Content          string `json:"content"`
+}
+
+func SendTermail(ctx context.Context, senderID int, req SendTermailRequest) (*Termail, error) {
+	receiver, err := GetUserByUsername(ctx, req.ReceiverUsername)
+	if err != nil {
+		return nil, fmt.Errorf("user not found: %s", req.ReceiverUsername)
+	}
+
+	var termail Termail
+	err = Pool.QueryRow(ctx,
+		"INSERT INTO termails (sender_id, receiver_id, subject, content) VALUES ($1, $2, $3, $4) RETURNING id, sender_id, receiver_id, subject, content, is_read, sent_at",
+		senderID, receiver.ID, req.Subject, req.Content,
+	).Scan(&termail.ID, &termail.SenderID, &termail.ReceiverID, &termail.Subject, &termail.Content, &termail.IsRead, &termail.SentAt)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &termail, nil
+}
+
+func GetInbox(ctx context.Context, userID int, limit, offset int) ([]Termail, error) {
+	query := `
+		SELECT t.id, t.sender_id, t.receiver_id, t.subject, t.content, t.is_read, t.sent_at, u.username as sender
+		FROM termails t
+		JOIN users u ON t.sender_id = u.id
+		WHERE t.receiver_id = $1
+		ORDER BY t.sent_at DESC
+		LIMIT $2 OFFSET $3
+	`
+
+	rows, err := Pool.Query(ctx, query, userID, limit, offset)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var termails []Termail
+	for rows.Next() {
+		var t Termail
+		err := rows.Scan(&t.ID, &t.SenderID, &t.ReceiverID, &t.Subject, &t.Content, &t.IsRead, &t.SentAt, &t.Sender)
+		if err != nil {
+			return nil, err
+		}
+		termails = append(termails, t)
+	}
+
+	return termails, nil
+}
+
+func MarkTermailAsRead(ctx context.Context, termailID, userID int) error {
+	_, err := Pool.Exec(ctx,
+		"UPDATE termails SET is_read = true WHERE id = $1 AND receiver_id = $2",
+		termailID, userID,
+	)
+	return err
+}
+
+func DeleteTermail(ctx context.Context, termailID, userID int) error {
+	result, err := Pool.Exec(ctx,
+		"DELETE FROM termails WHERE id = $1 AND receiver_id = $2",
+		termailID, userID,
+	)
+	if err != nil {
+		return err
+	}
+
+	rowsAffected := result.RowsAffected()
+	if rowsAffected == 0 {
+		return fmt.Errorf("termail not found or access denied")
+	}
+
+	return nil
+}
+
+func SearchTermails(ctx context.Context, userID int, query string, limit, offset int) ([]Termail, error) {
+	sqlQuery := `
+		SELECT t.id, t.sender_id, t.receiver_id, t.subject, t.content, t.is_read, t.sent_at, u.username as sender
+		FROM termails t
+		JOIN users u ON t.sender_id = u.id
+		WHERE t.receiver_id = $1 AND (t.subject ILIKE $2 OR t.content ILIKE $2 OR u.username ILIKE $2)
+		ORDER BY t.sent_at DESC
+		LIMIT $3 OFFSET $4
+	`
+
+	searchPattern := "%" + query + "%"
+	rows, err := Pool.Query(ctx, sqlQuery, userID, searchPattern, limit, offset)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var termails []Termail
+	for rows.Next() {
+		var t Termail
+		err := rows.Scan(&t.ID, &t.SenderID, &t.ReceiverID, &t.Subject, &t.Content, &t.IsRead, &t.SentAt, &t.Sender)
+		if err != nil {
+			return nil, err
+		}
+		termails = append(termails, t)
+	}
+
+	return termails, nil
+}
+
 func CleanupUnverifiedUsers(ctx context.Context) error {
 	_, err := Pool.Exec(ctx, `
 		DELETE FROM users