package main

import (
	"log"
	"os"
)

type Migration struct {
	Path     string
	Name     string
	Requires string
	Run      bool
}

func NewMigration(path string, name string, requires string) Migration {
	return Migration{
		Path:     path,
		Name:     name,
		Requires: requires,
		Run:      false,
	}
}

func (m *Migration) Bytes() ([]byte, error) {
	migrationPath := m.Path
	migrationBytes, err := os.ReadFile(migrationPath)

	if err != nil {
		return []byte{}, err
	}

	return migrationBytes, nil
}

func (m *Migration) Text() (string, error) {
	migrationBytes, err := m.Bytes()
	return string(migrationBytes), err
}

func (m *Migration) Sql() (string, error) {
	migrationBytes, err := m.Bytes()

	return string(StripComments(migrationBytes)), err
}

// Applies a migration to the given database connection.
//
// If an error is returned while trying to read the migration file
// or execute the SQL it contains, the error is returned.
func (m *Migration) Apply(db DB) error {
	migrationSql, err := m.Sql()

	if err != nil {
		return err
	}
	log.Printf("SQL: %s", migrationSql)

	err = db.Execute(migrationSql)

	if err != nil {
		return err
	}

	return nil

}