// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

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

#include "chrome/browser/extensions/extension_service.h"
#include "chrome/browser/extensions/extension_util.h"
#include "chrome/browser/profiles/profile.h"
#include "extensions/browser/event_router.h"
#include "extensions/common/extension.h"
#include "extensions/common/manifest_handlers/background_info.h"

namespace extensions {

UpdateInstallGate::UpdateInstallGate(ExtensionService* service)
    : service_(service) {}

InstallGate::Action UpdateInstallGate::ShouldDelay(const Extension* extension,
                                                   bool install_immediately) {
  // Allow installation when |install_immediately| is set or ExtensionService
  // is not ready. UpdateInstallGate blocks update when the old version of
  // the extension is not idle (i.e. in use). When ExtensionService is not
  // ready, the old version is definitely idle, so the installation is allowed
  // to proceeded. This essentially allows the delayed installation to happen
  // during the initialization of ExtensionService.
  if (install_immediately || !service_->is_ready())
    return INSTALL;

  const Extension* old = service_->GetInstalledExtension(extension->id());
  // If there is no old extension, this is not an update, so don't delay.
  if (!old)
    return INSTALL;

  if (extensions::BackgroundInfo::HasPersistentBackgroundPage(old)) {
    const char kOnUpdateAvailableEvent[] = "runtime.onUpdateAvailable";
    // Delay installation if the extension listens for the onUpdateAvailable
    // event.
    return extensions::EventRouter::Get(service_->profile())
                   ->ExtensionHasEventListener(extension->id(),
                                               kOnUpdateAvailableEvent)
               ? DELAY
               : INSTALL;
  } else {
    // Delay installation if the extension is not idle.
    return !extensions::util::IsExtensionIdle(extension->id(),
                                              service_->profile())
               ? DELAY
               : INSTALL;
  }
}

}  // namespace extensions