/**
 * Same example as client-stubs, but implementing the asynchronous
 * logic by using GLib/D-Bus wrapper functions directly. This version
 * of the asynchronous client does not require the generated stubs.
 *
 * This maemo code example is licensed under a MIT-style license,
 * that can be found in the file called "License" in the same
 * directory as this file.
 * Copyright (c) 2007-2008 Nokia Corporation. All rights reserved.
 */

#include <glib.h>
#include <dbus/dbus-glib.h>
#include <stdlib.h> /* exit */

/* Pull the common symbolic defines. */
#include "common-defs.h"

/**
 * Print out an error message and optionally quit (if fatal is TRUE)
 */
static void handleError(const char* msg, const char* reason,
                                         gboolean fatal) {
  g_printerr(PROGNAME ": ERROR: %s (%s)\n", msg, reason);
  if (fatal) {
    exit(EXIT_FAILURE);
  }
}

/**
 * This function will be called when the async setvalue1 will either
 * complete, timeout or fail (same as before). The main difference in
 * using GLib/D-Bus wrappers is that we need to "collect" the return
 * value (or error). This is done with the _end_call function.
 *
 * Note that all callbacks that are to be registered for RPC async
 * notifications using dbus_g_proxy_begin_call must follow the
 * following prototype: DBusGProxyCallNotify .
 */
static void setValue1Completed(DBusGProxy* proxy,
                               DBusGProxyCall* call,
                               gpointer userData) {

  /* This will hold the GError object (if any). */
  GError* error = NULL;

  g_print(PROGNAME ":setValue1Completed\n");

  /* We next need to collect the results from the RPC call.
     The function returns FALSE on errors (which we check), although
     we could also check whether error-ptr is still NULL. */
  if (!dbus_g_proxy_end_call(proxy,
                             /* The call that we are collecting. */
                             call,
                             /* Where to store the error (if any). */
                             &error,
                             /* Next we list the GType codes for all
                                the arguments we expect back. In our
                                case there are none, so set to
                                invalid. */
                             G_TYPE_INVALID)) {
    /* Some error occurred while collecting the result. */
    g_printerr(PROGNAME " ERROR: %s\n", error->message);
    g_error_free(error);
  } else {
    g_print(PROGNAME " SUCCESS\n");
  }
}

/**
 * This function will be called repeatedly from within the mainloop
 * timer launch code.
 *
 * It will launch asynchronous RPC method to set value1 with ever
 * increasing argument.
 */
static gboolean timerCallback(DBusGProxy* remoteobj) {

  /* Local value that we will start updating to the remote object. */
  static gint localValue1 = -80;

  /* Start the first RPC.
     The call using GLib/D-Bus is only slightly more complex than the
     stubs. The overall operation is the same. */
  g_print(PROGNAME ":timerCallback launching setvalue1\n");
  dbus_g_proxy_begin_call(remoteobj,
                          /* Method name. */
                          "setvalue1",
                          /* Callback to call on "completion". */
                          setValue1Completed,
                          /* User-data to pass to callback. */
                          NULL,
                          /* Function to call to free userData after
                             callback returns. */
                          NULL,
                          /* First argument GType. */
                          G_TYPE_INT,
                          /* First argument value (passed by value) */
                          localValue1,
                          /* Terminate argument list. */
                          G_TYPE_INVALID);
  g_print(PROGNAME ":timerCallback setvalue1 launched\n");

  /* Step the local value forward. */
  localValue1 += 10;

  /* Repeat timer later. */
  return TRUE;
}

/**
 * The test program itself.
 *
 * 1) Setup GType/GSignal
 * 2) Create GMainLoop object
 * 3) Connect to the Session D-Bus
 * 4) Create a proxy GObject for the remote Value object
 * 5) Start a timer that will launch timerCallback once per second.
 * 6) Run main-loop (forever)
 */
int main(int argc, char** argv) {
  DBusGConnection* bus;
  /* The proxy object. */
  DBusGProxy* remoteValue;
  GMainLoop* mainloop;
  GError* error = NULL;

  g_type_init();

  mainloop = g_main_loop_new(NULL, FALSE);
  /* Failure to create the main loop is fatal (for us). */
  if (mainloop == NULL) {
    handleError("Failed to create the mainloop", "Unknown (OOM?)",
                TRUE);
  }
  g_print(PROGNAME ":main Connecting to Session D-Bus.\n");
  bus = dbus_g_bus_get(DBUS_BUS_SESSION, &error);
  if (error != NULL) {
    handleError("Could not connect to the Session bus", error->message,
                TRUE);
  }

  g_print(PROGNAME ":main Creating a GLib proxy object for Value.\n");
  remoteValue =
    dbus_g_proxy_new_for_name(bus,
                              VALUE_SERVICE_NAME, /* name */
                              VALUE_SERVICE_OBJECT_PATH, /* obj path */
                              VALUE_SERVICE_INTERFACE /* interface */);
  if (remoteValue == NULL) {
    handleError("Could not create the proxy object",
                "Unknown(dbus_g_proxy_new_for_name)", TRUE);
  }

  g_print(PROGNAME ":main Starting main loop (first timer in 1s).\n");
  g_timeout_add(1000, (GSourceFunc)timerCallback, remoteValue);

  /* Run the program. */
  g_main_loop_run(mainloop);
  /* Since the main loop is not stopped (by this code), we should not
     ever get here. The program might abort() for other reasons. */

  /* If it does, return failure as exit code. */
  return 1;
}