// Site-side member records for InstantAdPay.
// The chain is the source of truth for money, credits, and qualification;
// this module holds only what the chain doesn't: free members who haven't
// touched the chain yet, sponsor attribution before first purchase (spec §4),
// display handles, and join stats. Wiping this file = the clean reset between
// the Amoy dress rehearsal and mainnet launch.
const fs = require('fs');
const path = require('path');

let DATA_DIR = null;
const FILE = () => path.join(DATA_DIR, 'accounts.json');
let db = { v: 1, byAddress: {}, joins: 0 };

function load() {
  try { db = JSON.parse(fs.readFileSync(FILE(), 'utf8')); } catch (e) {}
  if (!db || db.v !== 1) db = { v: 1, byAddress: {}, joins: 0 };
}
function save() {
  try {
    const tmp = FILE() + '.tmp';
    fs.writeFileSync(tmp, JSON.stringify(db));
    fs.renameSync(tmp, FILE());
  } catch (e) { console.error('accounts save failed', e.message); }
}
function init(opts) { DATA_DIR = opts.dataDir; load(); }

function get(address) { return db.byAddress[(address || '').toLowerCase()] || null; }
function upsert(address, fields) {
  const a = (address || '').toLowerCase();
  if (!/^0x[0-9a-f]{40}$/.test(a)) return null;
  const cur = db.byAddress[a] || { created: Date.now() };
  db.byAddress[a] = Object.assign(cur, fields || {});
  save();
  return db.byAddress[a];
}
// Sponsor attribution: first touch wins, written on-chain at the member's
// first purchase/activation and permanent from then on.
function attributeSponsor(address, sponsorId) {
  const a = (address || '').toLowerCase();
  const cur = get(a);
  if (cur && cur.sponsorId) return cur.sponsorId; // first touch already set
  const id = Number(sponsorId) || 0;
  upsert(a, { sponsorId: id });
  db.joins += 1; save();
  return id;
}
function count() { return Object.keys(db.byAddress).length; }

module.exports = { init, get, upsert, attributeSponsor, count };