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

package satellitedb

import (
	"context"
	"math/big"
	"time"

	"github.com/zeebo/errs"

	"storj.io/storj/satellite/payments/coinpayments"
	"storj.io/storj/satellite/payments/stripecoinpayments"
	dbx "storj.io/storj/satellite/satellitedb/dbx"
)

// ensure that coinpaymentsTransaction implements stripecoinpayments.TransactionsDB.
var _ stripecoinpayments.TransactionsDB = (*coinpaymentsTransactions)(nil)

// coinpaymentsTransactions is Coinpayments transactions DB.
//
// architecture: Database
type coinpaymentsTransactions struct {
	db *dbx.DB
}

// Insert inserts new coinpayments transaction into DB.
func (db *coinpaymentsTransactions) Insert(ctx context.Context, tx stripecoinpayments.Transaction) (*stripecoinpayments.Transaction, error) {
	amount, err := tx.Amount.GobEncode()
	if err != nil {
		return nil, errs.Wrap(err)
	}
	received, err := tx.Received.GobEncode()
	if err != nil {
		return nil, errs.Wrap(err)
	}

	dbxCPTX, err := db.db.Create_CoinpaymentsTransaction(ctx,
		dbx.CoinpaymentsTransaction_Id(tx.ID.String()),
		dbx.CoinpaymentsTransaction_UserId(tx.AccountID[:]),
		dbx.CoinpaymentsTransaction_Address(tx.Address),
		dbx.CoinpaymentsTransaction_Amount(amount),
		dbx.CoinpaymentsTransaction_Received(received),
		dbx.CoinpaymentsTransaction_Status(tx.Status.Int()),
		dbx.CoinpaymentsTransaction_Key(tx.Key),
	)
	if err != nil {
		return nil, err
	}

	return fromDBXCoinpaymentsTransaction(dbxCPTX)
}

// Update updates status and received for set of transactions.
func (db *coinpaymentsTransactions) Update(ctx context.Context, updates []stripecoinpayments.TransactionUpdate) error {
	if len(updates) == 0 {
		return nil
	}

	return db.db.WithTx(ctx, func(ctx context.Context, tx *dbx.Tx) error {
		for _, update := range updates {
			received, err := update.Received.GobEncode()
			if err != nil {
				return errs.Wrap(err)
			}

			_, err = tx.Update_CoinpaymentsTransaction_By_Id(ctx,
				dbx.CoinpaymentsTransaction_Id(update.TransactionID.String()),
				dbx.CoinpaymentsTransaction_Update_Fields{
					Received: dbx.CoinpaymentsTransaction_Received(received),
					Status:   dbx.CoinpaymentsTransaction_Status(update.Status.Int()),
				},
			)
			if err != nil {
				return err
			}
		}

		return nil
	})
}

// ListPending returns paginated list of pending transactions.
func (db *coinpaymentsTransactions) ListPending(ctx context.Context, offset int64, limit int, before time.Time) (stripecoinpayments.TransactionsPage, error) {
	var page stripecoinpayments.TransactionsPage

	dbxTXs, err := db.db.Limited_CoinpaymentsTransaction_By_CreatedAt_LessOrEqual_And_Status_OrderBy_Desc_CreatedAt(
		ctx,
		dbx.CoinpaymentsTransaction_CreatedAt(before.UTC()),
		dbx.CoinpaymentsTransaction_Status(coinpayments.StatusPending.Int()),
		limit+1,
		offset,
	)
	if err != nil {
		return stripecoinpayments.TransactionsPage{}, err
	}

	if len(dbxTXs) == limit+1 {
		page.Next = true
		page.NextOffset = offset + int64(limit) + 1

		dbxTXs = dbxTXs[:len(dbxTXs)-1]
	}

	var txs []stripecoinpayments.Transaction
	for _, dbxTX := range dbxTXs {
		tx, err := fromDBXCoinpaymentsTransaction(dbxTX)
		if err != nil {
			return stripecoinpayments.TransactionsPage{}, err
		}

		txs = append(txs, *tx)
	}

	page.Transactions = txs
	return page, nil
}

// fromDBXCoinpaymentsTransaction converts *dbx.CoinpaymentsTransaction to *stripecoinpayments.Transaction.
func fromDBXCoinpaymentsTransaction(dbxCPTX *dbx.CoinpaymentsTransaction) (*stripecoinpayments.Transaction, error) {
	userID, err := bytesToUUID(dbxCPTX.UserId)
	if err != nil {
		return nil, errs.Wrap(err)
	}

	var amount, received big.Float
	if err := amount.GobDecode(dbxCPTX.Amount); err != nil {
		return nil, errs.Wrap(err)
	}
	if err := received.GobDecode(dbxCPTX.Received); err != nil {
		return nil, errs.Wrap(err)
	}

	return &stripecoinpayments.Transaction{
		ID:        coinpayments.TransactionID(dbxCPTX.Id),
		AccountID: userID,
		Address:   dbxCPTX.Address,
		Amount:    amount,
		Received:  received,
		Status:    coinpayments.Status(dbxCPTX.Status),
		Key:       dbxCPTX.Key,
		CreatedAt: dbxCPTX.CreatedAt,
	}, nil
}