// PAREIDOLIA — the séance.
//
// Latency theater for the awakening call (ARCHITECTURE.md §2): the moment the
// photo is taken, it dims to candlelight, mist drifts across it, a scanning
// shimmer passes, and whispered captions keep the visitor leaning in for the
// 45–60 seconds a cold ZeroGPU awakening can take. Nothing here spins; nothing
// here says "loading".
//
// Contract:
//   runSeance(containerEl, imgUrl) -> { resolve(record), fail(message) }
//
//   resolve(record)  cross-fades the candlelight away and hands the photo to
//                    the LIFE engine; returns a Promise of the overlay handle.
//   fail(message)    disperses the mist, shows the message in serif, and
//                    dispatches a bubbling 'seance:failed' CustomEvent on
//                    containerEl so the shell can offer "try again".
//   busy(message)    a DISTINCT, retryable state for a transient ZeroGPU
//                    quota/429 wall (the backend is healthy; this visitor is
//                    just out of free GPU seconds). Mist settles like fail()
//                    but it dispatches 'seance:busy' so the shell renders an
//                    honest 'try again / sign in' panel, NOT the generic veil.
//
// No imports from main.js / capture.js. Vanilla ES module, CSS injected once.

import { createOverlay } from "./overlay.js";

const WHISPERS = [
  "holding it to the light…",
  "there is something here…",
  "it has seen things…",
  "listening for a pulse…",
  "naming what it sees…",
  "do not startle it…",
];

const STYLE_ID = "pd-seance-style";

const CSS = `
.pd-seance {
  position: absolute; inset: 0; overflow: hidden;
  background: #0b0a09;
  font-family: "Iowan Old Style", "Palatino", Georgia, serif;
}
.pd-seance__photo {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: contain; display: block;
  filter: brightness(0.42) saturate(0.72) sepia(0.18);
  transition: filter 1.8s ease;
}
.pd-seance.is-resolving .pd-seance__photo {
  filter: brightness(0.97) saturate(0.97) sepia(0.04);
}
.pd-seance.is-failed .pd-seance__photo {
  filter: brightness(0.2) saturate(0.45) sepia(0.25);
}
/* busy is NOT a break — the photo waits, dimmed-but-warm, ready to try again */
.pd-seance.is-busy .pd-seance__photo {
  filter: brightness(0.32) saturate(0.7) sepia(0.2);
}
.pd-seance__candle {
  position: absolute; inset: 0; pointer-events: none;
  background:
    linear-gradient(to bottom, transparent 72%, rgba(7,5,3,0.66) 96%),
    radial-gradient(42% 34% at 50% 42%, rgba(244,194,108,0.16), transparent 70%),
    radial-gradient(85% 72% at 50% 46%, rgba(232,168,73,0.22), transparent 64%),
    radial-gradient(130% 110% at 50% 50%, transparent 46%, rgba(7,5,3,0.82) 100%);
  animation: pd-candle 5.6s ease-in-out infinite;
  transition: opacity 1.8s ease;
}
.pd-seance.is-resolving .pd-seance__candle,
.pd-seance.is-busy .pd-seance__candle { opacity: 0.35; animation: none; }
@keyframes pd-candle {
  0%, 100% { opacity: 1; }
  43% { opacity: 0.82; }
  58% { opacity: 0.94; }
  71% { opacity: 0.86; }
}
.pd-seance__mist {
  position: absolute; width: 75%; height: 60%; pointer-events: none;
  border-radius: 50%;
  background: radial-gradient(closest-side, rgba(239,230,212,0.19), rgba(232,168,73,0.08) 58%, transparent 75%);
  filter: blur(26px);
  mix-blend-mode: screen;
  transition: opacity 1.5s ease, transform 1.5s ease;
}
.pd-seance__mist.pd-m1 { top: -8%; left: -12%; animation: pd-drift1 13s ease-in-out infinite alternate; }
.pd-seance__mist.pd-m2 { top: 34%; right: -18%; animation: pd-drift2 17s ease-in-out infinite alternate; }
.pd-seance__mist.pd-m3 { bottom: -14%; left: 8%; width: 85%; animation: pd-drift3 11s ease-in-out infinite alternate; }
@keyframes pd-drift1 { from { transform: translate(0,0) scale(1); } to { transform: translate(9%, 6%) scale(1.18); } }
@keyframes pd-drift2 { from { transform: translate(0,0) scale(1.1); } to { transform: translate(-11%, -5%) scale(0.92); } }
@keyframes pd-drift3 { from { transform: translate(0,0) scale(1.05); } to { transform: translate(7%, -8%) scale(1.22); } }
.pd-seance.is-resolving .pd-seance__mist,
.pd-seance.is-failed .pd-seance__mist,
.pd-seance.is-busy .pd-seance__mist {
  opacity: 0 !important; transform: scale(1.9) !important; animation: none;
}
.pd-seance__shimmer {
  position: absolute; left: 0; right: 0; top: 0; height: 20%;
  pointer-events: none; mix-blend-mode: screen;
  background: linear-gradient(to bottom,
    transparent, rgba(232,168,73,0.1) 42%, rgba(239,230,212,0.16) 50%,
    rgba(232,168,73,0.1) 58%, transparent);
  filter: blur(5px);
  animation: pd-scan 6.8s cubic-bezier(0.45, 0.05, 0.55, 0.95) infinite;
  transition: opacity 1s ease;
}
@keyframes pd-scan {
  0% { transform: translateY(-110%); }
  62% { transform: translateY(520%); }
  100% { transform: translateY(520%); }
}
.pd-seance.is-resolving .pd-seance__shimmer,
.pd-seance.is-failed .pd-seance__shimmer,
.pd-seance.is-busy .pd-seance__shimmer { opacity: 0; animation-play-state: paused; }
.pd-seance__grain {
  position: absolute; inset: -55%; pointer-events: none; opacity: 0.055;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2'/%3E%3C/filter%3E%3Crect width='240' height='240' filter='url(%23n)' opacity='0.9'/%3E%3C/svg%3E");
  animation: pd-grain 1.7s steps(4) infinite;
}
@keyframes pd-grain {
  0% { transform: translate(0,0); } 25% { transform: translate(-2%,1.5%); }
  50% { transform: translate(1.7%,-1%); } 75% { transform: translate(-1%,-1.9%); }
  100% { transform: translate(0,0); }
}
.pd-seance__caption {
  position: absolute; left: 8%; right: 8%; bottom: 7%;
  text-align: center; pointer-events: none;
  color: rgba(239,230,212,0.86);
  font-style: italic; font-size: clamp(16px, 2.6vmin, 21px);
  letter-spacing: 0.05em; text-transform: lowercase;
  text-shadow: 0 1px 14px rgba(0,0,0,0.9), 0 0 30px rgba(232,168,73,0.18);
  opacity: 0; transition: opacity 0.7s ease;
}
.pd-seance__caption.is-shown { opacity: 1; }
.pd-seance__fail {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: 14px;
  padding: 8%; text-align: center; pointer-events: none;
  opacity: 0; transition: opacity 1.1s ease 0.5s;
}
.pd-seance.is-failed .pd-seance__fail { opacity: 1; }
.pd-seance__fail-msg {
  color: #efe6d4; font-style: italic;
  font-size: clamp(17px, 3.2vmin, 26px); letter-spacing: 0.04em;
  text-shadow: 0 1px 16px rgba(0,0,0,0.95);
}
.pd-seance__fail-hint {
  color: rgba(232,168,73,0.75); font-size: clamp(12px, 1.9vmin, 15px);
  letter-spacing: 0.14em; text-transform: lowercase;
}
`;

function injectStyle() {
  if (document.getElementById(STYLE_ID)) return;
  const s = document.createElement("style");
  s.id = STYLE_ID;
  s.textContent = CSS;
  document.head.appendChild(s);
}

function div(cls) {
  const d = document.createElement("div");
  d.className = cls;
  return d;
}

/**
 * One whisper built from the record's own named features — the medium says
 * what it found ("two bonnet bolts… symmetric…") right before the eyes open.
 * Falls back to a generic line when the record keeps its features to itself.
 */
function featureWhisper(record) {
  const feats = record?.candidate_features || record?.features || [];
  const eyeNames = feats
    .filter((f) => (f.role || "").startsWith("eye") && f.name)
    .map((f) => String(f.name).toLowerCase().replace(/^(left|right|upper|lower)\s+/, "").trim());
  if (eyeNames.length >= 2 && eyeNames[0] && eyeNames[0] === eyeNames[1]) {
    const plural = /s$/.test(eyeNames[0]) ? eyeNames[0] : eyeNames[0] + "s";
    return `two ${plural}… symmetric…`;
  }
  if (eyeNames.length >= 2) return `${eyeNames[0]}… and ${eyeNames[1]}… level…`;
  if (eyeNames.length === 1) return `${eyeNames[0]}… watching…`;
  return "something looked back…";
}

/** How long resolve() holds its record-whisper before the eye handoff. The
 *  shell reads this off the export to stage its own cross-fade around it. */
const WHISPER_BEAT_MS = 2100;

/**
 * Begin the séance over a freshly captured photo.
 *
 * @param {HTMLElement} containerEl positioned element the séance fills
 * @param {string} imgUrl the captured photo (object URL / data URL / path)
 * @param {object} [extra] non-contractual: `{ overlayOpts }` forwarded to
 *   createOverlay on resolve (the dev harness uses this for deterministic shots)
 * @returns {{resolve: (record: object) => Promise<object>, fail: (message: string) => void}}
 */
export function runSeance(containerEl, imgUrl, extra = {}) {
  injectStyle();
  if (getComputedStyle(containerEl).position === "static") {
    containerEl.style.position = "relative";
  }

  const wrap = div("pd-seance");
  const img = document.createElement("img");
  img.className = "pd-seance__photo";
  img.alt = "";
  img.decoding = "async";
  img.src = imgUrl;
  wrap.appendChild(img);
  wrap.appendChild(div("pd-seance__candle"));
  wrap.appendChild(div("pd-seance__mist pd-m1"));
  wrap.appendChild(div("pd-seance__mist pd-m2"));
  wrap.appendChild(div("pd-seance__mist pd-m3"));
  wrap.appendChild(div("pd-seance__shimmer"));
  wrap.appendChild(div("pd-seance__grain"));
  const caption = div("pd-seance__caption");
  wrap.appendChild(caption);
  const failBox = div("pd-seance__fail");
  const failMsg = div("pd-seance__fail-msg");
  const failHint = div("pd-seance__fail-hint");
  failHint.textContent = "let the mist settle, then try again";
  failBox.appendChild(failMsg);
  failBox.appendChild(failHint);
  wrap.appendChild(failBox);
  containerEl.appendChild(wrap);

  // ---- whispered captions: fade in, hold, fade out, ~4.2s cadence, loop ----
  let settled = false;     // resolve()/fail() called
  let whisperIdx = 0;
  let timer = 0;
  function whisperCycle() {
    if (settled) return;
    caption.textContent = WHISPERS[whisperIdx % WHISPERS.length];
    whisperIdx++;
    caption.classList.add("is-shown");
    timer = setTimeout(() => {
      caption.classList.remove("is-shown");
      timer = setTimeout(whisperCycle, 1050); // fade-out + breath
    }, 3150);
  }
  timer = setTimeout(whisperCycle, 800);

  function settle() {
    if (settled) return false;
    settled = true;
    clearTimeout(timer);
    caption.classList.remove("is-shown");
    return true;
  }

  /**
   * The spirits answered. First beat: ONE whisper derived from the record's
   * own named features (the medium says what it found). Then the candlelight
   * lifts, mist disperses, and the LIFE engine takes over with its emergence
   * — the cross-fade IS the reveal.
   * @param {object} record the awakening record
   * @returns {Promise<object>} the overlay handle from createOverlay
   */
  function resolve(record) {
    if (!settle()) return Promise.resolve(null);
    // the record-whisper beat — still under candlelight, before the eyes
    caption.textContent = featureWhisper(record);
    caption.classList.add("is-shown");
    const overlayOpts = extra.overlayOpts || {};
    return new Promise((done) => {
      setTimeout(() => {
        caption.classList.remove("is-shown");
        wrap.classList.add("is-resolving");
        const begin = () => {
          // let the light lift for a beat before the eyes condense
          setTimeout(() => {
            const overlay = createOverlay(wrap, record, img, { emerge: true, ...overlayOpts });
            containerEl.dispatchEvent(new CustomEvent("seance:resolved", {
              detail: { record, overlay }, bubbles: true, composed: true,
            }));
            done(overlay);
          }, 900);
        };
        if (img.complete && img.naturalWidth) begin();
        else img.decode().then(begin, begin);
      }, WHISPER_BEAT_MS - 300); // the caption's 0.7s fade overlaps the lift
    });
  }

  /**
   * The spirits declined (refusal, timeout, quota). Disperse the mist, speak
   * the message gently, and tell the shell so it can offer another attempt.
   * @param {string} message poetic, user-facing; never a stack trace
   */
  function fail(message) {
    if (!settle()) return;
    failMsg.textContent = message || "the spirits decline.";
    wrap.classList.add("is-failed");
    containerEl.dispatchEvent(new CustomEvent("seance:failed", {
      detail: { message: failMsg.textContent }, bubbles: true, composed: true,
    }));
  }

  /**
   * The spirits are OVERWHELMED, not absent — a transient ZeroGPU quota/429
   * wall. Settle the mist (like fail) but keep the photo warm-dimmed and tell
   * the shell to offer an honest, retryable 'try again / sign in' panel rather
   * than the generic veil. The reason is the server's own busy line.
   * @param {string} message poetic, user-facing; never a stack trace
   */
  function busy(message) {
    if (!settle()) return;
    wrap.classList.add("is-busy");
    containerEl.dispatchEvent(new CustomEvent("seance:busy", {
      detail: { message: message || "" }, bubbles: true, composed: true,
    }));
  }

  /** Non-contractual cleanup for the shell (removes the séance DOM). */
  function destroy() {
    settle();
    wrap.remove();
  }

  return { resolve, fail, busy, destroy, element: wrap };
}

// the shell stages its cross-fade around the record-whisper beat
runSeance.WHISPER_BEAT_MS = WHISPER_BEAT_MS;