/*
 *    Copyright (c) 2019, The OpenThread Authors.
 *    All rights reserved.
 *
 *    Redistribution and use in source and binary forms, with or without
 *    modification, are permitted provided that the following conditions are met:
 *    1. Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *    2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *    3. Neither the name of the copyright holder nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 *    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 *    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *    POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file
 * This file includes definitions for a d-bus object.
 */

#ifndef OTBR_DBUS_DBUS_OBJECT_HPP_
#define OTBR_DBUS_DBUS_OBJECT_HPP_

#include "openthread-br/config.h"

#ifndef OTBR_LOG_TAG
#define OTBR_LOG_TAG "DBUS"
#endif

#include <functional>
#include <memory>
#include <string>
#include <unordered_map>

#include <dbus/dbus.h>

#include "common/code_utils.hpp"
#include "common/types.hpp"
#include "dbus/common/constants.hpp"
#include "dbus/common/dbus_message_dump.hpp"
#include "dbus/common/dbus_message_helper.hpp"
#include "dbus/common/dbus_resources.hpp"
#include "dbus/server/dbus_request.hpp"

namespace otbr {
namespace DBus {

/**
 * This class is a base class for implementing a d-bus object.
 */
class DBusObject : private NonCopyable
{
public:
    using MethodHandlerType        = std::function<void(DBusRequest &)>;
    using AsyncPropertyHandlerType = std::function<void(DBusRequest &)>;
    using PropertyHandlerType      = std::function<otError(DBusMessageIter &)>;

    /**
     * The constructor of a d-bus object.
     *
     * @param[in] aConnection  The dbus-connection the object bounds to.
     * @param[in] aObjectPath  The path of the object.
     */
    DBusObject(DBusConnection *aConnection, const std::string &aObjectPath);

    /**
     * This method initializes the d-bus object.
     *
     * This method will register the object to the d-bus library.
     *
     * @retval OTBR_ERROR_NONE  Successfully registered the object.
     * @retval OTBR_ERROR_DBUS  Failed to ragister an object.
     */
    virtual otbrError Init(void);

    /**
     * This method registers the method handler.
     *
     * @param[in] aInterfaceName  The interface name.
     * @param[in] aMethodName     The method name.
     * @param[in] aHandler        The method handler.
     */
    void RegisterMethod(const std::string       &aInterfaceName,
                        const std::string       &aMethodName,
                        const MethodHandlerType &aHandler);

    /**
     * This method registers the get handler for a property.
     *
     * @param[in] aInterfaceName  The interface name.
     * @param[in] aPropertyName   The property name.
     * @param[in] aHandler        The method handler.
     */
    virtual void RegisterGetPropertyHandler(const std::string         &aInterfaceName,
                                            const std::string         &aPropertyName,
                                            const PropertyHandlerType &aHandler);

    /**
     * This method registers the set handler for a property.
     *
     * @param[in] aInterfaceName  The interface name.
     * @param[in] aPropertyName   The property name.
     * @param[in] aHandler        The method handler.
     */
    virtual void RegisterSetPropertyHandler(const std::string         &aInterfaceName,
                                            const std::string         &aPropertyName,
                                            const PropertyHandlerType &aHandler);

    /**
     * This method registers the async get handler for a property.
     *
     * @param[in] aInterfaceName  The interface name.
     * @param[in] aPropertyName   The property name.
     * @param[in] aHandler        The method handler.
     */
    virtual void RegisterAsyncGetPropertyHandler(const std::string              &aInterfaceName,
                                                 const std::string              &aPropertyName,
                                                 const AsyncPropertyHandlerType &aHandler);

    /**
     * This method sends a signal.
     *
     * @param[in] aInterfaceName  The interface name.
     * @param[in] aSignalName     The signal name.
     * @param[in] aArgs           The tuple to be encoded into the signal.
     *
     * @retval OTBR_ERROR_NONE  Signal successfully sent.
     * @retval OTBR_ERROR_DBUS  Failed to send the signal.
     */
    template <typename... FieldTypes>
    otbrError Signal(const std::string               &aInterfaceName,
                     const std::string               &aSignalName,
                     const std::tuple<FieldTypes...> &aArgs)
    {
        UniqueDBusMessage signalMsg = NewSignalMessage(aInterfaceName, aSignalName);
        otbrError         error     = OTBR_ERROR_NONE;

        VerifyOrExit(signalMsg != nullptr, error = OTBR_ERROR_DBUS);
        SuccessOrExit(error = otbr::DBus::TupleToDBusMessage(*signalMsg, aArgs));

        VerifyOrExit(dbus_connection_send(mConnection, signalMsg.get(), nullptr), error = OTBR_ERROR_DBUS);

    exit:
        return error;
    }

    /**
     * This method sends a property changed signal.
     *
     * @param[in] aInterfaceName  The interface name.
     * @param[in] aPropertyName   The property name.
     * @param[in] aValue          New value of the property.
     *
     * @retval OTBR_ERROR_NONE  Signal successfully sent.
     * @retval OTBR_ERROR_DBUS  Failed to send the signal.
     */
    template <typename ValueType>
    otbrError SignalPropertyChanged(const std::string &aInterfaceName,
                                    const std::string &aPropertyName,
                                    const ValueType   &aValue)
    {
        UniqueDBusMessage signalMsg = NewSignalMessage(DBUS_INTERFACE_PROPERTIES, DBUS_PROPERTIES_CHANGED_SIGNAL);
        DBusMessageIter   iter, subIter, dictEntryIter;
        otbrError         error = OTBR_ERROR_NONE;

        VerifyOrExit(signalMsg != nullptr, error = OTBR_ERROR_DBUS);
        dbus_message_iter_init_append(signalMsg.get(), &iter);

        // interface_name
        VerifyOrExit(DBusMessageEncode(&iter, aInterfaceName) == OTBR_ERROR_NONE, error = OTBR_ERROR_DBUS);

        // changed_properties
        VerifyOrExit(dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY,
                                                      "{" DBUS_TYPE_STRING_AS_STRING DBUS_TYPE_VARIANT_AS_STRING "}",
                                                      &subIter),
                     error = OTBR_ERROR_DBUS);
        VerifyOrExit(dbus_message_iter_open_container(&subIter, DBUS_TYPE_DICT_ENTRY, nullptr, &dictEntryIter),
                     error = OTBR_ERROR_DBUS);

        SuccessOrExit(error = DBusMessageEncode(&dictEntryIter, aPropertyName));
        SuccessOrExit(error = DBusMessageEncodeToVariant(&dictEntryIter, aValue));

        VerifyOrExit(dbus_message_iter_close_container(&subIter, &dictEntryIter), error = OTBR_ERROR_DBUS);
        VerifyOrExit(dbus_message_iter_close_container(&iter, &subIter), error = OTBR_ERROR_DBUS);

        // invalidated_properties
        SuccessOrExit(error = DBusMessageEncode(&iter, std::vector<std::string>()));

        if (otbrLogGetLevel() >= OTBR_LOG_DEBUG)
        {
            otbrLogDebug("Signal %s.%s", aInterfaceName.c_str(), aPropertyName.c_str());
            DumpDBusMessage(*signalMsg);
        }

        VerifyOrExit(dbus_connection_send(mConnection, signalMsg.get(), nullptr), error = OTBR_ERROR_DBUS);

    exit:
        return error;
    }

    /**
     * The destructor of a d-bus object.
     */
    virtual ~DBusObject(void);

    /**
     * Sends all outgoing messages, blocks until the message queue is empty.
     */
    void Flush(void);

protected:
    otbrError Initialize(bool aIsAsyncPropertyHandler);

private:
    void GetAllPropertiesMethodHandler(DBusRequest &aRequest);
    void GetPropertyMethodHandler(DBusRequest &aRequest);
    void SetPropertyMethodHandler(DBusRequest &aRequest);
    void AsyncGetPropertyMethodHandler(DBusRequest &aRequest);

    static DBusHandlerResult sMessageHandler(DBusConnection *aConnection, DBusMessage *aMessage, void *aData);
    DBusHandlerResult        MessageHandler(DBusConnection *aConnection, DBusMessage *aMessage);

    UniqueDBusMessage NewSignalMessage(const std::string &aInterfaceName, const std::string &aSignalName);

    std::unordered_map<std::string, MethodHandlerType>                                    mMethodHandlers;
    std::unordered_map<std::string, std::unordered_map<std::string, PropertyHandlerType>> mGetPropertyHandlers;
    std::unordered_map<std::string, std::unordered_map<std::string, AsyncPropertyHandlerType>>
                                                         mAsyncGetPropertyHandlers;
    std::unordered_map<std::string, PropertyHandlerType> mSetPropertyHandlers;
    DBusConnection                                      *mConnection;
    std::string                                          mObjectPath;
};

} // namespace DBus
} // namespace otbr

#endif // OTBR_DBUS_DBUS_SERVER_HPP_