proxyswitcher/background-chrome.js

// Chromium implementation. Chrome's proxy API uses a PAC script rather than
// Firefox's per-request proxy.onRequest listener.
let config = configManager.getConfig();

async function init() {
  await configManager.load();
  config = configManager.getConfig();
  await applyProxyConfig();
  configManager.addListener(() => {
    config = configManager.getConfig();
    applyProxyConfig().catch(error => console.error('Failed to apply proxy config:', error));
  });
}

function escapePacString(value) {
  return JSON.stringify(String(value));
}

function buildPacScript() {
  const rules = {};
  Object.entries(config.domains || {}).forEach(([domain, entry]) => {
    if (!entry || !entry.enabled || !entry.host || !entry.port) return;
    const scheme = entry.type === 'socks' ? 'SOCKS5' : 'PROXY';
    rules[domain] = `${scheme} ${entry.host}:${parseInt(entry.port, 10)}`;
  });

  return `function FindProxyForURL(url, host) {
    var rules = ${JSON.stringify(rules)};
    return Object.prototype.hasOwnProperty.call(rules, host) ? rules[host] : "DIRECT";
  }`;
}

async function applyProxyConfig() {
  const hasRules = Object.values(config.domains || {}).some(entry =>
    entry && entry.enabled && entry.host && entry.port
  );

  return chrome.proxy.settings.set({
    value: hasRules
      ? { mode: 'pac_script', pacScript: { data: buildPacScript(), mandatory: true } }
      : { mode: 'direct' },
    scope: 'regular'
  });
}

function getDomain(url) {
  try { return new URL(url).hostname.replace(/^www\./, ''); } catch (_) { return null; }
}

function sendConfigResponse(sendResponse, action) {
  if (action === 'getConfig') sendResponse({ config: configManager.getConfig() });
  else if (action === 'getProfiles') sendResponse({ profiles: configManager.getProfiles() });
  else return false;
  return true;
}

chrome.webRequest.onAuthRequired.addListener(
  (details, sendResponse) => {
    if (!details.isProxy) return sendResponse({});
    const entry = config.domains && config.domains[getDomain(details.url)];
    if (!entry || !entry.enabled || !entry.username || !entry.password) return sendResponse({});
    sendResponse({ authCredentials: { username: entry.username, password: entry.password } });
  },
  { urls: ['<all_urls>'] },
  ['blocking']
);

chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
  const direct = sendConfigResponse(sendResponse, message.action);
  if (direct) return true;

  const asyncActions = {
    updateDomain: () => configManager.updateDomain(message.domain, message.domainConfig),
    removeDomain: () => configManager.removeDomain(message.domain),
    updateProfile: () => configManager.updateProfile(message.profileName, message.profileConfig),
    removeProfile: () => configManager.removeProfile(message.profileName),
    updateSettings: () => configManager.updateSettings(message.settings || {}),
    reloadConfig: () => configManager.reload(),
    clearAllDomains: () => { configManager.config.domains = {}; return configManager.save(); },
    clearAllProfiles: () => { configManager.config.profiles = {}; return configManager.save(); },
    clearEverything: () => { configManager.config.domains = {}; configManager.config.profiles = {}; return configManager.save(); }
  };

  if (message.action === 'getProfile') {
    sendResponse({ profile: configManager.getProfileConfig(message.profileName) });
    return false;
  }
  if (message.action === 'toggleProxy') {
    const entry = configManager.getDomainConfig(message.domain);
    if (!entry) { sendResponse({ success: false, error: 'Domain not configured' }); return false; }
    entry.enabled = message.enabled;
    asyncActions.updateDomain = () => configManager.updateDomain(message.domain, entry);
  }
  const operation = asyncActions[message.action];
  if (!operation) return false;
  operation().then(() => sendResponse({ success: true })).catch(error =>
    sendResponse({ success: false, error: error.message })
  );
  return true;
});

init().catch(error => console.error('Failed to initialize Chrome proxy support:', error));