const { SMTPServer } = require("smtp-server");
const { simpleParser } = require("mailparser");
const express = require("express");

const SMTP_PORT = parseInt(process.env.SMTP_PORT || "25", 10);
const API_PORT = parseInt(process.env.API_PORT || "3025", 10);
const API_KEY = process.env.API_KEY || "";
const MAX_AGE_MS = 3600_000; // 1 saat

const store = new Map();

function extractCode(text) {
  if (!text) return null;
  const m = text.match(/\b(\d{4,8})\b/);
  return m ? m[1] : null;
}

function cleanup() {
  const now = Date.now();
  for (const [addr, mails] of store) {
    const fresh = mails.filter((m) => now - m.ts < MAX_AGE_MS);
    if (fresh.length) store.set(addr, fresh);
    else store.delete(addr);
  }
}
setInterval(cleanup, 60_000);

const smtp = new SMTPServer({
  secure: false,
  authOptional: true,
  disabledCommands: ["STARTTLS"],
  onData(stream, session, cb) {
    const chunks = [];
    stream.on("data", (c) => chunks.push(c));
    stream.on("end", async () => {
      try {
        const raw = Buffer.concat(chunks);
        const parsed = await simpleParser(raw);
        const recipients = session.envelope.rcptTo.map((r) =>
          r.address.toLowerCase()
        );
        const entry = {
          ts: Date.now(),
          from: parsed.from?.text || "",
          subject: parsed.subject || "",
          text: parsed.text || "",
          html: parsed.html || "",
          code: extractCode(parsed.text) || extractCode(parsed.subject),
        };
        for (const addr of recipients) {
          if (!store.has(addr)) store.set(addr, []);
          store.get(addr).push(entry);
          if (store.get(addr).length > 50) store.get(addr).shift();
        }
        console.log(
          `[MAIL] ${entry.from} -> ${recipients.join(",")} subj="${entry.subject}" code=${entry.code || "-"}`
        );
      } catch (e) {
        console.error("[MAIL] parse error:", e.message);
      }
      cb();
    });
  },
});

const app = express();

app.use((req, res, next) => {
  if (API_KEY && req.headers["x-api-key"] !== API_KEY) {
    return res.status(401).json({ error: "unauthorized" });
  }
  next();
});

app.get("/health", (_req, res) => {
  res.json({ status: "ok", stored: store.size });
});

app.get("/mail/:address", (req, res) => {
  const addr = req.params.address.toLowerCase();
  const mails = store.get(addr) || [];
  const limit = parseInt(req.query.limit || "10", 10);
  res.json({ address: addr, count: mails.length, mails: mails.slice(-limit) });
});

app.get("/code/:address", (req, res) => {
  const addr = req.params.address.toLowerCase();
  const mails = store.get(addr) || [];
  const last = [...mails].reverse().find((m) => m.code);
  if (last) {
    res.json({ address: addr, code: last.code, subject: last.subject, age_s: Math.round((Date.now() - last.ts) / 1000) });
  } else {
    res.json({ address: addr, code: null, message: "no code found" });
  }
});

app.get("/codes", (_req, res) => {
  const result = {};
  for (const [addr, mails] of store) {
    const last = [...mails].reverse().find((m) => m.code);
    if (last) result[addr] = { code: last.code, age_s: Math.round((Date.now() - last.ts) / 1000) };
  }
  res.json(result);
});

app.delete("/mail/:address", (req, res) => {
  store.delete(req.params.address.toLowerCase());
  res.json({ ok: true });
});

smtp.listen(SMTP_PORT, () => console.log(`[SMTP] listening on :${SMTP_PORT}`));
app.listen(API_PORT, () => console.log(`[API]  listening on :${API_PORT}`));

smtp.on("error", (e) => console.error("[SMTP] error:", e.message));