CondaInterface/CondaExecDialog.py

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

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

"""
Module implementing a dialog to show the output of a conda execution.
"""

from __future__ import unicode_literals
try:
    str = unicode
except NameError:
    pass

import json

from PyQt5.QtCore import pyqtSlot, QProcess, QTimer
from PyQt5.QtWidgets import QDialog, QDialogButtonBox, QAbstractButton

from E5Gui import E5MessageBox

from .Ui_CondaExecDialog import Ui_CondaExecDialog

import Preferences


class CondaExecDialog(QDialog, Ui_CondaExecDialog):
    """
    Class documentation goes here.
    """
    def __init__(self, configuration, venvManager, parent=None):
        """
        Constructor
        
        @param parent reference to the parent widget
        @type QWidget
        """
        super(CondaExecDialog, self).__init__(parent)
        self.setupUi(self)
        
        self.__venvName = configuration["logicalName"]
        self.__venvManager = venvManager
        
        self.__process = None
        self.__condaExe = Preferences.getConda("CondaExecutable")
        if not self.__condaExe:
            self.__condaExe = "conda"
    
    @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.Close):
            self.accept()
        elif button == self.buttonBox.button(QDialogButtonBox.Cancel):
            self.__finish()
    
    def start(self, arguments):
        """
        Public slot to start the conda command.
        
        @param arguments commandline arguments for conda program
        @type list of str
        """
        self.errorGroup.hide()
        self.progressLabel.hide()
        self.progressBar.hide()
        
        self.contents.clear()
        self.errors.clear()
        self.progressLabel.clear()
        self.progressBar.setValue(0)
        
        self.__bufferedStdout = None
        self.__json = "--json" in arguments
        self.__firstProgress = True
        
        self.__process = QProcess()
        self.__process.readyReadStandardOutput.connect(self.__readStdout)
        self.__process.readyReadStandardError.connect(self.__readStderr)
        self.__process.finished.connect(self.__finish)
        
        self.__process.start(self.__condaExe, arguments)
        procStarted = self.__process.waitForStarted(5000)
        if not procStarted:
            E5MessageBox.critical(
                self,
                self.tr("Conda Execution"),
                self.tr("""The conda executable could not be started. Is it"""
                        """ configured correctly?"""))
            self.__finish(1, 0)
        else:
            self.__logOutput(self.tr("Operation started.\n"))
    
    def __finish(self, exitCode, exitStatus, giveUp=False):
        """
        Private slot called when the process finished.
        
        It is called when the process finished or
        the user pressed the button.
        
        @param exitCode exit code of the process (integer)
        @param exitStatus exit status of the process (QProcess.ExitStatus)
        @keyparam giveUp flag indicating to not start another attempt (boolean)
        """
        if self.__process is not None and \
           self.__process.state() != QProcess.NotRunning:
            self.__process.terminate()
            QTimer.singleShot(2000, self.__process.kill)
            self.__process.waitForFinished(3000)
        
        self.buttonBox.button(QDialogButtonBox.Close).setEnabled(True)
        self.buttonBox.button(QDialogButtonBox.Cancel).setEnabled(False)
        self.buttonBox.button(QDialogButtonBox.Close).setDefault(True)
        
        self.__logOutput(self.tr("Operation finished.\n"))
        if self.__json:
            if self.__bufferedStdout:
                try:
                    jsonDict = json.loads(self.__bufferedStdout)
                except Exception as error:
                    self.__logError(str(error))
                    return
                
                if "success" in jsonDict and jsonDict["success"]:
                    if "prefix" in jsonDict:
                        prefix = jsonDict["prefix"]
                    elif "dst_prefix" in jsonDict:
                        prefix = jsonDict["dst_prefix"]
                    else:
                        prefix = ""
                    self.__venvManager.addVirtualEnv(self.__venvName,
                                                     prefix,
                                                     isConda=True)
    
    def __progressLabelString(self, text):
        """
        Private method to process a string and format it for the progress
        label.
        
        @param text text to be processed
        @type str
        @return formatted progress label string
        @rtype str
        """
        parts = text.split("|")
        return self.tr("{0} (Size: {1})".format(parts[0].strip(),
                                                parts[1].strip()))
    
    def __readStdout(self):
        """
        Private slot to handle the readyReadStandardOutput signal.
        
        It reads the output of the process, formats it and inserts it into
        the contents pane.
        """
        all_stdout = str(self.__process.readAllStandardOutput(),
                         Preferences.getSystem("IOEncoding"),
                         'replace')
        all_stdout = all_stdout.replace("\x00", "")
        if self.__json:
            for stdout in all_stdout.splitlines():
                try:
                    jsonDict = json.loads(stdout.replace("\x00", "").strip())
                    if "progress" in jsonDict:
                        self.progressLabel.setText(
                            self.__progressLabelString(jsonDict["fetch"]))
                        self.progressBar.setValue(
                            int(jsonDict["progress"] * 100))
                        if self.__firstProgress:
                            self.progressLabel.show()
                            self.progressBar.show()
                            self.__firstProgress = False
                    else:
                        if self.__bufferedStdout is None:
                            self.__bufferedStdout = stdout
                        else:
                            self.__bufferedStdout += stdout
                except (TypeError, ValueError):
                    if self.__bufferedStdout is None:
                        self.__bufferedStdout = stdout
                    else:
                        self.__bufferedStdout += stdout
        else:
            self.__logOutput(all_stdout)
    
    def __readStderr(self):
        """
        Private slot to handle the readyReadStandardError signal.
        
        It reads the error output of the process and inserts it into the
        error pane.
        """
        self.__process.setReadChannel(QProcess.StandardError)
        
        while self.__process.canReadLine():
            stderr = str(self.__process.readLine(),
                         Preferences.getSystem("IOEncoding"),
                         'replace')
            self.__logError(stderr)
    
    def __logOutput(self, stdout):
        """
        Private method to log some output.
        
        @param stdout output string to log
        @type str
        """
        self.contents.insertPlainText(stdout)
        self.contents.ensureCursorVisible()
    
    def __logError(self, stderr):
        """
        Private method to log an error.
        
        @param stderr error string to log
        @type str
        """
        self.errorGroup.show()
        self.errors.insertPlainText(stderr)
        self.errors.ensureCursorVisible()