package strategy

import (
	"fmt"
	"sig-pub/api/pb"
)

// GoldX 金叉策略
type GoldX struct {
	ISigStrategy
	short, long int16
}

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

func (s *GoldX) Meta() StrategyMeta {
	return StrategyMeta{
		Name: "GoldX",
		Desc: "金叉策略",
		Args: []Param{
			{Name: "short", Type: ParamTypeUInt, Desc: "短周期"},
			{Name: "long", Type: ParamTypeUInt, Desc: "长周期"},
		},
	}
}

func (s *GoldX) Init(param SigStrategyParam) (err error) { // 校验参数, 并根据参数初始化策略
	if s.short, err = param.GetInt16E("short"); err != nil {
		return
	}
	if s.long, err = param.GetInt16E("long"); err != nil {
		return
	}
	if s.long <= s.short {
		err = fmt.Errorf("param short should bigger then short")
		return
	}
	return
}

func (s *GoldX) Update(ctx ISigStrategyContext) (side pb.Side) {
	sma14 := ctx.IndicatorW("sma", s.short)
	sma28 := ctx.IndicatorW("sma", s.long)
	// 包装方法 crossover/crossunder
	s14 := sma14.Series(0, 2)
	s28 := sma28.Series(0, 2)
	crossover := s14[0] > s28[0] && s14[1] < s28[1]  // 上穿
	crossunder := s14[0] < s28[0] && s14[1] > s28[1] // 下穿
	if crossover {
		return pb.Side_BUY
	}
	if crossunder {
		return pb.Side_SELL
	}
	return
}