// The files an article was WRITTEN from, for reading beside it: a workspace's
// drafts, the rendered drafts and briefs under polemics/, and the notes a
// workspace keeps at its top level. Read-only -- this lists and serves, it
// never writes a workspace.
//
//   polemics/drafts/*.json     the drafts (source of truth)
//   polemics/out/*.{md,html}   what the drafts render to
//   polemics/*.md              BRIEF.md, NOTES.md, PRIVACY-SWEEP.md, …
//   <ws>/{NOTES,BRIEF,LEADS,PLAN,PRIVACY-SWEEP}.md
//   <ws>/site/PLAN.md, <ws>/site/MERGE-PLAN.md
import { readdir, realpath, stat } from "node:fs/promises";
import path from "node:path";
import { REPORTS_ROOT } from "../paths.mjs";

export const TOP_LEVEL = ["NOTES.md", "BRIEF.md", "LEADS.md", "PLAN.md", "PRIVACY-SWEEP.md"];
const SITE_LEVEL = ["PLAN.md", "MERGE-PLAN.md"];
export const WORKSPACE_EXT = /\.(md|html|json)$/;

const statFile = (p) => stat(/* turbopackIgnore: true */ p).then((s) => (s.isFile() ? s : null), () => null);

/**
 * Every listed file of one workspace: `{ rel, abs, kind, bytes, mtimeMs }`,
 * `kind` one of "draft" | "out" | "doc". Sorted: drafts, docs, outputs; by name.
 *
 * @param {string} wsDir
 */
export async function workspaceFiles(wsDir) {
  const out = [];
  const add = async (rel, kind) => {
    const abs = path.join(/* turbopackIgnore: true */ wsDir, rel);
    const st = await statFile(abs);
    if (st) out.push({ rel, abs, kind, bytes: st.size, mtimeMs: Math.round(st.mtimeMs) });
  };
  const ls = (rel) => readdir(/* turbopackIgnore: true */ path.join(/* turbopackIgnore: true */ wsDir, rel)).catch(() => []);
  for (const f of await ls("polemics/drafts")) if (f.endsWith(".json")) await add(`polemics/drafts/${f}`, "draft");
  for (const f of await ls("polemics/out")) if (/\.(md|html)$/.test(f)) await add(`polemics/out/${f}`, "out");
  for (const f of await ls("polemics")) if (f.endsWith(".md")) await add(`polemics/${f}`, "doc");
  for (const f of TOP_LEVEL) await add(f, "doc");
  for (const f of SITE_LEVEL) await add(`site/${f}`, "doc");
  const rank = { draft: 0, doc: 1, out: 2 };
  return out.sort((a, b) => rank[a.kind] - rank[b.kind] || a.rel.localeCompare(b.rel));
}

/**
 * A workspace file a client named, or null: `ws` must be a directory directly
 * under REPORTS_ROOT and `rel` one of the files workspaceFiles lists for it,
 * and its REAL path must stay inside the workspace.
 *
 * @param {string} ws  the workspace's name under REPORTS_ROOT
 * @param {string} rel
 * @param {{ reportsRoot?: string }} [opts]
 */
export async function workspaceFile(ws, rel, { reportsRoot = REPORTS_ROOT } = {}) {
  if (typeof ws !== "string" || !/^[A-Za-z0-9][A-Za-z0-9._-]*$/.test(ws) || ws === "..") return null;
  if (typeof rel !== "string" || rel.includes("\0") || rel.split("/").some((s) => s === ".." || s === "" || s === ".")) return null;
  const dir = path.join(/* turbopackIgnore: true */ reportsRoot, ws);
  const listed = (await workspaceFiles(dir)).find((f) => f.rel === rel);
  if (!listed) return null;
  const [realDir, realAbs] = await Promise.all([
    realpath(/* turbopackIgnore: true */ dir).catch(() => null),
    realpath(/* turbopackIgnore: true */ listed.abs).catch(() => null),
  ]);
  if (!realDir || !realAbs || !realAbs.startsWith(realDir + path.sep)) return null;
  return { ...listed, real: realAbs };
}