/*
 * Copyright 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "device.h"

#include "buffet/dbus-proxies.h"

using com::android::Weave::CommandProxyInterface;
using com::android::Weave::ManagerProxyInterface;

namespace weaved {

Device::Device(const scoped_refptr<dbus::Bus>& bus,
               const base::Closure& state_required_callback)
    : bus_{bus}, state_required_callback_{state_required_callback} {
  weaved_object_mgr_.reset(new com::android::Weave::ObjectManagerProxy{bus_});
  weaved_object_mgr_->SetCommandAddedCallback(
      base::Bind(&Device::OnCommandAdded, base::Unretained(this)));
  weaved_object_mgr_->SetCommandRemovedCallback(
      base::Bind(&Device::OnCommandRemoved, base::Unretained(this)));
  weaved_object_mgr_->SetManagerAddedCallback(
      base::Bind(&Device::OnManagerAdded, base::Unretained(this)));
  weaved_object_mgr_->SetManagerRemovedCallback(
      base::Bind(&Device::OnManagerRemoved, base::Unretained(this)));
}

Device::~Device() {
}

std::unique_ptr<Device> Device::CreateInstance(
    const scoped_refptr<dbus::Bus>& bus,
    const base::Closure& state_required_callback) {
  return std::unique_ptr<Device>{new Device{bus, state_required_callback}};
}

void Device::AddComponent(const std::string& component,
                          const std::vector<std::string>& traits) {
  ComponentEntry entry;
  entry.component = component;
  entry.traits = traits;
  components_.push_back(std::move(entry));
  if (proxy_)
    proxy_->AddComponent(component, traits, nullptr);
}

void Device::AddCommandHandler(const std::string& component,
                               const std::string& command_name,
                               const CommandHandlerCallback& callback) {
  for (const auto& entry : command_handlers_) {
    if (entry.command_name != command_name)
      continue;
    // The command names are the same, make sure we have different components.
    // This means that both component names are not empty and are different.
    CHECK(!component.empty() && !entry.component.empty() &&
          component != entry.component)
        << "Handler for " << component << ":" << command_name << " already set";
  }
  CommandHandlerEntry entry;
  entry.component = component;
  entry.command_name = command_name;
  entry.callback = callback;

  command_handlers_.push_back(std::move(entry));

  // If there are any commands already received, call the handler immediately.
  for (auto& pair : command_map_) {
    if (pair.first->name() == command_name &&
        (component.empty() || pair.first->component() == component)) {
      if (!pair.second)
        pair.second.reset(new Command{pair.first});
      callback.Run(pair.second);
    }
  }
}

bool Device::SetStateProperties(const std::string& component,
                                const brillo::VariantDictionary& dict,
                                brillo::ErrorPtr* error) {
  if (proxy_)
    return proxy_->UpdateState(component, dict, error);

  brillo::Error::AddTo(error, FROM_HERE, "weaved", "service_unavailable",
                       "Process 'weaved' is unreachable");
  return false;
}

bool Device::SetStateProperty(const std::string& component,
                              const std::string& name,
                              const brillo::Any& value,
                              brillo::ErrorPtr* error) {
  return SetStateProperties(component, brillo::VariantDictionary{{name, value}},
                            error);
}

void Device::AddCommandHandler(const std::string& command_name,
                               const CommandHandlerCallback& callback) {
  AddCommandHandler("", command_name, callback);
}

bool Device::SetStateProperties(const brillo::VariantDictionary& dict,
                                brillo::ErrorPtr* error) {
  return SetStateProperties("", dict, error);
}

bool Device::SetStateProperty(const std::string& name,
                              const brillo::Any& value,
                              brillo::ErrorPtr* error) {
  return SetStateProperty("", name, value, error);
}

void Device::OnCommandAdded(CommandProxyInterface* proxy) {
  std::shared_ptr<Command>& command = command_map_[proxy];
  const Device::CommandHandlerCallback* callback = FindHandlerForCommand(proxy);
  if (!callback)
    return;
  if (!command)
    command.reset(new Command{proxy});
  callback->Run(command);
}

void Device::OnCommandRemoved(const dbus::ObjectPath& object_path) {
  auto proxy = weaved_object_mgr_->GetCommandProxy(object_path);
  if (!proxy)
    return;
  command_map_.erase(proxy);
}

void Device::OnManagerAdded(ManagerProxyInterface* proxy) {
  proxy_ = proxy;
  for (const auto& entry : components_)
    proxy_->AddComponent(entry.component, entry.traits, nullptr);
  state_required_callback_.Run();
}

void Device::OnManagerRemoved(const dbus::ObjectPath& object_path) {
  proxy_ = nullptr;
}

const Device::CommandHandlerCallback* Device::FindHandlerForCommand(
    com::android::Weave::CommandProxyInterface* proxy) const {
  for (const auto& entry : command_handlers_) {
    if (proxy->name() == entry.command_name &&
        (entry.component.empty() || proxy->component() == entry.component)) {
      return &entry.callback;
    }
  }
  return nullptr;
}


}  // namespace weave