package com.xcong.excoin.modules.okxNewPrice;

import lombok.extern.slf4j.Slf4j;

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

/**
 * 网格价格队列构建器 — 从基底入场价生成双向价格队列和 OkxGridElement 列表。
 *
 * <h3>职责</h3>
 * <ul>
 *   <li>根据基底空头入场价，向下递减排空仓队列</li>
 *   <li>向上递增排多仓队列</li>
 *   <li>整合两队列为 OkxGridElement 列表并注入 {@link OkxConfig}</li>
 * </ul>
 *
 * <h3>线程安全</h3>
 * 本类为纯函数式（除 config.setStep / config.setGridElements 副作用外），
 * 每次调用返回新构建的对象，不持有可变状态。
 *
 * @author Administrator
 */
@Slf4j
public final class GridQueueBuilder {

    private GridQueueBuilder() { /* utility class */ }

    /**
     * 从基底入场价向下递减生成空仓价格队列，降序排列（大→小）。
     *
     * @param config   全局配置（step 会被计算并写入）
     * @param basePrice 空仓基底入场价
     * @return 空仓价格队列，按降序排列
     */
    public static List<BigDecimal> buildShortQueue(OkxConfig config, BigDecimal basePrice) {
        int prec = config.getPriceScale();
        BigDecimal step = basePrice.multiply(config.getGridRate()).setScale(prec, RoundingMode.HALF_UP);
        config.setStep(step); // 其它方法依赖此 step

        List<BigDecimal> queue = new ArrayList<>();
        BigDecimal elem = basePrice.subtract(step).setScale(prec, RoundingMode.HALF_UP);
        for (int i = 0; i < config.getGridQueueSize(); i++) {
            queue.add(elem);
            elem = elem.subtract(step).setScale(prec, RoundingMode.HALF_UP);
            if (elem.compareTo(BigDecimal.ZERO) <= 0) break;
        }
        queue.sort((a, b) -> b.compareTo(a)); // 降序
        log.info("[OKX] 空队列:{}", queue);
        return queue;
    }

    /**
     * 从基底入场价向上递增生成多仓价格队列，升序排列（小→大）。
     *
     * @param config   全局配置（使用已设置的 step）
     * @param basePrice 空仓基底入场价（对齐 Gate 版本，多仓队列也以此为基准）
     * @return 多仓价格队列，按升序排列
     */
    public static List<BigDecimal> buildLongQueue(OkxConfig config, BigDecimal basePrice) {
        int prec = config.getPriceScale();
        BigDecimal step = config.getStep();
        List<BigDecimal> queue = new ArrayList<>();
        BigDecimal elem = basePrice.add(step).setScale(prec, RoundingMode.HALF_UP);
        for (int i = 0; i < config.getGridQueueSize(); i++) {
            queue.add(elem);
            elem = elem.add(step).setScale(prec, RoundingMode.HALF_UP);
        }
        queue.sort(BigDecimal::compareTo); // 升序
        log.info("[OKX] 多队列:{}", queue);
        return queue;
    }

    /**
     * 将空/多仓队列整合为 OkxGridElement 列表。
     * <ul>
     *   <li>空仓网格: id = -1, -2, -3 …</li>
     *   <li>基底网格: id = 0（短仓入场价位置）</li>
     *   <li>多仓网格: id = +1, +2, +3 …</li>
     * </ul>
     * 每个网格元素包含两个方向的 {@link OkxTraderParam}（入场价 / 止盈价 / 数量）。
     *
     * @param config     全局配置
     * @param shortQueue 空仓价格队列
     * @param longQueue  多仓价格队列
     * @param basePrice  空仓基底入场价
     * @return 构建好的网格元素列表（已注入 config）
     */
    public static List<OkxGridElement> buildGridElements(OkxConfig config,
                                                          List<BigDecimal> shortQueue,
                                                          List<BigDecimal> longQueue,
                                                          BigDecimal basePrice) {
        List<OkxGridElement> elements = new ArrayList<>();
        int shortSize = shortQueue.size();
        int longSize = longQueue.size();
        int prec = config.getPriceScale();
        BigDecimal step = config.getStep();
        String qty = config.getQuantity();

        // ---- 空仓网格: id = -1, -2, … ----
        for (int i = 0; i < shortSize; i++) {
            int id = -(i + 1);
            Integer upId = (i == 0) ? 0 : id + 1;
            Integer downId = (i == shortSize - 1) ? null : id - 1;
            BigDecimal price = shortQueue.get(i);
            OkxTraderParam longParam = OkxTraderParam.builder()
                    .direction(OkxTraderParam.Direction.LONG)
                    .entryPrice(price).takeProfitPrice(price.add(step).setScale(prec, RoundingMode.HALF_UP)).quantity(qty).build();
            OkxTraderParam shortParam = OkxTraderParam.builder()
                    .direction(OkxTraderParam.Direction.SHORT)
                    .entryPrice(price).takeProfitPrice(price.subtract(step).setScale(prec, RoundingMode.HALF_UP)).quantity(qty).build();
            elements.add(OkxGridElement.builder().id(id).gridPrice(price).upId(upId).downId(downId)
                    .longTraderParam(longParam).shortTraderParam(shortParam).build());
        }

        // ---- 基底网格: id = 0 ----
        {
            BigDecimal price = basePrice;
            OkxTraderParam longParam = OkxTraderParam.builder()
                    .direction(OkxTraderParam.Direction.LONG)
                    .entryPrice(price).takeProfitPrice(price.add(step).setScale(prec, RoundingMode.HALF_UP)).quantity(qty).build();
            OkxTraderParam shortParam = OkxTraderParam.builder()
                    .direction(OkxTraderParam.Direction.SHORT)
                    .entryPrice(price).takeProfitPrice(price.subtract(step).setScale(prec, RoundingMode.HALF_UP)).quantity(qty).build();
            elements.add(OkxGridElement.builder().id(0).gridPrice(price)
                    .upId(shortSize > 0 ? 1 : null).downId(longSize > 0 ? -1 : null)
                    .longTraderParam(longParam).shortTraderParam(shortParam).build());
        }

        // ---- 多仓网格: id = 1, 2, … ----
        for (int i = 0; i < longSize; i++) {
            int id = i + 1;
            Integer downId = (i == 0) ? 0 : id - 1;
            Integer upId = (i == longSize - 1) ? null : id + 1;
            BigDecimal price = longQueue.get(i);
            OkxTraderParam longParam = OkxTraderParam.builder()
                    .direction(OkxTraderParam.Direction.LONG)
                    .entryPrice(price).takeProfitPrice(price.add(step).setScale(prec, RoundingMode.HALF_UP)).quantity(qty).build();
            OkxTraderParam shortParam = OkxTraderParam.builder()
                    .direction(OkxTraderParam.Direction.SHORT)
                    .entryPrice(price).takeProfitPrice(price.subtract(step).setScale(prec, RoundingMode.HALF_UP)).quantity(qty).build();
            elements.add(OkxGridElement.builder().id(id).gridPrice(price).upId(upId).downId(downId)
                    .longTraderParam(longParam).shortTraderParam(shortParam).build());
        }

        config.setGridElements(elements);
        log.info("[OKX] 网格元素列表已构建, 共{}个元素", elements.size());
        return elements;
    }
}