package gateio

import (
	"errors"
	"fmt"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/thrasher-corp/gocryptotrader/common"
	"github.com/thrasher-corp/gocryptotrader/config"
	"github.com/thrasher-corp/gocryptotrader/currency"
	exchange "github.com/thrasher-corp/gocryptotrader/exchanges"
	"github.com/thrasher-corp/gocryptotrader/exchanges/asset"
	"github.com/thrasher-corp/gocryptotrader/exchanges/orderbook"
	"github.com/thrasher-corp/gocryptotrader/exchanges/request"
	"github.com/thrasher-corp/gocryptotrader/exchanges/ticker"
	"github.com/thrasher-corp/gocryptotrader/exchanges/websocket/wshandler"
	log "github.com/thrasher-corp/gocryptotrader/logger"
)

// GetDefaultConfig returns a default exchange config
func (g *Gateio) GetDefaultConfig() (*config.ExchangeConfig, error) {
	g.SetDefaults()
	exchCfg := new(config.ExchangeConfig)
	exchCfg.Name = g.Name
	exchCfg.HTTPTimeout = exchange.DefaultHTTPTimeout
	exchCfg.BaseCurrencies = g.BaseCurrencies

	err := g.SetupDefaults(exchCfg)
	if err != nil {
		return nil, err
	}

	if g.Features.Supports.RESTCapabilities.AutoPairUpdates {
		err = g.UpdateTradablePairs(true)
		if err != nil {
			return nil, err
		}
	}

	return exchCfg, nil
}

// SetDefaults sets default values for the exchange
func (g *Gateio) SetDefaults() {
	g.Name = "GateIO"
	g.Enabled = true
	g.Verbose = true
	g.API.CredentialsValidator.RequiresKey = true
	g.API.CredentialsValidator.RequiresSecret = true

	g.CurrencyPairs = currency.PairsManager{
		AssetTypes: asset.Items{
			asset.Spot,
		},
		UseGlobalFormat: true,
		RequestFormat: &currency.PairFormat{
			Delimiter: "_",
		},
		ConfigFormat: &currency.PairFormat{
			Delimiter: "_",
			Uppercase: true,
		},
	}

	g.Features = exchange.Features{
		Supports: exchange.FeaturesSupported{
			REST:      true,
			Websocket: true,
			RESTCapabilities: exchange.ProtocolFeatures{
				AutoPairUpdates: true,
				TickerBatching:  true,
			},
			WithdrawPermissions: exchange.AutoWithdrawCrypto |
				exchange.NoFiatWithdrawals,
		},
		Enabled: exchange.FeaturesEnabled{
			AutoPairUpdates: true,
		},
	}

	g.Requester = request.New(g.Name,
		request.NewRateLimit(time.Second*10, gateioAuthRate),
		request.NewRateLimit(time.Second*10, gateioUnauthRate),
		common.NewHTTPClientWithTimeout(exchange.DefaultHTTPTimeout))

	g.API.Endpoints.URLDefault = gateioTradeURL
	g.API.Endpoints.URL = g.API.Endpoints.URLDefault
	g.API.Endpoints.URLSecondaryDefault = gateioMarketURL
	g.API.Endpoints.URLSecondary = g.API.Endpoints.URLSecondaryDefault
	g.API.Endpoints.WebsocketURL = gateioWebsocketEndpoint
	g.Websocket = wshandler.New()
	g.Websocket.Functionality = wshandler.WebsocketTickerSupported |
		wshandler.WebsocketTradeDataSupported |
		wshandler.WebsocketOrderbookSupported |
		wshandler.WebsocketKlineSupported |
		wshandler.WebsocketSubscribeSupported |
		wshandler.WebsocketUnsubscribeSupported |
		wshandler.WebsocketAuthenticatedEndpointsSupported |
		wshandler.WebsocketMessageCorrelationSupported
	g.WebsocketResponseMaxLimit = exchange.DefaultWebsocketResponseMaxLimit
	g.WebsocketResponseCheckTimeout = exchange.DefaultWebsocketResponseCheckTimeout
	g.WebsocketOrderbookBufferLimit = exchange.DefaultWebsocketOrderbookBufferLimit
}

// Setup sets user configuration
func (g *Gateio) Setup(exch *config.ExchangeConfig) error {
	if !exch.Enabled {
		g.SetEnabled(false)
		return nil
	}

	err := g.SetupDefaults(exch)
	if err != nil {
		return err
	}

	err = g.Websocket.Setup(g.WsConnect,
		g.Subscribe,
		g.Unsubscribe,
		exch.Name,
		exch.Features.Enabled.Websocket,
		exch.Verbose,
		gateioWebsocketEndpoint,
		exch.API.Endpoints.WebsocketURL,
		exch.API.AuthenticatedWebsocketSupport)
	if err != nil {
		return err
	}

	g.WebsocketConn = &wshandler.WebsocketConnection{
		ExchangeName:         g.Name,
		URL:                  g.Websocket.GetWebsocketURL(),
		ProxyURL:             g.Websocket.GetProxyAddress(),
		Verbose:              g.Verbose,
		ResponseCheckTimeout: exch.WebsocketResponseCheckTimeout,
		ResponseMaxLimit:     exch.WebsocketResponseMaxLimit,
		RateLimit:            gateioWebsocketRateLimit,
	}

	g.Websocket.Orderbook.Setup(
		exch.WebsocketOrderbookBufferLimit,
		true,
		false,
		false,
		false,
		exch.Name)
	return nil
}

// Start starts the GateIO go routine
func (g *Gateio) Start(wg *sync.WaitGroup) {
	wg.Add(1)
	go func() {
		g.Run()
		wg.Done()
	}()
}

// Run implements the GateIO wrapper
func (g *Gateio) Run() {
	if g.Verbose {
		g.PrintEnabledPairs()
	}

	if !g.GetEnabledFeatures().AutoPairUpdates {
		return
	}

	err := g.UpdateTradablePairs(false)
	if err != nil {
		log.Errorf(log.ExchangeSys, "%s failed to update tradable pairs. Err: %s", g.Name, err)
	}
}

// FetchTradablePairs returns a list of the exchanges tradable pairs
func (g *Gateio) FetchTradablePairs(asset asset.Item) ([]string, error) {
	return g.GetSymbols()
}

// UpdateTradablePairs updates the exchanges available pairs and stores
// them in the exchanges config
func (g *Gateio) UpdateTradablePairs(forceUpdate bool) error {
	pairs, err := g.FetchTradablePairs(asset.Spot)
	if err != nil {
		return err
	}

	return g.UpdatePairs(currency.NewPairsFromStrings(pairs), asset.Spot, false, forceUpdate)
}

// UpdateTicker updates and returns the ticker for a currency pair
func (g *Gateio) UpdateTicker(p currency.Pair, assetType asset.Item) (ticker.Price, error) {
	var tickerPrice ticker.Price
	result, err := g.GetTickers()
	if err != nil {
		return tickerPrice, err
	}
	pairs := g.GetEnabledPairs(assetType)
	for i := range pairs {
		for k := range result {
			if !strings.EqualFold(k, pairs[i].String()) {
				continue
			}
			tickerPrice = ticker.Price{
				Last:        result[k].Last,
				High:        result[k].High,
				Low:         result[k].Low,
				Volume:      result[k].BaseVolume,
				QuoteVolume: result[k].QuoteVolume,
				Open:        result[k].Open,
				Close:       result[k].Close,
				Pair:        pairs[i],
			}
			err = ticker.ProcessTicker(g.Name, &tickerPrice, assetType)
			if err != nil {
				log.Error(log.Ticker, err)
			}
		}
	}

	return ticker.GetTicker(g.Name, p, assetType)
}

// FetchTicker returns the ticker for a currency pair
func (g *Gateio) FetchTicker(p currency.Pair, assetType asset.Item) (ticker.Price, error) {
	tickerNew, err := ticker.GetTicker(g.GetName(), p, assetType)
	if err != nil {
		return g.UpdateTicker(p, assetType)
	}
	return tickerNew, nil
}

// FetchOrderbook returns orderbook base on the currency pair
func (g *Gateio) FetchOrderbook(p currency.Pair, assetType asset.Item) (orderbook.Base, error) {
	ob, err := orderbook.Get(g.GetName(), p, assetType)
	if err != nil {
		return g.UpdateOrderbook(p, assetType)
	}
	return ob, nil
}

// UpdateOrderbook updates and returns the orderbook for a currency pair
func (g *Gateio) UpdateOrderbook(p currency.Pair, assetType asset.Item) (orderbook.Base, error) {
	var orderBook orderbook.Base
	currency := g.FormatExchangeCurrency(p, assetType).String()

	orderbookNew, err := g.GetOrderbook(currency)
	if err != nil {
		return orderBook, err
	}

	for x := range orderbookNew.Bids {
		data := orderbookNew.Bids[x]
		orderBook.Bids = append(orderBook.Bids, orderbook.Item{Amount: data.Amount, Price: data.Price})
	}

	for x := range orderbookNew.Asks {
		data := orderbookNew.Asks[x]
		orderBook.Asks = append(orderBook.Asks, orderbook.Item{Amount: data.Amount, Price: data.Price})
	}

	orderBook.Pair = p
	orderBook.ExchangeName = g.GetName()
	orderBook.AssetType = assetType

	err = orderBook.Process()
	if err != nil {
		return orderBook, err
	}

	return orderbook.Get(g.Name, p, assetType)
}

// GetAccountInfo retrieves balances for all enabled currencies for the
// ZB exchange
func (g *Gateio) GetAccountInfo() (exchange.AccountInfo, error) {
	var info exchange.AccountInfo

	balance, err := g.GetBalances()
	if err != nil {
		return info, err
	}

	var balances []exchange.AccountCurrencyInfo

	switch l := balance.Locked.(type) {
	case map[string]interface{}:
		for x := range l {
			lockedF, err := strconv.ParseFloat(l[x].(string), 64)
			if err != nil {
				return info, err
			}

			balances = append(balances, exchange.AccountCurrencyInfo{
				CurrencyName: currency.NewCode(x),
				Hold:         lockedF,
			})
		}
	default:
		break
	}

	switch v := balance.Available.(type) {
	case map[string]interface{}:
		for x := range v {
			availAmount, err := strconv.ParseFloat(v[x].(string), 64)
			if err != nil {
				return info, err
			}

			var updated bool
			for i := range balances {
				if balances[i].CurrencyName == currency.NewCode(x) {
					balances[i].TotalValue = balances[i].Hold + availAmount
					updated = true
					break
				}
			}
			if !updated {
				balances = append(balances, exchange.AccountCurrencyInfo{
					CurrencyName: currency.NewCode(x),
					TotalValue:   availAmount,
				})
			}
		}
	default:
		break
	}

	info.Accounts = append(info.Accounts, exchange.Account{
		Currencies: balances,
	})

	info.Exchange = g.GetName()

	return info, nil
}

// GetFundingHistory returns funding history, deposits and
// withdrawals
func (g *Gateio) GetFundingHistory() ([]exchange.FundHistory, error) {
	var fundHistory []exchange.FundHistory
	return fundHistory, common.ErrFunctionNotSupported
}

// GetExchangeHistory returns historic trade data since exchange opening.
func (g *Gateio) GetExchangeHistory(p currency.Pair, assetType asset.Item) ([]exchange.TradeHistory, error) {
	return nil, common.ErrNotYetImplemented
}

// SubmitOrder submits a new order
// TODO: support multiple order types (IOC)
func (g *Gateio) SubmitOrder(order *exchange.OrderSubmission) (exchange.SubmitOrderResponse, error) {
	var submitOrderResponse exchange.SubmitOrderResponse
	if order == nil {
		return submitOrderResponse, exchange.ErrOrderSubmissionIsNil
	}

	if err := order.Validate(); err != nil {
		return submitOrderResponse, err
	}

	var orderTypeFormat string
	if order.OrderSide == exchange.BuyOrderSide {
		orderTypeFormat = exchange.BuyOrderSide.ToLower().ToString()
	} else {
		orderTypeFormat = exchange.SellOrderSide.ToLower().ToString()
	}

	var spotNewOrderRequestParams = SpotNewOrderRequestParams{
		Amount: order.Amount,
		Price:  order.Price,
		Symbol: order.Pair.String(),
		Type:   orderTypeFormat,
	}

	response, err := g.SpotNewOrder(spotNewOrderRequestParams)
	if response.OrderNumber > 0 {
		submitOrderResponse.OrderID = fmt.Sprintf("%v", response.OrderNumber)
	}

	if err == nil {
		submitOrderResponse.IsOrderPlaced = true
	}

	return submitOrderResponse, err
}

// ModifyOrder will allow of changing orderbook placement and limit to
// market conversion
func (g *Gateio) ModifyOrder(action *exchange.ModifyOrder) (string, error) {
	return "", common.ErrFunctionNotSupported
}

// CancelOrder cancels an order by its corresponding ID number
func (g *Gateio) CancelOrder(order *exchange.OrderCancellation) error {
	orderIDInt, err := strconv.ParseInt(order.OrderID, 10, 64)

	if err != nil {
		return err
	}
	_, err = g.CancelExistingOrder(orderIDInt, g.FormatExchangeCurrency(order.CurrencyPair,
		order.AssetType).String())

	return err
}

// CancelAllOrders cancels all orders associated with a currency pair
func (g *Gateio) CancelAllOrders(_ *exchange.OrderCancellation) (exchange.CancelAllOrdersResponse, error) {
	cancelAllOrdersResponse := exchange.CancelAllOrdersResponse{
		OrderStatus: make(map[string]string),
	}
	openOrders, err := g.GetOpenOrders("")
	if err != nil {
		return cancelAllOrdersResponse, err
	}

	uniqueSymbols := make(map[string]int)
	for i := range openOrders.Orders {
		uniqueSymbols[openOrders.Orders[i].CurrencyPair]++
	}

	for unique := range uniqueSymbols {
		err = g.CancelAllExistingOrders(-1, unique)
		if err != nil {
			cancelAllOrdersResponse.OrderStatus[unique] = err.Error()
		}
	}

	return cancelAllOrdersResponse, nil
}

// GetOrderInfo returns information on a current open order
func (g *Gateio) GetOrderInfo(orderID string) (exchange.OrderDetail, error) {
	var orderDetail exchange.OrderDetail

	orders, err := g.GetOpenOrders("")
	if err != nil {
		return orderDetail, errors.New("failed to get open orders")
	}
	for x := range orders.Orders {
		if orders.Orders[x].OrderNumber != orderID {
			continue
		}
		orderDetail.Exchange = g.GetName()
		orderDetail.ID = orders.Orders[x].OrderNumber
		orderDetail.RemainingAmount = orders.Orders[x].InitialAmount - orders.Orders[x].FilledAmount
		orderDetail.ExecutedAmount = orders.Orders[x].FilledAmount
		orderDetail.Amount = orders.Orders[x].InitialAmount
		orderDetail.OrderDate = time.Unix(orders.Orders[x].Timestamp, 0)
		orderDetail.Status = orders.Orders[x].Status
		orderDetail.Price = orders.Orders[x].Rate
		orderDetail.CurrencyPair = currency.NewPairDelimiter(orders.Orders[x].CurrencyPair,
			g.GetPairFormat(asset.Spot, false).Delimiter)
		if strings.EqualFold(orders.Orders[x].Type, exchange.AskOrderSide.ToString()) {
			orderDetail.OrderSide = exchange.AskOrderSide
		} else if strings.EqualFold(orders.Orders[x].Type, exchange.BidOrderSide.ToString()) {
			orderDetail.OrderSide = exchange.BuyOrderSide
		}
		return orderDetail, nil
	}
	return orderDetail, fmt.Errorf("no order found with id %v", orderID)
}

// GetDepositAddress returns a deposit address for a specified currency
func (g *Gateio) GetDepositAddress(cryptocurrency currency.Code, _ string) (string, error) {
	addr, err := g.GetCryptoDepositAddress(cryptocurrency.String())
	if err != nil {
		return "", err
	}

	// Waits for new generated address if not created yet, its variable per
	// currency
	if addr == gateioGenerateAddress {
		time.Sleep(10 * time.Second)
		addr, err = g.GetCryptoDepositAddress(cryptocurrency.String())
		if err != nil {
			return "", err
		}
		if addr == gateioGenerateAddress {
			return "", errors.New("new deposit address is being generated, please retry again shortly")
		}
		return addr, nil
	}

	return addr, err
}

// WithdrawCryptocurrencyFunds returns a withdrawal ID when a withdrawal is
// submitted
func (g *Gateio) WithdrawCryptocurrencyFunds(withdrawRequest *exchange.CryptoWithdrawRequest) (string, error) {
	return g.WithdrawCrypto(withdrawRequest.Currency.String(), withdrawRequest.Address, withdrawRequest.Amount)
}

// WithdrawFiatFunds returns a withdrawal ID when a
// withdrawal is submitted
func (g *Gateio) WithdrawFiatFunds(withdrawRequest *exchange.FiatWithdrawRequest) (string, error) {
	return "", common.ErrFunctionNotSupported
}

// WithdrawFiatFundsToInternationalBank returns a withdrawal ID when a
// withdrawal is submitted
func (g *Gateio) WithdrawFiatFundsToInternationalBank(withdrawRequest *exchange.FiatWithdrawRequest) (string, error) {
	return "", common.ErrFunctionNotSupported
}

// GetWebsocket returns a pointer to the exchange websocket
func (g *Gateio) GetWebsocket() (*wshandler.Websocket, error) {
	return g.Websocket, nil
}

// GetFeeByType returns an estimate of fee based on type of transaction
func (g *Gateio) GetFeeByType(feeBuilder *exchange.FeeBuilder) (float64, error) {
	if !g.AllowAuthenticatedRequest() && // Todo check connection status
		feeBuilder.FeeType == exchange.CryptocurrencyTradeFee {
		feeBuilder.FeeType = exchange.OfflineTradeFee
	}
	return g.GetFee(feeBuilder)
}

// GetActiveOrders retrieves any orders that are active/open
func (g *Gateio) GetActiveOrders(getOrdersRequest *exchange.GetOrdersRequest) ([]exchange.OrderDetail, error) {
	var currPair string
	if len(getOrdersRequest.Currencies) == 1 {
		currPair = getOrdersRequest.Currencies[0].String()
	}

	resp, err := g.GetOpenOrders(currPair)
	if err != nil {
		return nil, err
	}

	var orders []exchange.OrderDetail
	for i := range resp.Orders {
		if resp.Orders[i].Status != "open" {
			continue
		}

		symbol := currency.NewPairDelimiter(resp.Orders[i].CurrencyPair,
			g.GetPairFormat(asset.Spot, false).Delimiter)
		side := exchange.OrderSide(strings.ToUpper(resp.Orders[i].Type))
		orderDate := time.Unix(resp.Orders[i].Timestamp, 0)

		orders = append(orders, exchange.OrderDetail{
			ID:              resp.Orders[i].OrderNumber,
			Amount:          resp.Orders[i].Amount,
			Price:           resp.Orders[i].Rate,
			RemainingAmount: resp.Orders[i].FilledAmount,
			OrderDate:       orderDate,
			OrderSide:       side,
			Exchange:        g.Name,
			CurrencyPair:    symbol,
			Status:          resp.Orders[i].Status,
		})
	}

	exchange.FilterOrdersByTickRange(&orders, getOrdersRequest.StartTicks, getOrdersRequest.EndTicks)
	exchange.FilterOrdersBySide(&orders, getOrdersRequest.OrderSide)
	return orders, nil
}

// GetOrderHistory retrieves account order information
// Can Limit response to specific order status
func (g *Gateio) GetOrderHistory(getOrdersRequest *exchange.GetOrdersRequest) ([]exchange.OrderDetail, error) {
	var trades []TradesResponse
	for _, currency := range getOrdersRequest.Currencies {
		resp, err := g.GetTradeHistory(currency.String())
		if err != nil {
			return nil, err
		}
		trades = append(trades, resp.Trades...)
	}

	var orders []exchange.OrderDetail
	for _, trade := range trades {
		symbol := currency.NewPairDelimiter(trade.Pair,
			g.GetPairFormat(asset.Spot, false).Delimiter)
		side := exchange.OrderSide(strings.ToUpper(trade.Type))
		orderDate := time.Unix(trade.TimeUnix, 0)
		orders = append(orders, exchange.OrderDetail{
			ID:           strconv.FormatInt(trade.OrderID, 10),
			Amount:       trade.Amount,
			Price:        trade.Rate,
			OrderDate:    orderDate,
			OrderSide:    side,
			Exchange:     g.Name,
			CurrencyPair: symbol,
		})
	}

	exchange.FilterOrdersByTickRange(&orders, getOrdersRequest.StartTicks,
		getOrdersRequest.EndTicks)
	exchange.FilterOrdersBySide(&orders, getOrdersRequest.OrderSide)
	return orders, nil
}

// SubscribeToWebsocketChannels appends to ChannelsToSubscribe
// which lets websocket.manageSubscriptions handle subscribing
func (g *Gateio) SubscribeToWebsocketChannels(channels []wshandler.WebsocketChannelSubscription) error {
	g.Websocket.SubscribeToChannels(channels)
	return nil
}

// UnsubscribeToWebsocketChannels removes from ChannelsToSubscribe
// which lets websocket.manageSubscriptions handle unsubscribing
func (g *Gateio) UnsubscribeToWebsocketChannels(channels []wshandler.WebsocketChannelSubscription) error {
	g.Websocket.RemoveSubscribedChannels(channels)
	return nil
}

// GetSubscriptions returns a copied list of subscriptions
func (g *Gateio) GetSubscriptions() ([]wshandler.WebsocketChannelSubscription, error) {
	return g.Websocket.GetSubscriptions(), nil
}

// AuthenticateWebsocket sends an authentication message to the websocket
func (g *Gateio) AuthenticateWebsocket() error {
	_, err := g.wsServerSignIn()
	return err
}