package postgres

import (
	"database/sql"
	"embed"
	"errors"
	"go.unistack.org/unistack-org/pkgdash/config"

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

const (
	pathMigration = `migrations/postgres`
)

type Postgres struct {
	db *sql.DB
	fs embed.FS
}

func NewStorage(db *sql.DB) (interface{}, error) {
	return &Postgres{db: db}, nil
}

func NewStorageFS(fs embed.FS) func(*sql.DB) (interface{}, error) {
	return func(db *sql.DB) (interface{}, error) {
		return &Postgres{db: db, fs: fs}, nil
	}
}

func (s *Postgres) MigrateUp() error {
	driver, err := pgx.WithInstance(s.db, &pgx.Config{
		MigrationsTable: pgx.DefaultMigrationsTable,
		DatabaseName:    config.ServiceName,
	})
	if err != nil {
		return err
	}
	source, err := iofs.New(s.fs, pathMigration)
	if err != nil {
		return err
	}

	// TODO: pass own logger
	m, err := migrate.NewWithInstance("fs", source, config.ServiceName, driver)
	if err != nil {
		return err
	}

	if err = m.Up(); err != nil && !errors.Is(err, migrate.ErrNoChange) {
		return err
	}

	return nil
}

func (s *Postgres) MigrateDown() error {
	driver, err := pgx.WithInstance(s.db, &pgx.Config{
		MigrationsTable: pgx.DefaultMigrationsTable,
		DatabaseName:    config.ServiceName,
	})
	if err != nil {
		return err
	}
	source, err := iofs.New(s.fs, pathMigration)
	if err != nil {
		return err
	}

	// TODO: pass own logger
	m, err := migrate.NewWithInstance("fs", source, config.ServiceName, driver)
	if err != nil {
		return err
	}

	if err = m.Down(); err != nil && !errors.Is(err, migrate.ErrNoChange) {
		return err
	}

	return nil
}