package database

import (
	domainUpdate "RenewCMS/internal/domain/update"
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"github.com/glebarez/sqlite"
	"gorm.io/gorm"
)

const DriverSQLite = "sqlite"

const (
	sqliteBusyTimeoutMs = 5000
	sqliteResultBusy    = 5
	sqliteResultLocked  = 6
	sqlitePrimaryMask   = 0xff
	sqliteUniqueKey     = 2067
	sqlitePrimaryKey    = 1555
)

type sqliteDriver struct{}

func SQLiteDSN(dbName string) string {
	return fmt.Sprintf("%s?_pragma=busy_timeout(%d)", dbName, sqliteBusyTimeoutMs)
}

func (sqliteDriver) Open(file string) (*gorm.DB, error) {
	if err := os.MkdirAll(filepath.Dir(file), os.ModePerm); err != nil {
		return nil, fmt.Errorf("unable to create necessary subdirectories: %w", err)
	}
	return gorm.Open(sqlite.Open(SQLiteDSN(file)), &gorm.Config{})
}

func (sqliteDriver) NewBackup(db *gorm.DB, directory string, now func() time.Time) domainUpdate.DatabaseBackup {
	return NewSQLiteBackup(db, directory, now)
}

func (sqliteDriver) IsLockContention(err error) bool {
	code, ok := sqliteCode(err)
	primary := code & sqlitePrimaryMask
	return ok && (primary == sqliteResultBusy || primary == sqliteResultLocked)
}

func (sqliteDriver) IsUniqueViolation(err error) bool {
	code, ok := sqliteCode(err)
	return ok && (code == sqliteUniqueKey || code == sqlitePrimaryKey)
}

func sqliteCode(err error) (int, bool) {
	var coded interface{ Code() int }
	if !errors.As(err, &coded) {
		return 0, false
	}
	return coded.Code(), true
}