package com.deepchart.utils;

import com.deepchart.entity.KDJData;
import com.deepchart.entity.StockDailyData;

import java.util.*;

/**
 * KD指标分析工具类
 */
public class KDUtil {

    private static final int N = 9;         // 默认周期长度 
    private static final double SMOOTH_K = 1.0 / 3;   // K 平滑系数
    private static final double SMOOTH_D = 1.0 / 3;   // D 平滑系数 

    private static List<KDJData> calculateKD(List<StockDailyData> dataList) {
        if (dataList == null || dataList.size()  < N) {
            throw new IllegalArgumentException("数据不足，至少需要" + N + "条记录");
        }

        List<KDJData> kdList = new ArrayList<>();
        Deque<Double> highs = new ArrayDeque<>(N);
        Deque<Double> lows = new ArrayDeque<>(N);

        Double prevK = null;
        Double prevD = null;

        for (int i = 0; i < dataList.size();  i++) {
            StockDailyData data = dataList.get(i);
            highs.offerLast(data.getHighPrice());
            lows.offerLast(data.getLowPrice());

            if (highs.size()  > N) {
                highs.pollFirst();
                lows.pollFirst();
            }

            if (i >= N - 1) {
                double hhv = Collections.max(highs);
                double llv = Collections.min(lows);
                double rsv = ((data.getClosePrice()  - llv) / (hhv - llv)) * 100;

                double kValue = (prevK == null ? rsv : prevK * (1 - SMOOTH_K) + rsv * SMOOTH_K);
                double dValue = (prevD == null ? kValue : prevD * (1 - SMOOTH_D) + kValue * SMOOTH_D);

                kdList.add(new KDJData(data.getDate(), rsv, kValue, dValue, 0));
                prevK = kValue;
                prevD = dValue;
            } else {
                kdList.add(new KDJData(data.getDate(), 0, 0, 0, 0)); // 占位符
            }
        }

        return kdList;
    }

    public static String generateReport(List<StockDailyData> stockDataList) {
        List<KDJData> kdList = calculateKD(stockDataList);
        StringBuilder report = new StringBuilder();

        report.append("📈  股票KD指标分析报告\n");
        report.append("=======================\n");

        if (kdList.isEmpty())  {
            report.append("❌  数据不足，无法生成分析。\n");
            return report.toString();
        }

        KDJData latest = kdList.get(kdList.size()  - 1);
        KDJData previous = kdList.size()  >= 2 ? kdList.get(kdList.size()  - 2) : null;

        double k = latest.getK();
        double d = latest.getD();

        // 判断超买或超卖
        if (k > 80 && d > 80) {
            report.append("🔴  当前处于【超买】状态，注意回调风险。\n");
        } else if (k < 20 && d < 20) {
            report.append("🟢  当前处于【超卖】状态，关注反弹机会。\n");
        } else {
            report.append("🟡  当前处于中性区域，暂无明显买卖信号。\n");
        }

        // 判断金叉/死叉
        if (previous != null) {
            boolean isGoldenCross = previous.getK()  <= previous.getD()  && k > d;
            boolean isDeathCross = previous.getK()  >= previous.getD()  && k < d;

            if (isGoldenCross && d < 30) {
                report.append("✨  出现金叉（K线上穿D线），特别是在低位，是潜在买入信号。\n");
            } else if (isDeathCross && d > 70) {
                report.append("⚠️  出现死叉（K线下穿D线），尤其是在高位，建议谨慎卖出。\n");
            }
        }

        // 多空趋势判断
        if (k > 50 && d > 50 && k > d) {
            report.append("⬆️  当前为多头趋势，可考虑持股观望。\n");
        } else if (k < 50 && d < 50 && k < d) {
            report.append("⬇️  当前为空头趋势，宜控制仓位。\n");
        } else {
            report.append("🔄  当前为震荡行情，短线操作更适宜。\n");
        }

        return report.toString();
    }
}