package wallet

import (
	"context"
	"errors"

	"github.com/SamuelTariku/FortuneBet-Backend/internal/domain"
)

var (
	ErrWalletNotTransferable = errors.New("wallet is not transferable")
)

func (s *Service) CreateTransfer(ctx context.Context, transfer domain.CreateTransfer) (domain.Transfer, error) {
	return s.transferStore.CreateTransfer(ctx, transfer)
}

func (s *Service) GetAllTransfers(ctx context.Context) ([]domain.Transfer, error) {
	return s.transferStore.GetAllTransfers(ctx)
}

func (s *Service) GetTransferByID(ctx context.Context, id int64) (domain.Transfer, error) {
	return s.transferStore.GetTransferByID(ctx, id)
}

func (s *Service) UpdateTransferVerification(ctx context.Context, id int64, verified bool) error {
	return s.transferStore.UpdateTransferVerification(ctx, id, verified)
}

func (s *Service) TransferToWallet(ctx context.Context, senderID int64, receiverID int64, amount domain.Currency, paymentMethod domain.PaymentMethod, cashierID domain.ValidInt64) (domain.Transfer, error) {

	senderWallet, err := s.GetWalletByID(ctx, senderID)
	if err != nil {
		return domain.Transfer{}, err
	}

	if senderWallet.IsTransferable {
		return domain.Transfer{}, ErrWalletNotTransferable
	}

	receiverWallet, err := s.GetWalletByID(ctx, receiverID)
	if err != nil {
		return domain.Transfer{}, err
	}

	if receiverWallet.IsTransferable {
		return domain.Transfer{}, ErrWalletNotTransferable
	}

	// Deduct from sender
	if senderWallet.Balance < amount {
		return domain.Transfer{}, ErrBalanceInsufficient
	}

	err = s.walletStore.UpdateBalance(ctx, senderID, senderWallet.Balance-amount)

	if err != nil {
		return domain.Transfer{}, err
	}

	// Add to receiver
	err = s.walletStore.UpdateBalance(ctx, receiverID, receiverWallet.Balance+amount)

	if err != nil {
		return domain.Transfer{}, err
	}

	// Log the transfer so that if there is a mistake, it can be reverted
	transfer, err := s.transferStore.CreateTransfer(ctx, domain.CreateTransfer{
		SenderWalletID: domain.ValidInt64{
			Value: senderID,
			Valid: true,
		},
		CashierID:        cashierID,
		ReceiverWalletID: receiverID,
		Amount:           amount,
		Type:             domain.WALLET,
		PaymentMethod:    paymentMethod,
		Verified:         true,
	})
	if err != nil {
		return domain.Transfer{}, err
	}

	return transfer, nil
}