package com.datatool.service;

import com.datatool.config.TransferProperties;
import com.datatool.room.RoomService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.time.Instant;
import java.util.stream.Stream;

/**
 * 定时过期清理：扫描上传根目录下各房间目录，对“内存已无房间且目录年龄超过 room-expire-hours”的进行删除。
 */
@Component
public class ScheduledUploadCleanup {

    private static final Logger log = LoggerFactory.getLogger(ScheduledUploadCleanup.class);

    private static final String ROOM_CODE_PATTERN = "[0-9]{6}";

    private final UploadCleanupService uploadCleanupService;
    private final RoomService roomService;
    private final TransferProperties transferProperties;

    public ScheduledUploadCleanup(UploadCleanupService uploadCleanupService,
                                 RoomService roomService,
                                 TransferProperties transferProperties) {
        this.uploadCleanupService = uploadCleanupService;
        this.roomService = roomService;
        this.transferProperties = transferProperties;
    }

    @Scheduled(fixedRateString = "${datatool.transfer.cleanup-interval-ms:3600000}")
    public void cleanupExpiredRoomFolders() {
        Path root = uploadCleanupService.resolveUploadRoot();
        if (!Files.isDirectory(root)) {
            return;
        }
        int expireHours = transferProperties.getRoomExpireHours();
        long expireSeconds = expireHours * 3600L;
        long nowSeconds = Instant.now().getEpochSecond();

        try (Stream<Path> list = Files.list(root)) {
            list.filter(Files::isDirectory)
                    .map(Path::getFileName)
                    .map(Path::toString)
                    .filter(roomCode -> roomCode.matches(ROOM_CODE_PATTERN))
                    .forEach(roomCode -> {
                        if (roomService.hasRoom(roomCode)) {
                            return;
                        }
                        Path roomDir = root.resolve(roomCode);
                        try {
                            long lastModified = Files.getLastModifiedTime(roomDir).toInstant().getEpochSecond();
                            if (nowSeconds - lastModified >= expireSeconds) {
                                uploadCleanupService.deleteRoomFolder(roomCode);
                            }
                        } catch (IOException e) {
                            log.warn("[ScheduledUploadCleanup] 无法读取目录时间 roomCode={} error={}", roomCode, e.getMessage());
                        }
                    });
        } catch (IOException e) {
            log.warn("[ScheduledUploadCleanup] 列出上传目录失败 error={}", e.getMessage());
        }
    }
}