ProjectFlask/Project.py

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

# Copyright (c) 2020 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the Flask project support.
"""

import os

from PyQt5.QtCore import (
    pyqtSlot, QObject, QProcess, QProcessEnvironment, QTimer
)
from PyQt5.QtWidgets import QMenu

from E5Gui import E5MessageBox
from E5Gui.E5Action import E5Action
from E5Gui.E5Application import e5App

from Globals import isWindowsPlatform

import UI.PixmapCache
import Utilities

from .RunServerDialog import RunServerDialog


class Project(QObject):
    """
    Class implementing the Flask project support.
    """
    def __init__(self, plugin, iconSuffix, parent=None):
        """
        Constructor
        
        @param plugin reference to the plugin object
        @type ProjectFlaskPlugin
        @param iconSuffix suffix for the icons
        @type str
        @param parent parent
        @type QObject
        """
        super(Project, self).__init__(parent)
        
        self.__plugin = plugin
        self.__iconSuffix = iconSuffix
        self.__ui = parent

        self.__e5project = e5App().getObject("Project")
        self.__virtualEnvManager = e5App().getObject("VirtualEnvManager")
        
        self.__menus = {}   # dictionary with references to menus
         
##        self.__serverProc = None
        self.__serverDialog = None
       
        self.__flaskVersions = {
            "python": "",
            "flask": "",
            "werkzeug": "",
        }
    
    def initActions(self):
        """
        Public method to define the Flask actions.
        """
        self.actions = []
        
        ##############################
        ## run actions below        ##
        ##############################
        
        self.runServerAct = E5Action(
            self.tr('Run Server'),
            self.tr('Run &Server'),
            0, 0,
            self, 'flask_run_server')
        self.runServerAct.setStatusTip(self.tr(
            'Starts the Flask Web server'))
        self.runServerAct.setWhatsThis(self.tr(
            """<b>Run Server</b>"""
            """<p>Starts the Flask Web server.</p>"""
        ))
        self.runServerAct.triggered.connect(self.__runServer)
        self.actions.append(self.runServerAct)
        
        ##################################
        ## documentation action below   ##
        ##################################
        
        self.documentationAct = E5Action(
            self.tr('Documentation'),
            self.tr('D&ocumentation'),
            0, 0,
            self, 'flask_documentation')
        self.documentationAct.setStatusTip(self.tr(
            'Shows the help viewer with the Flask documentation'))
        self.documentationAct.setWhatsThis(self.tr(
            """<b>Documentation</b>"""
            """<p>Shows the help viewer with the Flask documentation.</p>"""
        ))
        self.documentationAct.triggered.connect(self.__showDocumentation)
        self.actions.append(self.documentationAct)
    
        ##############################
        ## about action below       ##
        ##############################
        
        self.aboutFlaskAct = E5Action(
            self.tr('About Flask'),
            self.tr('About &Flask'),
            0, 0,
            self, 'flask_about')
        self.aboutFlaskAct.setStatusTip(self.tr(
            'Shows some information about Flask'))
        self.aboutFlaskAct.setWhatsThis(self.tr(
            """<b>About Flask</b>"""
            """<p>Shows some information about Flask.</p>"""
        ))
        self.aboutFlaskAct.triggered.connect(self.__flaskInfo)
        self.actions.append(self.aboutFlaskAct)
    
    def initMenu(self):
        """
        Public method to initialize the Flask menu.
        
        @return the menu generated
        @rtype QMenu
        """
        self.__menus = {}   # clear menus references
        
        menu = QMenu(self.tr('&Flask'), self.__ui)
        menu.setTearOffEnabled(True)
        
        menu.addAction(self.runServerAct)
        menu.addSeparator()
        menu.addAction(self.documentationAct)
        menu.addSeparator()
        menu.addAction(self.aboutFlaskAct)
        
        self.__menus["main"] = menu
        
        return menu
    
    def getMenu(self, name):
        """
        Public method to get a reference to the requested menu.
        
        @param name name of the menu
        @type str
        @return reference to the menu or None, if no menu with the given
            name exists
        @rtype QMenu or None
        """
        if name in self.__menus:
            return self.__menus[name]
        else:
            return None
    
    def getMenuNames(self):
        """
        Public method to get the names of all menus.
        
        @return menu names
        @rtype list of str
        """
        return list(self.__menus.keys())
    
    ##################################################################
    ## slots below implement general functionality
    ##################################################################
    
    def projectClosed(self):
        """
        Public method to handle the closing of a project.
        """
##        if self.__serverProc is not None:
##            self.__serverProcFinished()
    
    def supportedPythonVariants(self):
        """
        Public method to get the supported Python variants.
        
        @return list of supported Python variants
        @rtype list of str
        """
        variants = []
        
        virtEnv = self.__getVirtualEnvironment()
        if virtEnv:
            fullCmd = self.getFlaskCommand()
            if fullCmd:
                variants.append("Python3")
        else:
            fullCmd = self.getFlaskCommand()
            if isWindowsPlatform():
                if fullCmd:
                    variants.append("Python3")
            else:
                fullCmds = Utilities.getExecutablePaths("flask")
                for fullCmd in fullCmds:
                    try:
                        with open(fullCmd, 'r', encoding='utf-8') as f:
                            l0 = f.readline()
                    except (IOError, OSError):
                        l0 = ""
                    if self.__isSuitableForVariant("Python3", l0):
                        variants.append("Python3")
                        break
        
        return variants
    
    def __isSuitableForVariant(self, variant, line0):
        """
        Private method to test, if a detected command file is suitable for the
        given Python variant.
        
        @param variant Python variant to test for
        @type str
        @param line0 first line of the executable
        @type str
        @return flag indicating a suitable file was found
        @rtype bool
        """
        l0 = line0.lower()
        ok = (variant.lower() in l0 or
              "{0}.".format(variant[-1]) in l0)
        ok |= "pypy3" in l0
        
        return ok
    
    def __getVirtualEnvironment(self):
        """
        Private method to get the path of the virtual environment.
        
        @return path of the virtual environment
        @rtype str
        """
        language = self.__e5project.getProjectLanguage()
        if language == "Python3":
            venvName = self.__plugin.getPreferences(
                "VirtualEnvironmentNamePy3")
        else:
            venvName = ""
        if venvName:
            virtEnv = self.__virtualEnvManager.getVirtualenvDirectory(
                venvName)
        else:
            virtEnv = ""
        
        if virtEnv and not os.path.exists(virtEnv):
            virtEnv = ""
        
        return virtEnv      # __IGNORE_WARNING_M834__
    
    def getFlaskCommand(self):
        """
        Public method to build the Flask command.
        
        @return full flask command
        @rtype str
        """
        cmd = "flask"
        
        virtualEnv = self.__getVirtualEnvironment()
        if isWindowsPlatform():
            fullCmds = [
                os.path.join(virtualEnv, "Scripts", cmd + '.exe'),
                os.path.join(virtualEnv, "bin", cmd + '.exe'),
                cmd     # fall back to just cmd
            ]
            for cmd in fullCmds:
                if os.path.exists(cmd):
                    break
        else:
            fullCmds = [
                os.path.join(virtualEnv, "bin", cmd),
                os.path.join(virtualEnv, "local", "bin", cmd),
                Utilities.getExecutablePath(cmd),
                cmd     # fall back to just cmd
            ]
            for cmd in fullCmds:
                if os.path.exists(cmd):
                    break
        return cmd
    
    @pyqtSlot()
    def __flaskInfo(self):
        """
        Private slot to show some info about Flask.
        """
        versions = self.getFlaskVersionStrings()
        url = "https://palletsprojects.com/p/flask/"
        
        msgBox = E5MessageBox.E5MessageBox(
            E5MessageBox.Question,
            self.tr("About Flask"),
            self.tr(
                "<p>Flask is a lightweight WSGI web application framework."
                " It is designed to make getting started quick and easy,"
                " with the ability to scale up to complex applications.</p>"
                "<p><table>"
                "<tr><td>Flask Version:</td><td>{0}</td></tr>"
                "<tr><td>Werkzeug Version:</td><td>{1}</td></tr>"
                "<tr><td>Python Version:</td><td>{2}</td></tr>"
                "<tr><td>Flask URL:</td><td><a href=\"{3}\">"
                "The Pallets Projects - Flask</a></td></tr>"
                "</table></p>"
            ).format(versions["flask"], versions["werkzeug"],
                     versions["python"], url),
            modal=True,
            buttons=E5MessageBox.Ok)
        msgBox.setIconPixmap(UI.PixmapCache.getPixmap(
            os.path.join("ProjectFlask", "icons",
                         "flask64-{0}".format(self.__iconSuffix))))
        msgBox.exec()
    
    def getFlaskVersionStrings(self):
        """
        Public method to get the Flask, Werkzeug and Python versions as a
        string.
        
        @return dictionary containing the Flask, Werkzeug and Python versions
        @rtype dict
        """
        if not self.__flaskVersions["flask"]:
            cmd = self.getFlaskCommand()
            proc = QProcess()
            proc.start(cmd, ["--version"])
            if proc.waitForFinished(10000):
                output = str(proc.readAllStandardOutput(), "utf-8")
                for line in output.lower().splitlines():
                    key, version = line.strip().split(None, 1)
                    self.__flaskVersions[key] = version
        
        return self.__flaskVersions
    
    def prepareRuntimeEnvironment(self, development=False):
        """
        Public method to prepare a QProcessEnvironment object and determine
        the appropriate working directory.
        
        @param development flag indicating development mode
        @type bool
        @return tuple containing the working directory and a prepared
            environment object to be used with QProcess
        @rtype tuple of (str, QProcessEnvironment)
        """
        mainScript = self.__e5project.getMainScript(normalized=True)
        if not mainScript:
            E5MessageBox.critical(
                self.__ui,
                self.tr("Prepare Environment"),
                self.tr("""The project has no configured main script"""
                        """ (= Flask application). Aborting..."""))
            return "", None
        
        scriptPath, scriptName = os.path.split(mainScript)
        if scriptName == "__init__.py":
            workdir, app = os.path.split(scriptPath)
        else:
            workdir, app = scriptPath, scriptName
        
        env = QProcessEnvironment.systemEnvironment()
        env.insert("FLASK_APP", app)
        if development:
            env.insert("FLASK_ENV", "development")
        
        return workdir, env
    
    ##################################################################
    ## slots below implement documentation functions
    ##################################################################
    
    def __showDocumentation(self):
        """
        Private slot to show the helpviewer with the Flask documentation.
        """
        page = self.__plugin.getPreferences("FlaskDocUrl")
        self.__ui.launchHelpViewer(page)
    
    ##################################################################
    ## slots below implement run functions
    ##################################################################
    
    # TODO: does the flask server support logging?
    def __runServer(self, logging=False):
        """
        Private slot to start the Flask Web server.
        
        @param logging flag indicating to enable logging
        @type bool
        """
        # TODO: implement this (flask run)
        workdir, env = self.prepareRuntimeEnvironment()
        if env is not None:
            cmd = self.getFlaskCommand()
            
            dlg = RunServerDialog()
            if dlg.startServer(cmd, workdir, env):
                dlg.show()
                self.__serverDialog = dlg
    
    def __runDevelopmentServer(self, logging=False):
        """
        Private slot to start the Flask Web server in development mode.
        
        @param logging flag indicating to enable logging
        @type bool
        """
        # TODO: implement this (flask run with FLASK_ENV=development)
    
##    def __serverProcFinished(self):
##        """
##        Private slot connected to the finished signal.
##        """
##        if (
##            self.__serverProc is not None and
##            self.__serverProc.state() != QProcess.NotRunning
##        ):
##            self.__serverProc.terminate()
##            QTimer.singleShot(2000, self.__serverProc.kill)
##            self.__serverProc.waitForFinished(3000)
##        self.__serverProc = None
    
    def __runPythonShell(self):
        """
        Private slot to start a Python console in the app context.
        """
        # TODO: implement this (flask shell)
    
    ##################################################################
    ## slots below implement various debugging functions
    ##################################################################
    
    def __showRoutes(self):
        """
        Private slot showing all URL dispatch routes.
        """
        # TODO: implement this (flask routes)