// lib/icons/sets.js
import { mkdir, readdir, readFile, rm, writeFile } from 'node:fs/promises';
import path from 'node:path';

const BUNDLED_SET = 'devices';              // read-only, ships in public/icons/devices
let setsDir = process.env.ICON_SETS_DIR || '/var/lib/void/icon-sets';
let bundledDir = path.resolve('public/icons/devices');
export function _setDirs({ setsDir: s, bundledDir: b }) { if (s) setsDir = s; if (b) bundledDir = b; }

const SLUG = /^[a-z0-9-]+$/;
const FILE = /^[a-z0-9-]+\.(svg|png)$/;
function okSet(s) { return SLUG.test(s); }

async function listDir(dir) {
  try { return (await readdir(dir)).filter(f => FILE.test(f)).sort(); } catch { return []; }
}

export async function listSets() {
  const out = [{ set: BUNDLED_SET, readonly: true, icons: await listDir(bundledDir) }];
  let uploaded = [];
  try { uploaded = await readdir(setsDir, { withFileTypes: true }); } catch { /* none yet */ }
  for (const d of uploaded) {
    if (d.isDirectory() && okSet(d.name) && d.name !== BUNDLED_SET) {
      out.push({ set: d.name, readonly: false, icons: await listDir(path.join(setsDir, d.name)) });
    }
  }
  return out;
}

// Resolve an on-disk path for serving. Throws on bad slugs.
export function iconPath(set, file) {
  if (!okSet(set) || !FILE.test(file)) throw new Error('bad_slug');
  return set === BUNDLED_SET ? path.join(bundledDir, file) : path.join(setsDir, set, file);
}

export async function readIcon(set, file) {
  return readFile(iconPath(set, file));
}

export async function writeIcon(set, name, buffer) {
  if (set === BUNDLED_SET) throw new Error('reserved_set');
  if (!okSet(set) || !FILE.test(name)) throw new Error('bad_slug');
  const dir = path.join(setsDir, set);
  await mkdir(dir, { recursive: true });
  await writeFile(path.join(dir, name), buffer);
}

export async function deleteSet(set) {
  if (set === BUNDLED_SET) throw new Error('reserved_set');
  if (!okSet(set)) throw new Error('bad_slug');
  await rm(path.join(setsDir, set), { recursive: true, force: true });
}