src/main/java/com/pt/controller/TrackerController.java

package com.pt.controller;

import com.pt.service.TorrentMetaService;
import com.pt.service.TrackerService;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLDecoder;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.util.HashMap;
import java.util.Map;

@RestController
@RequestMapping("/api/tracker")
@CrossOrigin(origins = "*")
public class TrackerController {

    @Autowired
    private TrackerService trackerService;

    @Autowired
    private TorrentMetaService torrentMetaService;

    // tracker相应bt客户端的announce请求
    @GetMapping("/announce")
    public void announce(
            @RequestParam(value = "passkey", required = false) String passkey,
            @RequestParam(value = "info_hash") String encodedInfoHash,
            @RequestParam(value = "peer_id") String encodedPeerId,
            @RequestParam(value = "port") int port,
            @RequestParam(value = "uploaded") long uploaded,
            @RequestParam(value = "downloaded") long downloaded,
            @RequestParam(value = "left") long left,
            @RequestParam(value = "event", defaultValue = "") String event,
            @RequestParam(value = "compact", defaultValue = "1") int compact,
            @RequestParam(value = "numwant", defaultValue = "50") int numwant,
            HttpServletRequest request,
            HttpServletResponse response
    ) throws IOException {
        try {

            System.out.println("TrackerController------------------------announce");
            // 解码 info_hash 和 peer_id（从URL编码的字符串转为字节数组）
            System.out.println("TrackerController------------------------announce: info_hash=" + encodedInfoHash + ", peer_id=" + encodedPeerId);
            String decodedInfoHash = URLDecoder.decode(encodedInfoHash, StandardCharsets.ISO_8859_1);
            String decodedPeerId = URLDecoder.decode(encodedPeerId, StandardCharsets.ISO_8859_1);

            // 转换为字节数组
            byte[] infoHashBytes = decodedInfoHash.getBytes(StandardCharsets.ISO_8859_1);
            byte[] peerIdBytes = decodedPeerId.getBytes(StandardCharsets.ISO_8859_1);

            // 验证 info_hash 长度
//            if (infoHashBytes.length != 20) {
//                throw new IllegalArgumentException("Invalid info_hash length");
//            }

            // 获取客户端IP
            String ip = request.getRemoteAddr();
            System.out.println("Client IP: " + ip);

            // 将参数封装为 Map 传给服务层
            Map<String, Object> params = new HashMap<>();
            params.put("info_hash", decodedInfoHash);
            params.put("peer_id", decodedPeerId);
            params.put("port", port);
            params.put("uploaded", uploaded);
            params.put("downloaded", downloaded);
            params.put("left", left);
            params.put("event", event);
            params.put("compact", compact);
            params.put("numwant", numwant);
            params.put("ip", ip);
            params.put("passkey", passkey);

            byte[] bencodedResponse = trackerService.handleAnnounce(params, ip, event);
            response.setContentType("application/x-bittorrent");
            response.getOutputStream().write(bencodedResponse);

        } catch (IllegalArgumentException e) {
            System.out.println("TrackerService-----------------------Error processing announce request111: " + e.getMessage());
            e.printStackTrace();
            String errorResponse = "d14:failure reason" + e.getMessage().length() + ":" + e.getMessage() + "e";
            response.setContentType("application/x-bittorrent");
            response.getOutputStream().write(errorResponse.getBytes(StandardCharsets.ISO_8859_1));
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("TrackerService-----------------------Error processing announce request222: " + e.getMessage());
            String errorResponse = "d14:failure reason20:Internal server errore";
            response.setContentType("application/x-bittorrent");
            response.getOutputStream().write(errorResponse.getBytes(StandardCharsets.ISO_8859_1));
        }
    }


}