/* =========================================================================
   pricing.js — fetch /api/pricing, render the rate table + cost estimator
   • populates the model dropdown for the calculator
   • recomputes credits on any input change
   • live filter on the rate table
   ========================================================================= */

(function () {
  'use strict';

  var API = '/api/pricing';
  var reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

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

  function fmtPrice(n) {
    if (n == null) return '—';
    if (n < 0.01) return '$' + n.toFixed(4);
    if (n < 1) return '$' + n.toFixed(3);
    return '$' + n.toFixed(2);
  }

  function fmtCredits(n) {
    return Number(n || 0).toLocaleString();
  }

  // strip the leading "free:" or "anthropic/" prefix for a friendlier display,
  // but keep the full id as a title tooltip
  function shortName(full) {
    var n = full.replace(/^free:/, '');
    var slash = n.indexOf('/');
    return slash >= 0 ? n.slice(slash + 1) : n;
  }

  function providerOf(full) {
    var n = full.replace(/^free:/, '');
    var slash = n.indexOf('/');
    return slash >= 0 ? n.slice(0, slash) : '';
  }

  var STATE = { models: [], rate: null };

  async function load() {
    var body = document.getElementById('rates-body');
    try {
      var res = await fetch(API);
      if (!res.ok) throw new Error('status ' + res.status);
      var data = await res.json();
      STATE.models = data.models || [];
      STATE.rate = data.rate || { credits_per_usd: 10000, input_ratio: 1 / 3 };
      renderTable(STATE.models);
      populateCalculator(STATE.models);
    } catch (e) {
      if (body) body.innerHTML = '<tr><td colspan="5" class="rates-empty">Couldn\u2019t load rates. Please try again.</td></tr>';
    }
  }

  function renderTable(models) {
    var body = document.getElementById('rates-body');
    if (!body) return;
    if (!models.length) {
      body.innerHTML = '<tr><td colspan="5" class="rates-empty">No models match your filter.</td></tr>';
      return;
    }
    var html = '';
    for (var i = 0; i < models.length; i++) {
      var m = models[i];
      var prov = providerOf(m.model);
      var badge = m.free ? '<span class="free-badge">free</span>' : '';
      html +=
        '<tr>' +
          '<td><span class="model-name" title="' + esc(m.model) + '">' + esc(shortName(m.model)) + '</span>' + badge +
            (prov ? '<div style="font-size:.7rem;color:var(--ink-soft,#6b5b7a);">' + esc(prov) + '</div>' : '') + '</td>' +
          '<td class="num">' + fmtPrice(m.usd_per_1m_input) + '</td>' +
          '<td class="num">' + fmtPrice(m.usd_per_1m_output) + '</td>' +
          '<td class="num">' + fmtCredits(m.credits_per_1k_output) + '</td>' +
          '<td class="num">' + fmtCredits(m.targets) + '</td>' +
        '</tr>';
    }
    body.innerHTML = html;
  }

  function populateCalculator(models) {
    var sel = document.getElementById('calc-model');
    if (!sel) return;
    // sort: non-free (claude) first, then by output price descending so premium surfaces
    var sorted = models.slice().sort(function (a, b) {
      if (a.free !== b.free) return a.free ? 1 : -1;
      return b.usd_per_1m_output - a.usd_per_1m_output;
    });
    var opts = '';
    for (var i = 0; i < sorted.length; i++) {
      opts += '<option value="' + esc(sorted[i].model) + '">' + esc(sorted[i].model) + '</option>';
    }
    sel.innerHTML = opts;
    recalc();
  }

  function lookup(name) {
    for (var i = 0; i < STATE.models.length; i++) {
      if (STATE.models[i].model === name) return STATE.models[i];
    }
    return null;
  }

  function recalc() {
    var sel = document.getElementById('calc-model');
    var inEl = document.getElementById('calc-in');
    var outEl = document.getElementById('calc-out');
    var credEl = document.getElementById('calc-result').querySelector('.cr-credits');
    var usdEl = document.getElementById('calc-usd');
    if (!sel || !inEl || !outEl || !credEl) return;

    var m = lookup(sel.value);
    var tokIn = Math.max(0, parseInt(inEl.value, 10) || 0);
    var tokOut = Math.max(0, parseInt(outEl.value, 10) || 0);
    if (!m) { credEl.textContent = '—'; usdEl.textContent = ''; return; }

    // input priced at 1/3 of output
    var inPrice = m.usd_per_1m_output * STATE.rate.input_ratio;
    var usd = (tokIn * inPrice + tokOut * m.usd_per_1m_output) / 1e6;
    var credits = Math.round(usd * (STATE.rate.credits_per_usd || 10000));
    if ((tokIn || tokOut) && credits < 1) credits = 1;
    if (!tokIn && !tokOut) credits = 0;

    credEl.textContent = fmtCredits(credits);
    usdEl.textContent = credits > 0 ? ('\u2248 $' + (credits / (STATE.rate.credits_per_usd || 10000)).toFixed(4) + ' USD') : '';
  }

  // wire up events once DOM is ready
  function init() {
    load();
    var sel = document.getElementById('calc-model');
    var inEl = document.getElementById('calc-in');
    var outEl = document.getElementById('calc-out');
    var search = document.getElementById('rate-search');
    if (sel) sel.addEventListener('change', recalc);
    if (inEl) inEl.addEventListener('input', recalc);
    if (outEl) outEl.addEventListener('input', recalc);
    if (search) search.addEventListener('input', function () {
      var q = search.value.trim().toLowerCase();
      if (!q) { renderTable(STATE.models); return; }
      renderTable(STATE.models.filter(function (m) {
        return m.model.toLowerCase().indexOf(q) >= 0;
      }));
    });
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', init);
  } else {
    init();
  }
})();