package postgres

import (
	"errors"
	"fmt"
	"net/url"

	"drive.local/drivev2/db/migrations"
	"github.com/golang-migrate/migrate/v4"
	pgx5migrate "github.com/golang-migrate/migrate/v4/database/pgx/v5"
	"github.com/golang-migrate/migrate/v4/source/iofs"
)

// Migrate applies every pending forward migration using an advisory lock.
func Migrate(databaseURL string) (returnErr error) {
	sourceDriver, err := iofs.New(migrations.Files, ".")
	if err != nil {
		return fmt.Errorf("open embedded migrations: %w", err)
	}

	migrationURL, err := url.Parse(databaseURL)
	if err != nil {
		return fmt.Errorf("parse database URL for migrations: %w", err)
	}
	migrationURL.Scheme = "pgx5"
	query := migrationURL.Query()
	query.Set("x-multi-statement", "true")
	query.Set("x-statement-timeout", "30000")
	if query.Get("connect_timeout") == "" {
		query.Set("connect_timeout", "30")
	}
	migrationURL.RawQuery = query.Encode()

	databaseDriver, err := (&pgx5migrate.Postgres{}).Open(migrationURL.String())
	if err != nil {
		return fmt.Errorf("open migration database: %w", err)
	}

	runner, err := migrate.NewWithInstance("iofs", sourceDriver, "pgx5", databaseDriver)
	if err != nil {
		return errors.Join(
			fmt.Errorf("create migration runner: %w", err),
			sourceDriver.Close(),
			databaseDriver.Close(),
		)
	}
	defer func() {
		sourceErr, databaseErr := runner.Close()
		returnErr = errors.Join(returnErr, sourceErr, databaseErr)
	}()

	if err := runner.Up(); err != nil && !errors.Is(err, migrate.ErrNoChange) {
		return fmt.Errorf("apply database migrations: %w", err)
	}
	return nil
}