/* =========================================================================
   billing.js — the credits & wallet console
   • fetches /auth/me for billing state (enabled, balance, deposit, key)
   • renders the key-reveal banner on first signup (?new=1)
   • renders balance / deposit / key-prefix cards
   • polls /api/me/balance every 10s for a live feel
   • gracefully hides if billing isn't configured (unmetered mode)
   ========================================================================= */

(async function () {
  'use strict';

  var grid = document.getElementById('billing-grid');
  var section = document.getElementById('billing-section');
  if (!grid || !section) return; // not on the dashboard page

  var reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var pollTimer = null;
  var lastBalance = -1;

  /* ---- escape helpers --------------------------------------------------- */
  function esc(s) {
    return String(s).replace(/[&<>"']/g, function (c) {
      return { '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;' }[c];
    });
  }

  /* ---- inline SVG icons (no external dep, mobile-robust) ---------------- */
  var ICON = {
    wallet: '<svg class="bc-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M21 12V7H5a2 2 0 0 1 0-4h14v4"/><path d="M3 5v14a2 2 0 0 0 2 2h16v-5"/><path d="M18 12a2 2 0 0 0 0 4h4v-4Z"/></svg>',
    deposit: '<svg class="bc-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><rect x="2" y="5" width="20" height="14" rx="2"/><line x1="2" y1="10" x2="22" y2="10"/></svg>',
    key: '<svg class="bc-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M21 2l-2 2m-7.61 7.61a5.5 5.5 0 1 1-7.778 7.778 5.5 5.5 0 0 1 7.777-7.777zm0 0L15.5 7.5m0 0l3 3L22 7l-3-3"/></svg>' /* (kept for the reveal banner; key card moved to the hero) */,
    alert: '<svg class="bc-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z"/><line x1="12" y1="9" x2="12" y2="13"/><line x1="12" y1="17" x2="12.01" y2="17"/></svg>'
  };

  /* ---- copy-to-clipboard with feedback ---------------------------------- */
  function copyButton(text) {
    var btn = document.createElement('button');
    btn.type = 'button';
    btn.className = 'copy-btn';
    btn.textContent = 'Copy';
    btn.addEventListener('click', function () {
      navigator.clipboard.writeText(text).then(function () {
        btn.classList.add('copied');
        btn.textContent = 'Copied!';
        setTimeout(function () { btn.classList.remove('copied'); btn.textContent = 'Copy'; }, 1500);
      }).catch(function () {
        // fallback for non-secure contexts
        var ta = document.createElement('textarea');
        ta.value = text; document.body.appendChild(ta); ta.select();
        try { document.execCommand('copy'); btn.classList.add('copied'); btn.textContent = 'Copied!'; } catch (e) {}
        document.body.removeChild(ta);
        setTimeout(function () { btn.classList.remove('copied'); btn.textContent = 'Copy'; }, 1500);
      });
    });
    return btn;
  }

  /* ---- render the key-reveal banner (first signup only) --------------- */
  function renderKeyReveal(plaintextKey) {
    var banner = document.createElement('div');
    banner.className = 'key-reveal';
    banner.setAttribute('role', 'alert');
    banner.innerHTML =
      '<svg class="kr-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.6" stroke-linecap="round" stroke-linejoin="round" aria-hidden="true"><path d="M21 2l-2 2m-7.61 7.61a5.5 5.5 0 1 1-7.778 7.778 5.5 5.5 0 0 1 7.777-7.777zm0 0L15.5 7.5m0 0l3 3L22 7l-3-3"/></svg>' +
      '<div class="kr-body">' +
        '<h3>Your API key — welcome aboard</h3>' +
        '<p>Here&rsquo;s your key. It&rsquo;s <code>sk-</code> + your deposit address, so you can always find it again on the dashboard — no need to panic if you lose it. Use it as <code>Authorization: Bearer</code> for API calls outside the browser.</p>' +
        '<div class="kr-key">' +
          '<code>' + esc(plaintextKey) + '</code>' +
        '</div>' +
      '</div>' +
      '<button type="button" class="kr-dismiss" aria-label="Dismiss" title="Got it">\u00d7</button>';
    section.parentNode.insertBefore(banner, section); // insert before the grid section

    // copy button
    var keyWrap = banner.querySelector('.kr-key');
    keyWrap.appendChild(copyButton(plaintextKey));

    // dismiss → clear the one-time reveal server-side + remove the banner
    banner.querySelector('.kr-dismiss').addEventListener('click', function () {
      fetch('/auth/clear-reveal', { method: 'POST' }).catch(function () {});
      banner.remove();
    });
  }

  /* ---- render the billing cards (balance + deposit; key lives in the hero) */
  function renderCards(billing) {
    var bal = billing.balance || 0;
    var lowCls = bal === 0 ? 'is-zero' : (bal < 50 ? 'is-low' : '');
    var flash = (lastBalance >= 0 && lastBalance !== bal) ? ' flash' : '';
    lastBalance = bal;

    // balance card
    var balCard = document.createElement('div');
    balCard.className = 'bill-card ' + lowCls;
    balCard.innerHTML =
      ICON.wallet +
      '<span class="bc-label">credits</span>' +
      '<span class="bc-value' + flash + '">' + bal.toLocaleString() + '</span>' +
      '<span class="bc-sub">\u2248 $' + (bal / 10000).toFixed(4) + ' USD</span>';

    // deposit card (the wallet address you send ETH to)
    var depCard = document.createElement('div');
    depCard.className = 'bill-card';
    depCard.innerHTML =
      ICON.deposit +
      '<span class="bc-label">deposit (Base L2)</span>' +
      '<span class="bc-sub" style="margin-top:.2rem;"><code>' + esc(billing.deposit_address) + '</code></span>';
    var depCopy = copyButton(billing.deposit_address);
    depCopy.style.marginTop = '.4rem';
    depCard.appendChild(depCopy);

    grid.innerHTML = '';
    grid.appendChild(balCard);
    grid.appendChild(depCard);

    // trigger the flash animation
    if (flash && !reduceMotion) {
      var val = balCard.querySelector('.bc-value');
      void val.offsetWidth; // force reflow
      val.classList.add('flash');
    }
  }

  /* ---- render the "out of credits" state -------------------------------- */
  function renderEmpty() {
    grid.innerHTML =
      '<div class="bill-card is-zero" style="grid-column:1/-1;flex-direction:row;align-items:center;gap:1rem;">' +
        ICON.alert +
        '<div><div class="bc-value" style="font-size:1.1rem;">No credits remaining</div>' +
        '<div class="bc-sub" style="text-transform:none;letter-spacing:0;">Send ETH to your deposit address above to top up. Credits appear within 60 seconds.</div></div>' +
      '</div>';
  }

  /* ---- render the transaction history table (ledger) --------------- */
  function fmtTime(iso) {
    if (!iso) return '\u2014';
    try {
      var d = new Date(iso);
      return d.toLocaleString(undefined, { month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit' });
    } catch (e) { return iso; }
  }

  function renderLedger(entries) {
    var wrap = document.getElementById('ledger-wrap');
    var body = document.getElementById('ledger-body');
    var empty = document.getElementById('ledger-empty');
    if (!wrap || !body) return;
    if (!entries || !entries.length) {
      body.innerHTML = '';
      wrap.hidden = false;
      if (empty) empty.hidden = false;
      return;
    }
    if (empty) empty.hidden = true;
    // newest first
    var rows = entries.slice().reverse().slice(0, 50);
    var html = '';
    for (var i = 0; i < rows.length; i++) {
      var e = rows[i];
      var isDeposit = e.type === 'deposit';
      var cls = isDeposit ? 'is-deposit' : 'is-burn';
      var sign = isDeposit ? '+' : '\u2212';
      var detail;
      if (isDeposit) {
        detail = (typeof e.eth === 'number' ? e.eth.toFixed(6) : e.eth) + ' ETH' +
          (e.usd ? ' (\u2248 $' + e.usd + ')' : '');
      } else {
        detail = esc(e.model || 'model') + ' \u00b7 ' +
          (e.tok_in || 0) + ' in / ' + (e.tok_out || 0) + ' out';
      }
      html +=
        '<tr class="' + cls + '">' +
          '<td>' + esc(fmtTime(e.ts)) + '</td>' +
          '<td><span class="tag ' + cls + '">' + (isDeposit ? 'deposit' : 'usage') + '</span></td>' +
          '<td class="ledger-detail">' + detail + '</td>' +
          '<td class="num">' + sign + (e.credits || e.cost || 0).toLocaleString() + '</td>' +
        '</tr>';
    }
    body.innerHTML = html;
    wrap.hidden = false;
  }

  /* ---- poll balance every 10s (live feel without websockets) ------------ */
  async function pollBalance() {
    try {
      var r = await fetch('/api/me/balance');
      if (!r.ok) return;
      var d = await r.json();
      if (d.balance !== lastBalance) {
        renderCards({ balance: d.balance, deposit_address: grid._deposit || '' });
        if (d.balance === 0) renderEmpty();
      }
    } catch (e) { /* network blip — retry next cycle */ }
  }

  /* ---- bootstrap -------------------------------------------------------- */
  try {
    var res = await fetch('/auth/me');
    if (!res.ok) { section.hidden = true; return; }
    var me = await res.json();

    // billing not configured → hide the section (unmetered mode)
    if (!me.billing || !me.billing.enabled) {
      section.hidden = true;
      return;
    }

    // not provisioned yet (shouldn't happen post-callback, but be safe)
    if (!me.billing.provisioned) {
      section.hidden = true;
      return;
    }

    // reveal the key on first signup
    if (me.reveal_key) {
      renderKeyReveal(me.reveal_key);
    }

    // stash deposit + prefix for the poller
    grid._deposit = me.billing.deposit_address;
    grid._prefix = me.billing.key_prefix;

    // render + show
    renderCards(me.billing);
    if (me.billing.balance === 0) renderEmpty();

    // transaction history
    renderLedger((me.billing.ledger && me.billing.ledger.entries) || []);

    section.hidden = false;

    // start polling
    pollTimer = setInterval(pollBalance, 10000);
  } catch (e) {
    section.hidden = true; // network error — hide gracefully
  }

  // stop polling when the page unloads
  window.addEventListener('beforeunload', function () {
    if (pollTimer) clearInterval(pollTimer);
  });
})();