// Cyphesis Online RPG Server and AI Engine
// Copyright (C) 2004 Alistair Riddoch
//
// 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, or
// (at your option) any later version.
// 
// 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

// $Id: CommMDNSPublisher.cpp,v 1.18 2007-12-05 01:01:51 alriddoch Exp $

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#undef PACKAGE
#undef PACKAGE_NAME
#undef PACKAGE_STRING
#undef PACKAGE_TARNAME
#undef PACKAGE_VERSION
#undef PACKAGE_BUGREPORT
#undef VERSION

#include "CommMDNSPublisher.h"

#include "CommServer.h"
#include "ServerRouting.h"

#include "common/log.h"
#include "common/const.h"
#include "common/debug.h"
#include "common/globals.h"
#include "common/BaseWorld.h"
#include "common/compose.hpp"

#include <iostream>

#if defined(HAVE_LIBHOWL)

#include <discovery/discovery.h>

#include <cassert>

static const bool debug_flag = false;

static sw_result reply_callback(sw_discovery,
                                sw_discovery_oid,
                                sw_discovery_publish_status status,
                                sw_opaque)
{
    if (status == SW_DISCOVERY_PUBLISH_STARTED) {
        // log(NOTICE, "Started publishing using MDNS");
    } else if (status == SW_DISCOVERY_PUBLISH_STOPPED) {
        // log(NOTICE, "Stopped publishing using MDNS");
    } else if (status == SW_DISCOVERY_PUBLISH_NAME_COLLISION) {
        log(WARNING, "Name collision publishing using howl MDNS");
    } else if (status == SW_DISCOVERY_PUBLISH_INVALID) {
        log(WARNING, "Invalid error publishing using howl MDNS");
    } else {
        log(ERROR, "Unknown error code using howl MDNS");
    }
    return SW_OKAY;
}

CommMDNSPublisher::CommMDNSPublisher(CommServer & svr) : Idle(svr),
                                                         CommSocket(svr),
                                                         m_session(0)
{
}

CommMDNSPublisher::~CommMDNSPublisher()
{
    if (m_session != 0) {
        sw_discovery_fina(m_session);
        m_session = 0;
    }
}

int CommMDNSPublisher::setup()
{
    if (sw_discovery_init(&m_session) != SW_OKAY) {
        log(WARNING, "Unable to create MDNS publisher session");
        return -1;
    }

    if (sw_discovery_publish(m_session, 0,
                             m_commServer.m_server.getName().c_str(),
                             "_worldforge._tcp.", NULL, NULL,
                             client_port_num, NULL, 0,
                             reply_callback, this, &m_oid) != SW_OKAY) {
        log(WARNING, "Unable to publish our presence using MDNS");
        return -1;
    }
    return 0;
}

void CommMDNSPublisher::idle(time_t t)
{
}

int CommMDNSPublisher::getFd() const
{
    assert(m_session != 0);

    return sw_discovery_socket(m_session);
}

bool CommMDNSPublisher::isOpen() const
{
    assert(m_session != 0);

    return sw_discovery_socket(m_session) != -1;
}

bool CommMDNSPublisher::eof()
{
    return false;
}

int CommMDNSPublisher::read()
{
    assert(m_session != 0);

    if (sw_discovery_read_socket(m_session) != SW_OKAY) {
        log(WARNING, "Error publishing our presence using MDNS. Disabled.");
        return -1;
    }

    return 0;
}

void CommMDNSPublisher::dispatch()
{
}

#elif defined(HAVE_AVAHI)

#include <avahi-client/client.h>
#include <avahi-client/publish.h>

#include <avahi-common/error.h>

static const bool debug_flag = false;

static void avahi_client_callback(AvahiClient * s,
                                  AvahiClientState state,
                                  void * userdata)
{
    CommMDNSPublisher * cmp = (CommMDNSPublisher*)userdata;

    switch (state) {
        case AVAHI_CLIENT_S_RUNNING:
            // Check we have not already started them
            if (cmp->m_group == 0) {
                cmp->setup_service(s);
            }
            break;

        case AVAHI_CLIENT_S_COLLISION:
            log(WARNING, "Name collision while publishing using howl MDNS");
            break;

        case AVAHI_CLIENT_FAILURE:
            log(WARNING, "Failure while publishing using howl MDNS");
            break;

        case AVAHI_CLIENT_CONNECTING:
            log(ERROR, "Avahi returned connecting, but we did not specify NO_FAIL");
            break;

        case AVAHI_CLIENT_S_REGISTERING:
            break;
    }
}

void group_callback(AvahiEntryGroup * g,
                    AvahiEntryGroupState state,
                    void * userdata)
{
     switch (state) {
         case AVAHI_ENTRY_GROUP_ESTABLISHED :
             /* The entry group has been established successfully */

             break;
 
         case AVAHI_ENTRY_GROUP_COLLISION : {
             log(NOTICE, "Avahi callback reported group collision");
             
             /* A service name collision happened. Let's pick a new name */
             // char * n = avahi_alternative_service_name(name);
             // avahi_free(name);
             // name = n;
             
             // fprintf(stderr, "Service name collision, renaming service to '%s'\n", name);
             
             /* And recreate the services */
             // create_services(avahi_entry_group_get_client(g));
             break;
         }
 
         case AVAHI_ENTRY_GROUP_FAILURE :
             log(NOTICE, "Avahi callback reported group failure");
 
             /* Some kind of failure happened while we were registering our services */
             // avahi_simple_poll_quit(simple_poll);
             break;
 
         case AVAHI_ENTRY_GROUP_UNCOMMITED:
             log(NOTICE, "Avahi callback reported group uncommited");
             break;
         case AVAHI_ENTRY_GROUP_REGISTERING:
             log(NOTICE, "Avahi callback reported group registering");
             break;
     }
}

struct AvahiWatch {
    CommMDNSPublisher * m_publisher;
    AvahiWatchEvent m_requiredEvent;
    AvahiWatchCallback m_callback;
    AvahiWatchEvent m_events;
    void * m_userdata;
};

static AvahiWatch* watch_new(const AvahiPoll *api,
                             int fd,
                             AvahiWatchEvent event,
                             AvahiWatchCallback callback,
                             void *userdata)
{
    debug(std::cout << "avahi_watch_new " << fd << std::endl << std::flush;);
    CommMDNSPublisher * cmp = (CommMDNSPublisher*)api->userdata;
    if (cmp->getFd() != -1) {
        log(ERROR, "Avahi asked for multiple fds. Unable to comply.");
    } else {
        cmp->m_avahiFd = fd;
    }

    if (!event & AVAHI_WATCH_IN) {
        log(ERROR, "Avahi watcher does not require read events.");
    }
    if (event & ~AVAHI_WATCH_IN) {
        log(WARNING, "Avahi watcher requires unsupported events.");
    }

    AvahiWatch * aw = new AvahiWatch;
    aw->m_publisher = cmp;
    aw->m_requiredEvent = event;
    aw->m_callback = callback;
    aw->m_events = (AvahiWatchEvent)0;
    aw->m_userdata = userdata;

    cmp->m_avahiWatch = aw;
    return aw;
}

static void watch_update(AvahiWatch *w, AvahiWatchEvent event)
{
    debug(std::cout << "avahi_watch_update" << std::endl << std::flush;);
    w->m_requiredEvent = event;
}

static AvahiWatchEvent watch_get_events(AvahiWatch *w)
{
    debug(std::cout << "avahi_watch_get_events" << std::endl << std::flush;);
    return w->m_events;
}

static void watch_free(AvahiWatch *w)
{
    debug(std::cout << "avahi_watch_free" << std::endl << std::flush;);
    log(WARNING, "avahi watch_free handler called");
}

struct AvahiTimeout {
    CommMDNSPublisher * m_publisher;
    struct timeval m_tv;
    AvahiTimeoutCallback m_callback;
    void * m_userdata;
};

static AvahiTimeout* timeout_new(const AvahiPoll * api,
                                 const struct timeval * tv,
                                 AvahiTimeoutCallback callback,
                                 void *userdata)
{
    debug(std::cout << "avahi_timeout_new " << tv << " " << callback << std::endl << std::flush;);
    CommMDNSPublisher * cmp = (CommMDNSPublisher*)api->userdata;

    AvahiTimeout * at = new AvahiTimeout;
    at->m_publisher = cmp;
    if (tv != 0) {
        at->m_tv = *tv;
    } else {
        at->m_tv.tv_sec = 0;
    }
    at->m_callback = callback;
    at->m_userdata = userdata;

    cmp->m_avahiTimeouts.insert(at);

    return at;
}

static void timeout_update(AvahiTimeout * at, const struct timeval *tv)
{
    debug(std::cout << "avahi_timeout_update " << at << std::endl << std::flush;);

    if (tv != 0) {
        at->m_tv = *tv;
    } else {
        at->m_tv.tv_sec = 0;
    }
}

static void timeout_free(AvahiTimeout * at)
{
    debug(std::cout << "avahi_timeout_free " << at << std::endl << std::endl << std::flush;);
    at->m_publisher->m_avahiTimeouts.erase(at);
    delete at;
}

CommMDNSPublisher::CommMDNSPublisher(CommServer & svr) : Idle(svr),
                                                         CommSocket(svr),
                                                         m_avahiFd(-1),
                                                         m_group(0)
{
}

CommMDNSPublisher::~CommMDNSPublisher()
{
    // Finalise and delete
}

int CommMDNSPublisher::setup()
{
    AvahiPoll poll = { this,
                       watch_new,
                       watch_update,
                       watch_get_events,
                       watch_free,
                       timeout_new,
                       timeout_update,
                       timeout_free
                     };

    m_avahiClient = avahi_client_new(&poll, (AvahiClientFlags)0, &avahi_client_callback, this, &m_avahiError);

    if (m_avahiClient == 0) {
        log(ERROR, "Avahi client creation failed");
        return -1;
    }

    if (m_avahiFd == -1) {
        log(ERROR, "Avahi client has not registed a file descriptor");
        return -1;
    }

    return 0;
}

void CommMDNSPublisher::setup_service(AvahiClient * client)
{
    if (m_group == 0) {
        m_group = avahi_entry_group_new(client, &group_callback, this);
    }

    if (m_group == 0) {
        log(ERROR, String::compose("Avahi group creation failure. %1",
                                   avahi_strerror(avahi_client_errno(client))));
        return;
    }

    AvahiStringList * txt;
    txt = avahi_string_list_new(String::compose("builddate=%1", std::string(consts::buildTime)+", "+std::string(consts::buildDate)).c_str(),
                                String::compose("clients=%1", m_commServer.m_server.getClients()).c_str(),
                                String::compose("ruleset=%1", m_commServer.m_server.getRuleset()).c_str(),
                                String::compose("server=%1", "cyphesis").c_str(),
                                String::compose("uptime=%1", m_commServer.m_server.m_world.upTime()).c_str(),
                                String::compose("version=%1", std::string(consts::version)).c_str(),
                                NULL);

    int ret;
    ret = avahi_entry_group_add_service_strlst(m_group,
                                               AVAHI_IF_UNSPEC,
                                               AVAHI_PROTO_UNSPEC,
                                               (AvahiPublishFlags)0,
                                               m_commServer.m_server.getName().c_str(),
                                               "_worldforge._tcp", NULL, NULL,
                                               client_port_num, txt);
    avahi_string_list_free(txt);
    if (ret < 0) {
        log(ERROR, "Avahi service publish failed");
        return;
    }

    ret = avahi_entry_group_commit(m_group);
    if (ret < 0) {
        log(ERROR, "Avahi service commit failed");
        return;
    }
}

void CommMDNSPublisher::idle(time_t t)
{
    std::set<AvahiTimeout *>::const_iterator I = m_avahiTimeouts.begin();
    std::set<AvahiTimeout *>::const_iterator Iend = m_avahiTimeouts.end();
    for (; I != Iend; ++I) {
        if ((*I)->m_tv.tv_sec == 0) {
            continue;
        }
        if ((*I)->m_tv.tv_sec <= t) {
            debug(std::cout << "TImeout " << (*I) << " is now due" << std::endl << std::flush;);
            (*I)->m_callback(*I, (*I)->m_userdata);
            (*I)->m_tv.tv_sec = 0;
        }
    }
}

int CommMDNSPublisher::getFd() const
{
    return m_avahiFd;
}

bool CommMDNSPublisher::isOpen() const
{
    return m_avahiFd != -1;
}

bool CommMDNSPublisher::eof()
{
    return false;
}

int CommMDNSPublisher::read()
{
    assert(m_avahiWatch != 0);
    m_avahiWatch->m_events = AVAHI_WATCH_IN;
    m_avahiWatch->m_callback(m_avahiWatch, m_avahiFd, AVAHI_WATCH_IN, m_avahiWatch->m_userdata);
    m_avahiWatch->m_events = (AvahiWatchEvent)0;
    return 0;
}

void CommMDNSPublisher::dispatch()
{
}

#endif // defined(HAVE_LIBHOWL)