package com.zy.core.move;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.serializer.SerializerFeature;
import com.zy.common.utils.RedisUtil;
import com.zy.core.enums.RedisKeyType;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

@Component
public class StationMoveSessionRegistry {

    private static final int SESSION_EXPIRE_SECONDS = 60 * 60 * 24;

    @Autowired
    private RedisUtil redisUtil;

    public synchronized StationMoveSession load(Integer taskNo) {
        if (taskNo == null || taskNo <= 0 || redisUtil == null) {
            return null;
        }
        Object sessionObj = redisUtil.get(buildKey(taskNo));
        if (sessionObj == null) {
            return null;
        }
        try {
            return JSON.parseObject(String.valueOf(sessionObj), StationMoveSession.class);
        } catch (Exception ignore) {
            return null;
        }
    }

    public synchronized void save(StationMoveSession session) {
        if (session == null || session.getTaskNo() == null || session.getTaskNo() <= 0 || redisUtil == null) {
            return;
        }
        long now = System.currentTimeMillis();
        if (session.getCreatedAt() == null || session.getCreatedAt() <= 0L) {
            session.setCreatedAt(now);
        }
        session.setUpdatedAt(now);
        redisUtil.set(buildKey(session.getTaskNo()),
                JSON.toJSONString(session, SerializerFeature.DisableCircularReferenceDetect),
                SESSION_EXPIRE_SECONDS);
    }

    public synchronized void delete(Integer taskNo) {
        if (taskNo == null || taskNo <= 0 || redisUtil == null) {
            return;
        }
        redisUtil.del(buildKey(taskNo));
    }

    public synchronized boolean isActiveRoute(Integer taskNo, Integer routeVersion) {
        StationMoveSession session = load(taskNo);
        return session != null
                && session.isActive()
                && routeVersion != null
                && Objects.equals(routeVersion, session.getRouteVersion());
    }

    public synchronized boolean shouldSkipOutOrderDecision(Integer taskNo, Integer currentStationId) {
        StationMoveSession session = load(taskNo);
        if (session == null || !session.isActive() || currentStationId == null) {
            return false;
        }
        List<Integer> fullPathStationIds = session.getFullPathStationIds();
        if (fullPathStationIds == null || !fullPathStationIds.contains(currentStationId)) {
            return false;
        }
        if (StationMoveDispatchMode.CIRCLE == session.getDispatchMode()) {
            return true;
        }
        return !Objects.equals(currentStationId, session.getCurrentRouteTargetStationId());
    }

    public synchronized boolean isCircleDecisionStation(Integer taskNo, Integer currentStationId) {
        StationMoveSession session = load(taskNo);
        return session != null
                && session.isActive()
                && StationMoveDispatchMode.CIRCLE == session.getDispatchMode()
                && currentStationId != null
                && Objects.equals(currentStationId, session.getNextDecisionStationId());
    }

    public synchronized boolean isCircleTransitStation(Integer taskNo, Integer currentStationId) {
        StationMoveSession session = load(taskNo);
        if (session == null
                || !session.isActive()
                || StationMoveDispatchMode.CIRCLE != session.getDispatchMode()
                || currentStationId == null
                || Objects.equals(currentStationId, session.getNextDecisionStationId())) {
            return false;
        }
        List<Integer> fullPathStationIds = session.getFullPathStationIds();
        return fullPathStationIds != null && fullPathStationIds.contains(currentStationId);
    }

    public synchronized StationMoveSession registerPlan(Integer taskNo,
                                                        String threadImpl,
                                                        Integer currentStationId,
                                                        Integer businessTargetStationId,
                                                        StationMoveTriggerType triggerType,
                                                        StationMoveDispatchMode dispatchMode,
                                                        Integer currentRouteTargetStationId,
                                                        Integer nextDecisionStationId,
                                                        List<Integer> fullPathStationIds,
                                                        boolean cancelActive,
                                                        String cancelReason) {
        if (taskNo == null || taskNo <= 0) {
            return null;
        }
        StationMoveSession current = load(taskNo);
        StationMoveSession next = new StationMoveSession();
        next.setTaskNo(taskNo);
        next.setThreadImpl(threadImpl);
        next.setRouteVersion(current == null || current.getRouteVersion() == null ? 1 : current.getRouteVersion() + 1);
        next.setCurrentStationId(currentStationId);
        next.setBusinessTargetStationId(businessTargetStationId);
        next.setTriggerType(triggerType);
        next.setDispatchMode(dispatchMode);
        next.setCurrentRouteTargetStationId(currentRouteTargetStationId);
        next.setNextDecisionStationId(nextDecisionStationId);
        next.setStatus(StationMoveSession.STATUS_WAITING);
        next.setCancelReason(cancelReason);
        next.setFullPathStationIds(copyIntegerList(fullPathStationIds));
        next.setPathSignature(buildPathSignature(fullPathStationIds));
        save(next);
        return next;
    }

    public synchronized boolean isSameActivePath(Integer taskNo, List<Integer> fullPathStationIds) {
        StationMoveSession session = load(taskNo);
        if (session == null || !session.isActive()) {
            return false;
        }
        return Objects.equals(session.getPathSignature(), buildPathSignature(fullPathStationIds));
    }

    public synchronized void markSegmentIssued(Integer taskNo, Integer routeVersion) {
        StationMoveSession session = load(taskNo);
        if (session == null || !Objects.equals(session.getRouteVersion(), routeVersion)) {
            return;
        }
        session.setStatus(StationMoveSession.STATUS_RUNNING);
        session.setLastIssuedAt(System.currentTimeMillis());
        save(session);
    }

    public synchronized void updateCurrentStation(Integer taskNo, Integer routeVersion, Integer currentStationId) {
        StationMoveSession session = load(taskNo);
        if (session == null || !Objects.equals(session.getRouteVersion(), routeVersion)) {
            return;
        }
        session.setCurrentStationId(currentStationId);
        if (!StationMoveSession.STATUS_CANCEL_PENDING.equals(session.getStatus())) {
            session.setStatus(StationMoveSession.STATUS_RUNNING);
        }
        save(session);
    }

    public synchronized void markCancelPending(Integer taskNo, String cancelReason) {
        StationMoveSession session = load(taskNo);
        if (session == null || !session.isActive()) {
            return;
        }
        session.setStatus(StationMoveSession.STATUS_CANCEL_PENDING);
        session.setCancelReason(cancelReason);
        save(session);
    }

    public synchronized void markCancelled(Integer taskNo, Integer routeVersion, Integer currentStationId, String cancelReason) {
        updateTerminal(taskNo, routeVersion, currentStationId, StationMoveSession.STATUS_CANCELLED, cancelReason);
    }

    public synchronized void markBlocked(Integer taskNo, Integer routeVersion, Integer currentStationId) {
        updateTerminal(taskNo, routeVersion, currentStationId, StationMoveSession.STATUS_BLOCKED, null);
    }

    public synchronized void markTimeout(Integer taskNo, Integer routeVersion, Integer currentStationId) {
        updateTerminal(taskNo, routeVersion, currentStationId, StationMoveSession.STATUS_TIMEOUT, null);
    }

    public synchronized void markFinished(Integer taskNo, Integer routeVersion, Integer currentStationId) {
        updateTerminal(taskNo, routeVersion, currentStationId, StationMoveSession.STATUS_FINISHED, null);
    }

    public synchronized StationMoveSession buildCircleSessionCommandSource(Integer taskNo) {
        StationMoveSession session = load(taskNo);
        if (session == null || !session.isActive() || StationMoveDispatchMode.CIRCLE != session.getDispatchMode()) {
            return null;
        }
        return session;
    }

    private void updateTerminal(Integer taskNo,
                                Integer routeVersion,
                                Integer currentStationId,
                                String status,
                                String cancelReason) {
        StationMoveSession session = load(taskNo);
        if (session == null || !Objects.equals(session.getRouteVersion(), routeVersion)) {
            return;
        }
        session.setCurrentStationId(currentStationId);
        session.setStatus(status);
        session.setCancelReason(cancelReason);
        save(session);
    }

    private String buildKey(Integer taskNo) {
        return RedisKeyType.STATION_MOVE_SESSION_.key + taskNo;
    }

    private String buildPathSignature(List<Integer> fullPathStationIds) {
        if (fullPathStationIds == null || fullPathStationIds.isEmpty()) {
            return "";
        }
        StringBuilder builder = new StringBuilder();
        for (Integer stationId : fullPathStationIds) {
            if (stationId == null) {
                continue;
            }
            if (builder.length() > 0) {
                builder.append("->");
            }
            builder.append(stationId);
        }
        return builder.toString();
    }

    private List<Integer> copyIntegerList(List<Integer> source) {
        List<Integer> result = new ArrayList<>();
        if (source != null) {
            result.addAll(source);
        }
        return result;
    }
}