protocol.ts

import * as fs from 'node:fs';
import * as path from 'node:path';

import { app } from 'electron';

import { openFiddle } from './files';
import { ipcMainManager } from './ipc';
import { isDevMode } from './utils/devmode';
import { getOrCreateMainWindow } from './windows';
import { IpcEvents } from '../ipc-events';

const PROTOCOL = 'electron-fiddle';
const squirrelPath = path.resolve(
  path.dirname(process.execPath),
  '..',
  'electron-fiddle.exe',
);

const handlePotentialProtocolLaunch = (url: string) => {
  if (!app.isReady()) {
    app.once('ready', () => handlePotentialProtocolLaunch(url));
    return;
  }

  const parsed = new URL(url.replace(/\/$/, ''));
  if (!parsed.pathname || !parsed.hostname) return;

  const pathParts = parsed.pathname.split('/').slice(1);

  switch (parsed.hostname) {
    // electron-fiddle://gist/blub
    case 'gist':
      if (pathParts.length === 1) {
        // We only have a gist ID
        ipcMainManager.send(IpcEvents.LOAD_GIST_REQUEST, [
          {
            id: pathParts[0],
          },
        ]);
      } else if (pathParts.length === 2) {
        // We have a gist owner and gist ID, we can ignore the owner
        ipcMainManager.send(IpcEvents.LOAD_GIST_REQUEST, [
          {
            id: pathParts[1],
          },
        ]);
      } else {
        // This is a super invalid gist launch
        return;
      }
      break;
    // electron-fiddle://electron/{tag}/{path}
    case 'electron':
      if (pathParts.length > 1) {
        // First part is the tag name (e.g. v22.0.0)
        // Rest is the path to the example
        ipcMainManager.send(IpcEvents.LOAD_ELECTRON_EXAMPLE_REQUEST, [
          {
            tag: pathParts[0],
            path: pathParts.slice(1).join('/'),
          },
        ]);
      } else {
        // This is an invalid electron launch
        return;
      }
      break;
    default:
      return;
  }
  getOrCreateMainWindow().then((window) => window.focus());
};

const isProtocolString = (arg: string) => arg.startsWith(`${PROTOCOL}://`);

export const findProtocolArg = (argv: string[]) => {
  return argv.find((arg) => isProtocolString(arg));
};

const scanArgv = (argv: Array<string>) => {
  const protocolArg = findProtocolArg(argv);
  if (protocolArg) {
    console.info('Found protocol arg in argv:', protocolArg);
    handlePotentialProtocolLaunch(protocolArg);
  }
};

const scanNpmArgv = (argv: string) => {
  const parsedArgv = JSON.parse(argv);
  const { original: args } = parsedArgv;
  scanArgv(args);
};

export const listenForProtocolHandler = () => {
  const gotTheLock = app.requestSingleInstanceLock();
  if (!gotTheLock) app.quit();

  app.removeAllListeners('open-url');
  app.on('open-url', (_, url) => {
    if (isProtocolString(url)) {
      handlePotentialProtocolLaunch(url);
    }
  });

  app.removeAllListeners('second-instance');
  app.on('second-instance', (_event, commandLine, _workingDirectory) => {
    // Someone tried to run a second instance
    scanArgv(commandLine);
  });

  app.on('open-file', async (_, path) => {
    if (!path || path.length < 1) {
      return;
    }
    const files = await openFiddle(path);
    ipcMainManager.send(IpcEvents.FS_OPEN_FIDDLE, [path, files]);
  });

  // pass protocol URL via npm start args in dev mode
  if (isDevMode() && process.env.npm_config_argv) {
    scanNpmArgv(process.env.npm_config_argv);
  } else {
    scanArgv(process.argv);
  }
};

export const setupProtocolHandler = () => {
  if (process.platform === 'win32' && !fs.existsSync(squirrelPath)) return;
  if (!app.isDefaultProtocolClient(PROTOCOL, squirrelPath)) {
    app.setAsDefaultProtocolClient(PROTOCOL, squirrelPath);
  }
};