/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2012-2016 Symless Ltd.
 * Copyright (C) 2012 Nick Bolton
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file LICENSE that should have accompanied this file.
 * 
 * This package 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/>.
 */

// TODO: split this class into windows and unix to get rid
// of all the #ifdefs!

#include "synergy/DaemonApp.h"

#include "synergy/App.h"
#include "synergy/ArgParser.h"
#include "synergy/ServerArgs.h"
#include "synergy/ClientArgs.h"
#include "ipc/IpcClientProxy.h"
#include "ipc/IpcMessage.h"
#include "ipc/IpcLogOutputter.h"
#include "net/SocketMultiplexer.h"
#include "arch/XArch.h"
#include "base/Log.h"
#include "base/TMethodJob.h"
#include "base/TMethodEventJob.h"
#include "base/EventQueue.h"
#include "base/log_outputters.h"
#include "base/Log.h"

#if SYSAPI_WIN32

#include "arch/win32/ArchMiscWindows.h"
#include "arch/win32/XArchWindows.h"
#include "synergy/Screen.h"
#include "platform/MSWindowsScreen.h"
#include "platform/MSWindowsDebugOutputter.h"
#include "platform/MSWindowsWatchdog.h"
#include "platform/MSWindowsEventQueueBuffer.h"

#define WIN32_LEAN_AND_MEAN
#include <Windows.h>

#endif

#include <string>
#include <iostream>
#include <sstream>

using namespace std;

DaemonApp* DaemonApp::s_instance = NULL;

int
mainLoopStatic()
{
    DaemonApp::s_instance->mainLoop(true);
    return kExitSuccess;
}

int
unixMainLoopStatic(int, const char**)
{
    return mainLoopStatic();
}

#if SYSAPI_WIN32
int
winMainLoopStatic(int, const char**)
{
    return ArchMiscWindows::runDaemon(mainLoopStatic);
}
#endif

DaemonApp::DaemonApp() :
    m_ipcServer(nullptr),
    m_ipcLogOutputter(nullptr),
    #if SYSAPI_WIN32
    m_watchdog(nullptr),
    #endif
    m_events(nullptr),
    m_fileLogOutputter(nullptr)
{
    s_instance = this;
}

DaemonApp::~DaemonApp()
{
}

int
DaemonApp::run(int argc, char** argv)
{
#if SYSAPI_WIN32
    // win32 instance needed for threading, etc.
    ArchMiscWindows::setInstanceWin32(GetModuleHandle(NULL));
#endif
    
    Arch arch;
    arch.init();

    Log log;
    EventQueue events;
    m_events = &events;

    bool uninstall = false;
    try
    {
#if SYSAPI_WIN32
        // sends debug messages to visual studio console window.
        log.insert(new MSWindowsDebugOutputter());
#endif

        // default log level to system setting.
        string logLevel = arch.setting("LogLevel");
        if (logLevel != "")
            log.setFilter(logLevel.c_str());

        bool foreground = false;

        for (int i = 1; i < argc; ++i) {
            string arg(argv[i]);

            if (arg == "/f" || arg == "-f") {
                foreground = true;
            }
#if SYSAPI_WIN32
            else if (arg == "/install") {
                uninstall = true;
                arch.installDaemon();
                return kExitSuccess;
            }
            else if (arg == "/uninstall") {
                arch.uninstallDaemon();
                return kExitSuccess;
            }
#endif
            else {
                stringstream ss;
                ss << "Unrecognized argument: " << arg;
                foregroundError(ss.str().c_str());
                return kExitArgs;
            }
        }

        if (foreground) {
            // run process in foreground instead of daemonizing.
            // useful for debugging.
            mainLoop(false, foreground);
        }
        else {
#if SYSAPI_WIN32
            arch.daemonize("Synergy", winMainLoopStatic);
#elif SYSAPI_UNIX
            arch.daemonize("Synergy", unixMainLoopStatic);
#endif
        }

        return kExitSuccess;
    }
    catch (XArch& e) {
        String message = e.what();
        if (uninstall && (message.find("The service has not been started") != String::npos)) {
            // TODO: if we're keeping this use error code instead (what is it?!).
            // HACK: this message happens intermittently, not sure where from but
            // it's quite misleading for the user. they thing something has gone
            // horribly wrong, but it's just the service manager reporting a false
            // positive (the service has actually shut down in most cases).
        }
        else {
            foregroundError(message.c_str());
        }
        return kExitFailed;
    }
    catch (std::exception& e) {
        foregroundError(e.what());
        return kExitFailed;
    }
    catch (...) {
        foregroundError("Unrecognized error.");
        return kExitFailed;
    }
}

void
DaemonApp::mainLoop(bool logToFile, bool foreground)
{
    try
    {
        DAEMON_RUNNING(true);
        
        if (logToFile) {
            m_fileLogOutputter = new FileLogOutputter(logFilename().c_str());
            CLOG->insert(m_fileLogOutputter);
        }

        // create socket multiplexer.  this must happen after daemonization
        // on unix because threads evaporate across a fork().
        SocketMultiplexer multiplexer;

        // uses event queue, must be created here.
        m_ipcServer = new IpcServer(m_events, &multiplexer);

        // send logging to gui via ipc, log system adopts outputter.
        m_ipcLogOutputter = new IpcLogOutputter(*m_ipcServer, kIpcClientGui, true);
        CLOG->insert(m_ipcLogOutputter);
        
#if SYSAPI_WIN32
        m_watchdog = new MSWindowsWatchdog(false, *m_ipcServer, *m_ipcLogOutputter, foreground);
        m_watchdog->setFileLogOutputter(m_fileLogOutputter);
#endif
        
        m_events->adoptHandler(
            m_events->forIpcServer().messageReceived(), m_ipcServer,
            new TMethodEventJob<DaemonApp>(this, &DaemonApp::handleIpcMessage));

        m_ipcServer->listen();
        
#if SYSAPI_WIN32

        // install the platform event queue to handle service stop events.
        m_events->adoptBuffer(new MSWindowsEventQueueBuffer(m_events));
        
        String command = ARCH->setting("Command");
        bool elevate = ARCH->setting("Elevate") == "1";
        if (command != "") {
            LOG((CLOG_INFO "using last known command: %s", command.c_str()));
            m_watchdog->setCommand(command, elevate);
        }

        m_watchdog->startAsync();
#endif
        m_events->loop();

#if SYSAPI_WIN32
        m_watchdog->stop();
        delete m_watchdog;
#endif

        m_events->removeHandler(
            m_events->forIpcServer().messageReceived(), m_ipcServer);
        
        CLOG->remove(m_ipcLogOutputter);
        delete m_ipcLogOutputter;
        delete m_ipcServer;
        
        DAEMON_RUNNING(false);
    }
    catch (std::exception& e) {
        LOG((CLOG_CRIT "An error occurred: %s", e.what()));
    }
    catch (...) {
        LOG((CLOG_CRIT "An unknown error occurred.\n"));
    }
}

void
DaemonApp::foregroundError(const char* message)
{
#if SYSAPI_WIN32
    MessageBox(NULL, message, "Synergy Service", MB_OK | MB_ICONERROR);
#elif SYSAPI_UNIX
    cerr << message << endl;
#endif
}

std::string
DaemonApp::logFilename()
{
    string logFilename;
    logFilename = ARCH->setting("LogFilename");
    if (logFilename.empty()) {
        logFilename = ARCH->getLogDirectory();
        logFilename.append("/");
        logFilename.append(LOG_FILENAME);
    }

    return logFilename;
}

void
DaemonApp::handleIpcMessage(const Event& e, void*)
{
    IpcMessage* m = static_cast<IpcMessage*>(e.getDataObject());
    switch (m->type()) {
        case kIpcCommand: {
            IpcCommandMessage* cm = static_cast<IpcCommandMessage*>(m);
            String command = cm->command();

            // if empty quotes, clear.
            if (command == "\"\"") {
                command.clear();
            }

            if (!command.empty()) {
                LOG((CLOG_DEBUG "new command, elevate=%d command=%s", cm->elevate(), command.c_str()));

                std::vector<String> argsArray;
                ArgParser::splitCommandString(command, argsArray);
                ArgParser argParser(NULL);
                const char** argv = argParser.getArgv(argsArray);
                ServerArgs serverArgs;
                ClientArgs clientArgs;
                int argc = static_cast<int>(argsArray.size());
                bool server = argsArray[0].find("synergys") != String::npos ? true : false;
                ArgsBase* argBase = NULL;

                if (server) {
                    argParser.parseServerArgs(serverArgs, argc, argv);
                    argBase = &serverArgs;
                }
                else {
                    argParser.parseClientArgs(clientArgs, argc, argv);
                    argBase = &clientArgs;
                }

                delete[] argv;
                
                String logLevel(argBase->m_logFilter);
                if (!logLevel.empty()) {
                    try {
                        // change log level based on that in the command string
                        // and change to that log level now.
                        ARCH->setting("LogLevel", logLevel);
                        CLOG->setFilter(logLevel.c_str());
                    }
                    catch (XArch& e) {
                        LOG((CLOG_ERR "failed to save LogLevel setting, %s", e.what()));
                    }
                }
            }
            else {
                LOG((CLOG_DEBUG "empty command, elevate=%d", cm->elevate()));
            }

            try {
                // store command in system settings. this is used when the daemon
                // next starts.
                ARCH->setting("Command", command);

                // TODO: it would be nice to store bools/ints...
                ARCH->setting("Elevate", String(cm->elevate() ? "1" : "0"));
            }
            catch (XArch& e) {
                LOG((CLOG_ERR "failed to save settings, %s", e.what()));
            }

#if SYSAPI_WIN32
            // tell the relauncher about the new command. this causes the
            // relauncher to stop the existing command and start the new
            // command.
            m_watchdog->setCommand(command, cm->elevate());
#endif
            break;
        }

        case kIpcHello:
            IpcHelloMessage* hm = static_cast<IpcHelloMessage*>(m);
            String type;
            switch (hm->clientType()) {
                case kIpcClientGui: type = "gui"; break;
                case kIpcClientNode: type = "node"; break;
                default: type = "unknown"; break;
            }

            LOG((CLOG_DEBUG "ipc hello, type=%s", type.c_str()));

#if SYSAPI_WIN32
            String watchdogStatus = m_watchdog->isProcessActive() ? "active" : "idle";
            LOG((CLOG_INFO "service status: %s", watchdogStatus.c_str()));
#endif

            m_ipcLogOutputter->notifyBuffer();
            break;
    }
}