// export-vals.ts: copy vals' code out of Val Town with its REST API.
//
//   deno run -A export-vals.ts                   every val your API key can list
//   deno run -A export-vals.ts user/val ...      just these (public ones need no key)
//
// The key is read from VAL_TOWN_API_KEY or ~/.valtown-api-key. Each val's
// files (main branch) go to ~/valtown-export/<val>/, and
// ~/valtown-export/vals.json records every file's trigger type, its
// val.run or email address, and the names (not values) of the val's
// environment variables. Nothing on Val Town changes.
const API = "https://api.val.town";
const HOME = Deno.env.get("HOME")!;
const OUT = Deno.env.get("EXPORT_DIR") ?? `${HOME}/valtown-export`;
let key = Deno.env.get("VAL_TOWN_API_KEY");
if (!key) {
  try {
    key = (await Deno.readTextFile(`${HOME}/.valtown-api-key`)).trim();
  } catch { /* public vals only */ }
}

async function api(path: string, raw = false) {
  const res = await fetch(path.startsWith("http") ? path : API + path, {
    headers: key ? { Authorization: `Bearer ${key}` } : {},
  });
  if (!res.ok) throw new Error(`${res.status} ${path}: ${await res.text()}`);
  return raw ? res.text() : res.json();
}

// Follow links.next through a paginated list.
async function all(path: string) {
  const items = [];
  let next: string | undefined = path;
  while (next) {
    const page = await api(next);
    items.push(...page.data);
    next = page.links?.next;
  }
  return items;
}

let vals;
if (Deno.args.length) {
  vals = [];
  for (const a of Deno.args) {
    const [user, name] = a.replace(/^.*val\.town\/x\//, "").split("/");
    vals.push(await api(`/v2/alias/vals/${user}/${name}`));
  }
} else {
  if (!key) throw new Error("Set VAL_TOWN_API_KEY or write it to ~/.valtown-api-key");
  vals = await all("/v2/me/vals?offset=0&limit=100");
}

await Deno.mkdir(OUT, { recursive: true });
const seen = new Set<string>();
const report = [];
for (const val of vals) {
  let dir = val.name;
  if (seen.has(dir)) dir = `${val.author.username}-${val.name}`;
  seen.add(dir);
  const files = await all(
    `/v2/vals/${val.id}/files?path=&recursive=true&offset=0&limit=100`,
  );
  for (const f of files) {
    if (f.type === "directory") continue;
    const text = await api(
      `/v2/vals/${val.id}/files/content?path=${encodeURIComponent(f.path)}`,
      true,
    );
    const path = `${OUT}/${dir}/${f.path}`;
    await Deno.mkdir(path.slice(0, path.lastIndexOf("/")), { recursive: true });
    await Deno.writeTextFile(path, text);
  }
  let env: string[] = [];
  if (key && !Deno.args.length) {
    try {
      env = (await all(`/v2/vals/${val.id}/environment_variables/?offset=0&limit=100`))
        .map((e) => e.key);
    } catch { /* not allowed for this val */ }
  }
  const triggers = files
    .filter((f) => ["http", "interval", "email"].includes(f.type))
    .map((f) => ({
      file: f.path,
      type: f.type === "interval" ? "cron" : f.type,
      address: f.links.endpoint ?? f.links.email,
    }));
  report.push({
    dir,
    name: `${val.author.username}/${val.name}`,
    privacy: val.privacy,
    url: val.links.html,
    files: files.filter((f) => f.type !== "directory").length,
    triggers,
    env,
  });
  console.log(`${dir}: ${report.at(-1)!.files} files`);
  for (const t of triggers) console.log(`  ${t.type.padEnd(5)} ${t.file} ${t.address ?? ""}`);
  if (env.length) console.log(`  env   ${env.join(" ")}`);
}
await Deno.writeTextFile(`${OUT}/vals.json`, JSON.stringify(report, null, 2) + "\n");
console.log(`\n${report.length} vals in ${OUT}; summary in ${OUT}/vals.json`);