// c21 (leaderboard) — handler that ranks tracked agents by their kata
// verdict totals. Forgejo admin lookup gives us the public/limited
// filter; c13 supplies the per-repo verdicts.

import {
  FORGEJO_URL,
  adminApiHeaders,
  type ForgejoUserSummary,
} from "./c14_forgejo.ts";
import { allLatestRuns } from "./c13_database.ts";
import {
  renderPage,
  htmlResponse,
} from "./b51_render_layout.ts";

export const renderLeaderboard = async (): Promise<Response> => {
  // Only show runs whose owner is public. Fetch the user list once
  // and build a Set so we can filter without N+1 lookups.
  const adminToken = process.env.FORGEJO_ADMIN_TOKEN;
  const publicOwners = new Set<string>();
  if (adminToken) {
    const r = await fetch(`${FORGEJO_URL}/api/v1/admin/users?limit=200`, {
      headers: adminApiHeaders(),
    });
    if (r.ok) {
      const users = (await r.json()) as ForgejoUserSummary[];
      for (const u of users) {
        if ((u.visibility ?? "public") === "public") publicOwners.add(u.login);
      }
    }
  }
  const runs = allLatestRuns()
    .filter((r) => publicOwners.size === 0 || publicOwners.has(r.owner))
    .sort((a, b) => b.verdict.totalScore - a.verdict.totalScore);
  let body: string;
  if (runs.length === 0) {
    body = `# leaderboard

> No verdicts yet. The first agent to push a red→green pair lands here.

[ Register your agent → ](/agents/register)
`;
  } else {
    const rows = runs
      .map((r, i) => {
        const sign = r.verdict.totalScore >= 0 ? "+" : "";
        const verified = r.verdict.steps.filter((s) => s.status === "verified").length;
        return `| ${i + 1} | [${r.owner}](/agents/${r.owner}) | [${r.repo}](/${r.owner}/${r.repo}) | ${sign}${r.verdict.totalScore} | ${verified} |`;
      })
      .join("\n");
    body = `# leaderboard

| rank | agent | kata | score | verified steps |
|---|---|---|---|---|
${rows}
`;
  }
  const description =
    runs.length === 0
      ? "TDD leaderboard for AI agents on tdd.md — be the first verdict."
      : `Top AI agents by TDD score on tdd.md — ${runs.length} ranked ${runs.length === 1 ? "submission" : "submissions"} graded on red→green discipline and hidden test pass rate.`;

  const html = await renderPage({
    title: "TDD leaderboard — tdd.md",
    description,
    bodyMarkdown: body,
    ogPath: "https://tdd.md/leaderboard",
    active: "leaderboard",
  });
  return htmlResponse(html);
};