/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is guacd.
 *
 * The Initial Developer of the Original Code is
 * Michael Jumper.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include <stdlib.h>
#include <time.h>

#include <guacamole/guacio.h>
#include <guacamole/client.h>
#include <guacamole/log.h>
#include <guacamole/error.h>

#include "client.h"
#include "thread.h"

void __guacd_sleep(int millis) {

    struct timespec sleep_period;

    sleep_period.tv_sec =   millis / 1000;
    sleep_period.tv_nsec = (millis % 1000) * 1000000L;

    nanosleep(&sleep_period, NULL);

}

void guac_client_stop(guac_client* client) {
    client->state = STOPPING;
}

void* __guac_client_output_thread(void* data) {

    guac_client* client = (guac_client*) data;
    guac_socket* socket = client->socket;

    guac_timestamp last_ping_timestamp = guac_protocol_get_timestamp();

    /* Guacamole client output loop */
    while (client->state == RUNNING) {

        /* Occasionally ping client with repeat of last sync */
        guac_timestamp timestamp = guac_protocol_get_timestamp();
        if (timestamp - last_ping_timestamp > GUAC_SYNC_FREQUENCY) {

            /* Record time of last synnc */
            last_ping_timestamp = timestamp;

            /* Send sync */
            if (guac_protocol_send_sync(socket, client->last_sent_timestamp)) {
                guac_client_log_error(client, "Error sending \"sync\" instruction: %s", guac_status_string(guac_error));
                guac_client_stop(client);
                return NULL;
            }

            /* Flush */
            if (guac_socket_flush(socket)) {
                guac_client_log_error(client, "Error flushing output: %s", guac_status_string(guac_error));
                guac_client_stop(client);
                return NULL;
            }

        }

        /* Handle server messages */
        if (client->handle_messages) {

            /* Only handle messages if synced within threshold */
            if (client->last_sent_timestamp - client->last_received_timestamp
                    < GUAC_SYNC_THRESHOLD) {

                int retval = client->handle_messages(client);
                if (retval) {
                    guac_client_log_error(client, "Error handling server messages: %s", guac_status_string(guac_error));
                    guac_client_stop(client);
                    return NULL;
                }

                /* Sleep as necessary */
                __guacd_sleep(GUAC_SERVER_MESSAGE_HANDLE_FREQUENCY);

                /* Send sync instruction */
                client->last_sent_timestamp = guac_protocol_get_timestamp();
                if (guac_protocol_send_sync(socket, client->last_sent_timestamp)) {
                    guac_client_log_error(client, "Error sending \"sync\" instruction: %s", guac_status_string(guac_error));
                    guac_client_stop(client);
                    return NULL;
                }

                if (guac_socket_flush(socket)) {
                    guac_client_log_error(client, "Error flushing output: %s", guac_status_string(guac_error));
                    guac_client_stop(client);
                    return NULL;
                }

            }

            /* If sync threshold exceeded, don't spin waiting for resync */
            else
                __guacd_sleep(GUAC_SERVER_MESSAGE_HANDLE_FREQUENCY);

        }

        /* If no message handler, just sleep until next sync ping */
        else
            __guacd_sleep(GUAC_SYNC_FREQUENCY);

    } /* End of output loop */

    guac_client_stop(client);
    return NULL;

}

void* __guac_client_input_thread(void* data) {

    guac_client* client = (guac_client*) data;
    guac_socket* socket = client->socket;

    /* Guacamole client input loop */
    while (client->state == RUNNING) {

        /* Read instruction */
        guac_instruction* instruction =
            guac_protocol_read_instruction(socket, GUAC_USEC_TIMEOUT);

        /* Stop on error */
        if (instruction == NULL) {
            guac_client_log_error(client, "Error reading instruction: %s", guac_status_string(guac_error));
            guac_client_stop(client);
            return NULL;
        }

        /* Call handler, stop on error */
        if (guac_client_handle_instruction(client, instruction) < 0) {
            guac_client_log_error(client, "Error in client \"%s\" instruction handler: %s", instruction->opcode, guac_status_string(guac_error));
            guac_instruction_free(instruction);
            guac_client_stop(client);
            return NULL;
        }

        /* Free allocated instruction */
        guac_instruction_free(instruction);

    }

    return NULL;

}

int guac_start_client(guac_client* client) {

    guac_thread input_thread, output_thread;

    if (guac_thread_create(&output_thread, __guac_client_output_thread, (void*) client)) {
        return -1;
    }

    if (guac_thread_create(&input_thread, __guac_client_input_thread, (void*) client)) {
        guac_client_stop(client);
        guac_thread_join(output_thread);
        return -1;
    }

    /* Wait for I/O threads */
    guac_thread_join(input_thread);
    guac_thread_join(output_thread);

    /* Done */
    return 0;

}