package database

import (
	"context"
	"database/sql"
	"fmt"
)

// Migrate creates the tables this application needs, if they don't already
// exist. This is intentionally the simplest possible approach
// (CREATE TABLE IF NOT EXISTS run on every startup) and is fine for a
// learning project with a single table.
//
// For a real production project you'd want a proper migration tool (e.g.
// golang-migrate/migrate) that tracks a version number, supports
// incremental "up"/"down" migrations, and can safely evolve a schema that
// already has production data in it. This function is a deliberate
// shortcut around that complexity for now.
func Migrate(ctx context.Context, db *sql.DB) error {
	_, err := db.ExecContext(ctx, `
		CREATE TABLE IF NOT EXISTS users (
			id            INT AUTO_INCREMENT PRIMARY KEY,
			email         VARCHAR(255) NOT NULL UNIQUE,
			password_hash VARCHAR(255) NOT NULL DEFAULT '',
			google_id     VARCHAR(255) NOT NULL DEFAULT '',
			created_at    DATETIME NOT NULL
		)`)
	if err != nil {
		return fmt.Errorf("migrate users table: %w", err)
	}
	return nil
}