// Copyright (c) 2012 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/api/preference/preference_helpers.h"

#include "base/json/json_writer.h"
#include "base/values.h"
#include "chrome/browser/extensions/event_router.h"
#include "chrome/browser/extensions/extension_prefs.h"
#include "chrome/browser/extensions/extension_service.h"
#include "chrome/browser/prefs/pref_service.h"
#include "chrome/browser/profiles/profile.h"

namespace extensions {
namespace preference_helpers {

namespace {

const char kIncognitoPersistent[] = "incognito_persistent";
const char kIncognitoSessionOnly[] = "incognito_session_only";
const char kRegular[] = "regular";
const char kRegularOnly[] = "regular_only";

const char kLevelOfControlKey[] = "levelOfControl";

const char kNotControllable[] = "not_controllable";
const char kControlledByOtherExtensions[] = "controlled_by_other_extensions";
const char kControllableByThisExtension[] = "controllable_by_this_extension";
const char kControlledByThisExtension[] = "controlled_by_this_extension";

}  // namespace

bool StringToScope(const std::string& s,
                   extensions::ExtensionPrefsScope* scope) {
  if (s == kRegular)
    *scope = extensions::kExtensionPrefsScopeRegular;
  else if (s == kRegularOnly)
    *scope = extensions::kExtensionPrefsScopeRegularOnly;
  else if (s == kIncognitoPersistent)
    *scope = extensions::kExtensionPrefsScopeIncognitoPersistent;
  else if (s == kIncognitoSessionOnly)
    *scope = extensions::kExtensionPrefsScopeIncognitoSessionOnly;
  else
    return false;
  return true;
}

const char* GetLevelOfControl(
    Profile* profile,
    const std::string& extension_id,
    const std::string& browser_pref,
    bool incognito) {
  PrefService* prefs = incognito ? profile->GetOffTheRecordPrefs()
                                 : profile->GetPrefs();
  bool from_incognito = false;
  bool* from_incognito_ptr = incognito ? &from_incognito : NULL;
  const PrefService::Preference* pref =
      prefs->FindPreference(browser_pref.c_str());
  CHECK(pref);
  extensions::ExtensionPrefs* ep =
      profile->GetExtensionService()->extension_prefs();

  if (!pref->IsExtensionModifiable())
    return kNotControllable;

  if (ep->DoesExtensionControlPref(extension_id,
                                   browser_pref,
                                   from_incognito_ptr)) {
    return kControlledByThisExtension;
  }

  if (ep->CanExtensionControlPref(extension_id, browser_pref, incognito))
    return kControllableByThisExtension;

  return kControlledByOtherExtensions;
}

void DispatchEventToExtensions(
    Profile* profile,
    const std::string& event_name,
    ListValue* args,
    extensions::APIPermission::ID permission,
    bool incognito,
    const std::string& browser_pref) {
  extensions::EventRouter* router = profile->GetExtensionEventRouter();
  if (!router || !router->HasEventListener(event_name))
    return;
  ExtensionService* extension_service = profile->GetExtensionService();
  const ExtensionSet* extensions = extension_service->extensions();
  extensions::ExtensionPrefs* extension_prefs =
      extension_service->extension_prefs();
  for (ExtensionSet::const_iterator it = extensions->begin();
       it != extensions->end(); ++it) {
    std::string extension_id = (*it)->id();
    // TODO(bauerb): Only iterate over registered event listeners.
    if (router->ExtensionHasEventListener(extension_id, event_name) &&
        (*it)->HasAPIPermission(permission) &&
        (!incognito || (*it)->incognito_split_mode() ||
         extension_service->CanCrossIncognito(*it))) {
      // Inject level of control key-value.
      DictionaryValue* dict;
      bool rv = args->GetDictionary(0, &dict);
      DCHECK(rv);
      std::string level_of_control =
          GetLevelOfControl(profile, extension_id, browser_pref, incognito);
      dict->SetString(kLevelOfControlKey, level_of_control);

      // If the extension is in incognito split mode,
      // a) incognito pref changes are visible only to the incognito tabs
      // b) regular pref changes are visible only to the incognito tabs if the
      //    incognito pref has not alredy been set
      Profile* restrict_to_profile = NULL;
      bool from_incognito = false;
      if ((*it)->incognito_split_mode()) {
        if (incognito && extension_service->IsIncognitoEnabled(extension_id)) {
          restrict_to_profile = profile->GetOffTheRecordProfile();
        } else if (!incognito &&
                   extension_prefs->DoesExtensionControlPref(
                       extension_id,
                       browser_pref,
                       &from_incognito) &&
                   from_incognito) {
          restrict_to_profile = profile;
        }
      }

      scoped_ptr<ListValue> args_copy(args->DeepCopy());
      router->DispatchEventToExtension(
          extension_id, event_name, args_copy.Pass(), restrict_to_profile,
          GURL());
    }
  }
}

}  // namespace preference_helpers
}  // namespace extensions