import streamlit.components.v1 as components

# Sicherheitsnetz-Timer (ms): das Ausblenden geschieht primaer ueber das 'ended'-Event des
# Videos (exakt am Ende). Dieser Timer greift nur, falls 'ended' mal nicht feuert
# (z. B. Autoplay blockiert). Grosszuegig ueber der Videolaenge (~15,8 s) waehlen.
INTRO_FALLBACK_MS = 20000
# Statische URL (Streamlit Static Serving). Beim Live-Test ggf. auf "./static/intro.mp4"
# oder "/static/intro.mp4" korrigieren, falls "app/static/..." 404 liefert.
_INTRO_SRC = "app/static/intro.mp4"
_SEEN_KEY = "einrechnung_intro_seen"


def render_intro_overlay(fallback_ms: int = INTRO_FALLBACK_MS,
                         intro_src: str = _INTRO_SRC,
                         seen_key: str = _SEEN_KEY) -> None:
    """Injiziert ein einmaliges Intro-Overlay (MP4) in die Streamlit-Elternseite (Ansatz A).

    Ein unsichtbarer components.html-Baustein (Hoehe 0) fuehrt JS aus, das ein
    position:fixed-Overlay in window.parent.document einfuegt - ein echtes Overlay ueber der
    Seite. Die Animation ist ein <video> (autoplay, muted, ohne Steuerleiste, ohne Loop):
    Ausblenden exakt am Ende via 'ended'-Event (Timer nur als Sicherheitsnetz). Autoplay nur
    einmal pro Browser (localStorage), "Ueberspringen"-Button + Replay-Button oben rechts
    (Replay aendert den "gesehen"-Merker nicht).
    """
    html = f"""
<script>
(function() {{
  var doc = window.parent.document;
  if (window.parent.__introInstalled) return;   // Rerun-Schutz: nur einmal pro Seitenladen
  window.parent.__introInstalled = true;

  var FALLBACK = {fallback_ms};
  var SRC = {intro_src!r};
  var SEEN_KEY = {seen_key!r};

  var style = doc.createElement('style');
  style.textContent = `
    #eir-backdrop {{
      position: fixed; inset: 0; z-index: 2147483646;
      display: flex; align-items: center; justify-content: center;
      background: rgba(8,8,10,0.82); -webkit-backdrop-filter: blur(2px); backdrop-filter: blur(2px);
      opacity: 0; transition: opacity .45s ease; pointer-events: none;
    }}
    #eir-backdrop.eir-show {{ opacity: 1; pointer-events: auto; }}
    #eir-panel {{
      position: relative; width: min(50vw, 1100px); aspect-ratio: 16 / 9;
      max-width: 94vw; max-height: 88vh;
      background: #0a0a0a; border-radius: 16px; overflow: hidden;
      box-shadow: 0 24px 80px rgba(0,0,0,0.6), 0 0 0 1px rgba(245,126,26,0.25);
    }}
    @media (max-width: 820px) {{ #eir-panel {{ width: 92vw; }} }}
    #eir-video {{ width: 100%; height: 100%; display: block; object-fit: contain; background: #0a0a0a; }}
    #eir-skip {{
      position: absolute; top: 10px; right: 12px; z-index: 2;
      font: 600 13px/1 -apple-system, BlinkMacSystemFont, sans-serif;
      color: #eee; background: rgba(0,0,0,0.45); border: 1px solid rgba(255,255,255,0.18);
      padding: 7px 12px; border-radius: 999px; cursor: pointer; user-select: none;
    }}
    #eir-skip:hover {{ background: rgba(0,0,0,0.7); }}
    #eir-replay {{
      position: fixed; top: 12px; right: 72px; z-index: 2147483647;
      width: 40px; height: 40px; border-radius: 50%;
      display: flex; align-items: center; justify-content: center; cursor: pointer;
      background: #17171a; border: 1px solid rgba(245,126,26,0.55);
      box-shadow: 0 2px 10px rgba(0,0,0,0.35);
    }}
    #eir-replay:hover {{ background: #202024; }}
    #eir-replay svg {{ width: 16px; height: 16px; }}
  `;
  doc.head.appendChild(style);

  var replay = doc.createElement('div');
  replay.id = 'eir-replay';
  replay.title = 'Intro erneut abspielen';
  replay.innerHTML = '<svg viewBox="0 0 24 24" fill="#F57E1A"><path d="M8 5v14l11-7z"/></svg>';
  doc.body.appendChild(replay);

  // Den ▶-Button links NEBEN Streamlits Menue-Leiste (oben rechts) platzieren, statt darueber.
  // Die Toolbar (Deploy + ⋮-Menue) rendert asynchron -> mehrfach nachjustieren + bei Resize.
  function positionReplay() {{
    var win = window.parent, gap = 12, fallback = 72;
    var tb = doc.querySelector('[data-testid="stToolbar"]');
    var rightPx = fallback;
    if (tb) {{
      var cluster = win.innerWidth - tb.getBoundingClientRect().left;   // Breite des Menue-Clusters
      if (cluster > 8 && cluster < win.innerWidth * 0.6) rightPx = Math.round(cluster) + gap;
    }}
    replay.style.right = rightPx + 'px';
  }}
  positionReplay();
  [150, 500, 1200].forEach(function(t) {{ setTimeout(positionReplay, t); }});
  window.parent.addEventListener('resize', positionReplay);

  var backdrop = doc.createElement('div');
  backdrop.id = 'eir-backdrop';
  backdrop.innerHTML =
    '<div id="eir-panel">' +
      '<div id="eir-skip">Überspringen ✕</div>' +
      '<video id="eir-video" muted playsinline preload="none" src="' + SRC + '"></video>' +
    '</div>';
  doc.body.appendChild(backdrop);

  var video = doc.getElementById('eir-video');
  var skip = doc.getElementById('eir-skip');
  var hideTimer = null;

  function hide() {{
    clearTimeout(hideTimer);
    backdrop.classList.remove('eir-show');
    setTimeout(function() {{ try {{ video.pause(); }} catch (e) {{}} }}, 500);
  }}

  function show() {{
    backdrop.classList.add('eir-show');
    try {{ video.currentTime = 0; }} catch (e) {{}}   // Neustart von vorn (auch bei Replay)
    var p = video.play();
    if (p && p.catch) p.catch(function() {{}});        // Autoplay-Ablehnung ignorieren
    clearTimeout(hideTimer);
    hideTimer = setTimeout(hide, FALLBACK);            // Sicherheitsnetz, falls 'ended' ausbleibt
  }}

  video.addEventListener('ended', hide);               // exaktes Ausblenden am Videoende
  skip.addEventListener('click', hide);
  backdrop.addEventListener('click', function(e) {{ if (e.target === backdrop) hide(); }});
  replay.addEventListener('click', show);

  var seen;
  try {{ seen = window.parent.localStorage.getItem(SEEN_KEY); }} catch (e) {{ seen = null; }}
  if (seen !== '1') {{
    try {{ window.parent.localStorage.setItem(SEEN_KEY, '1'); }} catch (e) {{}}
    show();
  }}
}})();
</script>
"""
    components.html(html, height=0)