/******************************************************************************************************
 * (C) 2014 markummitchell@github.com. This file is part of Engauge Digitizer, which is released      *
 * under GNU General Public License version 2 (GPLv2) or (at your option) any later version. See file *
 * LICENSE or go to gnu.org/licenses for details. Distribution requires prior written permission.     *
 ******************************************************************************************************/

#include "ColorFilterMode.h"
#include "FittingCurveCoefficients.h"
#include "ImportImageExtensions.h"
#include "Logger.h"
#include "MainWindow.h"
#include <QApplication>
#include <QCoreApplication>
#include <QDebug>
#include <QDir>
#include <QFileInfo>
#include <QMessageBox>
#include <QObject>
#include <QProcessEnvironment>
#include <QStyleFactory>
#include "TranslatorContainer.h"
#include "ZoomFactor.h"

using namespace std;

const QString CMD_DEBUG ("debug");
const QString CMD_DROP_REGRESSION ("dropregression");
const QString CMD_ERROR_REPORT ("errorreport");
const QString CMD_EXPORT_ONLY ("exportonly");
const QString CMD_EXTRACT_IMAGE_ONLY ("extractimageonly");
const QString CMD_FILE_CMD_SCRIPT ("filecmdscript");
const QString CMD_GNUPLOT ("gnuplot");
const QString CMD_HELP ("help");
const QString CMD_REGRESSION ("regression");
const QString CMD_RESET ("reset");
const QString CMD_STYLE ("style"); // Qt handles this
const QString CMD_STYLES ("styles"); // Not to be confused with -style option that qt handles
const QString CMD_UPGRADE ("upgrade");
const QString DASH ("-");
const QString DASH_DEBUG ("-" + CMD_DEBUG);
const QString DASH_DROP_REGRESSION ("-" + CMD_DROP_REGRESSION);
const QString DASH_ERROR_REPORT ("-" + CMD_ERROR_REPORT);
const QString DASH_EXTRACT_IMAGE_ONLY ("-" + CMD_EXTRACT_IMAGE_ONLY);
const QString DASH_EXPORT_ONLY ("-" + CMD_EXPORT_ONLY);
const QString DASH_FILE_CMD_SCRIPT ("-" + CMD_FILE_CMD_SCRIPT);
const QString DASH_GNUPLOT ("-" + CMD_GNUPLOT);
const QString DASH_HELP ("-" + CMD_HELP);
const QString DASH_REGRESSION ("-" + CMD_REGRESSION);
const QString DASH_RESET ("-" + CMD_RESET);
const QString DASH_STYLE ("-" + CMD_STYLE);
const QString DASH_STYLES ("-" + CMD_STYLES);
const QString DASH_UPGRADE ("-" + CMD_UPGRADE);
const QString ENGAUGE_LOG_FILE (".engauge.log");

// Prototypes
bool checkFileExists (const QString &file);
QString engaugeLogFilename ();
bool engaugeLogFilenameAttempt (const QString &path,
                                QString &pathAndFile);
void parseCmdLine (int argc,
                   char **argv,
                   bool &isDebug,
                   bool &isDropRegression,
                   bool &isReset,
                   QString &errorReportFile,
                   QString &fileCmdScriptFile,
                   bool &isErrorReportRegressionTest,
                   bool &isGnuplot,
                   bool &isExportOnly,
                   bool &isExtractImageOnly,
                   QString &extractImageOnlyExtension,
                   bool &isUpgrade,
                   QStringList &loadStartupFiles,
                   QStringList &commandLineWithoutLoadStartupFiles);
void sanityCheckLoadStartupFiles (bool isRepeatingFlag,
                                  const QString &dashForRepeatingFlag,
                                  const QString &errorReportFile,
                                  const QString &fileCmdScriptFile,
                                  const QStringList &loadStartupFiles);
void sanityCheckValue (bool requiredCondition,
                       const QString &arg,
                       const QString &msgUnadorned);
void showMessageAndQuit (const QString &msg);
void showStylesAndQuit ();
void showUsageAndQuit ();
void upgradeFiles (const QStringList &loadStartupFiles);

// Functions
bool checkFileExists (const QString &file)
{
  QFileInfo check (file);
  return check.exists() && check.isFile();
}

QString engaugeLogFilename()
{
  QString pathAndFile; // Return empty value in OSX which is unused

#if !defined(OSX_RELEASE) && !defined(WIN_RELEASE) && !defined(APPIMAGE_RELEASE)
  QProcessEnvironment env;

  // Make multiple attempts until a directory is found where the log file can be written
  if (!engaugeLogFilenameAttempt (QCoreApplication::applicationDirPath(), pathAndFile)) {
    if (!engaugeLogFilenameAttempt (env.value ("HOME"), pathAndFile)) {
      if (!engaugeLogFilenameAttempt (env.value ("TEMP"), pathAndFile)) {
        pathAndFile = ENGAUGE_LOG_FILE; // Current directory will have to do
      }
    }
  }
#endif

  return pathAndFile;
}

bool engaugeLogFilenameAttempt (const QString &path,
                                QString &pathAndFile)
{
  bool success = false;

  // Test if file can be opened. Checking permissions on directory is unreliable in Windows/OSX
  pathAndFile = QString ("%1%2%3")
                         .arg (path)
                         .arg (QDir::separator())
                         .arg (ENGAUGE_LOG_FILE);
  QFile file (pathAndFile);
  if (file.open(QIODevice::WriteOnly | QIODevice::Text)) {
    // Success
    file.close();
    file.remove(); // Cleanup
    success = true;
  }

  return success;
}

int main(int argc, char *argv[])
{
  qRegisterMetaType<ColorFilterMode> ("ColorFilterMode");
  qRegisterMetaType<FittingCurveCoefficients> ("FilterCurveCoefficients");
  qRegisterMetaType<ZoomFactor> ("ZoomFactor");

  QApplication app(argc, argv);

  // Translations
  TranslatorContainer translatorContainer (app); // Must exist until execution terminates

  // Command line
  bool isDebug, isDropRegression, isReset, isGnuplot, isErrorReportRegressionTest, isExportOnly, isExtractImageOnly, isUpgrade;
  QString errorReportFile, extractImageOnlyExtension, fileCmdScriptFile;
  QStringList loadStartupFiles, commandLineWithoutLoadStartupFiles;
  parseCmdLine (argc,
                argv,
                isDebug,
                isDropRegression,
                isReset,
                errorReportFile,
                fileCmdScriptFile,
                isErrorReportRegressionTest,
                isGnuplot,
                isExportOnly,
                isExtractImageOnly,
                extractImageOnlyExtension,
                isUpgrade,
                loadStartupFiles,
                commandLineWithoutLoadStartupFiles);

  // Logging
  initializeLogging ("engauge",
                     engaugeLogFilename(),
                     isDebug);
  LOG4CPP_INFO_S ((*mainCat)) << "main args=" << QApplication::arguments().join (" ").toLatin1().data();

  // Upgrade or run normally
  int rtn = 0;
  if (isUpgrade) {
    upgradeFiles (loadStartupFiles);
  } else {
    // Create and show main window
    MainWindow w (errorReportFile,
                  fileCmdScriptFile,
                  isDropRegression,
                  isErrorReportRegressionTest,
                  isGnuplot,
                  isReset,
                  isExportOnly,
                  isExtractImageOnly,
                  extractImageOnlyExtension,
                  loadStartupFiles,
                  commandLineWithoutLoadStartupFiles);
    w.show();

    // Event loop
    rtn = app.exec();
  }

  return rtn;
}

void parseCmdLine (int argc,
                   char **argv,
                   bool &isDebug,
                   bool &isDropRegression,
                   bool &isReset,
                   QString &errorReportFile,
                   QString &fileCmdScriptFile,
                   bool &isErrorReportRegressionTest,
                   bool &isGnuplot,
                   bool &isExportOnly,
                   bool &isExtractImageOnly,
                   QString &extractImageOnlyExtension,
                   bool &isUpgrade,
                   QStringList &loadStartupFiles,
                   QStringList &commandLineWithoutLoadStartupFiles)
{
  bool showUsage = false;

  ImportImageExtensions importImageExtensions;

  // State
  bool nextIsErrorReportFile = false;
  bool nextIsExtractImageOnly = false;
  bool nextIsFileCmdScript = false;

  // Defaults
  isDebug = false;
  isDropRegression = false;
  isReset = false;
  errorReportFile = "";
  fileCmdScriptFile = "";
  isErrorReportRegressionTest = false;
  isGnuplot = false;
  isExportOnly = false;
  isExtractImageOnly = false;
  extractImageOnlyExtension = "";
  isUpgrade = false;

  for (int i = 1; i < argc; i++) {

    bool isLoadStartupFile = false;

    if (nextIsErrorReportFile) {
      sanityCheckValue (checkFileExists (argv [i]),
                        argv [i],
                        QObject::tr ("is not a valid file name"));
      errorReportFile = argv [i];
      nextIsErrorReportFile = false;
    } else if (nextIsExtractImageOnly) {
      sanityCheckValue (importImageExtensions.offers (argv [i]),
                        argv [i],
                        QObject::tr ("is not a valid image file extension"));
      extractImageOnlyExtension = argv [i];
      nextIsExtractImageOnly = false;
    } else if (nextIsFileCmdScript) {
      sanityCheckValue (checkFileExists (argv [i]),
                        argv [i],
                        QObject::tr ("is not a valid file name"));
      fileCmdScriptFile = argv [i];
      nextIsFileCmdScript = false;
    } else if (strcmp (argv [i], DASH_DEBUG.toLatin1().data()) == 0) {
      isDebug = true;
    } else if (strcmp (argv [i], DASH_DROP_REGRESSION.toLatin1().data()) == 0) {
      isDropRegression = true;
    } else if (strcmp (argv [i], DASH_ERROR_REPORT.toLatin1().data()) == 0) {
      nextIsErrorReportFile = true;
    } else if (strcmp (argv [i], DASH_EXPORT_ONLY.toLatin1().data()) == 0) {
      isExportOnly = true;
    } else if (strcmp (argv [i], DASH_EXTRACT_IMAGE_ONLY.toLatin1().data()) == 0) {
      isExtractImageOnly = true;
      nextIsExtractImageOnly = true;
    } else if (strcmp (argv [i], DASH_FILE_CMD_SCRIPT.toLatin1().data()) == 0) {
      nextIsFileCmdScript = true;
    } else if (strcmp (argv [i], DASH_GNUPLOT.toLatin1().data()) == 0) {
      isGnuplot = true;
    } else if (strcmp (argv [i], DASH_HELP.toLatin1().data()) == 0) {
      showUsage = true; // User requested help
    } else if (strcmp (argv [i], DASH_REGRESSION.toLatin1().data()) == 0) {
      isErrorReportRegressionTest = true;
    } else if (strcmp (argv [i], DASH_RESET.toLatin1().data()) == 0) {
      isReset = true;
    } else if (strcmp (argv [i], DASH_STYLE.toLatin1().data()) == 0) {
      // This branch never executes because Qt strips out '-style <style>' and processes it.
      // This comment is here just to document that special handling
    } else if (strcmp (argv [i], DASH_STYLES.toLatin1().data()) == 0) {
      showStylesAndQuit ();
    } else if (strcmp (argv [i], DASH_UPGRADE.toLatin1().data()) == 0) {
      isUpgrade = true;
    } else if (strncmp (argv [i], DASH.toLatin1().data(), 1) == 0) {
      showUsage = true; // User entered an unrecognized token
    } else {
      // MainWindow will change current directory (which is often some obscure application directory),
      // so relative paths must be changed in advance to absolute so the files can still be found
      QString fileName = argv [i];
      QFileInfo fInfo (fileName);
      if (fInfo.isRelative() && !fileName.startsWith ("http")) {
        fileName = fInfo.absoluteFilePath();
      }

      isLoadStartupFile = true;
      loadStartupFiles << fileName; // Save file name
    }

    // keep command line arguments
    if (!isLoadStartupFile) {
      commandLineWithoutLoadStartupFiles << argv [i];
    }
  }

  // Sanity checks
  sanityCheckLoadStartupFiles (isExportOnly,
                               DASH_EXPORT_ONLY,
                               errorReportFile,
                               fileCmdScriptFile,
                               loadStartupFiles);
  sanityCheckLoadStartupFiles (isExtractImageOnly,
                               DASH_EXTRACT_IMAGE_ONLY,
                               errorReportFile,
                               fileCmdScriptFile,
                               loadStartupFiles);

  // Usage
  if (showUsage || nextIsErrorReportFile || nextIsExtractImageOnly || nextIsFileCmdScript) {

    showUsageAndQuit ();

  }
}

void sanityCheckLoadStartupFiles (bool isRepeatingFlag,
                                  const QString &dashForRepeatingFlag,
                                  const QString &errorReportFile,
                                  const QString &fileCmdScriptFile,
                                  const QStringList &loadStartupFiles)
{
  if (isRepeatingFlag && (!errorReportFile.isEmpty() ||
                          !fileCmdScriptFile.isEmpty() ||
                          loadStartupFiles.size() == 0)) {

    // Condition that at only load files are specified, and there is at least one of them, is not satisfied so
    // show more specific error message than showUsageAndQuit, and then quit
    QString msg;
    QTextStream str (&msg);
    str << dashForRepeatingFlag.toLatin1().data() << " " << QObject::tr ("is used only with one or more load files");
    showMessageAndQuit (msg);
  }
}

void sanityCheckValue (bool requiredCondition,
                       const QString &arg,
                       const QString &msgUnadorned)
{
  if (!requiredCondition) {

    // Required condition is not satisfied. Show a more specific error message than showUsageAndQuit and then quit
    QString msg = QString ("%1 %2")
        .arg (arg)
        .arg (msgUnadorned);
    showMessageAndQuit (msg);
  }
}

void showMessageAndQuit (const QString &msg)
{
  // Show message in QMessageBox instead of cout or cerr since console output is disabled in Microsoft Windows
  QMessageBox::critical (nullptr,
                         QObject::tr ("Engauge Digitizer"),
                         msg);
  exit (0);
}

void showStylesAndQuit ()
{
  QString msg;
  QTextStream str (&msg);
  str << QObject::tr ("Available styles") << ": " << QStyleFactory::keys ().join (", ");
  showMessageAndQuit (msg);
}

void showUsageAndQuit ()
{
  QString msg;
  QTextStream str (&msg);
  str << "<html>Usage: engauge "
      << "[" << DASH_DEBUG.toLatin1().data() << "] "
      << "[" << DASH_DROP_REGRESSION.toLatin1().data() << "] "
      << "[" << DASH_ERROR_REPORT.toLatin1().data() << " &lt;file&gt;] "
      << "[" << DASH_EXPORT_ONLY.toLatin1().data() << "] "
      << "[" << DASH_EXTRACT_IMAGE_ONLY.toLatin1().data() << " &lt;extension&gt;] "
      << "[" << DASH_FILE_CMD_SCRIPT.toLatin1().data() << " &lt;file&gt; "
      << "[" << DASH_GNUPLOT.toLatin1().data() << "] "
      << "[" << DASH_HELP.toLatin1().data() << "] "
      << "[" << DASH_REGRESSION.toLatin1().data() << "] "
      << "[" << DASH_RESET.toLatin1().data () << "] "
      << "[" << DASH_STYLE.toLatin1().data () << " &lt;style&gt;] "
      << "[" << DASH_STYLES.toLatin1().data () << "] "
      << "[&lt;load_file1&gt;] [&lt;load_file2&gt;] ..." << endl
      << "<table>"
      << "<tr>"
      << "<td>" << DASH_DEBUG.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Enables extra debug information. Used for debugging").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_DROP_REGRESSION.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Indicates files opened at startup are for testing drag and drop. Used for regression testing").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_ERROR_REPORT.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Specifies an error report file as input. Used for debugging and regression testing").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_EXPORT_ONLY.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Export each loaded startup file, which must have all axis points defined, then stop").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_EXTRACT_IMAGE_ONLY.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Extract image in each loaded startup file to a file with the specified extension, then stop").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_FILE_CMD_SCRIPT.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Specifies a file command script file as input. Used for debugging and testing").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_GNUPLOT.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Output diagnostic gnuplot input files. Used for debugging").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_HELP.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Show this help information").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_REGRESSION.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Executes the error report file or file command script. Used for regression testing").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_RESET.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Removes all stored settings, including window positions. Used when windows start up offscreen").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_STYLE.toLatin1().data() << "</td>"
      << "<td>"
      << QString ("%1 %2")
         .arg (QObject::tr ("Set the window style to one of the styles listed by the command line option"))
         .arg (DASH_STYLES).toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_STYLES.toLatin1().data() << "</td>"
      << "<td>"
      << QString ("%1 %2")
         .arg (QObject::tr ("Show a list of available styles that can be used with the command line option"))
         .arg (DASH_STYLE).toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << DASH_UPGRADE.toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("Upgrade files opened at startup to the most recent version").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "<tr>"
      << "<td>" << QString ("&lt;load file&gt; ").toLatin1().data() << "</td>"
      << "<td>"
      << QObject::tr ("File(s) to be imported or opened at startup").toLatin1().data()
      << "</td>"
      << "</tr>"
      << "</table></html>";

  showMessageAndQuit (msg);
}

void upgradeFiles (const QStringList &loadStartupFiles)
{
  QString FILE_SUFFIX (".dig");
  QString UPGRADE_TOKEN ("_upgrade");

  QString msg;

  QStringList::const_iterator itr;
  for (itr = loadStartupFiles.begin(); itr != loadStartupFiles.end(); itr++) {

    QString filenameOld = *itr;
    QString filenameNew;

    // First try to insert upgrade token before file prefix if it is recognized
    if (filenameOld.endsWith (FILE_SUFFIX,
                              Qt::CaseInsensitive)) {
      QString withoutSuffix = filenameOld.left (filenameOld.size () - FILE_SUFFIX.size ());
      filenameNew = QString ("%1%2%3")
          .arg (withoutSuffix)
          .arg (UPGRADE_TOKEN)
          .arg (FILE_SUFFIX);
    } else {

      // Otherwise append upgrade token
      filenameNew = QString ("%1%2")
          .arg (filenameOld)
          .arg (UPGRADE_TOKEN);
    }

    // Get old file
    Document document (filenameOld);

    // Make new file
    QFile file (filenameNew);
    if (!file.open (QFile::WriteOnly)) {

      msg += QString ("%1 %2")
        .arg (QObject::tr ("Could not write to"))
        .arg (filenameNew);

    } else {

      QXmlStreamWriter writer (&file);
      writer.setAutoFormatting (true);
      writer.writeStartDocument();
      writer.writeDTD ("<!DOCTYPE engauge>");
      document.saveXml (writer);
      writer.writeEndDocument ();

      msg += QString ("%1 %2 %3 %4")
        .arg (QObject::tr ("Upgraded"))
        .arg (filenameOld)
        .arg (QObject::tr ("to"))
        .arg (filenameNew);
    }
  }

  // Do not show a message using QMessageBox since upgrade mode may be called hundreds
  // of times successively by python scripts. Logging is used instead
  LOG4CPP_INFO_S ((*mainCat)) << "Upgrade results: " << msg.toLatin1().data ();
  
  exit (0);
}