package sessionimport

import (
	"fmt"

	"github.com/gotd/td/session"
	"github.com/gotd/td/session/tdesktop"
)

// ConvertTdataSession reads a Telegram Desktop tdata/ folder and builds a
// gotd session.Data. localPassword is the local-storage password used to decrypt
// the tdata blob; pass an empty string when the desktop client did not set a
// local password (the common case for 协议号).
func ConvertTdataSession(tdataDir, localPassword string) (*session.Data, error) {
	accounts, err := tdesktop.Read(tdataDir, []byte(localPassword))
	if err != nil {
		return nil, fmt.Errorf("read tdata: %w", err)
	}
	if len(accounts) == 0 {
		return nil, fmt.Errorf("no accounts found in tdata")
	}
	data, err := session.TDesktopSession(accounts[0])
	if err != nil {
		return nil, fmt.Errorf("convert tdesktop account: %w", err)
	}
	return data, nil
}