/*
GNU General Public License version 3 notice

Copyright (C) 2012 Mihawk <luiz@netdome.biz>. All rights reserved.

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 3 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, see < http://www.gnu.org/licenses/ >.
*/

#include "SshClient.h"
#include "App.h"
#include "Settings.h"
#include <QProcess>
#include <QRegExp>
#include <QDateTime>
#include <QTimerEvent>
#include <QStringList>
#include <Pinger.h>
#include <QDebug>

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SshClient::SshClient(App* app, QObject *parent) :
  QObject(parent),
  myApp(app),
  myProcess(new QProcess(this)),
  myCommandRegex(new QRegExp("^([0-9]{4}-[0-9]{2}-[0-9]{2}\\s[0-9]{2}:[0-9]{2}:[0-9]{2})\\s(\\+[0-9]{4}):\\s(.+)$")),
  myConnectedFlag(false),
  myConnectionTimerID(0),
  myPingTimerID(0),
  myPongTimerID(0)
{
  connect(myProcess, SIGNAL(readyRead()), SLOT(read()));
  connect(myProcess, SIGNAL(finished(int)), SLOT(exited(int)));
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
SshClient::~SshClient()
{
  delete myCommandRegex;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool SshClient::isConnected() const
{
  return myConnectedFlag;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::read()
{
  QString data(myProcess->readAll().trimmed());
  if(data.isEmpty())
    return;

  QStringList lines = data.split("\n", QString::SkipEmptyParts);
  QString line;
  foreach(line, lines)
  {
    line = line.trimmed();
    if(myCommandRegex->indexIn(line) != -1)
    {
      QDateTime time = QDateTime::fromString(myCommandRegex->cap(1), "yyyy-MM-dd HH:mm:ss");
      time = time.addSecs(-myCommandRegex->cap(2).toInt()/100*60*60);

      parse(time,
            myCommandRegex->cap(3).section(' ', 0, 0),
            myCommandRegex->cap(3).section(' ', 1)
           );
    }
  }
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::exited(int)
{
  reconnect();
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::ping()
{
  write("PING\n");
  myPingTimerID = startTimer(30000);
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::pong()
{
  killTimer(myPingTimerID);
  myPingTimerID = -1;
  myPongTimerID = startTimer(30000);
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::write(const QString &data)
{
  myProcess->write(data.toLatin1());
  myProcess->waitForBytesWritten();
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::parse(const QDateTime &time, const QString &command, const QString &commandData)
{
  /* JOINED - Another user has just joined central */
  if(command == "JOINED")
  {
    QRegExp a("^User '([a-zA-Z]+)'.+$");
    if(a.indexIn(commandData) != -1)
    {
      if(!myClients.contains(a.capturedTexts().at(1)))
        myClients.push_back(a.capturedTexts().at(1));
    }
    return;
  }

  /* PARTED - Another user has left central */
  if(command == "PARTED")
  {
    QRegExp a("^User '([a-zA-Z]+)'.+$");
    if(a.indexIn(commandData) != -1)
      myClients.removeAll(a.capturedTexts().at(1));
    return;
  }

  /* HELLO - Server acknowledge */
  if(command == "HELLO")
  {
    ping();
    myConnectedFlag = true;
    killTimer(myConnectionTimerID);
    myConnectionTimerID = -1;
    emit connected();
    return;
  }

  /* PING PONG - The connection is still up */
  if(command == "PONG")
  {
    pong();
    return;
  }

  /* SYS - Central generic message */
  if(command == "SYS")
  {
    myApp->print("Central Message: " + commandData + "\n");
    return;
  }

  /* BC - Broadcast order from central */
  if(command == "BC")
  {
    QRegExp a("^([A-Za-z0-9]+) (.+),(.+),(.+),'(.+)','(.+)'$");
    if(a.indexIn(commandData) == -1)
      return;

    if(a.cap(2) == "QDEV" && !Settings::globalInstance()->developerMode()) //developer mode not enabled ignore this message from developers
      return;

    int serverCount, userCount;

    myApp->broadcast(a.cap(3) + " " + a.cap(5) + " - " + a.cap(4) + " : " + a.cap(6), &serverCount, &userCount);
    if(userCount)
      write("BC_RE " + a.cap(1) + " Players=" + QString::number(userCount) + ",Servers=" + QString::number(serverCount) + "\n");

    return;
  }

  /* BC_ID - Broadcast reply with the ID of the broadcast you just generated */
  if(command == "BC_ID")
  {
    //BC_ID 4e5fca581569e168c7a86a0a9a91949f for: QDEV,-dev-,qw://123.123
    //    qDebug() << commandData;
    QRegExp a("^([A-Za-z0-9]+) for: .+,-(.+)-,qw://(.+) [0-9]+/[0-9]+$");
    if(a.indexIn(commandData) == -1)
      return;

    QString hash = a.cap(1);
    //QString frequency = a.cap(2);
    QString server = a.cap(3);

    myApp->setReplyHashAndWaitForReply(server, hash);

    return;
  }

  /* BC_RE - Broadcast reply to increment the counters */
  if(command == "BC_RE")
  {
    QRegExp a("^([A-Za-z0-9]+) (Users|Players)=([0-9]+),(Channels|Servers)=([0-9]+)$");
    if(a.indexIn(commandData) == -1)
      return;

    QString hash = a.cap(1);
    QString userType = a.cap(2);
    QString channelType = a.cap(4);
    int     userCount = 0;
    int     channelCount = 0;
    int     playerCount = 0;
    int     serverCount = 0;

    if(userType == "Users")
    {
      userCount = a.cap(3).toInt();
      playerCount = 0;
    }
    else if(userType == "Players")
    {
      playerCount = a.cap(3).toInt();
      userCount = 0;
    }

    if(channelType == "Channels")
    {
      channelCount = a.cap(5).toInt();
      serverCount = 0;
    }
    else if(channelType == "Servers")
    {
      serverCount = a.cap(5).toInt();
      channelCount = 0;
    }

    //    qDebug() << commandData;

    myApp->incrementReplyCounters(hash, userCount, channelCount, playerCount, serverCount);

    return;
  }

  /* DNS_RE - Reply from REQ_DNS, returns the HostName for the requested ip:port pair */
  if(command == "DNS_RE")
  {
    QRegExp a("^([0-9]+\\.[0-9]+\\.[0-9]+\\.[0-9]+:[0-9]+) ([0-9A-Za-z][A-Za-z0-9\\-\\.]+)$");
    if(a.indexIn(commandData) == -1)
      return;
    myApp->setServerHostName(a.cap(1), a.cap(2));
    return;
  }

  /* COMMANDS - List of commands allowed for me */
  if(command == "COMMANDS")
  {
    myCommands = commandData.split(", ", QString::SkipEmptyParts);
    return;
  }

  /* ROLES - List of roles I exert */
  if(command == "ROLES")
  {
    myRoles = commandData.split(", ", QString::SkipEmptyParts);
    return;
  }

  /* REQ_ASSIGNMENTS - Central is requesting the server list I have */
  if(command == "REQ_ASSIGNMENTS")
  {
    myApp->print("Server list requested... Sending it now!\n");
    // TODO: Maybe fetching server data directly from ActiveClients list is a better idea
    Settings::ServerList serverList = Settings::globalInstance()->serverList();
    Settings::Server server;
    foreach(server, serverList)
    {
      // Let the reply be send after the pinging is done
      Pinger* pinger = new Pinger(QHostAddress(server.address), server.port, this);
      connect(pinger, SIGNAL(finished(QHostAddress,quint16,int)), SLOT(assignmentsReply(QHostAddress,quint16,int)));
      pinger->ping();
    }
    return;
  }

  /* REQ_PING  - Requests an given server ping */
  if(command == "REQ_PING")
  {
    QStringList splitCmd = commandData.split(":");
    if(splitCmd.size() < 2)
    {
      write("Malformed REQ_PING command.\n");
      return;
    }
    QString server = splitCmd.at(0);
    quint16 port = splitCmd.at(1).toUShort();

    Pinger* pinger = new Pinger(QHostAddress(server), port, this);
    connect(pinger, SIGNAL(finished(QHostAddress,quint16,int)), SLOT(serverPong(QHostAddress,quint16,int)));
    pinger->ping();
    return;
  }

  /* REQ_ASSIGN */
  if(command == "REQ_ASSIGN")
  {
    QRegExp rx("(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}):(\\d{1,5})");
    if(rx.indexIn(commandData) == -1)
    {
      write("Malformed REQ_ASSIGN request.\n");
      return;
    }
    if(myApp->addClient(rx.cap(1), rx.cap(2).toUShort()))
      write("ASSIGN_RE " + rx.cap(1) + ":" + rx.cap(2) + " OK\n");
    else
      write("ASSIGN_RE " + rx.cap(1) + ":" + rx.cap(2) + " FAILED Client already on my list.\n");
    return;
  }

  /* REQ_UNASSIGN */
  if(command == "REQ_UNASSIGN")
  {
    QRegExp rx("(\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}):(\\d{1,5})");
    if(rx.indexIn(commandData) == -1)
    {
      write("Malformed REQ_UNASSIGN request.\n");
      return;
    }
    if(myApp->removeClient(rx.cap(1), rx.cap(2).toUShort()))
      write("UNASSIGN_RE " + rx.cap(1) + ":" + rx.cap(2) + " OK\n");
    else
      write("UNASSIGN_RE " + rx.cap(1) + ":" + rx.cap(2) + " FAILED Client not found on my list.\n");
    return;
  }

  /* REQ_MAXSERVERS - Reply with the maximum number of servers we can handle */
  if(command == "REQ_MAXSERVERS")
  {
    write("MAXSERVERS_RE " + QString::number(Settings::globalInstance()->maxServers()) + "\n");
    return;
  }

  myApp->print("Unparsed cmd from central: " + time.toString() + " " + command + " " + commandData + "\n");
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool SshClient::connectToHost(const QString &user, const QString &host, quint16 port)
{
  myProcess->start("ssh", QStringList() << user + "@" + host << "-p " + QString::number(port));
  myUsername = user;
  myHostname = host;
  myPort = port;

  bool r = myProcess->waitForStarted();
  if(!r)
    return false;
  else
  {
    myConnectionTimerID = startTimer(60000*3); // up to 3 minutes of waiting
    return true;
  }
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::reconnect()
{
  if(!myUsername.isEmpty() && !myHostname.isEmpty())
    connectToHost(myUsername, myHostname, myPort);
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::disconnectFromHost()
{
  killTimer(myConnectionTimerID);
  killTimer(myPingTimerID);
  killTimer(myPongTimerID);
  myConnectionTimerID = myPingTimerID = myPongTimerID = -1;

  myProcess->terminate();
  myProcess->waitForFinished();

  myConnectedFlag = false;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::timerEvent(QTimerEvent *e)
{
  if(e->timerId() == myConnectionTimerID)
  {
    myApp->print("Timedout while trying to connect to central...\n");
    disconnectFromHost();
    emit error(ConnectionTimedOutError);
    return;
  }

  if(e->timerId() == myPingTimerID)
  {
    myApp->print("Ping with no pong! Disconnecting from central...\n");
    disconnectFromHost();
    emit error(ConnectionTimedOutError);
    return;
  }

  if(e->timerId() == myPongTimerID)
  {
    killTimer(myPongTimerID);
    myPongTimerID = -1;
    ping();
    return;
  }
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::serverPong(const QHostAddress &host, quint16 port, int ms)
{
  write("PING_RE " + host.toString() + ":" + QString::number(port) + "," + QString::number(ms) + "\n");
  sender()->deleteLater();
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void SshClient::assignmentsReply(const QHostAddress &host, quint16 port, int ms)
{
  QString fullAddress = host.toString() + ":" + QString::number(port);

  write("ASSIGNMENTS_RE " + host.toString() + ":" + QString::number(port) + "," + QString::number(ms) + "\n");

  sender()->deleteLater();
}