// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/extensions/chrome_process_manager_delegate.h"

#include "base/check_op.h"
#include "base/command_line.h"
#include "build/build_config.h"
#include "build/chromeos_buildflags.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/extensions/extension_management.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/profiles/profile_manager.h"
#include "chrome/browser/ui/browser_window/public/browser_window_interface.h"
#include "chrome/browser/ui/browser_window/public/global_browser_collection.h"
#include "components/user_manager/user_manager.h"
#include "extensions/browser/extensions_browser_client.h"
#include "extensions/browser/process_manager.h"
#include "extensions/browser/process_manager_factory.h"
#include "extensions/common/extension.h"
#include "extensions/common/permissions/permissions_data.h"

#if BUILDFLAG(IS_CHROMEOS)
#include "ash/constants/ash_switches.h"
#include "chrome/browser/extensions/component_extensions_allowlist/allowlist.h"
#include "chromeos/ash/components/browser_context_helper/browser_context_types.h"
#endif

namespace extensions {

ChromeProcessManagerDelegate::ChromeProcessManagerDelegate() {
  DCHECK(g_browser_process);
  // The profile manager can be null in unit tests.
  if (ProfileManager* profile_manager = g_browser_process->profile_manager()) {
    profile_manager_observation_.Observe(profile_manager);
    // All profiles must be observed, so make sure none have been created
    // that we missed.
    DCHECK_EQ(0U, profile_manager->GetLoadedProfiles().size());
  }
  browser_collection_observation_.Observe(
      GlobalBrowserCollection::GetInstance());
}

ChromeProcessManagerDelegate::~ChromeProcessManagerDelegate() {
  DCHECK(!g_browser_process)
      << "ChromeProcessManagerDelegate expects to be shut down during "
         "BrowserProcess shutdown, after |g_browser_process| is set to null";
}

bool ChromeProcessManagerDelegate::AreBackgroundPagesAllowedForContext(
    content::BrowserContext* context) const {
  Profile* profile = Profile::FromBrowserContext(context);

  bool is_normal_session = !profile->IsGuestSession() &&
                           !profile->IsSystemProfile();

  // Disallow if the current session is a Guest mode session or login screen but
  // the current browser context is *not* off-the-record. Such context is
  // artificial and background page shouldn't be created in it.
  // http://crbug.com/41080781
  return is_normal_session || profile->IsOffTheRecord();
}

bool ChromeProcessManagerDelegate::IsExtensionBackgroundPageAllowed(
    content::BrowserContext* context,
    const Extension& extension) const {
#if BUILDFLAG(IS_CHROMEOS)
  Profile* profile = Profile::FromBrowserContext(context);

  const bool is_auth_screen_profile =
      (ash::IsSigninBrowserContext(profile) ||
       ash::IsLockScreenBrowserContext(profile)) &&
      !profile->IsOffTheRecord();

  if (is_auth_screen_profile) {
    // Check for flag.
    if (base::CommandLine::ForCurrentProcess()->HasSwitch(
            ash::switches::kDisableLoginScreenApps)) {
      return false;
    }

    // Get login screen apps installed by policy.
    base::DictValue login_screen_apps_list =
        ExtensionManagementFactory::GetForBrowserContext(context)
            ->GetForceInstallList();

    // For the ChromeOS login profile, only allow apps installed by device
    // policy or that are explicitly allowlisted.
    return login_screen_apps_list.Find(extension.id()) ||
           IsComponentExtensionAllowlistedForSignInProfile(extension.id());
  }

#endif

  return AreBackgroundPagesAllowedForContext(context);
}

bool ChromeProcessManagerDelegate::DeferCreatingStartupBackgroundHosts(
    content::BrowserContext* context) const {
  // The profile may not be valid yet if it is still being initialized.
  // In that case, defer loading, since it depends on an initialized profile.
  // Background hosts will be loaded later via OnProfileAdded.
  return !ExtensionsBrowserClient::Get()->IsValidContext(context);
}

void ChromeProcessManagerDelegate::OnBrowserCreated(
    BrowserWindowInterface* browser) {
  Profile* profile = browser->GetProfile();
  DCHECK(profile);

  // Inform the process manager for this profile that the window is ready.
  // We continue to observe the notification in case browser windows open for
  // a related incognito profile or other regular profiles.
  ProcessManager::Get(profile)->MaybeCreateStartupBackgroundHosts();

  // For incognito profiles also inform the original profile's process manager
  // that the window is ready. This will usually be a no-op because the
  // original profile's process manager should have been informed when the
  // non-incognito window opened.
  if (profile->IsOffTheRecord()) {
    ProcessManager::Get(profile->GetOriginalProfile())
        ->MaybeCreateStartupBackgroundHosts();
  }
}

void ChromeProcessManagerDelegate::OnProfileAdded(Profile* profile) {
  observed_profiles_.AddObservation(profile);

  // The profile might have been initialized asynchronously (in parallel with
  // extension system startup). Now that initialization is complete the
  // ProcessManager can load deferred background pages.
  //
  // The process manager service might not be available for some irregular
  // profiles, like the System Profile.
  if (ProcessManager* process_manager = ProcessManager::Get(profile)) {
    process_manager->MaybeCreateStartupBackgroundHosts();
  }
}

void ChromeProcessManagerDelegate::OnProfileManagerDestroying() {
  profile_manager_observation_.Reset();
}

void ChromeProcessManagerDelegate::OnOffTheRecordProfileCreated(
    Profile* off_the_record_profile) {
  observed_profiles_.AddObservation(off_the_record_profile);
}

void ChromeProcessManagerDelegate::OnProfileWillBeDestroyed(Profile* profile) {
  observed_profiles_.RemoveObservation(profile);

  // Close background hosts when the last profile is closed so that they
  // have time to shutdown various objects on different threads. The
  // KeyedService::Shutdown override is called too late in the shutdown
  // sequence. http://crbug.com/40952676
  auto close_background_hosts = [](Profile* profile) {
    ProcessManager* manager =
        ProcessManagerFactory::GetForBrowserContextIfExists(profile);
    if (manager) {
      manager->CloseBackgroundHosts();
    }
  };

  close_background_hosts(profile);

  // If this profile owns an incognito profile, but it is destroyed before the
  // incognito profile is destroyed, then close the incognito background hosts
  // as well. This happens in a few tests. http://crbug.com/40247368
  if (!profile->IsOffTheRecord() && profile->HasPrimaryOTRProfile()) {
    Profile* otr = profile->GetPrimaryOTRProfile(/*create_if_needed=*/true);
    close_background_hosts(otr);
    if (observed_profiles_.IsObservingSource(otr)) {
      observed_profiles_.RemoveObservation(otr);
    }
  }
}

void ChromeProcessManagerDelegate::StartTearDown() {
  browser_collection_observation_.Reset();
}

}  // namespace extensions