package service

import (
	"level_go/internal/model"
	"math"
	"sort"

	"gorm.io/gorm"
)

type StockService struct {
	DB *gorm.DB
}

func roundTo4(val float64) float64 {
	return math.Round(val*10000) / 10000
}

func (s *StockService) AnalyzePerformance(startDate, endDate string) ([]model.AnalysisResponse, error) {
	var results []model.AnalysisResponse

	var limits []struct {
		TsCode string
		Name   string
		Open   float64
		High   float64
	}

	// 1. 查找涨停股票
	query := `
		SELECT l.ts_code, l.name, d.open, d.high 
		FROM stock_limit_data l 
		LEFT JOIN stock_daily d ON l.ts_code = d.ts_code AND l.trade_date = d.trade_date
		WHERE l.trade_date = ? AND l.status = 1`

	if err := s.DB.Raw(query, startDate).Scan(&limits).Error; err != nil {
		return nil, err
	}

	// 2. 分析区间数据
	for _, stock := range limits {
		var dailies []model.StockDaily
		s.DB.Where("ts_code = ? AND trade_date BETWEEN ? AND ?", stock.TsCode, startDate, endDate).
			Order("trade_date ASC").Find(&dailies)

		if len(dailies) == 0 {
			continue
		}

		// A. 找最高点
		maxPrice := -1.0
		maxIdx := 0
		for i, d := range dailies {
			if d.High >= maxPrice {
				maxPrice = d.High
				maxIdx = i
			}
		}

		// B. 找最高点后的最低点
		postData := dailies[maxIdx+1:]
		var minLow, dropPct, reboundPct float64

		if len(postData) > 0 {
			minLow = postData[0].Low
			for _, p := range postData {
				if p.Low < minLow {
					minLow = p.Low
				}
			}
			lastClose := postData[len(postData)-1].Close
			dropPct = roundTo4(((maxPrice - minLow) / maxPrice) * 100)
			if minLow > 0 {
				reboundPct = roundTo4(((lastClose - minLow) / minLow) * 100)
			}
		}

		results = append(results, model.AnalysisResponse{
			Code:       stock.TsCode,
			Name:       stock.Name,
			DayOpen:    stock.Open,
			DayHigh:    stock.High,
			MaxHigh:    maxPrice,
			MaxDate:    dailies[maxIdx].TradeDate.Format("2006-01-02"),
			PostMinLow: minLow,
			DropPct:    dropPct,
			ReboundPct: reboundPct,
		})
	}

	// 3. 按降幅排序
	sort.Slice(results, func(i, j int) bool {
		return results[i].DropPct > results[j].DropPct
	})

	return results, nil
}