package bitstamp

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"time"

	"github.com/thrasher-corp/gocryptotrader/common"
	"github.com/thrasher-corp/gocryptotrader/common/crypto"
	"github.com/thrasher-corp/gocryptotrader/currency"
	exchange "github.com/thrasher-corp/gocryptotrader/exchanges"
	"github.com/thrasher-corp/gocryptotrader/exchanges/order"
	"github.com/thrasher-corp/gocryptotrader/exchanges/websocket/wshandler"
	log "github.com/thrasher-corp/gocryptotrader/logger"
)

const (
	bitstampAPIURL                = "https://www.bitstamp.net/api"
	bitstampAPIVersion            = "2"
	bitstampAPITicker             = "ticker"
	bitstampAPITickerHourly       = "ticker_hour"
	bitstampAPIOrderbook          = "order_book"
	bitstampAPITransactions       = "transactions"
	bitstampAPIEURUSD             = "eur_usd"
	bitstampAPIBalance            = "balance"
	bitstampAPIUserTransactions   = "user_transactions"
	bitstampAPIOpenOrders         = "open_orders"
	bitstampAPIOrderStatus        = "order_status"
	bitstampAPICancelOrder        = "cancel_order"
	bitstampAPICancelAllOrders    = "cancel_all_orders"
	bitstampAPIMarket             = "market"
	bitstampAPIWithdrawalRequests = "withdrawal_requests"
	bitstampAPIOpenWithdrawal     = "withdrawal/open"
	bitstampAPIBitcoinWithdrawal  = "bitcoin_withdrawal"
	bitstampAPILTCWithdrawal      = "ltc_withdrawal"
	bitstampAPIETHWithdrawal      = "eth_withdrawal"
	bitstampAPIBCHWithdrawal      = "bch_withdrawal"
	bitstampAPIBitcoinDeposit     = "bitcoin_deposit_address"
	bitstampAPILitecoinDeposit    = "ltc_address"
	bitstampAPIEthereumDeposit    = "eth_address"
	bitstampAPIBitcoinCashDeposit = "bch_address"
	bitstampAPIUnconfirmedBitcoin = "unconfirmed_btc"
	bitstampAPITransferToMain     = "transfer-to-main"
	bitstampAPITransferFromMain   = "transfer-from-main"
	bitstampAPIXrpWithdrawal      = "xrp_withdrawal"
	bitstampAPIXrpDeposit         = "xrp_address"
	bitstampAPIReturnType         = "string"
	bitstampAPITradingPairsInfo   = "trading-pairs-info"

	bitstampAuthRate   = 8000
	bitstampUnauthRate = 8000
	bitstampTimeLayout = "2006-1-2 15:04:05"
)

// Bitstamp is the overarching type across the bitstamp package
type Bitstamp struct {
	exchange.Base
	WebsocketConn *wshandler.WebsocketConnection
}

// GetFee returns an estimate of fee based on type of transaction
func (b *Bitstamp) GetFee(feeBuilder *exchange.FeeBuilder) (float64, error) {
	var fee float64

	switch feeBuilder.FeeType {
	case exchange.CryptocurrencyTradeFee:
		balance, err := b.GetBalance()
		if err != nil {
			return 0, err
		}
		fee = b.CalculateTradingFee(feeBuilder.Pair.Base,
			feeBuilder.Pair.Quote,
			feeBuilder.PurchasePrice,
			feeBuilder.Amount,
			balance)
	case exchange.CyptocurrencyDepositFee:
		fee = 0
	case exchange.InternationalBankDepositFee:
		fee = getInternationalBankDepositFee(feeBuilder.Amount)
	case exchange.InternationalBankWithdrawalFee:
		fee = getInternationalBankWithdrawalFee(feeBuilder.Amount)
	case exchange.OfflineTradeFee:
		fee = getOfflineTradeFee(feeBuilder.PurchasePrice, feeBuilder.Amount)
	}
	if fee < 0 {
		fee = 0
	}
	return fee, nil
}

// getOfflineTradeFee calculates the worst case-scenario trading fee
func getOfflineTradeFee(price, amount float64) float64 {
	return 0.0025 * price * amount
}

// getInternationalBankWithdrawalFee returns international withdrawal fee
func getInternationalBankWithdrawalFee(amount float64) float64 {
	fee := amount * 0.0009

	if fee < 15 {
		return 15
	}
	return fee
}

// getInternationalBankDepositFee returns international deposit fee
func getInternationalBankDepositFee(amount float64) float64 {
	fee := amount * 0.0005

	if fee < 7.5 {
		return 7.5
	}
	if fee > 300 {
		return 300
	}
	return fee
}

// CalculateTradingFee returns fee on a currency pair
func (b *Bitstamp) CalculateTradingFee(base, quote currency.Code, purchasePrice, amount float64, balances Balances) float64 {
	var fee float64
	if v, ok := balances[base.String()]; ok {
		switch quote {
		case currency.BTC:
			fee = v.BTCFee
		case currency.USD:
			fee = v.USDFee
		case currency.EUR:
			fee = v.EURFee
		}
	}
	return fee * purchasePrice * amount
}

// GetTicker returns ticker information
func (b *Bitstamp) GetTicker(currency string, hourly bool) (Ticker, error) {
	response := Ticker{}
	tickerEndpoint := bitstampAPITicker

	if hourly {
		tickerEndpoint = bitstampAPITickerHourly
	}

	path := fmt.Sprintf(
		"%s/v%s/%s/%s/",
		b.API.Endpoints.URL,
		bitstampAPIVersion,
		tickerEndpoint,
		strings.ToLower(currency),
	)
	return response, b.SendHTTPRequest(path, &response)
}

// GetOrderbook Returns a JSON dictionary with "bids" and "asks". Each is a list
// of open orders and each order is represented as a list holding the price and
// the amount.
func (b *Bitstamp) GetOrderbook(currency string) (Orderbook, error) {
	type response struct {
		Timestamp int64      `json:"timestamp,string"`
		Bids      [][]string `json:"bids"`
		Asks      [][]string `json:"asks"`
	}
	resp := response{}

	path := fmt.Sprintf(
		"%s/v%s/%s/%s/",
		b.API.Endpoints.URL,
		bitstampAPIVersion,
		bitstampAPIOrderbook,
		strings.ToLower(currency),
	)

	err := b.SendHTTPRequest(path, &resp)
	if err != nil {
		return Orderbook{}, err
	}

	orderbook := Orderbook{}
	orderbook.Timestamp = resp.Timestamp

	for _, x := range resp.Bids {
		price, err := strconv.ParseFloat(x[0], 64)
		if err != nil {
			log.Error(log.ExchangeSys, err)
			continue
		}
		amount, err := strconv.ParseFloat(x[1], 64)
		if err != nil {
			log.Error(log.ExchangeSys, err)
			continue
		}
		orderbook.Bids = append(orderbook.Bids, OrderbookBase{price, amount})
	}

	for _, x := range resp.Asks {
		price, err := strconv.ParseFloat(x[0], 64)
		if err != nil {
			log.Error(log.ExchangeSys, err)
			continue
		}
		amount, err := strconv.ParseFloat(x[1], 64)
		if err != nil {
			log.Error(log.ExchangeSys, err)
			continue
		}
		orderbook.Asks = append(orderbook.Asks, OrderbookBase{price, amount})
	}

	return orderbook, nil
}

// GetTradingPairs returns a list of trading pairs which Bitstamp
// currently supports
func (b *Bitstamp) GetTradingPairs() ([]TradingPair, error) {
	var result []TradingPair

	path := fmt.Sprintf("%s/v%s/%s",
		b.API.Endpoints.URL,
		bitstampAPIVersion,
		bitstampAPITradingPairsInfo)

	return result, b.SendHTTPRequest(path, &result)
}

// GetTransactions returns transaction information
// value paramater ["time"] = "minute", "hour", "day" will collate your
// response into time intervals. Implementation of value in test code.
func (b *Bitstamp) GetTransactions(currencyPair string, values url.Values) ([]Transactions, error) {
	var transactions []Transactions
	path := common.EncodeURLValues(
		fmt.Sprintf(
			"%s/v%s/%s/%s/",
			b.API.Endpoints.URL,
			bitstampAPIVersion,
			bitstampAPITransactions,
			strings.ToLower(currencyPair),
		),
		values,
	)

	return transactions, b.SendHTTPRequest(path, &transactions)
}

// GetEURUSDConversionRate returns the conversion rate between Euro and USD
func (b *Bitstamp) GetEURUSDConversionRate() (EURUSDConversionRate, error) {
	rate := EURUSDConversionRate{}
	path := fmt.Sprintf("%s/%s", b.API.Endpoints.URL, bitstampAPIEURUSD)

	return rate, b.SendHTTPRequest(path, &rate)
}

// GetBalance returns full balance of currency held on the exchange
func (b *Bitstamp) GetBalance() (Balances, error) {
	var balance map[string]string
	err := b.SendAuthenticatedHTTPRequest(bitstampAPIBalance, true, nil, &balance)
	if err != nil {
		return nil, err
	}

	balances := make(map[string]Balance)
	for k := range balance {
		curr := k[0:3]
		_, ok := balances[strings.ToUpper(curr)]
		if !ok {
			avail, _ := strconv.ParseFloat(balance[curr+"_available"], 64)
			bal, _ := strconv.ParseFloat(balance[curr+"_balance"], 64)
			reserved, _ := strconv.ParseFloat(balance[curr+"_reserved"], 64)
			withdrawalFee, _ := strconv.ParseFloat(balance[curr+"_withdrawal_fee"], 64)
			currBalance := Balance{
				Available:     avail,
				Balance:       bal,
				Reserved:      reserved,
				WithdrawalFee: withdrawalFee,
			}
			switch strings.ToUpper(curr) {
			case currency.USD.String():
				eurFee, _ := strconv.ParseFloat(balance[curr+"eur_fee"], 64)
				currBalance.EURFee = eurFee
			case currency.EUR.String():
				usdFee, _ := strconv.ParseFloat(balance[curr+"usd_fee"], 64)
				currBalance.USDFee = usdFee
			default:
				btcFee, _ := strconv.ParseFloat(balance[curr+"btc_fee"], 64)
				currBalance.BTCFee = btcFee
				eurFee, _ := strconv.ParseFloat(balance[curr+"eur_fee"], 64)
				currBalance.EURFee = eurFee
				usdFee, _ := strconv.ParseFloat(balance[curr+"usd_fee"], 64)
				currBalance.USDFee = usdFee
			}
			balances[strings.ToUpper(curr)] = currBalance
		}
	}
	return balances, nil
}

// GetUserTransactions returns an array of transactions
func (b *Bitstamp) GetUserTransactions(currencyPair string) ([]UserTransactions, error) {
	type Response struct {
		Date          string      `json:"datetime"`
		TransactionID int64       `json:"id"`
		Type          int         `json:"type,string"`
		USD           interface{} `json:"usd"`
		EUR           interface{} `json:"eur"`
		XRP           interface{} `json:"xrp"`
		BTC           interface{} `json:"btc"`
		BTCUSD        interface{} `json:"btc_usd"`
		Fee           float64     `json:"fee,string"`
		OrderID       int64       `json:"order_id"`
	}
	var response []Response

	if currencyPair == "" {
		if err := b.SendAuthenticatedHTTPRequest(bitstampAPIUserTransactions,
			true,
			url.Values{},
			&response); err != nil {
			return nil, err
		}
	} else {
		if err := b.SendAuthenticatedHTTPRequest(bitstampAPIUserTransactions+"/"+currencyPair,
			true,
			url.Values{},
			&response); err != nil {
			return nil, err
		}
	}

	processNumber := func(i interface{}) float64 {
		switch t := i.(type) {
		case float64:
			return t
		case string:
			amt, _ := strconv.ParseFloat(t, 64)
			return amt
		default:
			return 0
		}
	}

	var transactions []UserTransactions
	for x := range response {
		tx := UserTransactions{}
		tx.Date = response[x].Date
		tx.TransactionID = response[x].TransactionID
		tx.Type = response[x].Type
		tx.EUR = processNumber(response[x].EUR)
		tx.XRP = processNumber(response[x].XRP)
		tx.USD = processNumber(response[x].USD)
		tx.BTC = processNumber(response[x].BTC)
		tx.BTCUSD = processNumber(response[x].BTCUSD)
		tx.Fee = response[x].Fee
		tx.OrderID = response[x].OrderID
		transactions = append(transactions, tx)
	}

	return transactions, nil
}

// GetOpenOrders returns all open orders on the exchange
func (b *Bitstamp) GetOpenOrders(currencyPair string) ([]Order, error) {
	var resp []Order
	path := fmt.Sprintf(
		"%s/%s", bitstampAPIOpenOrders, strings.ToLower(currencyPair),
	)

	return resp, b.SendAuthenticatedHTTPRequest(path, true, nil, &resp)
}

// GetOrderStatus returns an the status of an order by its ID
func (b *Bitstamp) GetOrderStatus(orderID int64) (OrderStatus, error) {
	resp := OrderStatus{}
	req := url.Values{}
	req.Add("id", strconv.FormatInt(orderID, 10))

	return resp,
		b.SendAuthenticatedHTTPRequest(bitstampAPIOrderStatus, false, req, &resp)
}

// CancelExistingOrder cancels order by ID
func (b *Bitstamp) CancelExistingOrder(orderID int64) (CancelOrder, error) {
	var req = url.Values{}
	req.Add("id", strconv.FormatInt(orderID, 10))

	var result CancelOrder
	err := b.SendAuthenticatedHTTPRequest(bitstampAPICancelOrder, true, req, &result)
	if err != nil {
		return result, err
	}

	return result, nil
}

// CancelAllExistingOrders cancels all open orders on the exchange
func (b *Bitstamp) CancelAllExistingOrders() (bool, error) {
	result := false

	return result,
		b.SendAuthenticatedHTTPRequest(bitstampAPICancelAllOrders, false, nil, &result)
}

// PlaceOrder places an order on the exchange.
func (b *Bitstamp) PlaceOrder(currencyPair string, price, amount float64, buy, market bool) (Order, error) {
	var req = url.Values{}
	req.Add("amount", strconv.FormatFloat(amount, 'f', -1, 64))
	req.Add("price", strconv.FormatFloat(price, 'f', -1, 64))
	response := Order{}
	orderType := order.Buy.Lower()

	if !buy {
		orderType = order.Sell.Lower()
	}

	var path string
	if market {
		path = fmt.Sprintf("%s/%s/%s", orderType, bitstampAPIMarket, strings.ToLower(currencyPair))
	} else {
		path = fmt.Sprintf("%s/%s", orderType, strings.ToLower(currencyPair))
	}

	return response,
		b.SendAuthenticatedHTTPRequest(path, true, req, &response)
}

// GetWithdrawalRequests returns withdrawal requests for the account
// timedelta - positive integer with max value 50000000 which returns requests
// from number of seconds ago to now.
func (b *Bitstamp) GetWithdrawalRequests(timedelta int64) ([]WithdrawalRequests, error) {
	var resp []WithdrawalRequests
	if timedelta > 50000000 || timedelta < 0 {
		return resp, errors.New("time delta exceeded, max: 50000000 min: 0")
	}

	value := url.Values{}
	value.Set("timedelta", strconv.FormatInt(timedelta, 10))

	if timedelta == 0 {
		value = url.Values{}
	}

	return resp,
		b.SendAuthenticatedHTTPRequest(bitstampAPIWithdrawalRequests, false, value, &resp)
}

// CryptoWithdrawal withdraws a cryptocurrency into a supplied wallet, returns ID
// amount - The amount you want withdrawn
// address - The wallet address of the cryptocurrency
// symbol - the type of crypto ie "ltc", "btc", "eth"
// destTag - only for XRP  default to ""
// instant - only for bitcoins
func (b *Bitstamp) CryptoWithdrawal(amount float64, address, symbol, destTag string, instant bool) (CryptoWithdrawalResponse, error) {
	var req = url.Values{}
	req.Add("amount", strconv.FormatFloat(amount, 'f', -1, 64))
	req.Add("address", address)
	resp := CryptoWithdrawalResponse{}
	var endpoint string

	switch strings.ToLower(symbol) {
	case currency.BTC.Lower().String():
		if instant {
			req.Add("instant", "1")
		} else {
			req.Add("instant", "0")
		}
		endpoint = bitstampAPIBitcoinWithdrawal
	case currency.LTC.Lower().String():
		endpoint = bitstampAPILTCWithdrawal
	case currency.ETH.Lower().String():
		endpoint = bitstampAPIETHWithdrawal
	case currency.XRP.Lower().String():
		if destTag != "" {
			req.Add("destination_tag", destTag)
		}
		endpoint = bitstampAPIXrpWithdrawal
	case currency.BCH.Lower().String():
		endpoint = bitstampAPIBCHWithdrawal
	default:
		return resp, errors.New("incorrect symbol")
	}

	return resp, b.SendAuthenticatedHTTPRequest(endpoint, false, req, &resp)
}

// OpenBankWithdrawal Opens a bank withdrawal request (SEPA or international)
func (b *Bitstamp) OpenBankWithdrawal(amount float64, currency,
	name, iban, bic, address, postalCode, city, country,
	comment, withdrawalType string) (FIATWithdrawalResponse, error) {
	var req = url.Values{}
	req.Add("amount", strconv.FormatFloat(amount, 'f', -1, 64))
	req.Add("account_currency", currency)
	req.Add("name", name)
	req.Add("iban", iban)
	req.Add("bic", bic)
	req.Add("address", address)
	req.Add("postal_code", postalCode)
	req.Add("city", city)
	req.Add("country", country)
	req.Add("type", withdrawalType)
	req.Add("comment", comment)

	resp := FIATWithdrawalResponse{}
	return resp, b.SendAuthenticatedHTTPRequest(bitstampAPIOpenWithdrawal, true, req, &resp)
}

// OpenInternationalBankWithdrawal Opens a bank withdrawal request (international)
func (b *Bitstamp) OpenInternationalBankWithdrawal(amount float64, currency,
	name, iban, bic, address, postalCode, city, country,
	bankName, bankAddress, bankPostCode, bankCity, bankCountry, internationalCurrency,
	comment, withdrawalType string) (FIATWithdrawalResponse, error) {
	var req = url.Values{}
	req.Add("amount", strconv.FormatFloat(amount, 'f', -1, 64))
	req.Add("account_currency", currency)
	req.Add("name", name)
	req.Add("iban", iban)
	req.Add("bic", bic)
	req.Add("address", address)
	req.Add("postal_code", postalCode)
	req.Add("city", city)
	req.Add("country", country)
	req.Add("type", withdrawalType)
	req.Add("comment", comment)
	req.Add("currency", internationalCurrency)
	req.Add("bank_name", bankName)
	req.Add("bank_address", bankAddress)
	req.Add("bank_postal_code", bankPostCode)
	req.Add("bank_city", bankCity)
	req.Add("bank_country", bankCountry)

	resp := FIATWithdrawalResponse{}
	return resp, b.SendAuthenticatedHTTPRequest(bitstampAPIOpenWithdrawal, true, req, &resp)
}

// GetCryptoDepositAddress returns a depositing address by crypto
// crypto - example "btc", "ltc", "eth", "xrp" or "bch"
func (b *Bitstamp) GetCryptoDepositAddress(crypto currency.Code) (string, error) {
	var resp string
	v2Resp := struct {
		Address string `json:"address"`
	}{}

	switch crypto {
	case currency.BTC:
		return resp,
			b.SendAuthenticatedHTTPRequest(bitstampAPIBitcoinDeposit, false, nil, &resp)

	case currency.LTC:
		return v2Resp.Address,
			b.SendAuthenticatedHTTPRequest(bitstampAPILitecoinDeposit, true, nil, &v2Resp)

	case currency.ETH:
		return v2Resp.Address,
			b.SendAuthenticatedHTTPRequest(bitstampAPIEthereumDeposit, true, nil, &v2Resp)

	case currency.XRP:
		return v2Resp.Address,
			b.SendAuthenticatedHTTPRequest(bitstampAPIXrpDeposit, true, nil, &v2Resp)

	case currency.BCH:
		return v2Resp.Address,
			b.SendAuthenticatedHTTPRequest(bitstampAPIBitcoinCashDeposit, true, nil, &v2Resp)

	default:
		return resp, fmt.Errorf("unsupported cryptocurrency string %s", crypto)
	}
}

// GetUnconfirmedBitcoinDeposits returns unconfirmed transactions
func (b *Bitstamp) GetUnconfirmedBitcoinDeposits() ([]UnconfirmedBTCTransactions, error) {
	var response []UnconfirmedBTCTransactions

	return response,
		b.SendAuthenticatedHTTPRequest(bitstampAPIUnconfirmedBitcoin, false, nil, &response)
}

// TransferAccountBalance transfers funds from either a main or sub account
// amount - to transfers
// currency - which currency to transfer
// subaccount - name of account
// toMain - bool either to or from account
func (b *Bitstamp) TransferAccountBalance(amount float64, currency, subAccount string, toMain bool) error {
	var req = url.Values{}
	req.Add("amount", strconv.FormatFloat(amount, 'f', -1, 64))
	req.Add("currency", currency)

	if subAccount == "" {
		return errors.New("missing subAccount parameter")
	}

	req.Add("subAccount", subAccount)

	var path string
	if toMain {
		path = bitstampAPITransferToMain
	} else {
		path = bitstampAPITransferFromMain
	}

	var resp interface{}

	return b.SendAuthenticatedHTTPRequest(path, true, req, &resp)
}

// SendHTTPRequest sends an unauthenticated HTTP request
func (b *Bitstamp) SendHTTPRequest(path string, result interface{}) error {
	return b.SendPayload(http.MethodGet,
		path,
		nil,
		nil,
		result,
		false,
		false,
		b.Verbose,
		b.HTTPDebugging,
		b.HTTPRecording)
}

// SendAuthenticatedHTTPRequest sends an authenticated request
func (b *Bitstamp) SendAuthenticatedHTTPRequest(path string, v2 bool, values url.Values, result interface{}) error {
	if !b.AllowAuthenticatedRequest() {
		return fmt.Errorf(exchange.WarningAuthenticatedRequestWithoutCredentialsSet, b.Name)
	}

	n := b.Requester.GetNonce(true).String()

	if values == nil {
		values = url.Values{}
	}

	values.Set("key", b.API.Credentials.Key)
	values.Set("nonce", n)
	hmac := crypto.GetHMAC(crypto.HashSHA256,
		[]byte(n+b.API.Credentials.ClientID+b.API.Credentials.Key),
		[]byte(b.API.Credentials.Secret))
	values.Set("signature", strings.ToUpper(crypto.HexEncodeToString(hmac)))

	if v2 {
		path = fmt.Sprintf("%s/v%s/%s/", b.API.Endpoints.URL, bitstampAPIVersion, path)
	} else {
		path = fmt.Sprintf("%s/%s/", b.API.Endpoints.URL, path)
	}

	if b.Verbose {
		log.Debugf(log.ExchangeSys, "Sending POST request to "+path)
	}

	headers := make(map[string]string)
	headers["Content-Type"] = "application/x-www-form-urlencoded"

	encodedValues := values.Encode()
	readerValues := bytes.NewBufferString(encodedValues)

	interim := json.RawMessage{}

	errCap := struct {
		Error  string      `json:"error"`
		Status string      `json:"status"`
		Reason interface{} `json:"reason"`
	}{}

	err := b.SendPayload(http.MethodPost,
		path,
		headers,
		readerValues,
		&interim,
		true,
		true,
		b.Verbose,
		b.HTTPDebugging,
		b.HTTPRecording)
	if err != nil {
		return err
	}

	if err := json.Unmarshal(interim, &errCap); err == nil {
		if errCap.Error != "" {
			return errors.New(errCap.Error)
		}
		if data, ok := errCap.Reason.(map[string][]string); ok {
			var details string
			for _, v := range data {
				details += strings.Join(v, "")
			}
			return errors.New(details)
		}

		if data, ok := errCap.Reason.(string); ok {
			return errors.New(data)
		}

		if errCap.Status != "" {
			return errors.New(errCap.Status)
		}
	}

	return json.Unmarshal(interim, result)
}

func parseTime(dateTime string) (time.Time, error) {
	return time.Parse(bitstampTimeLayout, dateTime)
}