# -*- coding: utf-8 -*-

# Copyright (c) 2019 - 2023 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a dialog to generate a requirements file for conda.
"""

import os

from PyQt6.QtCore import Qt, pyqtSlot
from PyQt6.QtWidgets import QAbstractButton, QApplication, QDialog, QDialogButtonBox

from eric7.EricGui.EricOverrideCursor import EricOverrideCursor
from eric7.EricWidgets import EricFileDialog, EricMessageBox
from eric7.EricWidgets.EricApplication import ericApp
from eric7.EricWidgets.EricPathPicker import EricPathPickerModes

from .Ui_CondaExportDialog import Ui_CondaExportDialog


class CondaExportDialog(QDialog, Ui_CondaExportDialog):
    """
    Class implementing a dialog to generate a requirements file for conda.
    """

    def __init__(self, conda, envName, envPrefix, parent=None):
        """
        Constructor

        @param conda reference to the master object
        @type Conda
        @param envName name of the environment to create the requirements
            file from
        @type str
        @param envPrefix prefix of the environment to create the requirements
            file from
        @type str
        @param parent reference to the parent widget
        @type QWidget
        """
        super().__init__(parent)
        self.setupUi(self)
        self.setWindowFlags(Qt.WindowType.Window)

        self.__refreshButton = self.buttonBox.addButton(
            self.tr("&Refresh"), QDialogButtonBox.ButtonRole.ActionRole
        )

        self.requirementsFilePicker.setMode(EricPathPickerModes.SAVE_FILE_MODE)
        self.requirementsFilePicker.setFilters(
            self.tr("Text Files (*.txt);;All Files (*)")
        )

        self.__conda = conda
        self.__prefix = envPrefix

        self.environmentLabel.setText("<b>{0}</b>".format(envName))

        self.__requirementsEdited = False
        self.__requirementsAvailable = False

        self.__updateButtons()

    def closeEvent(self, e):
        """
        Protected slot implementing a close event handler.

        @param e close event
        @type QCloseEvent
        """
        e.accept()

    @pyqtSlot(str)
    def on_requirementsFilePicker_textChanged(self, txt):
        """
        Private slot handling a change of the requirements file name.

        @param txt name of the requirements file
        @type str
        """
        self.__updateButtons()

    @pyqtSlot()
    def on_requirementsEdit_textChanged(self):
        """
        Private slot handling changes of the requirements text.
        """
        self.__requirementsEdited = True

    @pyqtSlot(QAbstractButton)
    def on_buttonBox_clicked(self, button):
        """
        Private slot called by a button of the button box clicked.

        @param button button that was clicked
        @type QAbstractButton
        """
        if button == self.buttonBox.button(QDialogButtonBox.StandardButton.Close):
            self.close()
        elif button == self.__refreshButton:
            self.__refresh()

    def __refresh(self):
        """
        Private slot to refresh the displayed list.
        """
        ok = (
            EricMessageBox.yesNo(
                self,
                self.tr("Generate Requirements"),
                self.tr(
                    """The requirements were changed. Do you want"""
                    """ to overwrite these changes?"""
                ),
            )
            if self.__requirementsEdited
            else True
        )
        if ok:
            self.start()

    def start(self):
        """
        Public method to start the command.
        """
        self.requirementsEdit.clear()
        self.__requirementsAvailable = False

        args = [
            "list",
            "--export",
            "--prefix",
            self.__prefix,
        ]

        with EricOverrideCursor():
            success, output = self.__conda.runProcess(args)

            if success:
                self.requirementsEdit.setPlainText(output)
                self.__requirementsAvailable = True
            else:
                self.requirementsEdit.setPlainText(
                    self.tr("No output generated by conda.")
                )

        self.__updateButtons()

        self.__requirementsEdited = False

    def __updateButtons(self):
        """
        Private method to set the state of the various buttons.
        """
        self.saveButton.setEnabled(
            self.__requirementsAvailable and bool(self.requirementsFilePicker.text())
        )
        self.saveToButton.setEnabled(self.__requirementsAvailable)
        self.copyButton.setEnabled(self.__requirementsAvailable)

        aw = ericApp().getObject("ViewManager").activeWindow()
        if aw and self.__requirementsAvailable:
            self.insertButton.setEnabled(True)
            self.replaceAllButton.setEnabled(True)
            self.replaceSelectionButton.setEnabled(aw.hasSelectedText())
        else:
            self.insertButton.setEnabled(False)
            self.replaceAllButton.setEnabled(False)
            self.replaceSelectionButton.setEnabled(False)

    def __writeToFile(self, fileName):
        """
        Private method to write the requirements text to a file.

        @param fileName name of the file to write to
        @type str
        """
        if os.path.exists(fileName):
            ok = EricMessageBox.warning(
                self,
                self.tr("Generate Requirements"),
                self.tr(
                    """The file <b>{0}</b> already exists. Do you want"""
                    """ to overwrite it?"""
                ).format(fileName),
            )
            if not ok:
                return

        try:
            with open(fileName, "w") as f:
                f.write(self.requirementsEdit.toPlainText())
        except OSError as err:
            EricMessageBox.critical(
                self,
                self.tr("Generate Requirements"),
                self.tr(
                    """<p>The requirements could not be written"""
                    """ to <b>{0}</b>.</p><p>Reason: {1}</p>"""
                ).format(fileName, str(err)),
            )

    @pyqtSlot()
    def on_saveButton_clicked(self):
        """
        Private slot to save the requirements text to the requirements file.
        """
        fileName = self.requirementsFilePicker.text()
        self.__writeToFile(fileName)

    @pyqtSlot()
    def on_saveToButton_clicked(self):
        """
        Private slot to write the requirements text to a new file.
        """
        fileName, selectedFilter = EricFileDialog.getSaveFileNameAndFilter(
            self,
            self.tr("Generate Requirements"),
            os.path.expanduser("~"),
            self.tr("Text Files (*.txt);;All Files (*)"),
            None,
            EricFileDialog.DontConfirmOverwrite,
        )
        if fileName:
            ext = os.path.splitext(fileName)[1]
            if not ext:
                ex = selectedFilter.split("(*")[1].split(")")[0]
                if ex:
                    fileName += ex
            self.__writeToFile(fileName)

    @pyqtSlot()
    def on_copyButton_clicked(self):
        """
        Private slot to copy the requirements text to the clipboard.
        """
        txt = self.requirementsEdit.toPlainText()
        cb = QApplication.clipboard()
        cb.setText(txt)

    @pyqtSlot()
    def on_insertButton_clicked(self):
        """
        Private slot to insert the requirements text at the cursor position
        of the current editor.
        """
        aw = ericApp().getObject("ViewManager").activeWindow()
        if aw:
            aw.beginUndoAction()
            cline, cindex = aw.getCursorPosition()
            aw.insertAt(self.requirementsEdit.toPlainText(), cline, cindex)
            aw.endUndoAction()

    @pyqtSlot()
    def on_replaceSelectionButton_clicked(self):
        """
        Private slot to replace the selected text of the current editor
        with the requirements text.
        """
        aw = ericApp().getObject("ViewManager").activeWindow()
        if aw:
            aw.beginUndoAction()
            aw.replaceSelectedText(self.requirementsEdit.toPlainText())
            aw.endUndoAction()

    @pyqtSlot()
    def on_replaceAllButton_clicked(self):
        """
        Private slot to replace the text of the current editor with the
        requirements text.
        """
        aw = ericApp().getObject("ViewManager").activeWindow()
        if aw:
            aw.setText(self.requirementsEdit.toPlainText())
