xzmaster/backend/src/main/java/com/xuezhanmaster/game/service/ResponseActionResolver.java

package com.xuezhanmaster.game.service;

import com.xuezhanmaster.game.domain.ActionType;
import com.xuezhanmaster.game.domain.ResponseActionResolution;
import com.xuezhanmaster.game.domain.ResponseActionResolutionBatch;
import com.xuezhanmaster.game.domain.ResponseActionWindow;
import org.springframework.stereotype.Component;

import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.Optional;

@Component
public class ResponseActionResolver {

    public Optional<ResponseActionResolutionBatch> resolve(
            ResponseActionWindow window,
            Map<Integer, ActionType> selections,
            int seatCount
    ) {
        // 只要有胡牌声明，就按一炮多响返回全部胡牌赢家，其它动作全部失效。
        List<ResponseActionResolution> huResolutions = selections.entrySet().stream()
                .filter(entry -> entry.getValue() == ActionType.HU)
                .sorted(Comparator.comparingInt(entry -> seatDistance(window.sourceSeatNo(), entry.getKey(), seatCount)))
                .map(entry -> new ResponseActionResolution(
                        entry.getValue(),
                        entry.getKey(),
                        window.sourceSeatNo(),
                        window.triggerTile()
                ))
                .toList();
        if (!huResolutions.isEmpty()) {
            // 一炮多响时保留所有胡牌赢家，后续由执行层逐个结算。
            return Optional.of(new ResponseActionResolutionBatch(ActionType.HU, huResolutions));
        }

        return selections.entrySet().stream()
                .filter(entry -> entry.getValue() != ActionType.PASS)
                .min(Comparator
                        .comparingInt((Map.Entry<Integer, ActionType> entry) -> priority(entry.getValue()))
                        .thenComparingInt(entry -> seatDistance(window.sourceSeatNo(), entry.getKey(), seatCount)))
                .map(entry -> new ResponseActionResolutionBatch(
                        entry.getValue(),
                        List.of(new ResponseActionResolution(
                                entry.getValue(),
                                entry.getKey(),
                                window.sourceSeatNo(),
                                window.triggerTile()
                        ))
                ));
    }

    private int priority(ActionType actionType) {
        return switch (actionType) {
            case HU -> 0;
            case GANG -> 1;
            case PENG -> 2;
            case PASS -> 3;
            default -> 99;
        };
    }

    private int seatDistance(int sourceSeatNo, int targetSeatNo, int seatCount) {
        return (targetSeatNo - sourceSeatNo + seatCount) % seatCount;
    }
}