package backtest

import (
	"fmt"
	"sig-pub/pkg/trade"
	"sig-pub/pkg/types"
	"sig-pub/pkg/types/decimals"
	"sig-pub/pkg/utils/collect"
	"sig-pub/pkg/utils/conver"
	"sig-pub/pkg/utils/lang"
	"sig-pub/pkg/zlog"
	"time"

	"github.com/govalues/decimal"
)

type BacktestTradeAccount struct {
	trader        *TradeSimulator             // 下单器
	traderOrderId int64                       // 订单id递增
	initialCash   float64                     // 初始资金
	cash          float64                     // 可用资金
	positions     map[string]*trade.Position  // 仓位信息，key: symbol, value: qty(不能持有同一交易产品反方向单, 交易中不能改变杠杆)
	orders        map[int64]*trade.TradeOrder // 所有交易单
	openTrades    map[string][]int64          // 未平仓交易单，key: symbol, value: tradeId
	closeTrades   []int64                     // 平仓交易单
	maxDrawdown   [4]float64                  // 最大回撤
}

func NewBacktestTradeAccount(cash float64) *BacktestTradeAccount {
	return &BacktestTradeAccount{
		trader:        NewTradeSimulator(0.0005, 0.0008),
		traderOrderId: 1,
		initialCash:   cash,
		cash:          cash,
		positions:     make(map[string]*trade.Position),
		orders:        make(map[int64]*trade.TradeOrder),
		openTrades:    make(map[string][]int64),
		maxDrawdown:   [4]float64{cash, cash, cash, cash},
	}
}

// GetCash 账户可交易资金
func (a *BacktestTradeAccount) GetCash() float64 {
	return a.cash
}

// OnPrice 交易产品价格更新
func (a *BacktestTradeAccount) OnPrice(instId string, price float64) {
	if pos, ok := a.positions[instId]; ok {
		pos.LastPx = price
	}
}

// Equity 账户净值
func (a *BacktestTradeAccount) CurrentEquity() float64 {
	equity := a.cash
	for _, pos := range a.positions {
		posQty := decimals.MustToFloat64(pos.Qty)
		// 保证金
		insure := pos.EntryPx * posQty / float64(pos.Leverage)
		// 浮盈
		var pnl float64
		if pos.Side == types.SideLong {
			pnl = (pos.LastPx - pos.EntryPx) * posQty
		} else {
			pnl = (pos.EntryPx - pos.LastPx) * posQty
		}
		equity += insure + pnl
	}
	return equity
}

// CurrentExposure 返回当前仓位的名义总敞口（绝对值）
func (a *BacktestTradeAccount) CurrentExposure() float64 {
	var sum float64
	for _, p := range a.positions {
		sum += p.EntryPx * decimals.MustToFloat64(p.Qty)
	}
	return sum
}

// IsSymbolOpen 指定交易对是否有持仓
func (a *BacktestTradeAccount) IsSymbolOpen(symbol string) bool {
	return a.positions[symbol] != nil
}

func (a *BacktestTradeAccount) GetOpenTradeInsts() (instIds []string) {
	for instId := range a.openTrades {
		instIds = append(instIds, instId)
	}
	return
}

func (a *BacktestTradeAccount) GetOpenTrades(instId string) []*trade.TradeOrder {
	var trades []*trade.TradeOrder
	for _, tradeId := range a.openTrades[instId] {
		trades = append(trades, a.orders[tradeId])
	}
	return trades
}

// 获取交易产品仓位
func (a *BacktestTradeAccount) GetPosition(instId string) *trade.Position {
	return a.positions[instId]
}

// GetSymbolOpenPosition 获取指定交易对的仓位信息
func (a *BacktestTradeAccount) GetSymbolOpenPosition(symbol string) *trade.Position {
	return a.positions[symbol]
}

// MarketOrder 市价下单
func (a *BacktestTradeAccount) MarketOrder(ticket trade.TradeTicket) (order *trade.TradeOrder, err error) {
	instId := ticket.InstId
	if pos, ok := a.positions[instId]; ok {
		// 检查反方向单
		if pos.Side != ticket.Side {
			err = fmt.Errorf("cannot open opposite side position")
			return
		}
		// 同方向杠杆倍数
		if pos.Leverage != ticket.Leverage {
			err = fmt.Errorf("cannot change leverage on existing position")
			return
		}
	}

	order = a.trader.ExecuteMarket(a.traderOrderId, instId, ticket)
	orderQty := decimals.MustToFloat64(order.Qty)
	cost := order.Price*orderQty/float64(order.Leverage) + order.Fee
	if cost > a.cash {
		// err = fmt.Errorf("insufficient cash")
		return
	}
	a.traderOrderId++
	a.cash -= cost
	a.orders[order.TradeId] = order
	a.openTrades[instId] = append(a.openTrades[instId], order.TradeId)

	// open/add position
	pos, ok := a.positions[instId]
	if !ok {
		pos = &trade.Position{
			InstId:   order.InstId,
			Side:     order.Side,
			Qty:      order.Qty,
			Leverage: order.Leverage,
			EntryPx:  order.Price,
			EntryTs:  order.Ctime,
			PeakPx:   order.Price,
			LastPx:   order.Price,
		}
		a.positions[instId] = pos
	} else {
		posQty := decimals.MustToFloat64(pos.Qty)
		orderQty := decimals.MustToFloat64(order.Qty)
		totalQty := decimals.MustAdd(pos.Qty, order.Qty)
		pos.EntryPx = (pos.EntryPx*posQty + order.Price*orderQty) / decimals.MustToFloat64(totalQty)
		pos.Qty = totalQty
		pos.LastPx = order.Price
		if pos.Side == types.SideLong && order.Price < pos.PeakPx {
			pos.PeakPx = order.Price
		}
		if pos.Side == types.SideShort && order.Price > pos.PeakPx {
			pos.PeakPx = order.Price
		}
	}
	return
}

// CloseTradeOrder 订单订单平仓
func (a *BacktestTradeAccount) CloseTradeOrder(ticket trade.TradeTicket) (err error) {
	instId := ticket.InstId
	// 检查仓位
	pos, ok := a.positions[instId]
	if !ok {
		err = fmt.Errorf("no open position for symbol: %s", instId)
		return
	}
	if pos.Side == ticket.Side {
		err = fmt.Errorf("cannot close position with same side trade")
		return
	}
	if ticket.Qty.Cmp(pos.Qty) > 0 {
		// ticket.Qty = pos.Qty
		err = fmt.Errorf("close quantity exceeds position quantity")
		return
	}

	order := a.trader.ExecuteMarket(a.traderOrderId, instId, ticket)
	a.traderOrderId++

	var insure, profit float64
	var entryPxs, entryPxAvg, entryTrades float64
	for _, tradeId := range ticket.TradesId {
		trade, ok := a.orders[tradeId]
		if !ok {
			continue
		}
		entryTrades++
		entryPxs += trade.Price
		order.EntryFee += trade.Fee
		order.EntryTime = lang.Ternary(order.EntryTime == 0, trade.Ctime, min(order.EntryTime, trade.Ctime))
		order.PeakPx = lang.Ternary(
			trade.Side == types.SideLong,
			max(order.PeakPx, trade.PeakPx),
			min(order.PeakPx, trade.PeakPx),
		)
		tradeQty := decimals.MustToFloat64(trade.Qty)

		// 计算盈利
		if trade.Side == types.SideLong {
			profit += tradeQty * (order.Price - trade.Price)
		} else {
			profit += tradeQty * (trade.Price - order.Price)
		}
	}
	if entryTrades == 0 {
		err = fmt.Errorf("entry error")
		return
	}

	entryPxAvg = entryPxs / entryTrades                      // 开仓平均价
	orderQty := decimals.MustToFloat64(order.Qty)            // 平仓数量
	insure = entryPxAvg * orderQty / float64(order.Leverage) // 开仓保证金
	a.cash += (insure + profit - order.Fee)                  // 平仓收益加到账户

	a.orders[order.TradeId] = order
	a.closeTrades = append(a.closeTrades, order.TradeId)
	if len(ticket.TradesId) > 0 {
		if trades, ok := a.openTrades[instId]; ok {
			// remove open trade order
			removes := collect.Remove(&trades, func(tradeId int64) bool {
				return collect.In(tradeId, ticket.TradesId...)
			})
			a.openTrades[instId] = trades
			if removes != len(ticket.TradesId) {
				zlog.Warningf("close ticket tradeId not exists: instId=%s, tradeId=%#v", ticket.InstId, ticket.TradesId)
			}
		}
		if len(a.openTrades[instId]) == 0 {
			delete(a.openTrades, instId)
		}
	}

	// update position
	pos.Qty = decimals.MustSub(pos.Qty, ticket.Qty)
	if pos.Qty.Cmp(decimal.Zero) <= 0 {
		delete(a.positions, instId)
		if _, ok := a.openTrades[instId]; ok {
			zlog.Warningf("close all position trades: %s", instId)
		}
	}

	// 账户净值
	currentEquity := a.CurrentEquity()
	// 平仓单统计
	order.LastPx = ticket.Price
	order.EntryPx = entryPxAvg
	order.Equity = currentEquity
	order.HoldTime = conver.TimeDurationFormat(time.Duration(order.Ctime-order.EntryTime)*time.Millisecond, ".")
	order.Profit = profit - order.Fee - order.EntryFee
	order.Trades = ticket.TradesId

	// 记录最大回撤 [high, low, highPrev, lowPrev]
	if currentEquity < a.maxDrawdown[1] {
		a.maxDrawdown[1] = currentEquity
	}
	if currentEquity > a.maxDrawdown[0] {
		if a.maxDrawdown[0]-a.maxDrawdown[1] > a.maxDrawdown[2]-a.maxDrawdown[3] {
			a.maxDrawdown[2], a.maxDrawdown[3] = a.maxDrawdown[0], a.maxDrawdown[1]
		}
		a.maxDrawdown[0] = currentEquity
		a.maxDrawdown[1] = currentEquity
	}
	return
}