import path from 'node:path';
import { resolveUserWorkspaceRoot, resolveZoneFilePath } from './user-space.mjs';

export const WORKSPACE_STORAGE_PREFIX = 'workspace://';

export function buildWorkspaceStorageKey(userId, categoryCode, relativeFilename) {
  const category = String(categoryCode ?? '').trim();
  const relativePath = String(relativeFilename ?? '').replace(/\\/g, '/').replace(/^\/+/, '');
  if (!userId || !category || !relativePath) {
    throw new Error('invalid workspace storage key parts');
  }
  if (relativePath.split('/').some((part) => part === '..' || part === '.')) {
    throw new Error('invalid workspace relative path');
  }
  return `${WORKSPACE_STORAGE_PREFIX}${userId}/${category}/${relativePath}`;
}

export function isWorkspaceStorageKey(storageKey) {
  return String(storageKey ?? '').startsWith(WORKSPACE_STORAGE_PREFIX);
}

export function resolveWorkspaceStoragePath(h5Root, storageKey) {
  if (!h5Root || !isWorkspaceStorageKey(storageKey)) return null;
  const rest = storageKey.slice(WORKSPACE_STORAGE_PREFIX.length);
  const slash = rest.indexOf('/');
  if (slash <= 0) return null;
  const userId = rest.slice(0, slash);
  const remainder = rest.slice(slash + 1);
  const slash2 = remainder.indexOf('/');
  if (slash2 <= 0) return null;
  const categoryCode = remainder.slice(0, slash2);
  const relativeFilename = remainder.slice(slash2 + 1);
  if (!relativeFilename) return null;
  const workspaceRoot = resolveUserWorkspaceRoot(h5Root, { id: userId });
  const resolved = path.resolve(resolveZoneFilePath(workspaceRoot, categoryCode, relativeFilename));
  const zoneRoot = path.resolve(resolveZoneFilePath(workspaceRoot, categoryCode, ''));
  if (resolved !== zoneRoot && !resolved.startsWith(`${zoneRoot}${path.sep}`)) {
    return null;
  }
  return resolved;
}