package migrator

import (
	"github.com/golang-migrate/migrate/v4"
	migratePGX "github.com/golang-migrate/migrate/v4/database/pgx"
	"github.com/golang-migrate/migrate/v4/source/iofs"
	"github.com/jackc/pgx/v4"
	"github.com/jackc/pgx/v4/stdlib"

	"git.zom.bi/fanir/feedizer/models/migrations"
)

type Migrator struct {
	m   *migrate.Migrate
	err error
}

func (m *Migrator) Error() error { return m.err }

func New(dbConfig string) *Migrator {
	source, err := iofs.New(migrations.FS, ".")
	if err != nil {
		return &Migrator{err: err}
	}

	connConfig, err := pgx.ParseConfig(dbConfig)
	if err != nil {
		return &Migrator{err: err}
	}
	connString := stdlib.RegisterConnConfig(connConfig)

	var p migratePGX.Postgres
	driver, err := p.Open(connString)
	if err != nil {
		return &Migrator{err: err}
	}

	m, err := migrate.NewWithInstance("iofs", source, "pgx", driver)
	if err != nil {
		return &Migrator{err: err}
	}

	return &Migrator{m: m}
}

// Migrate applies all migrations.
func (m *Migrator) Migrate() error {
	if m.err == nil {
		m.err = m.m.Up()
	}
	return m.err
}

// Purge purges the entire database by undoing all migrations.
func (m *Migrator) Purge() error {
	if m.err == nil {
		m.err = m.m.Down()
	}
	return m.err
}