// **************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: http://www.gnu.org/licenses/gpl.html       *
// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved        *
// **************************************************************************

#include "application.h"
#include <memory>
#include <zen/file_handling.h>
#include <wx/msgdlg.h>
#include <wx/tooltip.h> //wxWidgets v2.9
#include <wx/log.h>
#include <wx+/app_main.h>
#include <wx+/string_conv.h>
#include "comparison.h"
#include "algorithm.h"
#include "synchronization.h"
#include "ui/batch_status_handler.h"
#include "ui/check_version.h"
#include "ui/main_dlg.h"
#include "ui/switch_to_gui.h"
#include "lib/resources.h"
#include "lib/process_xml.h"
#include "lib/error_log.h"

#ifdef ZEN_WIN
#include <zen/win_ver.h>

#elif defined ZEN_LINUX
#include <gtk/gtk.h>
#endif

using namespace zen;
using namespace xmlAccess;


IMPLEMENT_APP(Application)

namespace
{
/*
boost::thread::id mainThreadId = boost::this_thread::get_id();

void onTerminationRequested()
{
std::wstring msg = boost::this_thread::get_id() == mainThreadId ?
                   L"Termination requested in main thread!\n\n" :
                   L"Termination requested in worker thread!\n\n";
msg += L"Please file a bug report at: http://sourceforge.net/projects/freefilesync";

wxSafeShowMessage(_("An exception occurred"), msg);
std::abort();
}
*/

#ifdef _MSC_VER
void crtInvalidParameterHandler(const wchar_t* expression, const wchar_t* function, const wchar_t* file, unsigned int line, uintptr_t pReserved) { assert(false); }
#endif


std::vector<Zstring> getCommandlineArgs(const wxApp& app)
{
    std::vector<Zstring> args;
#ifdef ZEN_WIN
    //we do the job ourselves! both wxWidgets and ::CommandLineToArgvW() parse "C:\" "D:\" as single line C:\" D:\"
    //-> "solution": we just don't support protected quotation mark!
    Zstring cmdLine = ::GetCommandLine(); //only way to get a unicode commandline
    while (endsWith(cmdLine, L' ')) //may end with space
        cmdLine.resize(cmdLine.size() - 1);

    auto iterStart = cmdLine.end(); //end() means: no token
    for (auto it = cmdLine.begin(); it != cmdLine.end(); ++it)
        if (*it == L' ') //space commits token
        {
            if (iterStart != cmdLine.end())
            {
                args.push_back(Zstring(iterStart, it));
                iterStart = cmdLine.end(); //expect consecutive blanks!
            }
        }
        else
        {
            //start new token
            if (iterStart == cmdLine.end())
                iterStart = it;

            if (*it == L'\"')
            {
                it = std::find(it + 1, cmdLine.end(), L'\"');
                if (it == cmdLine.end())
                    break;
            }
        }
    if (iterStart != cmdLine.end())
        args.push_back(Zstring(iterStart, cmdLine.end()));

    if (!args.empty())
        args.erase(args.begin()); //remove first argument which is exe path by convention: http://blogs.msdn.com/b/oldnewthing/archive/2006/05/15/597984.aspx

    std::for_each(args.begin(), args.end(),
                  [](Zstring& str)
    {
        if (str.size() >= 2 && startsWith(str, L'\"') && endsWith(str, L'\"'))
            str = Zstring(str.c_str() + 1, str.size() - 2);
    });

#else
    for (int i = 1; i < app.argc; ++i) //wxWidgets screws up once again making "argv implicitly convertible to a wxChar**" in 2.9.3,
        args.push_back(toZ(wxString(app.argv[i])));   //so we are forced to use this pitiful excuse for a range construction!!
#endif
    return args;
}

const wxEventType EVENT_ENTER_EVENT_LOOP = wxNewEventType();
}

//##################################################################################################################

bool Application::OnInit()
{
    //-> this seems rather useless:
    //std::set_terminate(onTerminationRequested); //unlike wxWidgets uncaught exception handling, this works for all worker threads

#ifdef ZEN_WIN
#ifdef _MSC_VER
    _set_invalid_parameter_handler(crtInvalidParameterHandler); //see comment in <zen/time.h>
#endif
    //Quote: "Best practice is that all applications call the process-wide ::SetErrorMode() function with a parameter of
    //SEM_FAILCRITICALERRORS at startup. This is to prevent error mode dialogs from hanging the application."
    ::SetErrorMode(SEM_FAILCRITICALERRORS);

#elif defined ZEN_LINUX
    ::gtk_init(nullptr, nullptr);
    ::gtk_rc_parse((getResourceDir() + "styles.gtk_rc").c_str()); //remove inner border from bitmap buttons
#endif

#ifdef ZEN_WIN
    wxToolTip::SetMaxWidth(-1); //disable tooltip wrapping -> Windows only
#endif
    //Windows User Experience Interaction Guidelines: tool tips should have 5s timeout, info tips no timeout => compromise:
    wxToolTip::SetAutoPop(7000); //http://msdn.microsoft.com/en-us/library/windows/desktop/aa511495.aspx

    SetAppName(L"FreeFileSync"); //if not set, the default is the executable's name!

    Connect(wxEVT_QUERY_END_SESSION, wxEventHandler(Application::onQueryEndSession), nullptr, this);
    Connect(wxEVT_END_SESSION,       wxEventHandler(Application::onQueryEndSession), nullptr, this);

    //do not call wxApp::OnInit() to avoid using wxWidgets command line parser

    //Note: app start is deferred: batch mode requires the wxApp eventhandler to be established for UI update events. This is not the case at the time of OnInit()!
    Connect(EVENT_ENTER_EVENT_LOOP, wxEventHandler(Application::onEnterEventLoop), nullptr, this);
    wxCommandEvent scrollEvent(EVENT_ENTER_EVENT_LOOP);
    AddPendingEvent(scrollEvent);

    return true; //true: continue processing; false: exit immediately.
}


int Application::OnExit()
{
    releaseWxLocale();
    return wxApp::OnExit();
}


void Application::onEnterEventLoop(wxEvent& event)
{
    Disconnect(EVENT_ENTER_EVENT_LOOP, wxEventHandler(Application::onEnterEventLoop), nullptr, this);

    //determine FFS mode of operation
    std::vector<Zstring> commandArgs = getCommandlineArgs(*this);
    launch(commandArgs);
}

#ifdef ZEN_MAC
/*
wxWidgets initialization sequence on OS X is a mess:
----------------------------------------------------
1. double click FFS app bundle or execute from command line without arguments
	OnInit()
	OnRun()
	onEnterEventLoop()
	MacNewFile()

2. double-click .ffs_gui file
	OnInit()
	OnRun()
	onEnterEventLoop()
	MacOpenFiles()

3. start from command line with .ffs_gui file as first argument
	OnInit()
	OnRun()
	MacOpenFiles() -> WTF!?
	onEnterEventLoop()
	MacNewFile()   -> yes, wxWidgets screws up once again: http://trac.wxwidgets.org/ticket/14558

=> solution: map Apple events to regular command line via launcher
*/
#endif


int Application::OnRun()
{
    auto processException = [](const std::wstring& msg)
    {
        //it's not always possible to display a message box, e.g. corrupted stack, however low-level file output works!
        logError(utfCvrtTo<std::string>(msg));
        wxSafeShowMessage(_("An exception occurred"), msg);
    };

    try
    {
        wxApp::OnRun();
    }
    catch (const std::exception& e) //catch all STL exceptions
    {
        processException(utfCvrtTo<std::wstring>(e.what()));
        return FFS_RC_EXCEPTION;
    }
    catch (...) //catch the rest
    {
        processException(L"Unknown error.");
        return FFS_RC_EXCEPTION;
    }

    return returnCode;
}


void Application::onQueryEndSession(wxEvent& event)
{
    if (auto mainWin = dynamic_cast<MainDialog*>(GetTopWindow()))
        mainWin->onQueryEndSession();
    OnExit(); //wxWidgets screws up again: http://trac.wxwidgets.org/ticket/3069
    //wxEntryCleanup(); -> gives popup "dll init failed" on XP
    std::exit(returnCode); //Windows will terminate anyway: destruct global objects
}


void runGuiMode();
void runGuiMode(const XmlGuiConfig& guiCfg, const std::vector<Zstring>& referenceFiles);
void runBatchMode(const XmlBatchConfig& batchCfg, const Zstring& referenceFile, FfsReturnCode& returnCode);
void showSyntaxHelp();


void Application::launch(const std::vector<Zstring>& commandArgs)
{
    //wxWidgets app exit handling is weird... we want the app to exit only if the logical main window is closed
    wxTheApp->SetExitOnFrameDelete(false); //avoid popup-windows from becoming temporary top windows leading to program exit after closure
    auto app = wxTheApp; //fix lambda/wxWigets/VC fuck up
    ZEN_ON_SCOPE_EXIT(if (!mainWindowWasSet()) app->ExitMainLoop();); //quit application, if no main window was set (batch silent mode)

    try
    {
        //tentatively set program language to OS default until GlobalSettings.xml is read later
        setLanguage(xmlAccess::XmlGlobalSettings().programLanguage); //throw FileError
    }
    catch (const FileError&) { assert(false); } //no messagebox: consider batch job!

    auto notifyError = [&](const std::wstring& msg, const std::wstring& header)
    {
        wxMessageBox(msg.c_str(), L"FreeFileSync - " + header, wxOK | wxICON_ERROR);
        raiseReturnCode(returnCode, FFS_RC_ABORTED);
    };

    //parse command line arguments
    std::vector<Zstring> leftDirs;
    std::vector<Zstring> rightDirs;
    std::vector<std::pair<Zstring, XmlType>> configFiles; //XmlType: batch or GUI files only
    {
        const Zchar optionLeftDir [] = Zstr("-leftdir");
        const Zchar optionRightDir[] = Zstr("-rightdir");

        auto syntaxHelpRequested = [](const Zstring& arg)
        {
            auto it = std::find_if(arg.begin(), arg.end(), [](Zchar c) { return c != Zchar('/') && c != Zchar('-'); });
            const Zstring argTmp(it, arg.end());
            return argTmp == Zstr("help") ||
                   argTmp == Zstr("h")    ||
                   argTmp == Zstr("?");
        };

        for (auto it = commandArgs.begin(); it != commandArgs.end(); ++it)
            if (syntaxHelpRequested(*it))
                return showSyntaxHelp();
            else if (*it == optionLeftDir)
            {
                if (++it == commandArgs.end())
                {
                    notifyError(replaceCpy(_("A directory path is expected after %x."), L"%x", utfCvrtTo<std::wstring>(optionLeftDir)), _("Syntax error"));
                    return;
                }
                leftDirs.push_back(*it);
            }
            else if (*it == optionRightDir)
            {
                if (++it == commandArgs.end())
                {
                    notifyError(replaceCpy(_("A directory path is expected after %x."), L"%x", utfCvrtTo<std::wstring>(optionRightDir)), _("Syntax error"));
                    return;
                }
                rightDirs.push_back(*it);
            }
            else
            {
                Zstring filename = *it;
                if (!fileExists(filename)) //...be a little tolerant
                {
                    if (fileExists(filename + Zstr(".ffs_batch")))
                        filename += Zstr(".ffs_batch");
                    else if (fileExists(filename + Zstr(".ffs_gui")))
                        filename += Zstr(".ffs_gui");
                    else
                    {
                        notifyError(replaceCpy(_("Cannot open file %x."), L"%x", fmtFileName(filename)), _("Error"));
                        return;
                    }
                }

                switch (getXmlType(filename)) //throw()
                {
                    case XML_TYPE_GLOBAL:
                    case XML_TYPE_OTHER:
                        notifyError(replaceCpy(_("File %x does not contain a valid configuration."), L"%x", fmtFileName(filename)), _("Error"));
                        return;

                    case XML_TYPE_GUI:
                        configFiles.push_back(std::make_pair(filename, XML_TYPE_GUI));
                        break;
                    case XML_TYPE_BATCH:
                        configFiles.push_back(std::make_pair(filename, XML_TYPE_BATCH));
                        break;
                }
            }
    }

    if (leftDirs.size() != rightDirs.size())
    {
        notifyError(_("Unequal number of left and right directories specified."), _("Syntax error"));
        return;
    }

    auto hasNonDefaultConfig = [](const FolderPairEnh& fp)
    {
        return !(fp == FolderPairEnh(fp.leftDirectory,
                                     fp.rightDirectory,
                                     nullptr, nullptr, FilterConfig()));
    };

    auto replaceDirectories = [&](MainConfiguration& mainCfg)
    {
        if (!leftDirs.empty())
        {
            //check if config at folder-pair level is present: this probably doesn't make sense when replacing/adding the user-specified directories
            if (hasNonDefaultConfig(mainCfg.firstPair) || std::any_of(mainCfg.additionalPairs.begin(), mainCfg.additionalPairs.end(), hasNonDefaultConfig))
            {
                notifyError(_("The config file must not contain settings at directory pair level when directories are set via command line."), _("Syntax error"));
                return false;
            }

            mainCfg.additionalPairs.clear();
            for (size_t i = 0; i < leftDirs.size(); ++i)
                if (i == 0)
                {
                    mainCfg.firstPair.leftDirectory  = leftDirs [0];
                    mainCfg.firstPair.rightDirectory = rightDirs[0];
                }
                else
                    mainCfg.additionalPairs.push_back(FolderPairEnh(leftDirs [i],
                                                                    rightDirs[i],
                                                                    nullptr, nullptr, FilterConfig()));
        }
        return true;
    };

    //distinguish sync scenarios:
    //---------------------------
    if (configFiles.empty())
    {
        //gui mode: default startup
        if (leftDirs.empty())
            runGuiMode();
        //gui mode: default config with given directories
        else
        {
            XmlGuiConfig guiCfg;
            guiCfg.mainCfg.syncCfg.directionCfg.var = DirectionConfig::MIRROR;

            if (!replaceDirectories(guiCfg.mainCfg)) return;
            runGuiMode(guiCfg, std::vector<Zstring>());
        }
    }
    else if (configFiles.size() == 1)
    {
        const Zstring filename = configFiles[0].first;

        //batch mode
        if (configFiles[0].second == XML_TYPE_BATCH)
        {
            XmlBatchConfig batchCfg;
            try
            {
                readConfig(filename, batchCfg);
            }
            catch (const xmlAccess::FfsXmlError& e)
            {
                //batch mode: break on errors AND even warnings!
                notifyError(e.toString(), _("Error"));
                return;
            }
            if (!replaceDirectories(batchCfg.mainCfg)) return;
            runBatchMode(batchCfg, filename, returnCode);
        }
        //GUI mode: single config
        else
        {
            XmlGuiConfig guiCfg;
            try
            {
                readConfig(filename, guiCfg);
            }
            catch (const xmlAccess::FfsXmlError& e)
            {
                if (e.getSeverity() == FfsXmlError::WARNING)
                    wxMessageBox(e.toString(), L"FreeFileSync - " + _("Warning"), wxOK | wxICON_WARNING);
                //what about simulating changed config on parsing errors????
                else
                {
                    notifyError(e.toString(), _("Error"));
                    return;
                }
            }
            if (!replaceDirectories(guiCfg.mainCfg)) return;
            //what about simulating changed config due to directory replacement?
            //-> propably fine to not show as changed on GUI and not ask user to save on exit!

            runGuiMode(guiCfg, { filename }); //caveat: guiCfg and filename do not match if directories were set/replaced via command line!
        }
    }
    //gui mode: merged configs
    else
    {
        if (!leftDirs.empty())
        {
            notifyError(_("Directories cannot be set for more than one configuration file."), _("Syntax error"));
            return;
        }

        std::vector<Zstring> filenames;
        for (const auto& item : configFiles)
            filenames.push_back(item.first);

        XmlGuiConfig guiCfg; //structure to receive gui settings with default values
        try
        {
            readAnyConfig(filenames, guiCfg); //throw FfsXmlError
        }
        catch (const FfsXmlError& e)
        {
            if (e.getSeverity() == FfsXmlError::WARNING)
                wxMessageBox(e.toString(), L"FreeFileSync - " + _("Warning"), wxOK | wxICON_WARNING);
            //what about simulating changed config on parsing errors????
            else
            {
                notifyError(e.toString(), _("Error"));
                return;
            }
        }
        runGuiMode(guiCfg, filenames);
    }
}


void runGuiMode() { MainDialog::create(); }


void runGuiMode(const xmlAccess::XmlGuiConfig& guiCfg,
                const std::vector<Zstring>& referenceFiles)
{
    MainDialog::create(guiCfg, referenceFiles, nullptr, true); //startComparison == true!
}


void showSyntaxHelp()
{
    wxMessageBox(_("Syntax:") + L"\n" +
                 L"FreeFileSync [" + _("config files") + L"]\n[-leftdir " + _("directory") + L"] [-rightdir " + _("directory") + L"]" + L"\n" +
                 L"\n" +
                 _("config files") + L"\n" +
                 _("Any number of FreeFileSync .ffs_gui and/or .ffs_batch configuration files.") + L"\n\n"

                 L"-leftdir " + _("directory") + L" -rightdir " + _("directory") + L"\n" +
                 _("Any number of alternative directories for at most one config file."),
                 L"FreeFileSync - " + _("Command line"), wxOK | wxICON_INFORMATION);
}


void runBatchMode(const XmlBatchConfig& batchCfg, const Zstring& referenceFile, FfsReturnCode& returnCode)
{
    auto notifyError = [&](const std::wstring& msg, FfsReturnCode rc)
    {
        if (batchCfg.handleError == ON_ERROR_POPUP)
            wxMessageBox(msg.c_str(), L"FreeFileSync - " + _("Error"), wxOK | wxICON_ERROR);
        else //"exit" or "ignore"
            logError(utfCvrtTo<std::string>(msg));

        raiseReturnCode(returnCode, rc);
    };

    XmlGlobalSettings globalCfg;
    try
    {
        if (fileExists(getGlobalConfigFile()))
            readConfig(globalCfg); //throw FfsXmlError
        //else: globalCfg already has default values
    }
    catch (const xmlAccess::FfsXmlError& e)
    {
        assert(false);
        if (e.getSeverity() != FfsXmlError::WARNING) //ignore parsing errors: should be migration problems only *cross-fingers*
            return notifyError(e.toString(), FFS_RC_ABORTED); //abort sync!
    }

    try
    {
        setLanguage(globalCfg.programLanguage); //throw FileError
    }
    catch (const FileError& e)
    {
        notifyError(e.toString(), FFS_RC_FINISHED_WITH_WARNINGS);
        //continue!
    }

    //all settings have been read successfully...

    //regular check for program updates -> disabled for batch
    //if (batchCfg.showProgress && manualProgramUpdateRequired())
    //    checkForUpdatePeriodically(globalCfg.lastUpdateCheck);

    try //begin of synchronization process (all in one try-catch block)
    {

        const TimeComp timeStamp = localTime();

        const SwitchToGui switchBatchToGui(referenceFile, batchCfg, globalCfg); //prepare potential operational switch

        //class handling status updates and error messages
        BatchStatusHandler statusHandler(batchCfg.showProgress, //throw BatchAbortProcess
                                         extractJobName(referenceFile),
                                         timeStamp,
                                         batchCfg.logFileDirectory,
                                         batchCfg.logfilesCountLimit,
                                         globalCfg.lastSyncsLogFileSizeMax,
                                         batchCfg.handleError,
                                         switchBatchToGui,
                                         returnCode,
                                         batchCfg.mainCfg.onCompletion,
                                         globalCfg.gui.onCompletionHistory);

        const std::vector<FolderPairCfg> cmpConfig = extractCompareCfg(batchCfg.mainCfg);

        bool allowPwPrompt = false;
        switch (batchCfg.handleError)
        {
            case ON_ERROR_POPUP:
                allowPwPrompt = true;
                break;
            case ON_ERROR_IGNORE:
            case ON_ERROR_ABORT:
                break;
        }

        //batch mode: place directory locks on directories during both comparison AND synchronization
        std::unique_ptr<LockHolder> dirLocks;

        //COMPARE DIRECTORIES
        FolderComparison folderCmp;
        compare(globalCfg.fileTimeTolerance,
                globalCfg.optDialogs,
                allowPwPrompt,
                globalCfg.runWithBackgroundPriority,
                globalCfg.createLockFile,
                dirLocks,
                cmpConfig,
                folderCmp,
                statusHandler);

        //START SYNCHRONIZATION
        const std::vector<FolderPairSyncCfg> syncProcessCfg = extractSyncCfg(batchCfg.mainCfg);
        if (syncProcessCfg.size() != folderCmp.size())
            throw std::logic_error("Programming Error: Contract violation! " + std::string(__FILE__) + ":" + numberTo<std::string>(__LINE__));

        synchronize(timeStamp,
                    globalCfg.optDialogs,
                    globalCfg.verifyFileCopy,
                    globalCfg.copyLockedFiles,
                    globalCfg.copyFilePermissions,
                    globalCfg.transactionalFileCopy,
                    globalCfg.runWithBackgroundPriority,
                    syncProcessCfg,
                    folderCmp,
                    statusHandler);
    }
    catch (BatchAbortProcess&) {} //exit used by statusHandler

    try //save global settings to XML: e.g. ignored warnings
    {
        xmlAccess::writeConfig(globalCfg); //FfsXmlError
    }
    catch (const xmlAccess::FfsXmlError& e)
    {
        notifyError(e.toString(), FFS_RC_FINISHED_WITH_WARNINGS);
    }
}