package trading

import (
	"fmt"
	"sig-pub/api/pb"
	"sig-pub/pkg/data"
	"sig-pub/pkg/types"
	"sig-pub/pkg/types/series"
	"sig-pub/pkg/zlog"
	"sync"
	"sync/atomic"
)

const (
	MaxSeriesKlines    = 1000 // 有效k线数量
	MaxCapSeriesKlines = 1280 // 最大k线数量, slice扩容12次后cap=1280
)

// TradeInstanceKlineSeries 单个交易产品所有周期k线
type TradeInstanceKlineSeries struct {
	IntervalKlines *types.IntervalState[*KlineSeries]
	Status         atomic.Int32 // 交易产品状态
}

func NewTradeInstanceKlineSeries(exchange pb.ExchangeType, instId string) *TradeInstanceKlineSeries {
	si := new(TradeInstanceKlineSeries)
	si.Status.Store(int32(data.StatusNone))
	si.IntervalKlines = types.NewIntervalState[*KlineSeries]()

	for interval := range types.SupportedIntervals {
		si.IntervalKlines.Set(interval, NewKlineSeries(exchange, instId, interval))
	}
	return si
}

type KlineSeries struct {
	sync.RWMutex
	Exchange      pb.ExchangeType
	InstId        string
	Interval      types.Interval
	IntervalAdder types.IntervalAdder
	lastTs        int64
	klines        []*types.Kline
}

func NewKlineSeries(exchange pb.ExchangeType, instId string, interval types.Interval) *KlineSeries {
	intervalAdder, ok := types.SupportedIntervals[interval]
	if !ok {
		panic(fmt.Errorf("unsupport interval: %s", interval))
	}
	return &KlineSeries{
		Exchange:      exchange,
		InstId:        instId,
		Interval:      interval,
		IntervalAdder: intervalAdder,
		klines:        make([]*types.Kline, 0, MaxSeriesKlines/10),
	}
}

// Get [0]当前k线
func (s *KlineSeries) Get(offset int16) (k types.Kline, ok bool) {
	if ok = offset >= 0 && offset < MaxSeriesKlines; !ok {
		return
	}
	s.RLock()
	defer s.RUnlock()

	length := len(s.klines)
	index := (length - 1) - int(offset)
	if ok = index > 0 && index < length; !ok {
		return
	}
	return *(s.klines[index]), true
}

// Series 时间降序序列[count...offset]
// offset: 从序列尾部开始偏移量
// count: 从offset位置开始向序列头部k线条数
func (s *KlineSeries) Series(offset, count int16) (klines series.Klines, ok bool) {
	if ok = offset >= 0 && offset < MaxSeriesKlines; !ok {
		return
	}
	if ok = count > 0 && offset+count < MaxSeriesKlines; !ok {
		return
	}

	s.RLock()
	defer s.RUnlock()

	length := len(s.klines)
	indexEnd := (length - 1) - int(offset)
	indexStart := (length - 1) - int(offset) - int(count) + 1
	if ok = indexEnd >= 0 && indexEnd < length && indexStart >= 0 && indexStart < length; !ok {
		return
	}
	total := indexEnd - indexStart + 1
	klines = make(series.Klines, total)
	for i := indexStart; i <= indexEnd; i++ {
		offset := total - 1 - (i - indexStart)
		klines[offset] = *(s.klines[i])
	}
	return klines, true
}

func (s *KlineSeries) LastTs() int64 {
	return s.lastTs
}

// 检查k线序列完整
func (s *KlineSeries) Update(kline *types.Kline) (lastTs int64, serial bool) {
	s.Lock()
	defer s.Unlock()

	serial = true
	lastTs = s.lastTs
	if kline.Ts <= s.lastTs {
		return
	}
	// 检查k线是否连续
	if len(s.klines) > 0 {
		expectTs := s.IntervalAdder(s.lastTs, 1)
		if kline.Ts != expectTs {
			serial = false
			miss := (kline.Ts-s.lastTs)/s.IntervalAdder(0, 1) - 1
			zlog.Warningf("k线不连续: instId=%s(%s), interval=%s, miss=%d, lastTs=%d, got=%d, expected=%d", s.InstId, s.Exchange, s.Interval, miss, s.lastTs, kline.Ts, expectTs)
			return
		}
	}

	if len(s.klines) < MaxCapSeriesKlines {
		s.klines = append(s.klines, kline)
		// 容量超过0.65, 直接扩容到最大
		if capacity := cap(s.klines); capacity < MaxCapSeriesKlines && capacity > MaxCapSeriesKlines*0.65 {
			klines := make([]*types.Kline, len(s.klines), MaxCapSeriesKlines)
			copy(klines, s.klines)
			s.klines = klines
		}
	} else {
		// 循环复用切片空间，避免扩容
		length := len(s.klines)
		copy(s.klines, s.klines[length-MaxSeriesKlines+1:])
		s.klines[MaxSeriesKlines-1] = kline
		s.klines = s.klines[:MaxSeriesKlines]
	}
	s.lastTs = kline.Ts
	return
}