#!/usr/bin/env node
/**
 * List Gmail messages: id, from, subject (metadata only).
 *
 * Usage:
 *   npm run list-messages -w watcher
 *   npm run list-messages -w watcher -- --query 'newer_than:14d has:attachment filename:eml'
 *   npm run list-messages -w watcher -- --max 100 --json
 *
 * Options:
 *   --query <q>     Gmail search (default: newer_than:7d)
 *   --user <email>  Mailbox (default: first user with tokens)
 *   --max <n>       Max messages (default 50)
 *   --json          Print JSON lines instead of a table
 */

import { GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET } from "../src/config.js";
import { getUserByEmail, listUsersWithTokens } from "../src/db.js";
import { gmailClientForUser } from "../src/google.js";
import { header } from "../src/mime.js";

const DEFAULT_QUERY = "newer_than:7d";

function parseArgs(argv) {
  const out = {
    query: null,
    user: null,
    max: 50,
    json: false,
    help: false,
  };
  for (let i = 0; i < argv.length; i++) {
    const a = argv[i];
    if (a === "--help" || a === "-h") out.help = true;
    else if (a === "--json") out.json = true;
    else if (a === "--query") out.query = argv[++i];
    else if (a === "--user") out.user = argv[++i];
    else if (a === "--max") out.max = Math.max(1, Number(argv[++i]) || 50);
    else if (a.startsWith("--query=")) out.query = a.slice("--query=".length);
    else if (a.startsWith("--user=")) out.user = a.slice("--user=".length);
    else if (a.startsWith("--max=")) {
      out.max = Math.max(1, Number(a.slice("--max=".length)) || 50);
    }
  }
  return out;
}

async function listMessageIds(gmail, query, max) {
  const ids = [];
  let pageToken;
  while (ids.length < max) {
    const { data } = await gmail.users.messages.list({
      userId: "me",
      q: query,
      maxResults: Math.min(50, max - ids.length),
      pageToken,
    });
    for (const m of data.messages || []) {
      if (m.id) ids.push(m.id);
      if (ids.length >= max) break;
    }
    pageToken = data.nextPageToken;
    if (!pageToken) break;
  }
  return ids;
}

function metaFromPayload(payload) {
  return {
    from: header(payload, "From") || "",
    subject: header(payload, "Subject") || "(no subject)",
    date: header(payload, "Date") || "",
  };
}

async function main() {
  const args = parseArgs(process.argv.slice(2));
  if (args.help) {
    console.log(`Usage: list-messages [--query q] [--user email] [--max n] [--json]
Default query: ${DEFAULT_QUERY}`);
    process.exit(0);
  }

  if (!GOOGLE_CLIENT_ID || !GOOGLE_CLIENT_SECRET) {
    console.error("Missing GOOGLE_CLIENT_ID / GOOGLE_CLIENT_SECRET in .env");
    process.exit(1);
  }

  const users = listUsersWithTokens();
  if (!users.length) {
    console.error("No signed-in users with tokens. Sign in via the web UI first.");
    process.exit(1);
  }

  let user = users[0];
  if (args.user) {
    const byEmail = getUserByEmail(args.user);
    const byId = users.find((u) => String(u.id) === String(args.user));
    user = byEmail || byId || null;
    if (!user) {
      console.error(`User not found: ${args.user}`);
      process.exit(1);
    }
  }

  const gmail = await gmailClientForUser(user.id);
  const query = args.query || DEFAULT_QUERY;
  const ids = await listMessageIds(gmail, query, args.max);

  if (!args.json) {
    console.error(`# mailbox=${user.email} query=${JSON.stringify(query)} count=${ids.length}`);
  }

  for (const id of ids) {
    const { data } = await gmail.users.messages.get({
      userId: "me",
      id,
      format: "metadata",
      metadataHeaders: ["From", "Subject", "Date"],
    });
    const meta = metaFromPayload(data.payload || {});
    const row = {
      id,
      from: meta.from,
      subject: meta.subject,
      date: meta.date,
    };

    if (args.json) {
      console.log(JSON.stringify(row));
    } else {
      console.log(`${row.id}\t${row.from}\t${row.subject}`);
    }
  }
}

main().catch((err) => {
  console.error(err);
  process.exit(1);
});