package store_test

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

	"github.com/golang-migrate/migrate/v4"
	migratepgx "github.com/golang-migrate/migrate/v4/database/pgx/v5"
	"github.com/golang-migrate/migrate/v4/source/iofs"
	"github.com/stretchr/testify/require"

	_ "github.com/jackc/pgx/v5/stdlib" // register the "pgx" database/sql driver
)

// fileMigrator builds a golang-migrate instance from the on-disk migration files
// (not the embedded FS the production Migrate uses), so a test can step the schema
// up and down. os.DirFS(".") is rooted at the package dir; the SQL lives under
// "migrations". Mirrors store.Migrate's construction otherwise.
func fileMigrator(t *testing.T) *migrate.Migrate {
	t.Helper()
	db, err := sql.Open("pgx", dsn)
	require.NoError(t, err)
	t.Cleanup(func() { _ = db.Close() })

	drv, err := migratepgx.WithInstance(db, &migratepgx.Config{})
	require.NoError(t, err)
	src, err := iofs.New(os.DirFS("."), "migrations")
	require.NoError(t, err)
	m, err := migrate.NewWithInstance("iofs", src, "pgx", drv)
	require.NoError(t, err)
	t.Cleanup(func() { _, _ = m.Close() })
	return m
}

// loginEventsExists reports whether the login_events relation is present.
func loginEventsExists(t *testing.T) bool {
	t.Helper()
	var reg *string
	require.NoError(t, rawPool(t).QueryRow(context.Background(),
		`SELECT to_regclass('public.login_events')::text`).Scan(&reg))
	return reg != nil
}

// TestMigration010LoginEventsUpDown proves migration 010 is reversible: the down
// migration drops login_events cleanly and the up migration recreates it. A rotten
// down migration (forgotten DROP, dangling policy) would fail here rather than in
// production during a rollback. The test restores the schema to latest before
// returning so the shared embedded-postgres stays at HEAD for sibling tests.
func TestMigration010LoginEventsUpDown(t *testing.T) {
	newStore(t) // ensure the schema is migrated to latest (010 applied)
	require.True(t, loginEventsExists(t), "login_events must exist at latest migration")

	m := fileMigrator(t)
	require.NoError(t, m.Steps(-1), "down one migration must drop login_events")
	require.False(t, loginEventsExists(t), "login_events must be gone after the down migration")

	require.NoError(t, m.Steps(1), "up one migration must recreate login_events")
	require.True(t, loginEventsExists(t), "login_events must be restored after the up migration")
}