/**
 * AI Video Generation Benchmark — a static "display" space.
 *
 * Fetches the canonical benchmark JSON from mesmer.tools once at load and renders
 * a leaderboard + per-prompt video gallery. No input form, no per-visitor API
 * calls — the data is regenerated whenever the main site redeploys, so this page
 * stays current on its own.
 */

import { mountChrome, el } from "./shared/ui.js";
import { fetchData } from "./shared/api-client.js";
import { DATA, ENDPOINTS, siteUrl } from "./shared/config.js";

const FULL_BENCHMARK_URL = siteUrl(ENDPOINTS.benchmark.fullToolPath); // mesmer.tools/benchmarks/ai-video-generation

/* --- Formatting helpers --------------------------------------------------- */

function fmtSeconds(ms) {
  return ms == null ? "—" : `${(ms / 1000).toFixed(1)}s`;
}

function fmtCodeKB(chars) {
  return chars == null ? "—" : `${(chars / 1000).toFixed(1)} KB`;
}

function fmtCost(usd, estimate) {
  if (usd == null) return "—";
  return `${estimate ? "~$" : "$"}${usd.toFixed(2)}`;
}

function fmtDate(iso) {
  const d = new Date(iso);
  if (Number.isNaN(d.getTime())) return iso || "—";
  return d.toLocaleDateString("en-US", { year: "numeric", month: "short", day: "numeric" });
}

function runnerLabel(runner) {
  return runner === "claude-code-subagent" ? "Claude Code" : "OpenRouter";
}

function truncate(text, max = 90) {
  if (!text) return "";
  return text.length > max ? `${text.slice(0, max - 1).trimEnd()}…` : text;
}

/* --- Page shell ----------------------------------------------------------- */

const main = el("main", { className: "bm-main" });
main.appendChild(el("div", { className: "bm-state" },
  el("span", { className: "ms-spinner", "aria-hidden": "true" }),
  el("span", { text: "Loading benchmark…" }),
));

// Insert main first, then mount the shared chrome so ordering is header → main → footer.
const root = document.getElementById("app") || document.body;
root.appendChild(main);
mountChrome("benchmark");

/* --- Fetch + render ------------------------------------------------------- */

fetchData(DATA.videoBenchmark)
  .then((data) => {
    if (!data || !Array.isArray(data.summaries) || !Array.isArray(data.prompts)) {
      throw new Error("The benchmark data was empty or in an unexpected shape.");
    }
    renderBenchmark(data);
  })
  .catch((err) => {
    main.replaceChildren(
      el("div", { className: "bm-state is-error" },
        el("strong", { text: "Couldn't load the benchmark." }),
        el("span", { text: (err && err.message) || "Please try again in a moment." }),
        el("a", { className: "bm-retry", href: FULL_BENCHMARK_URL, target: "_blank", rel: "noopener",
          text: "See it on mesmer.tools →" }),
      ),
    );
  });

function renderBenchmark(data) {
  const { generatedAt, models = [], prompts = [], summaries = [], sections = [], totals = {} } = data;
  const ranking = Array.isArray(data.ranking) ? data.ranking : [];

  const modelBySlug = new Map(models.map((m) => [m.slug, m]));
  const rankOf = (slug) => {
    const i = ranking.indexOf(slug);
    return i >= 0 ? i + 1 : null;
  };

  const frag = document.createDocumentFragment();
  frag.appendChild(hero(generatedAt, models, prompts, totals));
  frag.appendChild(leaderboard(summaries));
  frag.appendChild(promptGallery(prompts, sections, modelBySlug, rankOf));
  frag.appendChild(ctaCard());

  main.replaceChildren(frag);
}

/* --- Hero ----------------------------------------------------------------- */

function hero(generatedAt, models, prompts, totals) {
  return el("section", { className: "bm-hero" },
    el("div", { className: "bm-hero-emoji", text: "🏁" }),
    el("h1", { className: "bm-title", text: "AI Video Generation Benchmark" }),
    el("p", { className: "bm-subtitle",
      text: `Which LLM writes the best motion-graphics code? ${models.length} models, ${prompts.length} briefs, rendered to video.` }),
    el("div", { className: "bm-method" },
      el("span", { className: "bm-method-icon", text: "🧪" }),
      el("p", { className: "bm-method-body" },
        el("strong", { text: "How it works. " }),
        "Every model got the same creative briefs and was asked to generate animation code, which was then compiled and rendered to video — the same pipeline for all, with no hand-fixing in between. Failed cards are the model's own: the code either didn't generate or crashed while rendering. The ranking below is editorial, judged by hand on output quality.",
      ),
    ),
    el("p", { className: "bm-updated",
      text: generatedAt
        ? `Updated ${fmtDate(generatedAt)} · ${totals.rendered ?? 0}/${totals.total ?? 0} videos rendered`
        : `${totals.rendered ?? 0}/${totals.total ?? 0} videos rendered · live from mesmer.tools` }),
  );
}

/* --- Leaderboard ---------------------------------------------------------- */

function leaderboard(summaries) {
  const head = el("tr", {},
    el("th", { text: "Rank" }),
    el("th", { text: "Model" }),
    el("th", { text: "Runner" }),
    el("th", { text: "Rendered" }),
    el("th", { text: "Avg time" }),
    el("th", { text: "Avg code" }),
    el("th", { text: "Cost" }),
    el("th", { text: "Tries" }),
  );

  const rows = summaries.map((s, i) => {
    const m = s.model || {};
    const isClaude = m.runner === "claude-code-subagent";
    const renderedCls = s.rendered === s.total ? "is-full" : s.rendered === 0 ? "is-zero" : "is-partial";
    return el("tr", {},
      el("td", { className: "bm-rank", text: String(i + 1) }),
      el("td", {},
        el("div", { className: "bm-model-name", text: m.displayName || m.slug || "—" }),
        el("div", { className: "bm-model-prov", text: m.provider || "" }),
      ),
      el("td", {},
        el("span", { className: `bm-badge ${isClaude ? "is-cc" : "is-or"}`, text: runnerLabel(m.runner) }),
      ),
      el("td", {},
        el("span", { className: `bm-rendered ${renderedCls}`, text: `${s.rendered}/${s.total}` }),
      ),
      el("td", { className: "bm-num", text: fmtSeconds(s.avgGenerationMs) }),
      el("td", { className: "bm-num", text: fmtCodeKB(s.avgCodeChars) }),
      el("td", { className: "bm-num", text: fmtCost(s.totalCostUsd, isClaude) }),
      el("td", { className: "bm-num", text: s.totalAttempts != null ? String(s.totalAttempts) : "—" }),
    );
  });

  return el("section", { className: "bm-section" },
    el("h2", { className: "bm-h2", text: "Leaderboard" }),
    el("p", { className: "bm-h2-note",
      text: "Ranked by hand after watching every model's videos. Claude models ran through Claude Code, so their gen times are omitted and cost is an estimate (~)." }),
    el("p", { className: "bm-scroll-hint", text: "← swipe the table for all columns →" }),
    el("div", { className: "bm-table-wrap" },
      el("table", { className: "bm-table" },
        el("thead", {}, head),
        el("tbody", {}, ...rows),
      ),
    ),
  );
}

/* --- Per-prompt video gallery -------------------------------------------- */

function promptGallery(prompts, sections, modelBySlug, rankOf) {
  const sectionByPrompt = new Map(sections.map((s) => [s.promptId, s]));

  const wrap = el("section", { className: "bm-section" },
    el("h2", { className: "bm-h2", text: "Every result, brief by brief" }),
    el("p", { className: "bm-h2-note", text: "Same prompt, every model. Best-ranked first; failures last." }),
  );

  for (const prompt of prompts) {
    const section = sectionByPrompt.get(prompt.id);
    if (!section || !Array.isArray(section.runs)) continue;

    const aspect = prompt.aspectRatio || "16:9";
    const grid = el("div", { className: "bm-grid", dataset: { aspect } });
    for (const run of section.runs) {
      grid.appendChild(videoCard(run, prompt, modelBySlug, rankOf));
    }

    wrap.appendChild(
      el("div", { className: "bm-prompt" },
        el("div", { className: "bm-prompt-head" },
          el("h3", { className: "bm-prompt-title", text: prompt.title || prompt.id }),
          el("span", { className: "bm-prompt-spec", text: `${prompt.aspectRatio} · ${prompt.fps}fps` }),
        ),
        el("details", { className: "bm-prompt-details" },
          el("summary", { text: "Show the full brief" }),
          el("div", { className: "bm-prompt-text", text: prompt.prompt || "" }),
        ),
        grid,
      ),
    );
  }

  return wrap;
}

function videoCard(run, prompt, modelBySlug, rankOf) {
  const m = modelBySlug.get(run.modelSlug) || {};
  const name = m.displayName || run.modelSlug;
  const rank = rankOf(run.modelSlug);
  const sub = [rank ? `#${rank}` : null, m.provider].filter(Boolean).join(" · ");
  const aspect = (prompt.aspectRatio || "16:9").replace(":", " / ");

  if (run.rendered && run.videoUrl) {
    const metaParts = [];
    if (run.generationMs != null) metaParts.push(`${(run.generationMs / 1000).toFixed(1)}s gen`);
    if (run.codeChars != null) metaParts.push(`${(run.codeChars / 1000).toFixed(1)} KB code`);

    return el("div", { className: "bm-card" },
      el("video", {
        src: run.videoUrl,
        controls: "",
        muted: "",
        loop: "",
        playsinline: "",
        preload: "metadata",
        width: String(prompt.width || ""),
        height: String(prompt.height || ""),
        "aria-label": `${name} — ${prompt.title}`,
      }),
      el("div", { className: "bm-card-name", text: name }),
      el("div", { className: "bm-card-sub", text: sub }),
      metaParts.length ? el("div", { className: "bm-card-meta", text: metaParts.join(" · ") }) : null,
    );
  }

  // Failed run — dashed placeholder sized to the brief's aspect ratio.
  const reason = run.error ? truncate(run.error) : "Code didn't compile";
  return el("div", { className: "bm-card is-fail" },
    el("div", { className: "bm-fail", style: { aspectRatio: aspect },
      text: run.codeUrl ? "Code didn't render" : "No usable code produced" }),
    el("div", { className: "bm-card-name", text: name }),
    el("div", { className: "bm-card-sub", text: sub }),
    el("div", { className: "bm-card-meta", text: reason }),
  );
}

/* --- CTA ------------------------------------------------------------------ */

function ctaCard() {
  return el("section", { className: "bm-cta" },
    el("h3", { text: "Want to compare them side by side?" }),
    el("p", { text: "The full interactive benchmark adds a lightbox, side-by-side compare, and the raw generated code for every model." }),
    el("a", { className: "bm-cta-btn", href: FULL_BENCHMARK_URL, target: "_blank", rel: "noopener",
      text: "See the full interactive benchmark with side-by-side compare →" }),
  );
}