package com.zy.acs.manager.core.service;

import com.zy.acs.framework.common.Cools;
import com.zy.acs.manager.core.domain.ReservedTimeWindow;
import com.zy.acs.manager.core.domain.TimeWindow;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * dynamic time window
 * Created by vincent on 11/1/2024
 */
@Service
public class TimeWindowService {

    public static final Map<String, List<TimeWindow>> TIME_WINDOW_MAP = new ConcurrentHashMap<>();

    // reserve --------------------------------------------------------------------

    public synchronized boolean reserveTimeWindows(String agvNo, List<String> pathList) {
        if (Cools.isEmpty(agvNo, pathList)) {
            return false;
        }

        long estimatedTime = System.currentTimeMillis();

        List<ReservedTimeWindow> reservedWindows = new ArrayList<>();

        for (int i = 0; i < pathList.size() - 1; i++) {
            String fromCode = pathList.get(i);
            String toCode = pathList.get(i + 1);
            String twKey = fromCode + "_" + toCode;

            long twStartTime = estimatedTime;
            long twEndTime = estimatedTime + estimateTravelTime(fromCode, toCode, agvNo);

            TimeWindow timeWindow = new TimeWindow(twStartTime, twEndTime, agvNo);

            boolean success = reserveTimeWindow(twKey, timeWindow);
            if (!success) {
                // 预定失败，释放已预定的时间窗口
                releaseReservedTimeWindows(reservedWindows);
                return false;
            }

            reservedWindows.add(new ReservedTimeWindow(twKey, timeWindow));

            estimatedTime = twEndTime;
        }

        return true;
    }

    // 预定时间窗口
    public synchronized boolean reserveTimeWindow(String twKey, TimeWindow window) {

        List<TimeWindow> windows = TIME_WINDOW_MAP.getOrDefault(twKey, new ArrayList<>());

        for (TimeWindow reservedWindow : windows) {
            if (reservedWindow.isConflict(window)) {
                return false;
            }
        }

        windows.add(window);
        TIME_WINDOW_MAP.put(twKey, windows);
        return true;
    }


    // release ------------------------------------------------------------------

    public synchronized void releasePathTimeWindows(String agvNo, List<String> pathList) {
        for (int i = 0; i < pathList.size() - 1; i++) {
            String fromCode = pathList.get(i);
            String toCode = pathList.get(i + 1);
            String twKey = fromCode + "_" + toCode;

            // 查找并释放时间窗口
            releaseTimeWindow(twKey, agvNo);
        }
    }

    public synchronized void releaseTimeWindow(String twKey, String agvNo) {
        List<TimeWindow> windows = TIME_WINDOW_MAP.get(twKey);
        if (windows != null) {
            windows.removeIf(window -> window.getAgvNo().equals(agvNo));
            if (windows.isEmpty()) {
                TIME_WINDOW_MAP.remove(twKey);
            }
        }
    }

    private void releaseReservedTimeWindows(List<ReservedTimeWindow> reservedWindows) {
        for (ReservedTimeWindow reserved : reservedWindows) {
            releaseTimeWindow(reserved.getTwKey(), reserved.getTimeWindow().getAgvNo());
        }
    }

    // util --------------------------------------------------------------------------------------

    private long estimateTravelTime(String fromCode, String toCode, String agvNo) {
        // 根据距离和AGV速度估算行驶时间
        double distance = 1000;
        double speed = 2; // 获取AGV速度，单位：米/秒
        return (long) (distance / speed * 1000); // 转换为毫秒
    }

}