Files
CU_Points/backend/internal/users/repository.go
T
emilandClaude Sonnet 4.6 094c8953b6 fix: scan timestamptz into time.Time in users repository
Same pgx v5 binary protocol issue as admin service — created_at
in transactions cannot be scanned into *string.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-01 17:10:41 +03:00

111 lines
3.3 KiB
Go

package users
import (
"context"
"errors"
"fmt"
"time"
"github.com/jackc/pgx/v5"
"github.com/jackc/pgx/v5/pgxpool"
)
// ErrNotFound is returned when the requested user does not exist.
var ErrNotFound = errors.New("not found")
// Repository handles all database access for the users domain.
type Repository struct {
db *pgxpool.Pool
}
// NewRepository creates a new users Repository.
func NewRepository(db *pgxpool.Pool) *Repository {
return &Repository{db: db}
}
// GetByID fetches a user's profile by primary key.
// Returns ErrNotFound if no user exists with that ID.
func (r *Repository) GetByID(ctx context.Context, id string) (*Profile, error) {
var p Profile
err := r.db.QueryRow(ctx,
`SELECT id, email, name, COALESCE(student_id, ''), balance
FROM users WHERE id = $1`,
id,
).Scan(&p.ID, &p.Email, &p.Name, &p.StudentID, &p.Balance)
if err != nil {
if errors.Is(err, pgx.ErrNoRows) {
return nil, ErrNotFound
}
return nil, fmt.Errorf("repository.GetByID: %w", err)
}
return &p, nil
}
// UpdateBalance adds delta to the user's balance within an existing pgx transaction.
// delta is positive when earning points, negative when spending.
// Returns the new balance after the update via RETURNING, so the service can include
// it in the API response without a second query.
// The database CHECK (balance >= 0) acts as the last line of defense against overdrafts;
// this function will return an error if the constraint fires.
func (r *Repository) UpdateBalance(ctx context.Context, tx pgx.Tx, id string, delta int) (int, error) {
var newBalance int
err := tx.QueryRow(ctx,
`UPDATE users SET balance = balance + $1 WHERE id = $2 RETURNING balance`,
delta, id,
).Scan(&newBalance)
if err != nil {
return 0, fmt.Errorf("repository.UpdateBalance: %w", err)
}
return newBalance, nil
}
// CountTransactions returns the total number of transactions for the given user.
// Used alongside ListTransactions to populate pagination metadata.
func (r *Repository) CountTransactions(ctx context.Context, userID string) (int, error) {
var count int
err := r.db.QueryRow(ctx,
`SELECT COUNT(*) FROM transactions WHERE user_id = $1`,
userID,
).Scan(&count)
if err != nil {
return 0, fmt.Errorf("repository.CountTransactions: %w", err)
}
return count, nil
}
// ListTransactions returns paginated transactions for the given user, ordered newest first.
func (r *Repository) ListTransactions(ctx context.Context, userID string, limit, offset int) ([]Transaction, error) {
rows, err := r.db.Query(ctx, `
SELECT id,
amount,
type,
COALESCE(description, ''),
COALESCE(partner_id::text, ''),
created_at
FROM transactions
WHERE user_id = $1
ORDER BY created_at DESC
LIMIT $2 OFFSET $3`,
userID, limit, offset,
)
if err != nil {
return nil, fmt.Errorf("repository.ListTransactions: %w", err)
}
defer rows.Close()
var txs []Transaction
for rows.Next() {
var t Transaction
var createdAt time.Time
if err := rows.Scan(&t.ID, &t.Amount, &t.Type, &t.Description, &t.PartnerID, &createdAt); err != nil {
return nil, fmt.Errorf("repository.ListTransactions: scan: %w", err)
}
t.CreatedAt = createdAt.UTC().Format(time.RFC3339)
txs = append(txs, t)
}
if err := rows.Err(); err != nil {
return nil, fmt.Errorf("repository.ListTransactions: rows: %w", err)
}
return txs, nil
}