import { mkdirSync, readFileSync, writeFileSync } from "node:fs";
import { dirname, join } from "node:path";

import { app, safeStorage } from "electron/main";

type VaultStore = Record<string, string>;

function vaultPath(): string {
  return join(app.getPath("userData"), "desktop-vault.json");
}

function loadStore(): VaultStore {
  try {
    return JSON.parse(readFileSync(vaultPath(), "utf8")) as VaultStore;
  } catch {
    return {};
  }
}

function persistStore(store: VaultStore): void {
  const target = vaultPath();
  mkdirSync(dirname(target), { recursive: true });
  writeFileSync(target, JSON.stringify(store, null, 2), "utf8");
}

export function describeVaultBackend() {
  return {
    encryptionAvailable: safeStorage.isEncryptionAvailable(),
    backend:
      typeof safeStorage.getSelectedStorageBackend === "function"
        ? safeStorage.getSelectedStorageBackend()
        : "unknown",
    path: vaultPath(),
  };
}

export function writeEncrypted(key: string, value: string): void {
  if (!safeStorage.isEncryptionAvailable()) {
    throw new Error("safeStorage encryption is unavailable");
  }

  const store = loadStore();
  store[key] = safeStorage.encryptString(value).toString("base64");
  persistStore(store);
}

export function readEncrypted(key: string): string | null {
  const encoded = loadStore()[key];
  if (!encoded) {
    return null;
  }
  return safeStorage.decryptString(Buffer.from(encoded, "base64"));
}