#!/usr/bin/env node
// Installs the com.peachpasswords.sync native messaging host manifest into
// the per-browser NativeMessagingHosts directory so chrome.runtime.connectNative
// can find the Peach sync host binary at runtime.
//
// Unix (macOS / Linux): writes a JSON file under the user's NativeMessagingHosts
// directory. Windows requires a registry entry and is not handled directly —
// the script prints the JSON path and the registry key the user must add.
//
// Usage:
//   node scripts/install-native-sync-host.mjs --browser chrome --extension-id <id>
//   node scripts/install-native-sync-host.mjs --browser firefox
//
// Optional flags:
//   --host-path <abs-path>   Override the binary path (default: release build)
//   --dry-run                Print what would be written; do not touch the FS
import { mkdir, writeFile } from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import process from "node:process";
import { pathToFileURL } from "node:url";

import { buildNativeManifest } from "./generate-native-sync-manifest.mjs";

const HOST_FILENAME = "com.peachpasswords.sync.json";

function usage() {
  return [
    "Usage:",
    "  node scripts/install-native-sync-host.mjs --browser chrome --extension-id <id>",
    "  node scripts/install-native-sync-host.mjs --browser firefox [--extension-id <gecko-id>]",
    "",
    "Optional:",
    "  --host-path <abs-path>   Override binary path (default: release build)",
    "  --dry-run                Print the destination only; do not write",
  ].join("\n");
}

function parseArgs(argv) {
  const options = {};
  for (let i = 0; i < argv.length; i += 1) {
    const arg = argv[i];
    if (arg === "--help" || arg === "-h") {
      options.help = true;
      continue;
    }
    if (arg === "--dry-run") {
      options.dryRun = true;
      continue;
    }
    if (arg === "--show-dir") {
      options.showDir = true;
      continue;
    }
    if (arg === "--platform-override") {
      options.platformOverride = argv[i + 1];
      i += 1;
      continue;
    }
    if (arg === "--home-override") {
      options.homeOverride = argv[i + 1];
      i += 1;
      continue;
    }
    if (!arg.startsWith("--")) {
      throw new Error(`unexpected argument: ${arg}`);
    }
    const key = arg.slice(2);
    const value = argv[i + 1];
    if (!value || value.startsWith("--")) {
      throw new Error(`missing value for --${key}`);
    }
    options[toCamel(key)] = value;
    i += 1;
  }
  return options;
}

function toCamel(value) {
  return value.replace(/-([a-z])/g, (_, letter) => letter.toUpperCase());
}

/**
 * Resolves the OS-specific NativeMessagingHosts directory for the requested
 * browser. Returns `{ dir, registryHint }` — `registryHint` is only set on
 * Windows where a registry write is also required.
 */
export function resolveInstallDir(browser, platform = process.platform, home = os.homedir()) {
  if (browser !== "chrome" && browser !== "firefox") {
    throw new Error("--browser must be chrome or firefox");
  }

  if (platform === "darwin") {
    if (browser === "chrome") {
      return {
        dir: path.join(home, "Library", "Application Support", "Google", "Chrome", "NativeMessagingHosts"),
      };
    }
    return {
      dir: path.join(home, "Library", "Application Support", "Mozilla", "NativeMessagingHosts"),
    };
  }

  if (platform === "linux") {
    if (browser === "chrome") {
      return { dir: path.join(home, ".config", "google-chrome", "NativeMessagingHosts") };
    }
    return { dir: path.join(home, ".mozilla", "native-messaging-hosts") };
  }

  if (platform === "win32") {
    // Windows uses the registry. We still write the JSON to a stable path so
    // the registry value can point at it.
    const dir = path.join(home, "AppData", "Local", "Peach", "NativeMessagingHosts");
    const registryRoot =
      browser === "chrome"
        ? "HKEY_CURRENT_USER\\Software\\Google\\Chrome\\NativeMessagingHosts\\com.peachpasswords.sync"
        : "HKEY_CURRENT_USER\\Software\\Mozilla\\NativeMessagingHosts\\com.peachpasswords.sync";
    return {
      dir,
      registryHint: `Add a registry value at ${registryRoot} with the (Default) string set to ${path.join(
        dir,
        HOST_FILENAME
      )}`,
    };
  }

  throw new Error(`unsupported platform: ${platform}`);
}

async function main() {
  const options = parseArgs(process.argv.slice(2));
  if (options.help) {
    console.log(usage());
    return;
  }
  if (!options.browser) {
    throw new Error("--browser is required");
  }

  const platform = options.platformOverride ?? process.platform;
  const home = options.homeOverride ?? os.homedir();
  const { dir, registryHint } = resolveInstallDir(options.browser, platform, home);

  if (options.showDir) {
    process.stdout.write(JSON.stringify({ dir, registryHint: registryHint ?? null }));
    return;
  }

  const targetPath = path.join(dir, HOST_FILENAME);
  const manifest = await buildNativeManifest(options);
  const json = `${JSON.stringify(manifest, null, 2)}\n`;

  if (options.dryRun) {
    console.log(`Would write ${targetPath}`);
    process.stdout.write(json);
    if (registryHint) console.log(`\n${registryHint}`);
    return;
  }

  await mkdir(dir, { recursive: true });
  await writeFile(targetPath, json, { mode: 0o644 });
  console.log(`Installed ${targetPath}`);
  if (registryHint) {
    console.log(registryHint);
    console.log(
      "Run `reg add` with the path above, or use the Registry Editor — Windows requires this entry to discover the host."
    );
  }
}

if (import.meta.url === pathToFileURL(path.resolve(process.argv[1])).href) {
  main().catch((err) => {
    console.error(err instanceof Error ? err.message : String(err));
    console.error(usage());
    process.exitCode = 1;
  });
}