import { env } from "cloudflare:workers";
import { all, first } from "./db";
import { branchSha, listRefs } from "./git/refs";
import { withStore } from "./git/store";
import { renderMarkdown } from "./markdown";
import { REPO_SELECT } from "./repos";
import type { RepoRow } from "~/lib/types";

const DAY_MS = 24 * 60 * 60 * 1000;
const GRAPH_WEEKS = 52;
const WEEK_DAYS = 7;
const README_NAMES = new Set(["readme.md", "readme.markdown"]);
const MAX_README_BYTES = 256 * 1024;
const README_CACHE_TTL_SECONDS = 60 * 60 * 24 * 7;
const decoder = new TextDecoder();

export type ContributionDay = { date: string; count: number };

/** Daily repository activity counts (public repos unless `includePrivate`) for roughly the last year, oldest first, aligned to whole weeks. */
export async function contributionGraph(accountId: string, includePrivate: boolean): Promise<ContributionDay[]> {
  const now = Date.now();
  const today = new Date(now);
  const midnight = Date.UTC(today.getUTCFullYear(), today.getUTCMonth(), today.getUTCDate());
  const start = new Date(midnight - (GRAPH_WEEKS * WEEK_DAYS + today.getUTCDay()) * DAY_MS);
  const rows = await all<{ day: string; count: number }>(
    `SELECT strftime('%Y-%m-%d', ac.created_at / 1000, 'unixepoch') AS day, COUNT(*) AS count
     FROM activity ac LEFT JOIN repos r ON r.id = ac.repo_id
     WHERE ac.actor_id = ? AND ac.created_at >= ? AND ac.kind != 'view'
       AND r.id IS NOT NULL AND (? = 1 OR r.visibility = 'public')
     GROUP BY day`,
    accountId,
    start.getTime(),
    includePrivate ? 1 : 0,
  );
  const counts = new Map(rows.map((row) => [row.day, row.count]));
  const days: ContributionDay[] = [];
  for (let time = start.getTime(); time <= now; time += DAY_MS) {
    const date = new Date(time).toISOString().slice(0, 10);
    days.push({ date, count: counts.get(date) ?? 0 });
  }
  return days;
}

/** Renders README.md from the public `<name>/<name>` repo, cached in KV by commit. */
export async function profileReadme(accountName: string): Promise<string | null> {
  const repo = await first<RepoRow>(
    `${REPO_SELECT} WHERE a.name = ?1 AND r.name = ?1 AND r.visibility = 'public' AND r.status = 'ready'`,
    accountName,
  );
  if (!repo) return null;
  const refs = await listRefs(repo);
  const sha = branchSha(refs, repo.default_branch);
  if (!sha) return null;
  const cacheKey = `profile-readme:${repo.id}:${sha}`;
  const cached = await env.KV.get(cacheKey);
  if (cached !== null) return cached || null;
  const html = await withStore(repo.artifacts_name, async (store) => {
    const commit = await store.commit(sha);
    if (!commit) return "";
    const entries = await store.listTree(commit.treeSha, "");
    const entry = entries.find(
      (candidate) => candidate.type !== "tree" && README_NAMES.has(candidate.name.toLowerCase()),
    );
    if (!entry) return "";
    const bytes = await store.blob(entry.sha);
    if (!bytes || bytes.byteLength > MAX_README_BYTES) return "";
    return renderMarkdown(decoder.decode(bytes), {
      owner: repo.owner_name,
      repo: repo.name,
      ref: repo.default_branch,
      basePath: "",
    });
  });
  await env.KV.put(cacheKey, html, { expirationTtl: README_CACHE_TTL_SECONDS });
  return html || null;
}