import { repoDb } from "../scoped-db";
import { requestCredential } from "../token-scope";
import { loadRepo, repoPermission } from "../repos";
import { limitBrowse } from "../limits";
import { HttpError } from "../errors";
import { WORKFLOW_DIR } from "./spec";

const BADGE_PATH = /^\/([^/]+)\/([^/]+)\/actions\/workflows\/([^/]+\.ya?ml)\/badge\.svg$/;
const CHAR_WIDTH = 6.6;
const PADDING = 10;
const PUBLIC_MAX_AGE = 60;

const STATES: Record<string, { text: string; color: string }> = {
  success: { text: "passing", color: "#2ea043" },
  failure: { text: "failing", color: "#da3633" },
  cancelled: { text: "cancelled", color: "#6e7681" },
  skipped: { text: "skipped", color: "#6e7681" },
  none: { text: "no status", color: "#6e7681" },
};

function escapeXml(value: string): string {
  return value.replace(/[<>&"']/g, (char) => `&#${char.charCodeAt(0)};`);
}

export function badgeSvg(label: string, state: string): string {
  const status = STATES[state] ?? STATES.none;
  const left = Math.round(label.length * CHAR_WIDTH + PADDING * 2);
  const right = Math.round(status.text.length * CHAR_WIDTH + PADDING * 2);
  const width = left + right;
  const text = (x: number, value: string) =>
    `<text x="${x}" y="15" fill="#010101" fill-opacity=".3">${value}</text><text x="${x}" y="14">${value}</text>`;
  return `<svg xmlns="http://www.w3.org/2000/svg" width="${width}" height="20" role="img" aria-label="${escapeXml(label)}: ${status.text}">
<title>${escapeXml(label)}: ${status.text}</title>
<linearGradient id="s" x2="0" y2="100%"><stop offset="0" stop-color="#bbb" stop-opacity=".1"/><stop offset="1" stop-opacity=".1"/></linearGradient>
<clipPath id="r"><rect width="${width}" height="20" rx="3" fill="#fff"/></clipPath>
<g clip-path="url(#r)"><rect width="${left}" height="20" fill="#24292f"/><rect x="${left}" width="${right}" height="20" fill="${status.color}"/><rect width="${width}" height="20" fill="url(#s)"/></g>
<g fill="#fff" text-anchor="middle" font-family="Verdana,Geneva,DejaVu Sans,sans-serif" font-size="11">${text(left / 2, escapeXml(label))}${text(left + right / 2, status.text)}</g>
</svg>`;
}

/**
 * `/<owner>/<repo>/actions/workflows/<file>/badge.svg?branch=` — public repos are edge-cached briefly. Authorization
 * runs before the cache lookup and the cache key carries the repo's visibility and `updated_at`, so a badge cached
 * while the repo was public stops being served the moment it turns private (CI-A8).
 */
export async function handleBadge(request: Request, url: URL): Promise<Response | null> {
  const match = BADGE_PATH.exec(url.pathname);
  if (!match || request.method !== "GET") return null;
  try {
    await limitBrowse(null, request);
  } catch (error) {
    if (error instanceof HttpError) return new Response(error.message, { status: error.status });
    throw error;
  }
  const repo = await loadRepo(decodeURIComponent(match[1]), decodeURIComponent(match[2]));
  const viewer = repo ? (await requestCredential(request, true)).viewer : null;
  if (!repo || (await repoPermission(repo, viewer)) === "none") return new Response("Not found", { status: 404 });
  const isPublic = repo.visibility === "public";
  const cache = isPublic ? await caches.open("gitfor-badges") : null;
  const cacheKey = cache
    ? new Request(`${url.origin}${url.pathname}?${url.searchParams}&v=${repo.visibility}&u=${repo.updated_at}`, {
        method: "GET",
      })
    : null;
  if (cache && cacheKey) {
    const cached = await cache.match(cacheKey);
    if (cached) return cached;
  }
  const branch = url.searchParams.get("branch") ?? repo.default_branch;
  const event = url.searchParams.get("event");
  const path = `${WORKFLOW_DIR}/${decodeURIComponent(match[3])}`;
  const latest = await repoDb(repo.id).first<{ conclusion: string | null; workflow_name: string }>(
    `SELECT conclusion, workflow_name FROM workflow_runs WHERE repo_id = ? AND workflow_path = ? AND ref = ?
       AND status = 'completed' ${event ? "AND event = ?" : ""} ORDER BY run_number DESC LIMIT 1`,
    repo.id,
    path,
    `refs/heads/${branch}`,
    ...(event ? [event] : []),
  );
  const label = latest?.workflow_name ?? decodeURIComponent(match[3]).replace(/\.ya?ml$/, "");
  const response = new Response(badgeSvg(label.slice(0, 60), latest?.conclusion ?? "none"), {
    headers: {
      "content-type": "image/svg+xml; charset=utf-8",
      "cache-control": isPublic ? `public, max-age=${PUBLIC_MAX_AGE}` : "private, no-store",
    },
  });
  if (cache && cacheKey) await cache.put(cacheKey, response.clone());
  return response;
}