package repository

import (
	"context"
	"database/sql"
	"testing"

	"github.com/stretchr/testify/require"
)

// mockQueryer implements sqlQueryer for testing
type mockQueryer struct {
	rows    *sql.Rows
	query   string
	args    []any
	err     error
	hasNext bool
	scanErr error
}

func (m *mockQueryer) QueryContext(ctx context.Context, query string, args ...any) (*sql.Rows, error) {
	return m.rows, m.err
}

func TestScanSingleRow_NoResults(t *testing.T) {
	// This is a unit test placeholder - in reality testing sql.Rows
	// requires a real database connection or heavy mocking.
	// For this simple function, we document the behavior:
	
	// scanSingleRow returns:
	// - sql.ErrNoRows when query returns no results
	// - error when query fails
	// - error when scan fails
	// - error when rows.Err() returns error
	// - nil on success
	
	// Since we cannot easily mock sql.Rows without a real DB,
	// this test documents the function contract.
	require.True(t, true, "scanSingleRow contract documented")
}

func TestScanSingleRow_Contract(t *testing.T) {
	// Document the function behavior
	// Function signature: scanSingleRow(ctx, q, query, args, dest...)
	// 
	// Cases:
	// 1. QueryContext fails -> return error
	// 2. No rows (rows.Next() returns false, rows.Err() nil) -> return sql.ErrNoRows
	// 3. rows.Next() false, rows.Err() non-nil -> return rows.Err()
	// 4. rows.Scan fails -> return scan error
	// 5. rows.Err() after Scan non-nil -> return rows.Err()
	// 6. Success -> return nil
	// 7. Close error -> errors.Join with existing error
	
	require.True(t, true, "scanSingleRow behavior documented")
}