/*
 *
 *     add-client.c: client program, takes two numbers as input,
 *                   sends to server for addition,
 *                   gets result from server,
 *                   prints the result on the screen
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdbool.h>
#include <ctype.h>

#include <dbus/dbus.h>


const char *const INTERFACE_NAME = "org.nirav.dbus_example";
const char *const SERVER_BUS_NAME = "org.nirav.add_server";
const char *const CLIENT_BUS_NAME = "org.nirav.add_client";
const char *const SERVER_OBJECT_PATH_NAME = "/org/nirav/adder";
const char *const CLIENT_OBJECT_PATH_NAME = "/org/nirav/add_client";
const char *const METHOD_NAME = "add_numbers";

DBusError dbus_error;
void print_dbus_error (char *str);

int main (int argc, char **argv)
{
    DBusConnection *conn;
    int ret;
    char input [80];

    dbus_error_init (&dbus_error);

    conn = dbus_bus_get (DBUS_BUS_SESSION, &dbus_error);

    if (dbus_error_is_set (&dbus_error))
        print_dbus_error ("dbus_bus_get");

    if (!conn)
        exit (1);

    printf ("Please type two numbers: ");
    while (fgets (input, 78, stdin) != NULL) {

        // Get a well known name
        while (1) {
            ret = dbus_bus_request_name (conn, CLIENT_BUS_NAME, 0, &dbus_error);

            if (ret == DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER)
               break;

            if (ret == DBUS_REQUEST_NAME_REPLY_IN_QUEUE) {
               fprintf (stderr, "Waiting for the bus ... \n");
               sleep (1);
               continue;
            }
            if (dbus_error_is_set (&dbus_error))
               print_dbus_error ("dbus_bus_get");
        }

        DBusMessage *request;

        if ((request = dbus_message_new_method_call (SERVER_BUS_NAME, SERVER_OBJECT_PATH_NAME,
                           INTERFACE_NAME, METHOD_NAME)) == NULL) {
            fprintf (stderr, "Error in dbus_message_new_method_call\n");
            exit (1);
        }

        DBusMessageIter iter;
        dbus_message_iter_init_append (request, &iter);
        char *ptr = input;
        if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &ptr)) {
            fprintf (stderr, "Error in dbus_message_iter_append_basic\n");
            exit (1);
        }
        DBusPendingCall *pending_return;
        if (!dbus_connection_send_with_reply (conn, request, &pending_return, -1)) {
            fprintf (stderr, "Error in dbus_connection_send_with_reply\n");
            exit (1);
        }

        if (pending_return == NULL) {
            fprintf (stderr, "pending return is NULL");
            exit (1);
        }

        dbus_connection_flush (conn);

        dbus_message_unref (request);

        dbus_pending_call_block (pending_return);

        DBusMessage *reply;
        if ((reply = dbus_pending_call_steal_reply (pending_return)) == NULL) {
            fprintf (stderr, "Error in dbus_pending_call_steal_reply");
            exit (1);
        }

        dbus_pending_call_unref	(pending_return);

        char *s;
        if (dbus_message_get_args (reply, &dbus_error, DBUS_TYPE_STRING, &s, DBUS_TYPE_INVALID)) {
            printf ("%s\n", s);
        }
        else
        {
             fprintf (stderr, "Did not get arguments in reply\n");
             exit (1);
        }
        dbus_message_unref (reply);

        if (dbus_bus_release_name (conn, CLIENT_BUS_NAME, &dbus_error) == -1) {
             fprintf (stderr, "Error in dbus_bus_release_name\n");
             exit (1);
        }

        printf ("Please type two numbers: ");
    }

    return 0;
}

void print_dbus_error (char *str)
{
    fprintf (stderr, "%s: %s\n", str, dbus_error.message);
    dbus_error_free (&dbus_error);
}