// The stub DOM the page's script is loaded against, shared by page-smoke.js and
// native-bridge.js. It is deliberately thin: enough for every handler the script wires at load
// to find what it reaches for, and no more.
//
// `media` swaps the bare `#audio` proxy for something with the parts of HTMLMediaElement that
// matter -- a prototype carrying the real accessors, and events that actually dispatch -- because
// native.ts replaces that surface on the element and a proxy that answers everything would prove
// nothing about whether it worked.
const vm = require('vm');

function makeContext(html, script, { media = false } = {}) {
  // Ids in the page, and in the markup the script builds for its dialogs.
  const ids = new Set([...(html + script).matchAll(/\bid=(?:"([^"]+)"|([^\s>"']+))/g)].map(m => m[1] || m[2]));
  const missing = [];

  const el = (name) => new Proxy({ style: { setProperty(){}, getPropertyValue(){ return ''; } }, dataset: {}, classList: { add(){}, remove(){}, toggle(){}, contains(){ return false; } },
    value: '', textContent: '', innerHTML: '', hidden: false, children: [], firstElementChild: null,
    appendChild(){}, removeChild(){}, remove(){}, insertAdjacentHTML(){}, addEventListener(){},
    setAttribute(){}, getAttribute(){ return null; }, select(){}, setSelectionRange(){}, focus(){},
    replaceWith(){}, querySelector(){ return el('nested'); }, querySelectorAll(){ return []; },
    play(){ return Promise.resolve(); }, pause(){}, closest(){ return null; } },
    { get: (t, k) => k in t ? t[k] : undefined, set: (t, k, v) => (t[k] = v, true) });

  const body = el('body');
  const audio = media ? makeMediaElement() : null;
  if (media) {
    // native.ts reads has-video off the body to decide whether the host takes the file, so this
    // one has to be a real set rather than something that always says no.
    const classes = new Set();
    body.classList = {
      add: c => classes.add(c), remove: c => classes.delete(c),
      toggle: (c, on) => (on === undefined ? (classes.has(c) ? classes.delete(c) : classes.add(c)) : on ? classes.add(c) : classes.delete(c)),
      contains: c => classes.has(c),
    };
  }

  const document = {
    querySelector(sel) {
      if (sel === '#audio' && audio) return audio;
      if (sel.startsWith('#') && !ids.has(sel.slice(1))) { missing.push(sel); return null; }
      return el(sel);
    },
    querySelectorAll: () => [],
    createElement: () => el('created'),
    addEventListener(){}, body,
    documentElement: { dataset: {} },
  };

  const ctx = {
    document, console,
    window: { isSecureContext: false, addEventListener(){} },
    localStorage: { getItem: () => null, setItem(){}, removeItem(){} },
    navigator: { clipboard: undefined, sendBeacon(){}, mediaSession: undefined },
    fetch: (url) => Promise.resolve({
      ok: true, status: 200, text: () => Promise.resolve(''),
      json: () => Promise.resolve(
        String(url).includes('/api/settings')
          ? { schedule: 'every 60m', every_mins: 60, download_dir: '/tmp', max_total_gb: 0, max_age_days: 0 }
          : String(url).includes('/api/users')
            ? [{ id: 1, name: 'admin', admin: true, password: true }, { id: 2, name: 'sam', admin: false, password: false }]
            : /\/api\/(popular|directory)/.test(String(url))
              ? [{ id: 'f', title: 'A Feed', image: null, subscribers: 2, subscribed: true },
                 { id: 'g', title: null, image: null, subscribers: 1, subscribed: false }]
              : /entries/.test(String(url)) ? { total: 0, entries: [] } : []),
    }),
    EventSource: function () { this.close = () => {}; },
    MediaMetadata: function () {},
    Blob: function () {},
    setTimeout, clearTimeout, setInterval, clearInterval,
    confirm: () => false, prompt: () => null, alert(){},
    Date, Math, JSON, Object, Array, String, Number, Promise, Error, FormData: function(){},
    URLSearchParams, encodeURIComponent, decodeURIComponent, parseInt, parseFloat, isNaN,
  };
  if (media) {
    ctx.HTMLMediaElement = MediaElement;
    ctx.Event = Event;
    ctx.isFinite = isFinite;
    ctx.CSS = { escape: s => String(s) };
  }
  ctx.globalThis = ctx;
  ctx.window.location = { href: '', hash: '' };
  ctx.location = ctx.window.location;

  return { ctx, missing, audio, body, ids };
}

/* ---- just enough HTMLMediaElement for the shim to be worth testing ---- */

function Event(type) { this.type = type; }

function MediaElement() {
  this._src = ''; this._t = 0; this._dur = NaN; this._paused = true;
  this._ready = 0; this._vol = 1; this._rate = 1;
  this._listeners = {};
  this.dataset = {}; this.classList = { add(){}, remove(){}, toggle(){}, contains(){ return false; } };
  // Every call that reached the real element, so a test can say the host took over rather than
  // the element quietly playing as well.
  this.calls = [];
}
MediaElement.prototype.play = function(){ this.calls.push('play'); this._paused = false; return Promise.resolve(); };
MediaElement.prototype.pause = function(){ this.calls.push('pause'); this._paused = true; };
MediaElement.prototype.load = function(){ this.calls.push('load'); };
MediaElement.prototype.addEventListener = function(name, fn, opts){
  (this._listeners[name] || (this._listeners[name] = [])).push({ fn, once: !!(opts && opts.once) });
};
MediaElement.prototype.dispatchEvent = function(ev){
  for (const l of (this._listeners[ev.type] || []).slice()) {
    if (l.once) this._listeners[ev.type] = this._listeners[ev.type].filter(x => x !== l);
    l.fn(ev);
  }
  return true;
};
MediaElement.prototype.removeAttribute = function(name){ this.calls.push('removeAttribute:' + name); if (name === 'src') this._src = ''; };
MediaElement.prototype.setAttribute = function(){};
MediaElement.prototype.getAttribute = function(){ return null; };
const accessor = (k, field, log) => Object.defineProperty(MediaElement.prototype, k, {
  configurable: true,
  get(){ return this[field]; },
  set(v){ if (log) this.calls.push(k + ':' + v); this[field] = v; },
});
accessor('src', '_src', true);
accessor('currentTime', '_t', true);
accessor('volume', '_vol');
accessor('playbackRate', '_rate');
Object.defineProperty(MediaElement.prototype, 'duration', { configurable: true, get(){ return this._dur; } });
Object.defineProperty(MediaElement.prototype, 'paused', { configurable: true, get(){ return this._paused; } });
Object.defineProperty(MediaElement.prototype, 'readyState', { configurable: true, get(){ return this._ready; } });

function makeMediaElement(){ return new MediaElement(); }

module.exports = { makeContext, vm };