# ***************************************************************************
# *   Copyright (c) 2015 Bernd Hahnebach <bernd@bimstatik.org>              *
# *                                                                         *
# *   This file is part of the FreeCAD CAx development system.              *
# *                                                                         *
# *   This program is free software; you can redistribute it and/or modify  *
# *   it under the terms of the GNU Lesser General Public License (LGPL)    *
# *   as published by the Free Software Foundation; either version 2 of     *
# *   the License, or (at your option) any later version.                   *
# *   for detail see the LICENCE text file.                                 *
# *                                                                         *
# *   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 Library General Public License for more details.                  *
# *                                                                         *
# *   You should have received a copy of the GNU Library 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                                                                   *
# *                                                                         *
# ***************************************************************************

__title__ = "FreeCAD FEM solver calculix ccx tools task panel for the document object"
__author__ = "Bernd Hahnebach"
__url__ = "https://www.freecad.org"

## @package task_solver_ccxtools
#  \ingroup FEM
#  \brief task panel for solver ccx tools object

import os
import time
from PySide import QtCore
from PySide import QtGui
from PySide.QtCore import Qt
from PySide.QtGui import QApplication

import FreeCAD
import FreeCADGui

import FemGui


def unicode(text, *args):
    return str(text)


class _TaskPanel:
    """
    The TaskPanel for CalculiX ccx tools solver object
    """

    PREFS_PATH = "User parameter:BaseApp/Preferences/Mod/Fem/Ccx"

    def __init__(self, solver_object):
        self.form = FreeCADGui.PySideUic.loadUi(
            FreeCAD.getHomePath() + "Mod/Fem/Resources/ui/SolverCalculix.ui"
        )

        from femtools.ccxtools import CcxTools as ccx
        # we do not need to pass the analysis, it will be found on fea init
        # TODO: if there is not analysis object in document init of fea
        # will fail with an exception and task panel will not open
        # handle more smart by a pop up error message and still open
        # task panel, may be deactivate write and run button.
        self.fea = ccx(solver_object)
        self.fea.setup_working_dir()
        self.fea.setup_ccx()

        self.Calculix = QtCore.QProcess()
        self.Timer = QtCore.QTimer()
        self.Timer.start(300)

        self.fem_console_message = ""

        self.CCX_pipeline = None
        self.CCX_mesh_visibility = False

        # store visibility of possibly existing mesh object
        CCX_mesh = self.fea.analysis.Document.getObject("CCX_Results_Mesh")
        if CCX_mesh is not None:
            self.CCX_mesh_visibility = CCX_mesh.ViewObject.Visibility

        # Connect Signals and Slots
        QtCore.QObject.connect(
            self.form.tb_choose_working_dir,
            QtCore.SIGNAL("clicked()"),
            self.choose_working_dir
        )
        QtCore.QObject.connect(
            self.form.pb_write_inp,
            QtCore.SIGNAL("clicked()"),
            self.write_input_file_handler
        )
        QtCore.QObject.connect(
            self.form.pb_edit_inp,
            QtCore.SIGNAL("clicked()"),
            self.editCalculixInputFile
        )
        QtCore.QObject.connect(
            self.form.pb_run_ccx,
            QtCore.SIGNAL("clicked()"),
            self.runCalculix
        )
        QtCore.QObject.connect(
            self.form.rb_static_analysis,
            QtCore.SIGNAL("clicked()"),
            self.select_static_analysis
        )
        QtCore.QObject.connect(
            self.form.rb_frequency_analysis,
            QtCore.SIGNAL("clicked()"),
            self.select_frequency_analysis
        )
        QtCore.QObject.connect(
            self.form.rb_thermomech_analysis,
            QtCore.SIGNAL("clicked()"),
            self.select_thermomech_analysis
        )
        QtCore.QObject.connect(
            self.form.rb_check_mesh,
            QtCore.SIGNAL("clicked()"),
            self.select_check_mesh
        )
        QtCore.QObject.connect(
            self.form.rb_buckling_analysis,
            QtCore.SIGNAL("clicked()"),
            self.select_buckling_analysis
        )
        QtCore.QObject.connect(
            self.Calculix,
            QtCore.SIGNAL("started()"),
            self.calculixStarted
        )
        QtCore.QObject.connect(
            self.Calculix,
            QtCore.SIGNAL("stateChanged(QProcess::ProcessState)"),
            self.calculixStateChanged
        )
        QtCore.QObject.connect(
            self.Calculix,
            QtCore.SIGNAL("error(QProcess::ProcessError)"),
            self.calculixError
        )
        QtCore.QObject.connect(
            self.Calculix,
            QtCore.SIGNAL("finished(int)"),
            self.calculixFinished
        )
        QtCore.QObject.connect(
            self.Timer,
            QtCore.SIGNAL("timeout()"),
            self.UpdateText
        )

        self.update()

    def getStandardButtons(self):
        # only show a close button
        # def accept() in no longer needed, since there is no OK button
        return int(QtGui.QDialogButtonBox.Close)

    def reject(self):
        FreeCADGui.ActiveDocument.resetEdit()

    def update(self):
        "fills the widgets"
        self.form.le_working_dir.setText(self.fea.working_dir)
        if self.fea.solver.AnalysisType == "static":
            self.form.rb_static_analysis.setChecked(True)
        elif self.fea.solver.AnalysisType == "frequency":
            self.form.rb_frequency_analysis.setChecked(True)
        elif self.fea.solver.AnalysisType == "thermomech":
            self.form.rb_thermomech_analysis.setChecked(True)
        elif self.fea.solver.AnalysisType == "check":
            self.form.rb_check_mesh.setChecked(True)
        elif self.fea.solver.AnalysisType == "buckling":
            self.form.rb_buckling_analysis.setChecked(True)
        return

    def femConsoleMessage(self, message="", color="#000000"):
        self.fem_console_message = self.fem_console_message + (
            '<font color="#0000FF">{0:4.1f}:</font> <font color="{1}">{2}</font><br>'
            .format(time.time() - self.Start, color, message)
        )
        self.form.textEdit_Output.setText(self.fem_console_message)
        self.form.textEdit_Output.moveCursor(QtGui.QTextCursor.End)

    def printCalculiXstdout(self):

        out = self.Calculix.readAllStandardOutput()
        # print(type(out))
        # <class 'PySide2.QtCore.QByteArray'>

        if out.isEmpty():
            self.femConsoleMessage("CalculiX stdout is empty", "#FF0000")
            return False

        # https://forum.freecad.org/viewtopic.php?f=18&t=39195
        # convert QByteArray to a binary string an decode it to "utf-8"
        out = out.data().decode()  # "utf-8" can be omitted
        out = os.linesep.join([s for s in out.splitlines() if s])
        out = out.replace("\n", "<br>")
        # print(out)
        self.femConsoleMessage(out)

        if "*ERROR in e_c3d: nonpositive jacobian" in out:
            error_message = (
                "\n\nCalculiX returned an error due to "
                "nonpositive jacobian determinant in at least one element\n"
                "Use the run button on selected solver to get a better error output.\n"
            )
            FreeCAD.Console.PrintError(error_message)

        if "*ERROR" in out:
            return False
        else:
            return True

    def UpdateText(self):
        if(self.Calculix.state() == QtCore.QProcess.ProcessState.Running):
            self.form.l_time.setText("Time: {0:4.1f}: ".format(time.time() - self.Start))

    def calculixError(self, error=""):
        print("Error() {}".format(error))
        self.femConsoleMessage("CalculiX execute error: {}".format(error), "#FF0000")

    def calculixNoError(self):
        print("CalculiX done without error!")
        self.femConsoleMessage("CalculiX done without error!", "#00AA00")

    def calculixStarted(self):
        # print("calculixStarted()")
        FreeCAD.Console.PrintLog("calculix state: {}\n".format(self.Calculix.state()))
        self.form.pb_run_ccx.setText("Stop CalculiX")

    def calculixStateChanged(self, newState):
        if newState == QtCore.QProcess.ProcessState.Starting:
            self.femConsoleMessage("Starting CalculiX...")
        elif newState == QtCore.QProcess.ProcessState.Running:
            self.femConsoleMessage("CalculiX is running...")
        elif newState == QtCore.QProcess.ProcessState.NotRunning:
            self.femConsoleMessage("CalculiX stopped.")
        else:
            self.femConsoleMessage("Problems.")

    def calculixFinished(self, exitCode):
        # print("calculixFinished(), exit code: {}".format(exitCode))
        FreeCAD.Console.PrintLog("calculix state: {}\n".format(self.Calculix.state()))

        # Restore previous cwd
        QtCore.QDir.setCurrent(self.cwd)

        self.Timer.stop()

        if self.printCalculiXstdout():
            self.calculixNoError()
        else:
            self.calculixError()

        self.form.pb_run_ccx.setText("Re-run CalculiX")
        self.femConsoleMessage("Loading result sets...")
        self.form.l_time.setText("Time: {0:4.1f}: ".format(time.time() - self.Start))
        self.fea.reset_mesh_purge_results_checked()
        self.fea.inp_file_name = self.fea.inp_file_name

        # check if ccx is greater than 2.10, if not do not read results
        # https://forum.freecad.org/viewtopic.php?f=18&t=23548#p183829 Point 3
        # https://forum.freecad.org/viewtopic.php?f=18&t=23548&start=20#p183909
        # https://forum.freecad.org/viewtopic.php?f=18&t=23548&start=30#p185027
        # https://github.com/FreeCAD/FreeCAD/commit/3dd1c9f
        majorVersion, minorVersion = self.fea.get_ccx_version()
        if majorVersion == 2 and minorVersion <= 10:
            message = (
                "The used CalculiX version {}.{} creates broken output files. "
                "The result file will not be read by FreeCAD FEM. "
                "You still can try to read it stand alone with FreeCAD, but it is "
                "strongly recommended to upgrade CalculiX to a newer version.\n"
                .format(majorVersion, minorVersion)
            )
            QtGui.QMessageBox.warning(None, "Upgrade CalculiX", message)
            raise

        QApplication.setOverrideCursor(Qt.WaitCursor)
        try:
            self.fea.load_results()
        except Exception:
            FreeCAD.Console.PrintError("loading results failed\n")

        QApplication.restoreOverrideCursor()
        self.form.l_time.setText("Time: {0:4.1f}: ".format(time.time() - self.Start))

        # restore mesh object visibility
        CCX_mesh = self.fea.analysis.Document.getObject("ResultMesh")
        if CCX_mesh is not None:
            CCX_mesh.ViewObject.Visibility = self.CCX_mesh_visibility

    def choose_working_dir(self):
        wd = QtGui.QFileDialog.getExistingDirectory(None, "Choose CalculiX working directory",
                                                    self.fea.working_dir)
        if os.path.isdir(wd):
            self.fea.setup_working_dir(wd)
        self.form.le_working_dir.setText(self.fea.working_dir)

    def write_input_file_handler(self):
        self.Start = time.time()
        self.form.l_time.setText("Time: {0:4.1f}: ".format(time.time() - self.Start))
        QApplication.restoreOverrideCursor()
        if self.check_prerequisites_helper():
            QApplication.setOverrideCursor(Qt.WaitCursor)
            self.fea.write_inp_file()
            if self.fea.inp_file_name != "":
                self.femConsoleMessage("Write completed.")
                self.form.pb_edit_inp.setEnabled(True)
                self.form.pb_run_ccx.setEnabled(True)
            else:
                self.femConsoleMessage("Write .inp file failed!", "#FF0000")
            QApplication.restoreOverrideCursor()
        self.form.l_time.setText("Time: {0:4.1f}: ".format(time.time() - self.Start))

    def check_prerequisites_helper(self):
        self.Start = time.time()
        self.femConsoleMessage("Check dependencies...")
        self.form.l_time.setText("Time: {0:4.1f}: ".format(time.time() - self.Start))

        self.fea.update_objects()
        message = self.fea.check_prerequisites()
        if message != "":
            QtGui.QMessageBox.critical(None, "Missing prerequisite(s)", message)
            return False
        return True

    def start_ext_editor(self, ext_editor_path, filename):
        if not hasattr(self, "ext_editor_process"):
            self.ext_editor_process = QtCore.QProcess()
        if self.ext_editor_process.state() != QtCore.QProcess.Running:
            self.ext_editor_process.start(ext_editor_path, [filename])

    def editCalculixInputFile(self):
        print("editCalculixInputFile {}".format(self.fea.inp_file_name))
        ccx_prefs = FreeCAD.ParamGet(self.PREFS_PATH)
        if ccx_prefs.GetBool("UseInternalEditor", True):
            FemGui.open(self.fea.inp_file_name)
        else:
            ext_editor_path = ccx_prefs.GetString("ExternalEditorPath", "")
            if ext_editor_path:
                self.start_ext_editor(ext_editor_path, self.fea.inp_file_name)
            else:
                print(
                    "External editor is not defined in FEM preferences. "
                    "Falling back to internal editor"
                )
                FemGui.open(self.fea.inp_file_name)

    def runCalculix(self):
        if self.fea.ccx_binary_present is False:
            self.femConsoleMessage(
                "CalculiX can not be started. Missing or incorrect CalculiX binary: {}"
                .format(self.fea.ccx_binary)
            )
            # TODO deactivate the run button
            return
        # print("runCalculix")
        self.Start = time.time()

        self.femConsoleMessage("CalculiX binary: {}".format(self.fea.ccx_binary))
        self.femConsoleMessage("CalculiX input file: {}".format(self.fea.inp_file_name))
        self.femConsoleMessage("Run CalculiX...")

        FreeCAD.Console.PrintMessage(
            "run CalculiX at: {} with: {}\n"
            .format(self.fea.ccx_binary, self.fea.inp_file_name)
        )
        # change cwd because ccx may crash if directory has no write permission
        # there is also a limit of the length of file names so jump to the document directory

        # Set up for multi-threading. Note: same functionality as ccx_tools.py/start_ccx()
        ccx_prefs = FreeCAD.ParamGet(self.PREFS_PATH)
        env = QtCore.QProcessEnvironment.systemEnvironment()
        num_cpu_pref = ccx_prefs.GetInt("AnalysisNumCPUs", 1)
        if num_cpu_pref > 1:
            env.insert("OMP_NUM_THREADS", str(num_cpu_pref))
        else:
            cpu_count = os.cpu_count()
            if cpu_count is not None and cpu_count > 1:
                env.insert("OMP_NUM_THREADS", str(cpu_count))
        self.Calculix.setProcessEnvironment(env)

        self.cwd = QtCore.QDir.currentPath()
        fi = QtCore.QFileInfo(self.fea.inp_file_name)
        QtCore.QDir.setCurrent(fi.path())
        self.Calculix.start(self.fea.ccx_binary, ["-i", fi.baseName()])

        QApplication.restoreOverrideCursor()

    def select_analysis_type(self, analysis_type):
        if self.fea.solver.AnalysisType != analysis_type:
            self.fea.solver.AnalysisType = analysis_type
            self.form.pb_edit_inp.setEnabled(False)
            self.form.pb_run_ccx.setEnabled(False)

    def select_static_analysis(self):
        self.select_analysis_type("static")

    def select_frequency_analysis(self):
        self.select_analysis_type("frequency")

    def select_thermomech_analysis(self):
        self.select_analysis_type("thermomech")

    def select_check_mesh(self):
        self.select_analysis_type("check")

    def select_buckling_analysis(self):
        self.select_analysis_type("buckling")