package sig

import (
	"fmt"
	"sig-pub/pkg/indicator"
)

type IndicatorSummary struct {
	indicator.IIndicatorSummary
	indicatorContext        IOffsetIndicatorContext
	summaryIndicatorNewer   func() indicator.ISummaryIndicator
	cachedSummaryIndicators map[string]indicator.ISummaryIndicator
}

func NewIndicatorSummary(summaryIndicatorNewer func() indicator.ISummaryIndicator, indicatorContext IOffsetIndicatorContext) *IndicatorSummary {
	return &IndicatorSummary{
		summaryIndicatorNewer:   summaryIndicatorNewer,
		indicatorContext:        indicatorContext,
		cachedSummaryIndicators: make(map[string]indicator.ISummaryIndicator),
	}
}

// Summary 0 10, 0 20, 1 30
func (s *IndicatorSummary) Summary(offset, count int16) (summary any, rok bool) {
	key := fmt.Sprintf("%d,%d", offset, count)
	summaryIndicator, ok := s.cachedSummaryIndicators[key]

	if ok {
		s.indicatorContext.AddOffset(offset + count + 1)
		eliminater, ok := summaryIndicator.(indicator.ISummaryIndicatorEliminater)
		if ok {
			eliminater.Eliminate(s.indicatorContext)
		}
		s.indicatorContext.AddOffset(-(offset + count + 1))

		s.indicatorContext.AddOffset(offset)
		summaryIndicator.Accumulate(s.indicatorContext)
		summary, ok = summaryIndicator.Summary(s.indicatorContext)
		s.indicatorContext.AddOffset(-offset)
		return
	}

	// 初始化, 计算全量数据
	summaryIndicator = s.summaryIndicatorNewer()
	if err := summaryIndicator.Init(s.indicatorContext.Input()); err != nil {
		panic(err)
	}
	s.cachedSummaryIndicators[key] = summaryIndicator

	// 设置当前相对offset
	offset = offset + count
	s.indicatorContext.AddOffset(offset)
	for range count {
		summaryIndicator.Accumulate(s.indicatorContext)

		offset--
		s.indicatorContext.AddOffset(-1)
	}

	// 获取结果
	summary, rok = summaryIndicator.Summary(s.indicatorContext)
	// 计算结束后还原offset
	s.indicatorContext.AddOffset(-offset)
	return
}