package strategy

import (
	"sig-pub/pkg/types"
)

// GoldX 金叉策略
type GoldX struct {
	ISigStrategy
}

func (s *GoldX) New() ISigStrategy {
	return &GoldX{}
}

func (s *GoldX) Meta() StrategyMeta {
	return StrategyMeta{
		Name: "GoldX",
		Desc: "金叉策略",
		Input: []types.InputArg{
			{Name: "fast", Type: types.InputTypeUInt, Desc: "macd快线周期"},
			{Name: "slow", Type: types.InputTypeUInt, Desc: "macd慢线周期"},
			{Name: "singal", Type: types.InputTypeUInt, Desc: "macd信号线周期"},
		},
	}
}

// Init 校验参数, 并根据参数初始化策略
func (s *GoldX) Init(input types.Input) (err error) {
	return
}

func (s *GoldX) CandlePeriods(ctx ISingleSigStrategyContext) int16 {
	return max(
		ctx.Indicator("MACD", ctx.Input()).CandlePeriods(),
	)
}

// $MACD > 0 && #crossover($MACD.dea, $MACD.dif) -> long
func (s *GoldX) Update(ctx ISingleSigStrategyContext) (side types.Side) {
	macd := ctx.Indicator("MACD", ctx.Input())

	macdHist := macd.Get(0)
	macdDea := macd.StateSeries("dea", 0, 2)
	macdDif := macd.StateSeries("dif", 0, 2)

	// todo 包装方法 crossover/crossunder
	// 1.MACD DIF线接近或上穿零轴（表示整体多头市场）
	crossover := macdDif[0] > macdDea[0] && macdDif[1] < macdDea[1]  // 上穿
	crossunder := macdDif[0] < macdDea[0] && macdDif[1] > macdDea[1] // 下穿

	if crossover {
		// 2.附加确认条件: 柱状图从负值转为正值
		if macdHist > 0 {
			// todo 3.成交量放大（结合 OBV 等指标验证资金流入）。
			return types.SideLong
		}
	}
	if crossunder {
		if macdHist < 0 {
			return types.SideShort
		}
	}
	return
}