// Sponsor → downline messages: team comms delivered to members' on-site inbox
// (and by email). Distinct from solo ADS (which are paid and earn credits).
// Dual-mode: MySQL when DATABASE_URL is set, else a JSON file in the volume.
const fs = require('fs');
const path = require('path');
const db = require('./db');

let DATA_DIR = null;
const J = {
  db: null,
  FILE: () => path.join(DATA_DIR, 'sponsor-messages.json'),
  load() { try { this.db = JSON.parse(fs.readFileSync(this.FILE(), 'utf8')); } catch (e) { this.db = { nextId: 1, items: [] }; } },
  save() { try { fs.writeFileSync(this.FILE(), JSON.stringify(this.db)); } catch (e) {} }
};
function init(opts) { DATA_DIR = opts.dataDir; }
const DAY = 86400000;

// has this sponsor already broadcast within the last 24h? (1/day cap)
async function lastBroadcastAt(fromEmail) {
  const e = String(fromEmail || '').toLowerCase();
  if (db.enabled()) {
    const r = await db.q('SELECT MAX(sent) m FROM sponsor_messages WHERE from_email=?', [e]);
    return r.length && r[0].m ? Number(r[0].m) : 0;
  }
  if (!J.db) J.load();
  const mine = J.db.items.filter(i => i.fromEmail === e).map(i => i.sent);
  return mine.length ? Math.max(...mine) : 0;
}
// deliver one message to many recipients (already-resolved emails). Returns count.
async function deliver(fromMember, fromEmail, recipients, subject, body) {
  const now = Date.now();
  let n = 0;
  if (db.enabled()) {
    for (const to of recipients) {
      await db.q('INSERT INTO sponsor_messages (from_member,from_email,to_email,subject,body,sent) VALUES (?,?,?,?,?,?)',
        [fromMember || 0, fromEmail, to, subject, body, now]);
      n++;
    }
  } else {
    if (!J.db) J.load();
    for (const to of recipients) {
      J.db.items.push({ id: J.db.nextId++, fromMember: fromMember || 0, fromEmail, toEmail: to, subject, body, sent: now, readTs: 0 });
      n++;
    }
    J.save();
  }
  return n;
}
async function inbox(email) {
  const e = String(email || '').toLowerCase();
  if (db.enabled()) {
    const rows = await db.q(`SELECT id, from_member, subject, body, sent, read_ts FROM sponsor_messages
      WHERE to_email=? ORDER BY sent DESC LIMIT 100`, [e]);
    return rows.map(r => ({ id: r.id, fromMember: r.from_member, subject: r.subject, body: r.body,
      sent: Number(r.sent), read: !!r.read_ts }));
  }
  if (!J.db) J.load();
  return J.db.items.filter(i => i.toEmail === e).sort((a, b) => b.sent - a.sent).slice(0, 100)
    .map(i => ({ id: i.id, fromMember: i.fromMember, subject: i.subject, body: i.body, sent: i.sent, read: !!i.readTs }));
}
async function unreadCount(email) {
  const e = String(email || '').toLowerCase();
  if (db.enabled()) {
    const r = await db.q('SELECT COUNT(*) n FROM sponsor_messages WHERE to_email=? AND read_ts IS NULL', [e]);
    return r[0].n;
  }
  if (!J.db) J.load();
  return J.db.items.filter(i => i.toEmail === e && !i.readTs).length;
}
// the newest unread message (for the login modal)
async function newestUnread(email) {
  const e = String(email || '').toLowerCase();
  if (db.enabled()) {
    const rows = await db.q(`SELECT id, from_member, subject, body, sent FROM sponsor_messages
      WHERE to_email=? AND read_ts IS NULL ORDER BY sent DESC LIMIT 1`, [e]);
    if (!rows.length) return null;
    const r = rows[0];
    return { id: r.id, fromMember: r.from_member, subject: r.subject, body: r.body, sent: Number(r.sent) };
  }
  if (!J.db) J.load();
  const u = J.db.items.filter(i => i.toEmail === e && !i.readTs).sort((a, b) => b.sent - a.sent)[0];
  return u ? { id: u.id, fromMember: u.fromMember, subject: u.subject, body: u.body, sent: u.sent } : null;
}
async function markRead(email, id) {
  const e = String(email || '').toLowerCase();
  if (db.enabled()) {
    await db.q('UPDATE sponsor_messages SET read_ts=? WHERE id=? AND to_email=? AND read_ts IS NULL', [Date.now(), Number(id), e]);
    return { ok: true };
  }
  if (!J.db) J.load();
  const i = J.db.items.find(x => x.id === Number(id) && x.toEmail === e);
  if (i && !i.readTs) { i.readTs = Date.now(); J.save(); }
  return { ok: true };
}

module.exports = { init, lastBroadcastAt, deliver, inbox, unreadCount, newestUnread, markRead };