package database

import (
	"embed"
	"errors"
	"fmt"
	"log/slog"

	"github.com/golang-migrate/migrate/v4"
	_ "github.com/golang-migrate/migrate/v4/database/postgres"
	"github.com/golang-migrate/migrate/v4/source/iofs"
)

//go:embed migrations/*.sql
var migrationsFS embed.FS

// RunMigrations runs all pending database migrations
func RunMigrations(databaseURL string, logger *slog.Logger) error {
	logger.Info("running database migrations")

	// Create source driver from embedded files
	source, err := iofs.New(migrationsFS, "migrations")
	if err != nil {
		return fmt.Errorf("failed to create migration source: %w", err)
	}

	// Create migrate instance
	m, err := migrate.NewWithSourceInstance("iofs", source, databaseURL)
	if err != nil {
		return fmt.Errorf("failed to create migrate instance: %w", err)
	}
	defer m.Close()

	// Run migrations
	if err := m.Up(); err != nil {
		if errors.Is(err, migrate.ErrNoChange) {
			logger.Info("no new migrations to apply")
			return nil
		}
		return fmt.Errorf("failed to run migrations: %w", err)
	}

	// Get current version
	version, dirty, err := m.Version()
	if err != nil && !errors.Is(err, migrate.ErrNilVersion) {
		logger.Warn("failed to get migration version", "error", err)
	} else {
		logger.Info("migrations complete", "version", version, "dirty", dirty)
	}

	return nil
}