package wallet

import (
	"context"
	"errors"
	"fmt"

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

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

func (s *Service) CreateTransfer(ctx context.Context, transfer domain.CreateTransfer) (domain.Transfer, error) {
	// This is just a transfer log when
	return s.transferStore.CreateTransfer(ctx, transfer)
}

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

func (s *Service) GetTransferByReference(ctx context.Context, reference string) (domain.Transfer, error) {
	return s.transferStore.GetTransferByReference(ctx, reference)
}

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

func (s *Service) GetTransfersByWallet(ctx context.Context, walletID int64) ([]domain.Transfer, error) {
	return s.transferStore.GetTransfersByWallet(ctx, walletID)
}

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

func (s *Service) UpdateTransferStatus(ctx context.Context, id int64, status string) error {
	return s.transferStore.UpdateTransferStatus(ctx, id, status)
}


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.CreateTransfer(ctx, domain.CreateTransfer{
		SenderWalletID: domain.ValidInt64{
			Value: senderID,
			Valid: true,
		},
		ReceiverWalletID: domain.ValidInt64{
			Value: receiverID,
			Valid: true,
		},
		CashierID:     cashierID,
		Amount:        amount,
		Type:          domain.WALLET,
		PaymentMethod: paymentMethod,
		Verified:      true,
	})
	if err != nil {
		return domain.Transfer{}, err
	}

	return transfer, nil
}

func (s *Service) SendTransferNotification(ctx context.Context, senderWallet domain.Wallet, receiverWallet domain.Wallet,
	senderRole domain.Role, receiverRole domain.Role, amount domain.Currency) error {
	// Send notification to sender (this could be any role) that money was transferred
	senderWalletReceiverSide := domain.ReceiverFromRole(senderRole)

	senderNotify := &domain.Notification{
		RecipientID:     senderWallet.UserID,
		Type:            domain.NOTIFICATION_TYPE_TRANSFER_SUCCESS,
		Level:           domain.NotificationLevelSuccess,
		Reciever:        senderWalletReceiverSide,
		DeliveryChannel: domain.DeliveryChannelInApp,
		Payload: domain.NotificationPayload{
			Headline: "Wallet has been deducted",
			Message:  fmt.Sprintf(`%s %d has been transferred from your wallet`,senderWallet.Currency, amount),
		},
		Priority: 2,
		Metadata: []byte(fmt.Sprintf(`{
			"transfer_amount": %d,
			"current_balance": %d,
			"wallet_id": %d,
			"notification_type": "customer_facing"
		}`, amount, senderWallet.Balance, senderWallet.ID)),
	}

	// Sender notifications
	if err := s.notificationStore.SendNotification(ctx, senderNotify); err != nil {
		s.logger.Error("failed to send sender notification",
			"user_id", "",
			"error", err)
		return err
	}

	receiverWalletReceiverSide := domain.ReceiverFromRole(receiverRole)

	receiverNotify := &domain.Notification{
		RecipientID:     receiverWallet.UserID,
		Type:            domain.NOTIFICATION_TYPE_TRANSFER_SUCCESS,
		Level:           domain.NotificationLevelSuccess,
		Reciever:        receiverWalletReceiverSide,
		DeliveryChannel: domain.DeliveryChannelInApp,
		Payload: domain.NotificationPayload{
			Headline: "Wallet has been credited",
			Message:  fmt.Sprintf(`%s %d has been transferred to your wallet`,receiverWallet.Currency, amount),
		},
		Priority: 2,
		Metadata: []byte(fmt.Sprintf(`{
			"transfer_amount": %d,
			"current_balance": %d,
			"wallet_id": %d,
			"notification_type": "customer_facing"
		}`, amount, receiverWallet.Balance, receiverWallet.ID)),
	}
	// Sender notifications
	if err := s.notificationStore.SendNotification(ctx, receiverNotify); err != nil {
		s.logger.Error("failed to send sender notification",
			"user_id", "",
			"error", err)
		return err
	}

	return nil
}