// 远程日志接收器
// 监听 HTTP 端口，接收日志内容推送（POST /log，JSON 或纯文本），
// 按日期追加存入 received_logs/ 文件夹。日志内容直接传输，不做文件传输。
import { createServer } from "node:http";
import { mkdir, appendFile } from "fs/promises";
import { existsSync } from "fs";
import { resolve } from "path";

const PORT = parseInt(process.env.RECEIVER_PORT || "3200", 10);
const LOG_DIR = resolve("received_logs");

function now(iso: string): string {
  return iso ? iso : new Date().toISOString();
}

function fmtEntry(p: { level?: string; category?: string; message?: string; line?: string; ts?: string }): string {
  const ts = now(p.ts);
  const level = (p.level || "info").toUpperCase().padEnd(5);
  const category = p.category || "receiver";
  const message = p.message !== undefined ? p.message : "";
  return `[${ts}] [${level}] [${category}] ${message}`;
}

const server = createServer(async (req, res) => {
  res.setHeader("Access-Control-Allow-Origin", "*");
  res.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS");
  res.setHeader("Access-Control-Allow-Headers", "Content-Type");

  if (req.method === "OPTIONS") { res.writeHead(204); res.end(); return; }

  const url = new URL(req.url || "/", `http://localhost:${PORT}`);

  if (req.method === "GET") {
    res.writeHead(200, { "Content-Type": "application/json" });
    res.end(JSON.stringify({ status: "ok", name: "远程日志接收器", receivePath: "POST /log", port: PORT }));
    return;
  }

  if (req.method === "POST" && (url.pathname === "/log" || url.pathname === "/")) {
    let body = "";
    try {
      for await (const c of req) body += c;
    } catch {
      res.writeHead(400); res.end("bad request"); return;
    }

    let entry: string;
    let level = "info";
    let category = "receiver";
    try {
      const json = JSON.parse(body);
      if (typeof json === "string") {
        entry = json;
      } else if (json.line) {
        entry = json.line;
        level = json.level || level;
        category = json.category || category;
      } else {
        entry = fmtEntry({ level: json.level, category: json.category, message: json.message, ts: json.ts });
        level = json.level || level;
        category = json.category || category;
      }
    } catch {
      entry = fmtEntry({ level, category, message: body, ts: new Date().toISOString() });
    }

    try {
      if (!existsSync(LOG_DIR)) await mkdir(LOG_DIR, { recursive: true });
      const ts = new Date().toISOString().slice(0, 10);
      await appendFile(resolve(LOG_DIR, `received-${ts}.log`), entry + "\n", "utf-8");
      res.writeHead(200, { "Content-Type": "application/json" });
      res.end(JSON.stringify({ ok: true }));
    } catch (e) {
      res.writeHead(500, { "Content-Type": "application/json" });
      res.end(JSON.stringify({ ok: false, error: (e as any).message }));
    }
    return;
  }

  res.writeHead(404);
  res.end("Not Found");
});

server.listen(PORT, () => {
  console.log(`[remote_receiver] 远程日志接收器已启动: http://127.0.0.1:${PORT}/log （存入 ${LOG_DIR}）`);
});