feat: add building cache for caching remote domains

Author: piquark6046

builder/source/cache.ts

@@ -0,0 +1,46 @@
+import * as Zod from 'zod'
+import * as Fs from 'node:fs'
+import * as Process from 'node:process'
+import { FetchAdShieldDomains } from './references/index.js'
+
+const CachePath = Process.cwd() + '/.buildcache'
+const CacheDomainsPath = CachePath + '/domains.json'
+
+export function CreateCache(Domains: Set<string>) {
+  if (!Fs.existsSync(CachePath)) {
+    Fs.mkdirSync(CachePath)
+  } else if (!Fs.statSync(CachePath).isDirectory()) {
+    throw new Error('.buildcache exists and is not a directory!')
+  }
+  if (Fs.existsSync(CacheDomainsPath)) {
+    throw new Error('Cache already exists!')
+  }
+  Fs.writeFileSync(CacheDomainsPath, JSON.stringify([...Domains], null, 2), { encoding: 'utf-8' })
+}
+
+export async function LoadCache(): Promise<Set<string>> {
+  if (!Fs.existsSync(CacheDomainsPath)) {
+    throw new Error('Cache does not exist!')
+  }
+  const DomainsRaw = Fs.readFileSync(CacheDomainsPath, { encoding: 'utf-8' })
+  const DomainsArray: string[] = JSON.parse(DomainsRaw)
+  await Zod.array(Zod.string().refine((Value) => {
+    try {
+      new URLPattern(`https://${Value}/`)
+      return true
+    } catch {
+      return false
+    }
+  })).parseAsync(DomainsArray)
+  return new Set(DomainsArray)
+}
+
+export async function LoadDomainsFromCache(): Promise<Set<string>> {
+  if (!Fs.existsSync(CacheDomainsPath)) {
+    const Domains = await FetchAdShieldDomains()
+    CreateCache(Domains)
+    return Domains
+  } else {
+    return await LoadCache()
+  }
+}