Add full shop application: Go backend, PostgreSQL, Docker, Caddy and admin panel.

internal/repository/admin.go

@@ -0,0 +1,46 @@
+package repository
+
+import (
+	"context"
+	"errors"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"golang.org/x/crypto/bcrypt"
+)
+
+type AdminRepository struct {
+	pool *pgxpool.Pool
+}
+
+func NewAdminRepository(pool *pgxpool.Pool) *AdminRepository {
+	return &AdminRepository{pool: pool}
+}
+
+func (r *AdminRepository) Upsert(ctx context.Context, email, password string) error {
+	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
+	if err != nil {
+		return err
+	}
+
+	_, err = r.pool.Exec(ctx, `
+		INSERT INTO admins (email, password_hash)
+		VALUES ($1, $2)
+		ON CONFLICT (email) DO UPDATE SET password_hash = EXCLUDED.password_hash
+	`, email, string(hash))
+	return err
+}
+
+func (r *AdminRepository) Authenticate(ctx context.Context, email, password string) (bool, error) {
+	var hash string
+	err := r.pool.QueryRow(ctx, `
+		SELECT password_hash FROM admins WHERE email = $1
+	`, email).Scan(&hash)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return false, nil
+		}
+		return false, err
+	}
+	return bcrypt.CompareHashAndPassword([]byte(hash), []byte(password)) == nil, nil
+}