// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package stripecoinpayments

import (
	"context"
	"strconv"
	"time"

	"github.com/stripe/stripe-go"

	"storj.io/common/uuid"
	"storj.io/storj/satellite/payments"
	"storj.io/storj/satellite/payments/coinpayments"
)

const (
	// StripeDepositTransactionDescription is the description for Stripe
	// balance transactions representing STORJ deposits.
	StripeDepositTransactionDescription = "STORJ deposit"

	// StripeDepositBonusTransactionDescription is the description for Stripe
	// balance transactions representing bonuses received for STORJ deposits.
	StripeDepositBonusTransactionDescription = "STORJ deposit bonus"
)

// ensure that storjTokens implements payments.StorjTokens.
var _ payments.StorjTokens = (*storjTokens)(nil)

// storjTokens implements payments.StorjTokens.
//
// architecture: Service
type storjTokens struct {
	service *Service
}

// Deposit creates new deposit transaction with the given amount returning
// ETH wallet address where funds should be sent. There is one
// hour limit to complete the transaction. Transaction is saved to DB with
// reference to the user who made the deposit.
func (tokens *storjTokens) Deposit(ctx context.Context, userID uuid.UUID, amount int64) (_ *payments.Transaction, err error) {
	defer mon.Task()(&ctx, userID, amount)(&err)

	customerID, err := tokens.service.db.Customers().GetCustomerID(ctx, userID)
	if err != nil {
		return nil, Error.Wrap(err)
	}

	c, err := tokens.service.stripeClient.Customers().Get(customerID, nil)
	if err != nil {
		return nil, Error.Wrap(err)
	}

	rate, err := tokens.service.GetRate(ctx, coinpayments.CurrencySTORJ, coinpayments.CurrencyUSD)
	if err != nil {
		return nil, Error.Wrap(err)
	}

	tokenAmount := convertFromCents(rate, amount).SetPrec(payments.STORJTokenPrecision)

	tx, err := tokens.service.coinPayments.Transactions().Create(ctx,
		&coinpayments.CreateTX{
			Amount:      *tokenAmount,
			CurrencyIn:  coinpayments.CurrencySTORJ,
			CurrencyOut: coinpayments.CurrencySTORJ,
			BuyerEmail:  c.Email,
		},
	)
	if err != nil {
		return nil, Error.Wrap(err)
	}

	key, err := coinpayments.GetTransacationKeyFromURL(tx.CheckoutURL)
	if err != nil {
		return nil, Error.Wrap(err)
	}

	if err = tokens.service.db.Transactions().LockRate(ctx, tx.ID, rate); err != nil {
		return nil, Error.Wrap(err)
	}

	cpTX, err := tokens.service.db.Transactions().Insert(ctx,
		Transaction{
			ID:        tx.ID,
			AccountID: userID,
			Address:   tx.Address,
			Amount:    tx.Amount,
			Status:    coinpayments.StatusPending,
			Key:       key,
			Timeout:   tx.Timeout,
		},
	)
	if err != nil {
		return nil, Error.Wrap(err)
	}

	return &payments.Transaction{
		ID:        payments.TransactionID(tx.ID),
		Amount:    *payments.TokenAmountFromBigFloat(&tx.Amount),
		Rate:      *rate,
		Address:   tx.Address,
		Status:    payments.TransactionStatusPending,
		Timeout:   tx.Timeout,
		Link:      tx.CheckoutURL,
		CreatedAt: cpTX.CreatedAt,
	}, nil
}

// ListTransactionInfos fetches all transactions from the database for specified user, reconstructing checkout link.
func (tokens *storjTokens) ListTransactionInfos(ctx context.Context, userID uuid.UUID) (_ []payments.TransactionInfo, err error) {
	defer mon.Task()(&ctx, userID)(&err)

	txs, err := tokens.service.db.Transactions().ListAccount(ctx, userID)
	if err != nil {
		return nil, Error.Wrap(err)
	}

	var infos []payments.TransactionInfo
	for _, tx := range txs {
		link := coinpayments.GetCheckoutURL(tx.Key, tx.ID)

		var status payments.TransactionStatus
		switch tx.Status {
		case coinpayments.StatusPending:
			status = payments.TransactionStatusPending
		case coinpayments.StatusReceived:
			status = payments.TransactionStatusPaid
		case coinpayments.StatusCancelled:
			status = payments.TransactionStatusCancelled
		default:
			// unknown
			status = payments.TransactionStatus(tx.Status.String())
		}

		rate, err := tokens.service.db.Transactions().GetLockedRate(ctx, tx.ID)
		if err != nil {
			return nil, err
		}

		infos = append(infos,
			payments.TransactionInfo{
				ID:            []byte(tx.ID),
				Amount:        *payments.TokenAmountFromBigFloat(&tx.Amount),
				Received:      *payments.TokenAmountFromBigFloat(&tx.Received),
				AmountCents:   convertToCents(rate, &tx.Amount),
				ReceivedCents: convertToCents(rate, &tx.Received),
				Address:       tx.Address,
				Status:        status,
				Link:          link,
				ExpiresAt:     tx.CreatedAt.Add(tx.Timeout),
				CreatedAt:     tx.CreatedAt,
			},
		)
	}

	return infos, nil
}

// ListDepositBonuses returns all deposit bonuses from Stripe associated with user.
func (tokens *storjTokens) ListDepositBonuses(ctx context.Context, userID uuid.UUID) (_ []payments.DepositBonus, err error) {
	defer mon.Task()(&ctx, userID)(&err)

	cusID, err := tokens.service.db.Customers().GetCustomerID(ctx, userID)
	if err != nil {
		return nil, err
	}

	var bonuses []payments.DepositBonus
	it := tokens.service.stripeClient.CustomerBalanceTransactions().List(&stripe.CustomerBalanceTransactionListParams{Customer: stripe.String(cusID)})
	for it.Next() {
		tx := it.CustomerBalanceTransaction()

		if tx.Type != stripe.CustomerBalanceTransactionTypeAdjustment {
			continue
		}

		if tx.Description != StripeDepositBonusTransactionDescription {
			continue
		}

		percentage := int64(10)
		percentageStr, ok := tx.Metadata["percentage"]
		if ok {
			percentage, err = strconv.ParseInt(percentageStr, 10, 64)
			if err != nil {
				return nil, err
			}
		}

		bonuses = append(bonuses,
			payments.DepositBonus{
				TransactionID: []byte(tx.Metadata["txID"]),
				AmountCents:   -tx.Amount,
				Percentage:    percentage,
				CreatedAt:     time.Unix(tx.Created, 0),
			},
		)
	}

	return bonuses, nil
}