%%% @author Jean Parpaillon <jean.parpaillon@free.fr>
%%% @copyright (C) 2015, Jean Parpaillon
%%% @doc Specific methods for a proxy of an object implementing 
%%% 'org.freedesktop.DBus.Properties' interface.
%%%
%%% See <a href="https://dbus.freedesktop.org/doc/dbus-specification.html#standard-interfaces-properties">D-Bus specification</a>
%%% @end
%%% Created : 19 Oct 2015 by Jean Parpaillon <jean.parpaillon@free.fr>

-module(dbus_properties_proxy).

-include("dbus_client.hrl").
-include("dbus_properties.hrl").

-export([get/3,
         set/4,
         get_all/2,
         connect/2]).


%% @doc Get a property value
%% @end
-spec get(Proxy :: dbus_proxy:t(), Iface :: dbus_name(), Prop :: dbus_name()) -> term().
get(Proxy, Iface, Prop) ->
    case dbus_proxy:call(Proxy, ?DBUS_IFACE_PROPERTIES, <<"Get">>, [Iface, Prop]) of
        {ok, Value} -> 
	    Value;
        {error, Err} -> throw(Err)
    end.


%% @doc Set a property value
%% @end
-spec set(Proxy :: dbus_proxy:t(), Iface :: dbus_name(), Prop :: dbus_name(), Val :: term()) -> ok.
set(Proxy, Iface, Prop, Value) ->
    case dbus_proxy:call(Proxy, ?DBUS_IFACE_PROPERTIES, <<"Set">>, [Iface, Prop, Value]) of
        {ok, []} -> ok;
        {error, Err} -> throw(Err)
    end.


%% @doc Get a key-value list of properties
%% @end
-spec get_all(Proxy :: dbus_proxy:t(), Iface :: dbus_name()) -> [{dbus_name(), dbus_variant()}].
get_all(Proxy, Iface) ->
    case dbus_proxy:call(Proxy, ?DBUS_IFACE_PROPERTIES, <<"GetAll">>, [Iface]) of
        {ok, [Props]} -> Props;
        {error, Err} -> throw(Err)
    end.


%% @doc Connect to the 'PropertiesChanged' signal.
%% @end
-spec connect(Proxy :: dbus_proxy:t(), Handler :: dbus_proxy:handler()) -> ok | {error, term()}.
connect(Proxy, Handler) ->
    dbus_proxy:connect_signal(Proxy, ?DBUS_IFACE_PROPERTIES, <<"PropertiesChanged">>, Handler).