// Copyright (c) 2015 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 "components/policy/core/common/policy_loader_mac.h"

#include <utility>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/callback.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/mac/foundation_util.h"
#include "base/mac/scoped_cftyperef.h"
#include "base/sequenced_task_runner.h"
#include "base/strings/sys_string_conversions.h"
#include "base/values.h"
#include "build/build_config.h"
#include "components/policy/core/common/external_data_fetcher.h"
#include "components/policy/core/common/mac_util.h"
#include "components/policy/core/common/policy_bundle.h"
#include "components/policy/core/common/policy_load_status.h"
#include "components/policy/core/common/policy_map.h"
#include "components/policy/core/common/preferences_mac.h"
#include "components/policy/core/common/schema.h"
#include "components/policy/core/common/schema_map.h"

using base::ScopedCFTypeRef;

namespace policy {

PolicyLoaderMac::PolicyLoaderMac(
    scoped_refptr<base::SequencedTaskRunner> task_runner,
    const base::FilePath& managed_policy_path,
    MacPreferences* preferences)
    : AsyncPolicyLoader(task_runner),
      preferences_(preferences),
      managed_policy_path_(managed_policy_path),
      application_id_(kCFPreferencesCurrentApplication) {
}

PolicyLoaderMac::PolicyLoaderMac(
    scoped_refptr<base::SequencedTaskRunner> task_runner,
    const base::FilePath& managed_policy_path,
    MacPreferences* preferences,
    CFStringRef application_id)
    : AsyncPolicyLoader(task_runner),
      preferences_(preferences),
      managed_policy_path_(managed_policy_path),
      application_id_(application_id) {
}

PolicyLoaderMac::~PolicyLoaderMac() {
}

void PolicyLoaderMac::InitOnBackgroundThread() {
  if (!managed_policy_path_.empty()) {
    watcher_.Watch(
        managed_policy_path_, false,
        base::Bind(&PolicyLoaderMac::OnFileUpdated, base::Unretained(this)));
  }
}

std::unique_ptr<PolicyBundle> PolicyLoaderMac::Load() {
  preferences_->AppSynchronize(application_id_);
  std::unique_ptr<PolicyBundle> bundle(new PolicyBundle());

  // Load Chrome's policy.
  PolicyMap& chrome_policy =
      bundle->Get(PolicyNamespace(POLICY_DOMAIN_CHROME, std::string()));

  PolicyLoadStatusSample status;
  bool policy_present = false;
  const Schema* schema =
      schema_map()->GetSchema(PolicyNamespace(POLICY_DOMAIN_CHROME, ""));
  for (Schema::Iterator it = schema->GetPropertiesIterator(); !it.IsAtEnd();
       it.Advance()) {
    base::ScopedCFTypeRef<CFStringRef> name(
        base::SysUTF8ToCFStringRef(it.key()));
    base::ScopedCFTypeRef<CFPropertyListRef> value(
        preferences_->CopyAppValue(name, application_id_));
    if (!value)
      continue;
    policy_present = true;
    bool forced = preferences_->AppValueIsForced(name, application_id_);
    PolicyLevel level =
        forced ? POLICY_LEVEL_MANDATORY : POLICY_LEVEL_RECOMMENDED;
    // TODO(joaodasilva): figure the policy scope.
    std::unique_ptr<base::Value> policy = PropertyToValue(value);
    if (policy) {
      chrome_policy.Set(it.key(), level, POLICY_SCOPE_USER,
                        POLICY_SOURCE_PLATFORM, std::move(policy), nullptr);
    } else {
      status.Add(POLICY_LOAD_STATUS_PARSE_ERROR);
    }
  }

  if (!policy_present)
    status.Add(POLICY_LOAD_STATUS_NO_POLICY);

  // Load policy for the registered components.
  LoadPolicyForDomain(POLICY_DOMAIN_EXTENSIONS, "extensions", bundle.get());

  return bundle;
}

base::Time PolicyLoaderMac::LastModificationTime() {
  base::File::Info file_info;
  if (!base::GetFileInfo(managed_policy_path_, &file_info) ||
      file_info.is_directory) {
    return base::Time();
  }

  return file_info.last_modified;
}

#if defined(OS_MACOSX) && !defined(OS_IOS)

base::FilePath PolicyLoaderMac::GetManagedPolicyPath(CFStringRef bundle_id) {
  // This constructs the path to the plist file in which Mac OS X stores the
  // managed preference for the application. This is undocumented and therefore
  // fragile, but if it doesn't work out, AsyncPolicyLoader has a task that
  // polls periodically in order to reload managed preferences later even if we
  // missed the change.

  base::FilePath path;
  if (!base::mac::GetLocalDirectory(NSLibraryDirectory, &path))
    return base::FilePath();
  path = path.Append(FILE_PATH_LITERAL("Managed Preferences"));
  char* login = getlogin();
  if (!login)
    return base::FilePath();
  path = path.AppendASCII(login);
  return path.Append(base::SysCFStringRefToUTF8(bundle_id) + ".plist");
}

#endif

void PolicyLoaderMac::LoadPolicyForDomain(PolicyDomain domain,
                                          const std::string& domain_name,
                                          PolicyBundle* bundle) {
  std::string id_prefix(base::mac::BaseBundleID());
  id_prefix.append(".").append(domain_name).append(".");

  const ComponentMap* components = schema_map()->GetComponents(domain);
  if (!components)
    return;

  for (ComponentMap::const_iterator it = components->begin();
       it != components->end(); ++it) {
    PolicyMap policy;
    LoadPolicyForComponent(id_prefix + it->first, it->second, &policy);
    if (!policy.empty())
      bundle->Get(PolicyNamespace(domain, it->first)).Swap(&policy);
  }
}

void PolicyLoaderMac::LoadPolicyForComponent(
    const std::string& bundle_id_string,
    const Schema& schema,
    PolicyMap* policy) {
  // TODO(joaodasilva): Extensions may be registered in a ComponentMap
  // without a schema, to allow a graceful update of the Legacy Browser Support
  // extension on Windows. Remove this check once that support is removed.
  if (!schema.valid())
    return;

  base::ScopedCFTypeRef<CFStringRef> bundle_id(
      base::SysUTF8ToCFStringRef(bundle_id_string));
  preferences_->AppSynchronize(bundle_id);

  for (Schema::Iterator it = schema.GetPropertiesIterator(); !it.IsAtEnd();
       it.Advance()) {
    base::ScopedCFTypeRef<CFStringRef> pref_name(
        base::SysUTF8ToCFStringRef(it.key()));
    base::ScopedCFTypeRef<CFPropertyListRef> value(
        preferences_->CopyAppValue(pref_name, bundle_id));
    if (!value)
      continue;
    bool forced = preferences_->AppValueIsForced(pref_name, bundle_id);
    PolicyLevel level =
        forced ? POLICY_LEVEL_MANDATORY : POLICY_LEVEL_RECOMMENDED;
    std::unique_ptr<base::Value> policy_value = PropertyToValue(value);
    if (policy_value) {
      policy->Set(it.key(), level, POLICY_SCOPE_USER, POLICY_SOURCE_PLATFORM,
                  std::move(policy_value), nullptr);
    }
  }
}

void PolicyLoaderMac::OnFileUpdated(const base::FilePath& path, bool error) {
  if (!error)
    Reload(false);
}

}  // namespace policy