/* -*- Mode: C ; c-basic-offset: 4 -*- */
/*
    Copyright (C) 2007,2008 Nedko Arnaudov
    Copyright (C) 2007-2008 Juuso Alasuutari

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif

#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <dbus/dbus.h>

#include "jackdbus.h"
#include "controller_internal.h"
#include "xml.h"

unsigned char jack_controller_dbus_types[JACK_PARAM_MAX] =
{
    [JackParamInt] = DBUS_TYPE_INT32,
    [JackParamUInt] = DBUS_TYPE_UINT32,
    [JackParamChar] = DBUS_TYPE_BYTE,
    [JackParamString] = DBUS_TYPE_STRING,
    [JackParamBool] = DBUS_TYPE_BOOLEAN,
};

const char *jack_controller_dbus_type_signatures[JACK_PARAM_MAX] =
{
    [JackParamInt] = DBUS_TYPE_INT32_AS_STRING,
    [JackParamUInt] = DBUS_TYPE_UINT32_AS_STRING,
    [JackParamChar] = DBUS_TYPE_BYTE_AS_STRING,
    [JackParamString] = DBUS_TYPE_STRING_AS_STRING,
    [JackParamBool] = DBUS_TYPE_BOOLEAN_AS_STRING,
};

#define PARAM_TYPE_JACK_TO_DBUS(_) jack_controller_dbus_types[_]
#define PARAM_TYPE_JACK_TO_DBUS_SIGNATURE(_) jack_controller_dbus_type_signatures[_]

static
bool
jack_controller_jack_to_dbus_variant(
    jackctl_param_type_t type,
    const union jackctl_parameter_value *value_ptr,
    message_arg_t  *dbusv_ptr)
{
    switch (type)
    {
    case JackParamInt:
        dbusv_ptr->int32 = (dbus_int32_t)value_ptr->i;
        return true;
    case JackParamUInt:
        dbusv_ptr->uint32 = (dbus_uint32_t)value_ptr->ui;
        return true;
    case JackParamChar:
        dbusv_ptr->byte = value_ptr->c;
        return true;
    case JackParamString:
        dbusv_ptr->string = value_ptr->str;
        return true;
    case JackParamBool:
        dbusv_ptr->boolean = (dbus_bool_t)value_ptr->b;
        return true;
    }

    jack_error("Unknown JACK parameter type %i", (int)type);
    assert(0);
    return false;
}

static
bool
jack_controller_dbus_to_jack_variant(
    int type,
    const message_arg_t *dbusv_ptr,
    union jackctl_parameter_value *value_ptr)
{
    size_t len;

    switch (type)
    {
    case DBUS_TYPE_INT32:
        value_ptr->i = dbusv_ptr->int32;
        return true;
    case DBUS_TYPE_UINT32:
        value_ptr->ui = dbusv_ptr->uint32;
        return true;
    case DBUS_TYPE_BYTE:
        value_ptr->c = dbusv_ptr->byte;
        return true;
    case DBUS_TYPE_STRING:
        len = strlen(dbusv_ptr->string);
        if (len > JACK_PARAM_STRING_MAX)
        {
            jack_error("Parameter string value is too long (%u)", (unsigned int)len);
            return false;
        }
        memcpy(value_ptr->str, dbusv_ptr->string, len + 1);

        return true;
    case DBUS_TYPE_BOOLEAN:
        value_ptr->b = dbusv_ptr->boolean;
        return true;
    }

    jack_error("Unknown D-Bus parameter type %i", (int)type);
    return false;
}

/*
 * Construct a return message for a Get[Driver|Engine]ParameterValue method call.
 *
 * The operation can only fail due to lack of memory, in which case
 * there's no sense in trying to construct an error return. Instead,
 * call->reply will be set to NULL and handled in send_method_return().
 */
static void
jack_dbus_construct_method_return_parameter(
    struct jack_dbus_method_call *call,
    dbus_bool_t is_set,
    int type,
    const char *signature,
    message_arg_t default_value,
    message_arg_t value)
{
    DBusMessageIter iter;

    /* Create a new method return message. */
    call->reply = dbus_message_new_method_return (call->message);
    if (!call->reply)
    {
        goto fail;
    }

    dbus_message_iter_init_append (call->reply, &iter);

    /* Append the is_set argument. */
    if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_BOOLEAN, (const void *) &is_set))
    {
        goto fail_unref;
    }

    /* Append the 'default' and 'value' arguments. */
    if (!jack_dbus_message_append_variant(&iter, type, signature, &default_value))
    {
        goto fail_unref;
    }
    if (!jack_dbus_message_append_variant(&iter, type, signature, &value))
    {
        goto fail_unref;
    }

    return;

fail_unref:
    dbus_message_unref (call->reply);
    call->reply = NULL;

fail:
    jack_error ("Ran out of memory trying to construct method return");
}

#define controller_ptr ((struct jack_controller *)call->context)

static
void
jack_controller_dbus_get_available_drivers(
    struct jack_dbus_method_call *call)
{
    jack_dbus_construct_method_return_array_of_strings(
        call,
        controller_ptr->drivers_count,
        controller_ptr->driver_names);
}

static
void
jack_controller_dbus_get_selected_driver(
    struct jack_dbus_method_call *call)
{
    message_arg_t arg;

    if (controller_ptr->driver != NULL)
    {
        arg.string = jackctl_driver_get_name(controller_ptr->driver);
    }
    else
    {
        arg.string = NULL;
    }

    jack_dbus_construct_method_return_single(call, DBUS_TYPE_STRING, arg);
}

static
void
jack_controller_dbus_select_driver(
    struct jack_dbus_method_call *call)
{
    const char *driver_name;

    if (!jack_dbus_get_method_args(call, DBUS_TYPE_STRING, &driver_name, DBUS_TYPE_INVALID))
    {
        /* The method call had invalid arguments meaning that
         * jack_dbus_get_method_args() has constructed an error for us.
         */
        return;
    }

    if (!jack_controller_select_driver(controller_ptr, driver_name))
    {
        /* Couldn't find driver with the specified name. */
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_DRIVER,
            "Unknown driver \"%s\"",
            driver_name);
        return;
    }

    jack_controller_settings_save_auto(controller_ptr);

    jack_dbus_construct_method_return_empty(call);
}

static
void
jack_controller_get_parameters_info(
    struct jack_dbus_method_call *call,
    const JSList *parameters_list)
{
    DBusMessageIter iter, array_iter, struct_iter;
    unsigned char type;
    const char *str;

    call->reply = dbus_message_new_method_return (call->message);
    if (!call->reply)
    {
        goto fail;
    }

    dbus_message_iter_init_append (call->reply, &iter);

    /* Open the array. */
    if (!dbus_message_iter_open_container (&iter, DBUS_TYPE_ARRAY, "(ysss)", &array_iter))
    {
        goto fail_unref;
    }

    /* Append parameter descriptions to the array. */
    while (parameters_list != NULL)
    {
        /* Open the struct. */
        if (!dbus_message_iter_open_container (&array_iter, DBUS_TYPE_STRUCT, NULL, &struct_iter))
        {
            goto fail_close_unref;
        }

        /* Append parameter type. */
        type = PARAM_TYPE_JACK_TO_DBUS(jackctl_parameter_get_type((jackctl_parameter_t *)parameters_list->data));
        if (!dbus_message_iter_append_basic (&struct_iter, DBUS_TYPE_BYTE,
                                             (const void *) &type))
        {
            goto fail_close2_unref;
        }

        /* Append parameter name. */
        str = jackctl_parameter_get_name((jackctl_parameter_t *)parameters_list->data);
        if (!dbus_message_iter_append_basic (&struct_iter, DBUS_TYPE_STRING,
                                             (const void *) &str))
        {
            goto fail_close2_unref;
        }

        /* Append parameter short description. */
        str = jackctl_parameter_get_short_description((jackctl_parameter_t *)parameters_list->data);
        if (!dbus_message_iter_append_basic (&struct_iter, DBUS_TYPE_STRING,
                                             (const void *) &str))
        {
            goto fail_close2_unref;
        }

        /* Append parameter long description. */
        str = jackctl_parameter_get_long_description((jackctl_parameter_t *)parameters_list->data);
        if (!dbus_message_iter_append_basic (&struct_iter, DBUS_TYPE_STRING,
                                             (const void *) &str))
        {
            goto fail_close2_unref;
        }

        /* Close the struct. */
        if (!dbus_message_iter_close_container (&array_iter, &struct_iter))
        {
            goto fail_close_unref;
        }

        parameters_list = jack_slist_next(parameters_list);
    }

    /* Close the array. */
    if (!dbus_message_iter_close_container (&iter, &array_iter))
    {
        goto fail_unref;
    }

    return;

fail_close2_unref:
    dbus_message_iter_close_container (&iter, &struct_iter);

fail_close_unref:
    dbus_message_iter_close_container (&iter, &array_iter);

fail_unref:
    dbus_message_unref (call->reply);
    call->reply = NULL;

fail:
    jack_error ("Ran out of memory trying to construct method return");
}

static
void
jack_controller_get_parameter_info(
    struct jack_dbus_method_call *call,
    jackctl_parameter_t *parameter)
{
    DBusMessageIter iter, struct_iter;
    unsigned char type;
    const char *str;

    call->reply = dbus_message_new_method_return (call->message);
    if (!call->reply)
    {
        goto fail;
    }

    dbus_message_iter_init_append (call->reply, &iter);

    /* Open the struct. */
    if (!dbus_message_iter_open_container (&iter, DBUS_TYPE_STRUCT, NULL, &struct_iter))
    {
        goto fail_unref;
    }

    /* Append parameter type. */
    type = PARAM_TYPE_JACK_TO_DBUS(jackctl_parameter_get_type(parameter));
    if (!dbus_message_iter_append_basic (&struct_iter, DBUS_TYPE_BYTE,
                         (const void *) &type))
    {
        goto fail_close_unref;
    }

    /* Append parameter name. */
    str = jackctl_parameter_get_name(parameter);
    if (!dbus_message_iter_append_basic (&struct_iter, DBUS_TYPE_STRING,
                         (const void *) &str))
    {
        goto fail_close_unref;
    }

    /* Append parameter short description. */
    str = jackctl_parameter_get_short_description(parameter);
    if (!dbus_message_iter_append_basic (&struct_iter, DBUS_TYPE_STRING,
                         (const void *) &str))
    {
        goto fail_close_unref;
    }

    /* Append parameter long description. */
    str = jackctl_parameter_get_long_description(parameter);
    if (!dbus_message_iter_append_basic (&struct_iter, DBUS_TYPE_STRING,
                         (const void *) &str))
    {
        goto fail_close_unref;
    }

    /* Close the struct. */
    if (!dbus_message_iter_close_container (&iter, &struct_iter))
    {
        goto fail_unref;
    }

    return;

fail_close_unref:
    dbus_message_iter_close_container (&iter, &struct_iter);

fail_unref:
    dbus_message_unref (call->reply);
    call->reply = NULL;

fail:
    jack_error ("Ran out of memory trying to construct method return");
}

/*
 * Execute GetDriverParametersInfo method call.
 */
static
void
jack_controller_dbus_get_driver_parameters_info(
    struct jack_dbus_method_call *call)
{
    if (controller_ptr->driver == NULL)
    {
        jack_dbus_error (call, JACK_DBUS_ERROR_NEED_DRIVER,
                 "No driver selected");
        return;
    }

    jack_controller_get_parameters_info(
        call,
        jackctl_driver_get_parameters(controller_ptr->driver));
}

/*
 * Execute GetDriverParameterInfo method call.
 */
static
void
jack_controller_dbus_get_driver_parameter_info(
    struct jack_dbus_method_call *call)
{
    const char *parameter_name;
    jackctl_parameter_t *parameter;

    if (controller_ptr->driver == NULL)
    {
        jack_dbus_error (call, JACK_DBUS_ERROR_NEED_DRIVER,
                 "No driver selected");
        return;
    }

    if (!jack_dbus_get_method_args(call, DBUS_TYPE_STRING, &parameter_name, DBUS_TYPE_INVALID))
    {
        /* The method call had invalid arguments meaning that
         * jack_dbus_get_method_args() has constructed an error for us.
         */
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_driver_get_parameters(controller_ptr->driver), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_DRIVER_PARAMETER,
            "Unknown parameter \"%s\" for driver \"%s\"",
            parameter_name,
            jackctl_driver_get_name(controller_ptr->driver));
        return;
    }

    jack_controller_get_parameter_info(call, parameter);
}


/*
 * Execute GetDriverParameterValue method call.
 */
static void
jack_controller_dbus_get_driver_parameter_value(
    struct jack_dbus_method_call *call)
{
    const char *parameter_name;
    jackctl_parameter_t *parameter;
    int type;
    union jackctl_parameter_value jackctl_value;
    union jackctl_parameter_value jackctl_default_value;
    message_arg_t value;
    message_arg_t default_value;

    if (controller_ptr->driver == NULL)
    {
        jack_dbus_error (call, JACK_DBUS_ERROR_NEED_DRIVER,
                 "No driver selected");
        return;
    }

    if (!jack_dbus_get_method_args(call, DBUS_TYPE_STRING, &parameter_name, DBUS_TYPE_INVALID))
    {
        /* The method call had invalid arguments meaning that
         * get_method_args() has constructed an error for us.
         */
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_driver_get_parameters(controller_ptr->driver), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_DRIVER_PARAMETER,
            "Unknown parameter \"%s\" for driver \"%s\"",
            parameter,
            jackctl_driver_get_name(controller_ptr->driver));
        return;
    }
    
    type = jackctl_parameter_get_type(parameter);
    jackctl_default_value = jackctl_parameter_get_default_value(parameter);
    jackctl_value = jackctl_parameter_get_value(parameter);

    jack_controller_jack_to_dbus_variant(type, &jackctl_value, &value);
    jack_controller_jack_to_dbus_variant(type, &jackctl_default_value, &default_value);

    /* Construct the reply. */
    jack_dbus_construct_method_return_parameter(
        call,
        (dbus_bool_t)(jackctl_parameter_is_set(parameter) ? TRUE : FALSE),
        PARAM_TYPE_JACK_TO_DBUS(type),
        PARAM_TYPE_JACK_TO_DBUS_SIGNATURE(type),
        default_value,
        value);
}

static
void
jack_controller_dbus_set_driver_parameter_value(
    struct jack_dbus_method_call *call)
{
    const char *parameter_name;
    message_arg_t arg;
    int arg_type;
    jackctl_parameter_t *parameter;
    jackctl_param_type_t type;
    union jackctl_parameter_value value;

    if (controller_ptr->driver == NULL)
    {
        jack_dbus_error (call, JACK_DBUS_ERROR_NEED_DRIVER,
                 "No driver selected");
        return;
    }

    if (!jack_dbus_get_method_args_string_and_variant(call, &parameter_name, &arg, &arg_type))
    {
        /* The method call had invalid arguments meaning that
         * jack_dbus_get_method_args_string_and_variant() has constructed
         * an error for us.
         */
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_driver_get_parameters(controller_ptr->driver), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_DRIVER_PARAMETER,
            "Unknown parameter \"%s\" for driver \"%s\"",
            parameter,
            jackctl_driver_get_name(controller_ptr->driver));
        return;
    }

    type = jackctl_parameter_get_type(parameter);

    if (PARAM_TYPE_JACK_TO_DBUS(type) != arg_type)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_INVALID_ARGS,
            "Engine parameter value type mismatch: was expecting '%c', got '%c'",
            (char)PARAM_TYPE_JACK_TO_DBUS(type),
            (char)arg_type);
        return;
    }

    if (!jack_controller_dbus_to_jack_variant(
            arg_type,
            &arg,
            &value))
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_INVALID_ARGS,
            "Cannot convert engine parameter value");
        return;
    }

    jackctl_parameter_set_value(parameter, &value);

    jack_controller_settings_save_auto(controller_ptr);

    jack_dbus_construct_method_return_empty(call);
}

/*
 * Execute GetEngineParametersInfo method call.
 */
static
void
jack_controller_dbus_get_engine_parameters_info(
    struct jack_dbus_method_call *call)
{
    jack_controller_get_parameters_info(
        call,
        jackctl_server_get_parameters(controller_ptr->server));
}

/*
 * Execute GetEngineParameterInfo method call.
 */
static
void
jack_controller_dbus_get_engine_parameter_info(
    struct jack_dbus_method_call *call)
{
    const char *parameter_name;
    jackctl_parameter_t *parameter;

    if (!jack_dbus_get_method_args(call, DBUS_TYPE_STRING, &parameter_name, DBUS_TYPE_INVALID))
    {
        /* The method call had invalid arguments meaning that
         * jack_dbus_get_method_args() has constructed an error for us.
         */
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_server_get_parameters(controller_ptr->server), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_ENGINE_PARAMETER,
            "Unknown engine parameter \"%s\"",
            parameter);
        return;
    }

    jack_controller_get_parameter_info(call, parameter);
}

/*
 * Execute GetDriverParameterValue method call.
 */
static
void
jack_controller_dbus_get_engine_parameter_value(
    struct jack_dbus_method_call *call)
{
    const char *parameter_name;
    jackctl_parameter_t *parameter;
    jackctl_param_type_t type;
    union jackctl_parameter_value jackctl_value;
    union jackctl_parameter_value jackctl_default_value;
    message_arg_t value;
    message_arg_t default_value;

    if (!jack_dbus_get_method_args(call, DBUS_TYPE_STRING, &parameter_name, DBUS_TYPE_INVALID))
    {
        /* The method call had invalid arguments meaning that
         * jack_dbus_get_method_args() has constructed an error for us.
         */
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_server_get_parameters(controller_ptr->server), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_ENGINE_PARAMETER,
            "Unknown engine parameter \"%s\"",
            parameter);
        return;
    }

    type = jackctl_parameter_get_type(parameter);
    jackctl_default_value = jackctl_parameter_get_default_value(parameter);
    jackctl_value = jackctl_parameter_get_value(parameter);

    jack_controller_jack_to_dbus_variant(type, &jackctl_value, &value);
    jack_controller_jack_to_dbus_variant(type, &jackctl_default_value, &default_value);

    /* Construct the reply. */
    jack_dbus_construct_method_return_parameter(
        call,
        (dbus_bool_t)(jackctl_parameter_is_set(parameter) ? TRUE : FALSE),
        PARAM_TYPE_JACK_TO_DBUS(type),
        PARAM_TYPE_JACK_TO_DBUS_SIGNATURE(type),
        default_value,
        value);
}

static
void
jack_controller_dbus_set_engine_parameter_value(
    struct jack_dbus_method_call *call)
{
    const char *parameter_name;
    message_arg_t arg;
    int arg_type;
    jackctl_parameter_t *parameter;
    jackctl_param_type_t type;
    union jackctl_parameter_value value;

    if (!jack_dbus_get_method_args_string_and_variant (call, &parameter_name, &arg, &arg_type))
    {
        /* The method call had invalid arguments meaning that
         * jack_dbus_get_method_args_string_and_variant() has constructed
         * an error for us.
         */
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_server_get_parameters(controller_ptr->server), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_ENGINE_PARAMETER,
            "Unknown engine parameter \"%s\"",
            parameter);
        return;
    }

    type = jackctl_parameter_get_type(parameter);

    if (PARAM_TYPE_JACK_TO_DBUS(type) != arg_type)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_INVALID_ARGS,
            "Engine parameter value type mismatch: was expecting '%c', got '%c'",
            (char)PARAM_TYPE_JACK_TO_DBUS(type),
            (char)arg_type);
        return;
    }

    if (!jack_controller_dbus_to_jack_variant(
            arg_type,
            &arg,
            &value))
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_INVALID_ARGS,
            "Cannot convert engine parameter value");
        return;
    }

    jackctl_parameter_set_value(parameter, &value);

    jack_controller_settings_save_auto(controller_ptr);

    jack_dbus_construct_method_return_empty(call);
}

static
void
jack_controller_dbus_get_available_internals(
    struct jack_dbus_method_call *call)
{
    jack_dbus_construct_method_return_array_of_strings(
        call,
        controller_ptr->internals_count,
        controller_ptr->internal_names);
}

/*
 * Execute GetInternalParametersInfo method call.
 */
static
void
jack_controller_dbus_get_internal_parameters_info(
    struct jack_dbus_method_call *call)
{
    const char *internal_name;
    jackctl_internal_t * internal;

    if (!jack_dbus_get_method_args(call, DBUS_TYPE_STRING, &internal_name, DBUS_TYPE_INVALID))
    {
        /* The method call had invalid arguments meaning that
         * get_method_args() has constructed an error for us.
         */
        return;
    }

    internal = jack_controller_find_internal(controller_ptr->server, internal_name);
    if (internal == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_INTERNAL,
            "Unknown internal \"%s\"",
            internal_name);
        return;
    }

    jack_controller_get_parameters_info(call, jackctl_internal_get_parameters(internal));
}

/*
 * Execute GetInternalParameterInfo method call.
 */
static
void
jack_controller_dbus_get_internal_parameter_info(
    struct jack_dbus_method_call *call)
{
    const char *internal_name;
    const char *parameter_name;
    jackctl_parameter_t *parameter;
    jackctl_internal_t * internal;

    if (!jack_dbus_get_method_args(call, DBUS_TYPE_STRING, &internal_name, DBUS_TYPE_STRING, &parameter_name, DBUS_TYPE_INVALID))
    {
        /* The method call had invalid arguments meaning that
         * get_method_args() has constructed an error for us.
         */
        return;
    }

    internal = jack_controller_find_internal(controller_ptr->server, internal_name);
    if (internal == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_INTERNAL,
            "Unknown internal \"%s\"",
            internal_name);
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_internal_get_parameters(internal), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_DRIVER_PARAMETER,
            "Unknown parameter \"%s\" for driver \"%s\"",
            parameter_name,
            jackctl_driver_get_name(controller_ptr->driver));
        return;
    }

    jack_controller_get_parameter_info(call, parameter);
}

/*
 * Execute GetInternalParameterValue method call.
 */
static void
jack_controller_dbus_get_internal_parameter_value(
    struct jack_dbus_method_call *call)
{
    const char *internal_name;
    const char *parameter_name;
    jackctl_parameter_t *parameter;
    jackctl_internal_t * internal;
    int type;
    union jackctl_parameter_value jackctl_value;
    union jackctl_parameter_value jackctl_default_value;
    message_arg_t value;
    message_arg_t default_value;

    if (!jack_dbus_get_method_args(call, DBUS_TYPE_STRING, &internal_name, DBUS_TYPE_STRING, &parameter_name, DBUS_TYPE_INVALID))
    {
        /* The method call had invalid arguments meaning that
         * get_method_args() has constructed an error for us.
         */
        return;
    }

    internal = jack_controller_find_internal(controller_ptr->server, internal_name);
    if (internal == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_INTERNAL,
            "Unknown internal \"%s\"",
            internal_name);
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_internal_get_parameters(internal), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_DRIVER_PARAMETER,
            "Unknown parameter \"%s\" for driver \"%s\"",
            parameter,
            jackctl_driver_get_name(controller_ptr->driver));
        return;
    }
    
    type = jackctl_parameter_get_type(parameter);
    jackctl_default_value = jackctl_parameter_get_default_value(parameter);
    jackctl_value = jackctl_parameter_get_value(parameter);

    jack_controller_jack_to_dbus_variant(type, &jackctl_value, &value);
    jack_controller_jack_to_dbus_variant(type, &jackctl_default_value, &default_value);

    /* Construct the reply. */
    jack_dbus_construct_method_return_parameter(
        call,
        (dbus_bool_t)(jackctl_parameter_is_set(parameter) ? TRUE : FALSE),
        PARAM_TYPE_JACK_TO_DBUS(type),
        PARAM_TYPE_JACK_TO_DBUS_SIGNATURE(type),
        default_value,
        value);
}

static
void
jack_controller_dbus_set_internal_parameter_value(
    struct jack_dbus_method_call *call)
{
    const char *internal_name;
    const char *parameter_name;
    jackctl_internal_t * internal;
    message_arg_t arg;
    int arg_type;
    jackctl_parameter_t *parameter;
    jackctl_param_type_t type;
    union jackctl_parameter_value value;

    if (!jack_dbus_get_method_args_two_strings_and_variant(call, &internal_name, &parameter_name, &arg, &arg_type))
    {
        /* The method call had invalid arguments meaning that
         * jack_dbus_get_method_args_two_strings_and_variant() has constructed
         * an error for us.
         */
        return;
    }

    internal = jack_controller_find_internal(controller_ptr->server, internal_name);
    if (internal == NULL)
    {
       jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_INTERNAL,
            "Unknown internal \"%s\"",
            internal_name);
        return;
    }

    parameter = jack_controller_find_parameter(jackctl_internal_get_parameters(internal), parameter_name);
    if (parameter == NULL)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_UNKNOWN_DRIVER_PARAMETER,
            "Unknown parameter \"%s\" for driver \"%s\"",
            parameter,
            jackctl_driver_get_name(controller_ptr->driver));
        return;
    }

    type = jackctl_parameter_get_type(parameter);

    if (PARAM_TYPE_JACK_TO_DBUS(type) != arg_type)
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_INVALID_ARGS,
            "Engine parameter value type mismatch: was expecting '%c', got '%c'",
            (char)PARAM_TYPE_JACK_TO_DBUS(type),
            (char)arg_type);
        return;
    }

    if (!jack_controller_dbus_to_jack_variant(
            arg_type,
            &arg,
            &value))
    {
        jack_dbus_error(
            call,
            JACK_DBUS_ERROR_INVALID_ARGS,
            "Cannot convert engine parameter value");
        return;
    }

    jackctl_parameter_set_value(parameter, &value);

    jack_controller_settings_save_auto(controller_ptr);

    jack_dbus_construct_method_return_empty(call);
}


#undef controller_ptr

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetAvailableDrivers)
    JACK_DBUS_METHOD_ARGUMENT("drivers_list", "as", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetSelectedDriver)
    JACK_DBUS_METHOD_ARGUMENT("driver", "s", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(SelectDriver)
    JACK_DBUS_METHOD_ARGUMENT("driver", "s", false)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetDriverParametersInfo)
    JACK_DBUS_METHOD_ARGUMENT("parameter_info_array", "a(ysss)", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetDriverParameterInfo)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("parameter_info", "(ysss)", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetDriverParameterValue)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("is_set", "b", true)
    JACK_DBUS_METHOD_ARGUMENT("default", "v", true)
    JACK_DBUS_METHOD_ARGUMENT("value", "v", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(SetDriverParameterValue)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("value", "v", false)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetEngineParametersInfo)
    JACK_DBUS_METHOD_ARGUMENT("parameter_info_array", "a(ysss)", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetEngineParameterInfo)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("parameter_info", "(ysss)", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetEngineParameterValue)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("is_set", "b", true)
    JACK_DBUS_METHOD_ARGUMENT("default", "v", true)
    JACK_DBUS_METHOD_ARGUMENT("value", "v", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(SetEngineParameterValue)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("value", "v", false)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetAvailableInternals)
    JACK_DBUS_METHOD_ARGUMENT("internals_list", "as", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetInternalParametersInfo)
    JACK_DBUS_METHOD_ARGUMENT("internal", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("parameter_info_array", "a(ysss)", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetInternalParameterInfo)
    JACK_DBUS_METHOD_ARGUMENT("internal", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("parameter_info", "(ysss)", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(GetInternalParameterValue)
    JACK_DBUS_METHOD_ARGUMENT("internal", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("is_set", "b", true)
    JACK_DBUS_METHOD_ARGUMENT("default", "v", true)
    JACK_DBUS_METHOD_ARGUMENT("value", "v", true)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHOD_ARGUMENTS_BEGIN(SetInternalParameterValue)
    JACK_DBUS_METHOD_ARGUMENT("internal", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("parameter", "s", false)
    JACK_DBUS_METHOD_ARGUMENT("value", "v", false)
JACK_DBUS_METHOD_ARGUMENTS_END

JACK_DBUS_METHODS_BEGIN
    JACK_DBUS_METHOD_DESCRIBE(GetAvailableDrivers, jack_controller_dbus_get_available_drivers)
    JACK_DBUS_METHOD_DESCRIBE(GetSelectedDriver, jack_controller_dbus_get_selected_driver)
    JACK_DBUS_METHOD_DESCRIBE(SelectDriver, jack_controller_dbus_select_driver)
    JACK_DBUS_METHOD_DESCRIBE(GetDriverParametersInfo, jack_controller_dbus_get_driver_parameters_info)
    JACK_DBUS_METHOD_DESCRIBE(GetDriverParameterInfo, jack_controller_dbus_get_driver_parameter_info)
    JACK_DBUS_METHOD_DESCRIBE(GetDriverParameterValue, jack_controller_dbus_get_driver_parameter_value)
    JACK_DBUS_METHOD_DESCRIBE(SetDriverParameterValue, jack_controller_dbus_set_driver_parameter_value)
    JACK_DBUS_METHOD_DESCRIBE(GetEngineParametersInfo, jack_controller_dbus_get_engine_parameters_info)
    JACK_DBUS_METHOD_DESCRIBE(GetEngineParameterInfo, jack_controller_dbus_get_engine_parameter_info)
    JACK_DBUS_METHOD_DESCRIBE(GetEngineParameterValue, jack_controller_dbus_get_engine_parameter_value)
    JACK_DBUS_METHOD_DESCRIBE(SetEngineParameterValue, jack_controller_dbus_set_engine_parameter_value)
    JACK_DBUS_METHOD_DESCRIBE(GetAvailableInternals, jack_controller_dbus_get_available_internals)
    JACK_DBUS_METHOD_DESCRIBE(GetInternalParametersInfo, jack_controller_dbus_get_internal_parameters_info)
    JACK_DBUS_METHOD_DESCRIBE(GetInternalParameterInfo, jack_controller_dbus_get_internal_parameter_info)
    JACK_DBUS_METHOD_DESCRIBE(GetInternalParameterValue, jack_controller_dbus_get_internal_parameter_value)
    JACK_DBUS_METHOD_DESCRIBE(SetInternalParameterValue, jack_controller_dbus_set_internal_parameter_value)
JACK_DBUS_METHODS_END

JACK_DBUS_IFACE_BEGIN(g_jack_controller_iface_configure, "org.jackaudio.JackConfigure")
    JACK_DBUS_IFACE_EXPOSE_METHODS
JACK_DBUS_IFACE_END