package com.xcong.excoin.modules.okxNewPrice.indicator.macdAndMatrategy;

import java.math.BigDecimal;
import java.util.List;

/**
 * 示例用法
 * // 计算MACD（获取包含起始索引的结果）
 * MACDCalculator.MACDResult macdResult = MACDCalculator.calculateMACD(closePrices, 12, 26, 9);
 *
 * // 检测做空信号
 * boolean bearishSignal = BearishSignalDetector.isBearishSignalFormed(macdResult, closePrices);
 */
public class BearishSignalDetector {
    /**
     * 判断是否形成做空信号
     *
     * @param macdResult 包含MACD数据和有效起始索引的结果对象
     * @param closePrices 收盘价列表
     * @return 是否形成信号
     */
    public static boolean isBearishSignalFormed(MACDResult macdResult, List<BigDecimal> closePrices) {
        List<PriceData> macdData = macdResult.getMacdData();
        int startIdx = macdResult.getStartIndex();

        // 校验数据长度（至少需要两个有效DIF点）
        if (macdData.size() < 2 || closePrices.size() < startIdx + macdData.size()) {
            return false;
        }

        int currentMacdIndex = macdData.size() - 1;
        int currentCloseIndex = startIdx + currentMacdIndex;

        // 1. 判断顶背离
        boolean isTopDivergence = isTopDivergence(macdData, closePrices, currentMacdIndex, startIdx);

        // 2. 判断死叉
        boolean isDeathCross = isDeathCross(macdData, currentMacdIndex);

        return isTopDivergence && isDeathCross;
    }

    /**
     * 判断顶背离（需确保earlierHigh在recentHigh之前）
     */
    private static boolean isTopDivergence(List<PriceData> macdData, List<BigDecimal> closePrices,
                                           int currentMacdIndex, int startIdx) {
        // 计算对应closePrices的索引
        int currentCloseIndex = startIdx + currentMacdIndex;
        if (currentCloseIndex < 10 || macdData.size() < 5) {
            return false;
        }

        // 寻找最近的价格高点（至少在当前点的前2根K线范围内）
        int recentHighCloseIndex = findRecentHighWithRetrace(closePrices, currentCloseIndex - 5, currentCloseIndex);
        if (recentHighCloseIndex == -1) {
            return false;
        }

        // 寻找更早的高点（确保在recentHigh之前）
        int earlierHighCloseIndex = findRecentHighWithRetrace(closePrices, startIdx, recentHighCloseIndex - 1);
        if (earlierHighCloseIndex == -1) {
            return false;
        }

        // 转换为macdData的索引
        int recentHighMacdIndex = recentHighCloseIndex - startIdx;
        int earlierHighMacdIndex = earlierHighCloseIndex - startIdx;

        // 判断价格创新高但DIF走低
        BigDecimal recentHighPrice = closePrices.get(recentHighCloseIndex);
        BigDecimal earlierHighPrice = closePrices.get(earlierHighCloseIndex);
        boolean isPriceHigher = recentHighPrice.compareTo(earlierHighPrice) > 0;

        BigDecimal recentDif = macdData.get(recentHighMacdIndex).getDif();
        BigDecimal earlierDif = macdData.get(earlierHighMacdIndex).getDif();
        boolean isDifLower = recentDif.compareTo(earlierDif) < 0;

        return isPriceHigher && isDifLower;
    }

    /**
     * 寻找有效的高点（高点后需有至少1根K线下跌）
     */
    private static int findRecentHighWithRetrace(List<BigDecimal> prices, int startIndex, int endIndex) {
        if (startIndex < 0 || endIndex >= prices.size() || startIndex >= endIndex) {
            return -1;
        }

        int highIndex = -1;
        BigDecimal highPrice = BigDecimal.ZERO;

        // 从右向左搜索，找到第一个有效高点
        for (int i = endIndex; i >= startIndex; i--) {
            if (prices.get(i).compareTo(highPrice) > 0) {
                highPrice = prices.get(i);
                highIndex = i;
            }

            // 检查高点后是否有回调
            if (highIndex != -1 && i < endIndex) {
                if (prices.get(i + 1).compareTo(highPrice) < 0) {
                    return highIndex; // 找到确认回调的高点
                }
            }
        }

        return highIndex;
    }


    /**
     * 判断是否形成死叉（DIF下穿DEA）
     *
     * @param macdData MACD计算结果数据列表
     * @param currentIndex 当前数据点索引
     * @return 是否形成死叉
     */
    private static boolean isDeathCross(List<PriceData> macdData, int currentIndex) {
        if (currentIndex < 1) {
            return false;
        }

        PriceData current = macdData.get(currentIndex);
        PriceData previous = macdData.get(currentIndex - 1);

        // 前一期DIF >= DEA，当前期DIF < DEA
        return previous.getDif().compareTo(previous.getDea()) >= 0 &&
                current.getDif().compareTo(current.getDea()) < 0;
    }

}