/***************************************************************************

  musrview.cpp

  Author: Andreas Suter
  e-mail: andreas.suter@psi.ch

***************************************************************************/

/***************************************************************************
 *   Copyright (C) 2007-2026 by Andreas Suter                              *
 *   andreas.suter@psi.ch                                                  *
 *                                                                         *
 *   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.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

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

#include <cstdio>
#include <cstdlib>
#include <cstring>

#include <chrono>
#include <iostream>
#include <memory>
#include <sstream>
#include <string>
#include <vector>

#include <TApplication.h>
#include <TROOT.h>
#include <TSAXParser.h>
#include <TSystem.h>

#include <ROOT/RWebWindowsManager.hxx>

#ifdef HAVE_GIT_REV_H
#include "git-revision.h"
#endif

#include "PMusr.h"
#include "PMsgBox.h"
#include "PMsrHandler.h"
#include "PMusrWebCanvas.h"
#include "PRunDataHandler.h"
#include "PRunListCollection.h"
#include "PStartupHandler.h"

//--------------------------------------------------------------------------
/**
 * <p>Sends the usage description to the standard output.
 */
void musrview_syntax()
{
  std::cout << std::endl << "usage: musrview <msr-file> [Options]";
  std::cout << std::endl << "       <msr-file>: msr/mlog input file";
  std::cout << std::endl << "       Options:";
  std::cout << std::endl << "       --help    : display this help and exit.";
  std::cout << std::endl << "       --version : output version information and exit.";
  std::cout << std::endl << "       --show-dynamic-path : dumps the dynamic search paths and exit.";
  std::cout << std::endl << "       -f, --fourier: will directly present the Fourier transform of the <msr-file>.";
  std::cout << std::endl << "       -a, --avg: will directly present the averaged data/Fourier of the <msr-file>.";
  std::cout << std::endl << "       -1, --one_to_one: calculate theory points only at data points.";
  std::cout << std::endl << "       display options (musrview is web based, see the musrfit documentation):";
  std::cout << std::endl << "       --embedded : show the plots in an embedded browser window, i.e. musrview";
  std::cout << std::endl << "                    behaves like a stand-alone application. This is the default";
  std::cout << std::endl << "                    as long as ROOT provides the Qt6 web display.";
  std::cout << std::endl << "       --browser  : show the plots in the standard web browser of the system.";
  std::cout << std::endl << "       --browser=<kind> : use a specific display, e.g. chrome, firefox, qt6, server.";
  std::cout << std::endl << "                    'server' only prints the URL and starts no browser at all,";
  std::cout << std::endl << "                    which is what to use when musrfit runs on a remote machine.";
  std::cout << std::endl << "       --<graphic-format-extension>: ";
  std::cout << std::endl << "           will produce a graphics-output-file without opening a window.";
  std::cout << std::endl << "           the name is based on the <msr-file>, e.g. 3310.msr -> 3310_0.png";
  std::cout << std::endl << "           supported graphic-format-extension:";
  std::cout << std::endl << "           eps, pdf, gif, jpg, png, svg, xpm, root";
  std::cout << std::endl << "           example: musrview 3310.msr --png, will produce a files 3310_X.png";
  std::cout << std::endl << "                    where 'X' stands for the plot number (starting form 0)";
  std::cout << std::endl << "       --ascii: ";
  std::cout << std::endl << "           will produce an ascii dump of the data and fit as plotted.";
  std::cout << std::endl << "       --timeout <timeout>: <timeout> given in seconds after which musrview terminates.";
  std::cout << std::endl << "           If <timeout> <= 0, no timeout will take place. Default <timeout> is 0.";
  std::cout << std::endl << "       -s, --show-errMsgBox: if this tag is defined, error message boxes are shown,";
  std::cout << std::endl << "                             rather than only stderr output.";
  std::cout << std::endl << std::endl;
}

//--------------------------------------------------------------------------
/**
 * <p>Shows an error message in a message box.
 *
 * \param errMsg the message to be shown
 */
void musrview_error_msg(std::string errMsg)
{
  int argc=0;
  char **argv=nullptr;
  TApplication app("musrviewErrorMsg", &argc, argv);
  new PMsgBox(errMsg, gClient->GetRoot(), 600, 200);
  app.Run();
}

//--------------------------------------------------------------------------
/**
 * <p>Decides which web display musrview should use.
 *
 * <p>Unless the user asked for something specific, the embedded Qt6 WebEngine
 * window is preferred, since it makes musrview appear as the stand-alone
 * application it has always been. If ROOT was built without the Qt6 web
 * display, the standard browser of the system is used instead.
 *
 * \param requested what the user asked for, empty if nothing was requested
 *
 * \return the display string to be handed to ROOT::RWebWindow::Show()
 */
std::string musrview_select_display(const std::string &requested)
{
  if (!requested.empty())
    return requested;

  if (const char *env = gSystem->Getenv("MUSRVIEW_BROWSER"))
    if (strlen(env) > 0)
      return std::string(env);

  // prefer the embedded window if ROOT provides it
  gSystem->RedirectOutput("/dev/null", "a");
  const Int_t loaded = gSystem->Load("libROOTQt6WebDisplay");
  gSystem->RedirectOutput(nullptr);

  if (loaded >= 0)
    return "qt6";

  std::cout << std::endl << ">> musrview **INFO** ROOT has no Qt6 web display, using the standard browser.";
  std::cout << std::endl << ">>                   Rebuild ROOT with -Dqt6web=ON for an embedded window." << std::endl;

  return std::string();
}

//--------------------------------------------------------------------------
/**
 * <p>The musrview program is used to show muSR fit results in graphical form.
 * From it also Fourier transforms, difference between data an theory can be formed.
 *
 * <p>Since version 1.13 musrview is based on the ROOT7 web graphics: the plots
 * are rendered by JSROOT either in an embedded browser window or in the
 * standard browser of the system, while the C++ side only holds the data.
 *
 * <b>return:</b>
 * - PMUSR_SUCCESS if everthing went smooth
 * - PMUSR_WRONG_STARTUP_SYNTAX if syntax error is encountered
 * - line number if an error in the msr-file was encountered which cannot be handled.
 *
 * \param argc number of input arguments
 * \param argv list of input arguments
 */
int main(int argc, char *argv[])
{
  int result{PMUSR_SUCCESS};
  bool show_syntax{false};
  int  status;
  bool success{true};
  std::string fileName{};
  bool fourier{false};
  bool avg{false};
  bool theoAtData{false}; // theory points only at data points
  bool graphicsOutput{false};
  bool asciiOutput{false};
  std::string graphicsExtension{};
  std::string display{};
  int  timeout{0};
  bool show_errMsgBox{false};
  std::stringstream errMsg;

  // add default shared library path /usr/local/lib if not already persent
  const char *dsp = gSystem->GetDynamicPath();
  if (strstr(dsp, "/usr/local/lib") == nullptr)
    gSystem->AddDynamicPath("/usr/local/lib");

  // check input arguments
  if (argc == 1) {
    musrview_syntax();
    return PMUSR_SYNTAX_REQUEST;
  }
  for (int i=1; i<argc; i++) {
    if (strstr(argv[i], ".msr") || strstr(argv[i], ".mlog")) {
      if (fileName.empty()) {
        fileName = argv[i];
      } else {
        std::cerr << std::endl << "**ERROR** only one file name allowed." << std::endl;
        show_syntax = true;
        break;
      }
    } else if (!strcmp(argv[i], "--version")) {
#ifdef HAVE_CONFIG_H
#ifdef HAVE_GIT_REV_H
      std::cout << std::endl << "musrview version: " << PACKAGE_VERSION << ", git-branch: " << GIT_BRANCH << ", git-rev: " << GIT_CURRENT_SHA1 << " (" << BUILD_TYPE << "), ROOT version: " << ROOT_VERSION_USED << std::endl << std::endl;
#else
      std::cout << std::endl << "musrview version: " << PACKAGE_VERSION << " (" << BUILD_TYPE << "), ROOT version: " << ROOT_VERSION_USED << std::endl << std::endl;
#endif
#else
#ifdef HAVE_GIT_REV_H
      std::cout << std::endl << "musrview git-branch: " << GIT_BRANCH << ", git-rev: " << GIT_CURRENT_SHA1 << std::endl << std::endl;
#else
      std::cout << std::endl << "musrview version: unknown." << std::endl << std::endl;
#endif
#endif
      return PMUSR_SUCCESS;
    } else if (!strcmp(argv[i], "--show-dynamic-path")) {
      std::cout << std::endl << "musrview: internal dynamic search paths for shared libraries/root dictionaries:";
      std::cout << std::endl << "  '" << gSystem->GetDynamicPath() << "'" << std::endl << std::endl;
      return PMUSR_SUCCESS;
    } else if (!strcmp(argv[i], "--help")) {
      show_syntax = true;
      break;
    } else if (!strcmp(argv[i], "-f") || !strcmp(argv[i], "--fourier")) {
      fourier = true;
    } else if (!strcmp(argv[i], "-a") || !strcmp(argv[i], "--avg")) {
      avg = true;
    } else if (!strcmp(argv[i], "-1") || !strcmp(argv[i], "--one_to_one")) {
      theoAtData = true;
    } else if (!strcmp(argv[i], "--embedded")) {
      display = "qt6";
    } else if (!strcmp(argv[i], "--browser")) {
      display = "default";
    } else if (!strncmp(argv[i], "--browser=", 10)) {
      display = argv[i]+10;
      if (display.empty()) {
        show_syntax = true;
        break;
      }
    } else if (!strcmp(argv[i], "--eps") || !strcmp(argv[i], "--pdf") || !strcmp(argv[i], "--gif") ||
               !strcmp(argv[i], "--jpg") || !strcmp(argv[i], "--png") || !strcmp(argv[i], "--svg") ||
               !strcmp(argv[i], "--xpm") || !strcmp(argv[i], "--root")) {

      graphicsOutput = true;
      graphicsExtension = argv[i]+2;
    } else if (!strcmp(argv[i], "--ascii")) {
      asciiOutput = true;
    } else if (!strcmp(argv[i], "--timeout")) {
      if (i+1 < argc) {
        TString str(argv[i+1]);
        if (str.IsFloat()) {
          timeout = str.Atoi();
        } else {
          show_syntax = true;
          break;
        }
        i++;
      } else {
        show_syntax = true;
        break;
      }
    } else if (!strcmp(argv[i], "-s") || !strcmp(argv[i], "--show-errMsgBox")) {
      show_errMsgBox = true;
    } else {
      show_syntax = true;
      break;
    }
  }

  if (show_syntax) {
    musrview_syntax();
    return PMUSR_WRONG_STARTUP_SYNTAX;
  }

  const bool batchMode = graphicsOutput || asciiOutput;

  // read startup file
  std::string startup_path_name{};
  std::unique_ptr<TSAXParser> saxParser = std::make_unique<TSAXParser>();
  std::unique_ptr<PStartupHandler> startupHandler = std::make_unique<PStartupHandler>();
  if (!startupHandler->StartupFileFound()) {
    std::cerr << std::endl << ">> musrview **WARNING** couldn't find " << startupHandler->GetStartupFilePath().Data();
    std::cerr << std::endl;
  } else {
    startup_path_name = startupHandler->GetStartupFilePath().Data();
    saxParser->ConnectToHandler("PStartupHandler", startupHandler.get());
    // parsing the file via ParseFile() seems to lead to problems in certain
    // environments; use parseXmlFile (see PStartupHandler.cpp) instead
    status = parseXmlFile(saxParser.get(), startup_path_name.c_str());
    if (status) { // error
      std::cerr << std::endl << ">> musrview **WARNING** Reading/parsing musrfit_startup.xml failed.";
      std::cerr << std::endl << ">>                      Any graph will appear with random symbols and colors!";
      std::cerr << std::endl;
    } else {
      startupHandler->CheckLists();
    }
  }

  // read msr-file
  std::unique_ptr<PMsrHandler> msrHandler = std::make_unique<PMsrHandler>(fileName.c_str());
  status = msrHandler->ReadMsrFile();
  if (status != PMUSR_SUCCESS) {
    errMsg << msrHandler->GetLastErrorMsg();
    switch (status) {
      case PMUSR_MSR_FILE_NOT_FOUND:
        errMsg << "\n";
        errMsg << ">> musrview **ERROR** couldn't find '" << fileName << "'\n\n";
        break;
      case PMUSR_MSR_SYNTAX_ERROR:
        errMsg << "\n";
        errMsg << ">> musrview **SYNTAX ERROR** in file " << fileName << ", full stop here.\n\n";
        break;
      default:
        errMsg << "\n";
        errMsg << ">> musrview **UNKNOWN ERROR** when trying to read the msr-file.\n\n";
        break;
    }
    std::cerr << errMsg.str();
    if (show_errMsgBox)
      musrview_error_msg(errMsg.str());
    return status;
  }

  // make a plot list vector
  PMsrPlotList *msrPlotList = msrHandler->GetMsrPlotList();
  PIntVector plotList;
  bool runPresent;
  for (unsigned int i=0; i<msrPlotList->size(); i++) {
    for (unsigned int j=0; j<msrPlotList->at(i).fRuns.size(); j++) {
      runPresent = false;
      for (unsigned int k=0; k<plotList.size(); k++) {
        if (msrPlotList->at(i).fRuns[j] == static_cast<int>(plotList[k])) {
          runPresent = true;
          break;
        }
      }
      if (!runPresent)
        plotList.push_back(static_cast<int>(msrPlotList->at(i).fRuns[j]));
    }
  }

  // read all the necessary runs (raw data)
  std::unique_ptr<PRunDataHandler> dataHandler;
  if (startupHandler)
    dataHandler = std::make_unique<PRunDataHandler>(msrHandler.get(), startupHandler->GetDataPathList());
  else
    dataHandler = std::make_unique<PRunDataHandler>(msrHandler.get());

  dataHandler->ReadData();

  success = dataHandler->IsAllDataAvailable();
  if (!success) {
    errMsg << ">> musrview **ERROR** Couldn't read all data files, will quit ...\n";
    std::cerr << errMsg.str();
    if (show_errMsgBox)
      musrview_error_msg(errMsg.str());
    result = PMUSR_DATA_FILE_READ_ERROR;
  }

  // generate the necessary histogramms for the view
  std::unique_ptr<PRunListCollection> runListCollection;
  if (result == PMUSR_SUCCESS) {
    runListCollection = std::make_unique<PRunListCollection>(msrHandler.get(), dataHandler.get(), theoAtData);
    for (unsigned int i=0; i<msrHandler->GetMsrRunList()->size(); i++) {
      runPresent = false;
      for (unsigned int j=0; j<plotList.size(); j++) {
        if (static_cast<unsigned int>(plotList[j]) == i+1) {
          runPresent = true;
          break;
        }
      }
      if (runPresent) {
        success = runListCollection->Add(i, kView);
        if (!success) {
          errMsg << ">> musrview **ERROR** Couldn't handle run no " << i << " ";
          errMsg << (*msrHandler->GetMsrRunList())[i].GetRunName()->Data() << "\n";
          std::cerr << errMsg.str();
          if (show_errMsgBox)
            musrview_error_msg(errMsg.str());
          result = PMUSR_MSR_RUN_ERROR;
          break;
        }
      }
    }
  }

  if (result != PMUSR_SUCCESS) {
    plotList.clear();
    return result;
  }

  // A ROOT application is needed so that the web display and the graphics
  // export find a working environment.
  //
  // In the interactive case no TCanvas is created at all - the spectra travel
  // to JSROOT as a list of drawables - hence ROOT never opens a window of its
  // own. Only the graphics export builds a TCanvas, and that runs in batch.
  std::vector<char*> args;
  args.push_back(argv[0]);
  if (batchMode)
    args.push_back(const_cast<char*>("-b"));
  int cc = static_cast<int>(args.size());
  TApplication app("musrview", &cc, args.data());

  std::vector<std::unique_ptr<musrview::PMusrWebCanvas>> canvasList;

  bool ok = true;
  for (unsigned int i=0; i<msrHandler->GetMsrPlotList()->size(); i++) {
    auto canvas = std::make_unique<musrview::PMusrWebCanvas>(
                      static_cast<Int_t>(i), msrHandler->GetMsrTitle()->Data(),
                      1200, 900,
                      startupHandler ? startupHandler->GetFourierDefaults() : PMsrFourierStructure{},
                      startupHandler ? startupHandler->GetMarkerList() : PIntVector{},
                      startupHandler ? startupHandler->GetColorList() : PIntVector{},
                      batchMode, fourier, avg, theoAtData);

    // ugly but rootcling cannot handle the spirit-parser framework
    canvas->SetMsrHandler(msrHandler.get());
    canvas->SetRunListCollection(runListCollection.get());

    if (!canvas->Build()) {
      errMsg << ">> musrview **ERROR** " << canvas->GetLastError() << "\n";
      std::cerr << errMsg.str();
      if (show_errMsgBox)
        musrview_error_msg(errMsg.str());
      ok = false;
      result = PMUSR_MSR_RUN_ERROR;
      break;
    }

    canvas->SetTimeout(timeout);
    canvasList.push_back(std::move(canvas));
  }

  if (!ok) {
    canvasList.clear();
    plotList.clear();
    return result;
  }

  if (graphicsOutput) {
    for (auto &canvas : canvasList) {
      if (!canvas->SaveGraphics(graphicsExtension)) {
        std::cerr << std::endl << ">> musrview **ERROR** " << canvas->GetLastError() << std::endl;
        result = PMUSR_MSR_RUN_ERROR;
      }
    }
  }

  if (asciiOutput) {
    // generate the export data file name
    TString str(fileName.c_str());
    str.Remove(str.Last('.'));
    for (size_t i=0; i<canvasList.size(); i++) {
      TString name(str);
      if (canvasList.size() > 1) {
        name += "_";
        name += static_cast<Int_t>(i);
      }
      name += ".dat";
      if (!canvasList[i]->ExportData(name.Data())) {
        std::cerr << std::endl << ">> musrview **ERROR** " << canvasList[i]->GetLastError() << std::endl;
        result = PMUSR_MSR_RUN_ERROR;
      }
    }
  }

  if (!batchMode) {
    const std::string where = musrview_select_display(display);

    // one window per PLOT block, exactly as before
    ROOT::RWebWindowsManager::SetSingleConnMode(false);

    for (auto &canvas : canvasList) {
      if (!canvas->Show(where)) {
        std::cerr << std::endl << ">> musrview **ERROR** " << canvas->GetLastError() << std::endl;
        result = PMUSR_MSR_RUN_ERROR;
        ok = false;
        break;
      }
    }

    if (ok) {
      // run until every window has been closed, or until the timeout expired
      const auto start = std::chrono::steady_clock::now();
      while (true) {
        gSystem->ProcessEvents();
        gSystem->Sleep(20);

        bool allDone = true;
        for (auto &canvas : canvasList) {
          if (!canvas->IsDone()) {
            allDone = false;
            break;
          }
        }
        if (allDone)
          break;

        if (timeout > 0) {
          const auto now = std::chrono::steady_clock::now();
          if (std::chrono::duration_cast<std::chrono::seconds>(now-start).count() >= timeout) {
            std::cout << std::endl << ">> musrview: timeout of " << timeout << " s reached, terminating." << std::endl;
            break;
          }
        }
      }
    }

    // End the process here. Tearing down an RWebWindow which drives the
    // embedded display blocks, because the Qt event loop ROOT started on our
    // behalf is never stopped again. Everything of interest has been written by
    // now, so leave immediately rather than hang after the last window closed.
    std::cout.flush();
    std::cerr.flush();
    gSystem->Exit(result, kFALSE);
  }

  // only reached in batch mode, where no window was ever opened
  canvasList.clear();
  plotList.clear();

  return result;
}