// Copyright 2014 The Chromium OS 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 "buffet/commands/command_manager.h"

#include <base/files/file_enumerator.h>
#include <base/values.h>
#include <chromeos/dbus/exported_object_manager.h>
#include <chromeos/errors/error.h>

#include "buffet/commands/schema_constants.h"
#include "buffet/utils.h"

using chromeos::dbus_utils::ExportedObjectManager;

namespace buffet {

CommandManager::CommandManager()
    : CommandManager(base::WeakPtr<ExportedObjectManager>{}) {
}

CommandManager::CommandManager(
    const base::WeakPtr<ExportedObjectManager>& object_manager)
    : command_dispatcher_(object_manager) {
  command_queue_.AddOnCommandAddedCallback(
      base::Bind(&DBusCommandDispacher::OnCommandAdded,
                 base::Unretained(&command_dispatcher_)));
}

const CommandDictionary& CommandManager::GetCommandDictionary() const {
  return dictionary_;
}

bool CommandManager::LoadBaseCommands(const base::DictionaryValue& json,
                                      chromeos::ErrorPtr* error) {
  return base_dictionary_.LoadCommands(json, "", nullptr, error);
}

bool CommandManager::LoadBaseCommands(const base::FilePath& json_file_path,
                                      chromeos::ErrorPtr* error) {
  std::unique_ptr<const base::DictionaryValue> json = LoadJsonDict(
      json_file_path, error);
  if (!json)
    return false;
  return LoadBaseCommands(*json, error);
}

bool CommandManager::LoadCommands(const base::DictionaryValue& json,
                                  const std::string& category,
                                  chromeos::ErrorPtr* error) {
  bool result =
      dictionary_.LoadCommands(json, category, &base_dictionary_, error);
  for (const auto& cb : on_command_changed_)
    cb.Run();
  return result;
}

bool CommandManager::LoadCommands(const base::FilePath& json_file_path,
                                  chromeos::ErrorPtr* error) {
  std::unique_ptr<const base::DictionaryValue> json = LoadJsonDict(
      json_file_path, error);
  if (!json)
    return false;
  std::string category = json_file_path.BaseName().RemoveExtension().value();
  return LoadCommands(*json, category, error);
}

void CommandManager::Startup(const base::FilePath& definitions_path,
                             const base::FilePath& test_definitions_path) {
  LOG(INFO) << "Initializing CommandManager.";
  // Load global standard GCD command dictionary.
  base::FilePath base_command_file{definitions_path.Append("gcd.json")};
  LOG(INFO) << "Loading standard commands from " << base_command_file.value();
  CHECK(LoadBaseCommands(base_command_file, nullptr))
      << "Failed to load the standard command definitions.";

  auto LoadPackages = [this](const base::FilePath& root,
                             const base::FilePath::StringType& pattern) {
    base::FilePath device_command_dir{root.Append("commands")};
    VLOG(2) << "Looking for commands in " << root.value();
    base::FileEnumerator enumerator(device_command_dir, false,
                                    base::FileEnumerator::FILES,
                                    pattern);
    base::FilePath json_file_path = enumerator.Next();
    while (!json_file_path.empty()) {
      LOG(INFO) << "Loading command schema from " << json_file_path.value();
      CHECK(this->LoadCommands(json_file_path, nullptr))
          << "Failed to load the command definition file.";
      json_file_path = enumerator.Next();
    }
  };
  LoadPackages(definitions_path, FILE_PATH_LITERAL("*.json"));
  LoadPackages(test_definitions_path, FILE_PATH_LITERAL("*test.json"));
}

void CommandManager::AddCommand(
    std::unique_ptr<CommandInstance> command_instance) {
  command_queue_.Add(std::move(command_instance));
}

bool CommandManager::AddCommand(const base::DictionaryValue& command,
                                UserRole role,
                                std::string* id,
                                chromeos::ErrorPtr* error) {
  auto command_instance = buffet::CommandInstance::FromJson(
      &command, commands::attributes::kCommand_Visibility_Local,
      GetCommandDictionary(), nullptr, error);
  if (!command_instance)
    return false;

  UserRole minimal_role =
      command_instance->GetCommandDefinition()->GetMinimalRole();
  if (role < minimal_role) {
    chromeos::Error::AddToPrintf(
        error, FROM_HERE, errors::commands::kDomain, "access_denied",
        "User role '%s' less than minimal: '%s'", ToString(role).c_str(),
        ToString(minimal_role).c_str());
    return false;
  }

  *id = std::to_string(++next_command_id_);
  command_instance->SetID(*id);
  AddCommand(std::move(command_instance));
  return true;
}

CommandInstance* CommandManager::FindCommand(const std::string& id) const {
  return command_queue_.Find(id);
}

bool CommandManager::SetCommandVisibility(
    const std::vector<std::string>& command_names,
    CommandDefinition::Visibility visibility,
    chromeos::ErrorPtr* error) {
  if (command_names.empty())
    return true;

  std::vector<CommandDefinition*> definitions;
  definitions.reserve(command_names.size());

  // Find/validate command definitions first.
  for (const std::string& name : command_names) {
    CommandDefinition* def = dictionary_.FindCommand(name);
    if (!def) {
      chromeos::Error::AddToPrintf(error, FROM_HERE, errors::commands::kDomain,
                                   errors::commands::kInvalidCommandName,
                                   "Command '%s' is unknown", name.c_str());
      return false;
    }
    definitions.push_back(def);
  }

  // Now that we know that all the command names were valid,
  // update the respective commands' visibility.
  for (CommandDefinition* def : definitions)
    def->SetVisibility(visibility);
  for (const auto& cb : on_command_changed_)
    cb.Run();
  return true;
}

void CommandManager::AddOnCommandAddedCallback(
    const CommandQueue::Callback& callback) {
  command_queue_.AddOnCommandAddedCallback(callback);
}

void CommandManager::AddOnCommandRemovedCallback(
    const CommandQueue::Callback& callback) {
  command_queue_.AddOnCommandRemovedCallback(callback);
}

}  // namespace buffet