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

# Copyright (c) 2007 - 2020 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a dialog showing UML like diagrams.
"""


from PyQt5.QtCore import pyqtSlot, Qt, QFileInfo
from PyQt5.QtWidgets import QAction, QToolBar, QGraphicsScene

from E5Gui import E5MessageBox, E5FileDialog
from E5Gui.E5MainWindow import E5MainWindow

import UI.Config
import UI.PixmapCache


class UMLDialog(E5MainWindow):
    """
    Class implementing a dialog showing UML like diagrams.
    """
    NoDiagram = 255
    ClassDiagram = 0
    PackageDiagram = 1
    ImportsDiagram = 2
    ApplicationDiagram = 3
    
    FileVersions = ["1.0"]
    
    def __init__(self, diagramType, project, path="", parent=None,
                 initBuilder=True, **kwargs):
        """
        Constructor
        
        @param diagramType type of the diagram (one of ApplicationDiagram,
            ClassDiagram, ImportsDiagram, NoDiagram, PackageDiagram)
        @param project reference to the project object (Project)
        @param path file or directory path to build the diagram from (string)
        @param parent parent widget of the dialog (QWidget)
        @keyparam initBuilder flag indicating to initialize the diagram
            builder (boolean)
        @keyparam kwargs diagram specific data
        """
        super(UMLDialog, self).__init__(parent)
        self.setObjectName("UMLDialog")
        
        self.__diagramType = diagramType
        self.__project = project
        
        from .UMLGraphicsView import UMLGraphicsView
        self.scene = QGraphicsScene(0.0, 0.0, 800.0, 600.0)
        self.umlView = UMLGraphicsView(self.scene, parent=self)
        self.builder = self.__diagramBuilder(
            self.__diagramType, path, **kwargs)
        if self.builder and initBuilder:
            self.builder.initialize()
        
        self.__fileName = ""
        
        self.__initActions()
        self.__initToolBars()
        
        self.setCentralWidget(self.umlView)
        
        self.umlView.relayout.connect(self.__relayout)
        
        self.setWindowTitle(self.__diagramTypeString())
    
    def __initActions(self):
        """
        Private slot to initialize the actions.
        """
        self.closeAct = QAction(
            UI.PixmapCache.getIcon("close.png"),
            self.tr("Close"), self)
        self.closeAct.triggered.connect(self.close)
        
        self.openAct = QAction(
            UI.PixmapCache.getIcon("open.png"),
            self.tr("Load"), self)
        self.openAct.triggered.connect(self.load)
        
        self.saveAct = QAction(
            UI.PixmapCache.getIcon("fileSave.png"),
            self.tr("Save"), self)
        self.saveAct.triggered.connect(self.__save)
        
        self.saveAsAct = QAction(
            UI.PixmapCache.getIcon("fileSaveAs.png"),
            self.tr("Save As..."), self)
        self.saveAsAct.triggered.connect(self.__saveAs)
        
        self.saveImageAct = QAction(
            UI.PixmapCache.getIcon("fileSavePixmap.png"),
            self.tr("Save as Image"), self)
        self.saveImageAct.triggered.connect(self.umlView.saveImage)
        
        self.printAct = QAction(
            UI.PixmapCache.getIcon("print.png"),
            self.tr("Print"), self)
        self.printAct.triggered.connect(self.umlView.printDiagram)
        
        self.printPreviewAct = QAction(
            UI.PixmapCache.getIcon("printPreview.png"),
            self.tr("Print Preview"), self)
        self.printPreviewAct.triggered.connect(
            self.umlView.printPreviewDiagram)
    
    def __initToolBars(self):
        """
        Private slot to initialize the toolbars.
        """
        self.windowToolBar = QToolBar(self.tr("Window"), self)
        self.windowToolBar.setIconSize(UI.Config.ToolBarIconSize)
        self.windowToolBar.addAction(self.closeAct)
        
        self.fileToolBar = QToolBar(self.tr("File"), self)
        self.fileToolBar.setIconSize(UI.Config.ToolBarIconSize)
        self.fileToolBar.addAction(self.openAct)
        self.fileToolBar.addSeparator()
        self.fileToolBar.addAction(self.saveAct)
        self.fileToolBar.addAction(self.saveAsAct)
        self.fileToolBar.addAction(self.saveImageAct)
        self.fileToolBar.addSeparator()
        self.fileToolBar.addAction(self.printPreviewAct)
        self.fileToolBar.addAction(self.printAct)
        
        self.umlToolBar = self.umlView.initToolBar()
        
        self.addToolBar(Qt.TopToolBarArea, self.fileToolBar)
        self.addToolBar(Qt.TopToolBarArea, self.windowToolBar)
        self.addToolBar(Qt.TopToolBarArea, self.umlToolBar)
    
    def show(self, fromFile=False):
        """
        Public method to show the dialog.
        
        @keyparam fromFile flag indicating, that the diagram was loaded
            from file (boolean)
        """
        if not fromFile and self.builder:
            self.builder.buildDiagram()
        super(UMLDialog, self).show()
    
    def __relayout(self):
        """
        Private method to relayout the diagram.
        """
        if self.builder:
            self.builder.buildDiagram()
    
    def __diagramBuilder(self, diagramType, path, **kwargs):
        """
        Private method to instantiate a diagram builder object.
        
        @param diagramType type of the diagram
            (one of ApplicationDiagram, ClassDiagram, ImportsDiagram,
            PackageDiagram)
        @param path file or directory path to build the diagram from (string)
        @keyparam kwargs diagram specific data
        @return reference to the instantiated diagram builder
        @exception ValueError raised to indicate an illegal diagram type
        """
        if diagramType == UMLDialog.ClassDiagram:
            from .UMLClassDiagramBuilder import UMLClassDiagramBuilder
            return UMLClassDiagramBuilder(
                self, self.umlView, self.__project, path, **kwargs)
        elif diagramType == UMLDialog.PackageDiagram:
            from .PackageDiagramBuilder import PackageDiagramBuilder
            return PackageDiagramBuilder(
                self, self.umlView, self.__project, path, **kwargs)
        elif diagramType == UMLDialog.ImportsDiagram:
            from .ImportsDiagramBuilder import ImportsDiagramBuilder
            return ImportsDiagramBuilder(
                self, self.umlView, self.__project, path, **kwargs)
        elif diagramType == UMLDialog.ApplicationDiagram:
            from .ApplicationDiagramBuilder import ApplicationDiagramBuilder
            return ApplicationDiagramBuilder(
                self, self.umlView, self.__project, **kwargs)
        elif diagramType == UMLDialog.NoDiagram:
            return None
        else:
            raise ValueError(self.tr(
                "Illegal diagram type '{0}' given.").format(diagramType))
    
    def __diagramTypeString(self):
        """
        Private method to generate a readable string for the diagram type.
        
        @return readable type string (string)
        """
        if self.__diagramType == UMLDialog.ClassDiagram:
            return "Class Diagram"
        elif self.__diagramType == UMLDialog.PackageDiagram:
            return "Package Diagram"
        elif self.__diagramType == UMLDialog.ImportsDiagram:
            return "Imports Diagram"
        elif self.__diagramType == UMLDialog.ApplicationDiagram:
            return "Application Diagram"
        else:
            return "Illegal Diagram Type"
    
    def __save(self):
        """
        Private slot to save the diagram with the current name.
        """
        self.__saveAs(self.__fileName)
    
    @pyqtSlot()
    def __saveAs(self, filename=""):
        """
        Private slot to save the diagram.
        
        @param filename name of the file to write to (string)
        """
        if not filename:
            fname, selectedFilter = E5FileDialog.getSaveFileNameAndFilter(
                self,
                self.tr("Save Diagram"),
                "",
                self.tr("Eric Graphics File (*.e5g);;All Files (*)"),
                "",
                E5FileDialog.Options(E5FileDialog.DontConfirmOverwrite))
            if not fname:
                return
            ext = QFileInfo(fname).suffix()
            if not ext:
                ex = selectedFilter.split("(*")[1].split(")")[0]
                if ex:
                    fname += ex
            if QFileInfo(fname).exists():
                res = E5MessageBox.yesNo(
                    self,
                    self.tr("Save Diagram"),
                    self.tr("<p>The file <b>{0}</b> already exists."
                            " Overwrite it?</p>").format(fname),
                    icon=E5MessageBox.Warning)
                if not res:
                    return
            filename = fname
        
        lines = [
            "version: 1.0",
            "diagram_type: {0} ({1})".format(
                self.__diagramType, self.__diagramTypeString()),
            "scene_size: {0};{1}".format(self.scene.width(),
                                         self.scene.height()),
        ]
        persistenceData = self.builder.getPersistenceData()
        if persistenceData:
            lines.append("builder_data: {0}".format(persistenceData))
        lines.extend(self.umlView.getPersistenceData())
        
        try:
            f = open(filename, "w", encoding="utf-8")
            f.write("\n".join(lines))
            f.close()
        except (IOError, OSError) as err:
            E5MessageBox.critical(
                self,
                self.tr("Save Diagram"),
                self.tr(
                    """<p>The file <b>{0}</b> could not be saved.</p>"""
                    """<p>Reason: {1}</p>""").format(filename, str(err)))
            return
        
        self.__fileName = filename
    
    def load(self):
        """
        Public method to load a diagram from a file.
        
        @return flag indicating success (boolean)
        """
        filename = E5FileDialog.getOpenFileName(
            self,
            self.tr("Load Diagram"),
            "",
            self.tr("Eric Graphics File (*.e5g);;All Files (*)"))
        if not filename:
            # Cancelled by user
            return False
        
        try:
            f = open(filename, "r", encoding="utf-8")
            data = f.read()
            f.close()
        except (IOError, OSError) as err:
            E5MessageBox.critical(
                self,
                self.tr("Load Diagram"),
                self.tr(
                    """<p>The file <b>{0}</b> could not be read.</p>"""
                    """<p>Reason: {1}</p>""").format(filename, str(err)))
            return False
        
        lines = data.splitlines()
        if len(lines) < 3:
            self.__showInvalidDataMessage(filename)
            return False
        
        try:
            # step 1: check version
            linenum = 0
            key, value = lines[linenum].split(": ", 1)
            if (
                key.strip() != "version" or
                value.strip() not in UMLDialog.FileVersions
            ):
                self.__showInvalidDataMessage(filename, linenum)
                return False
            else:
                version = value
            
            # step 2: extract diagram type
            linenum += 1
            key, value = lines[linenum].split(": ", 1)
            if key.strip() != "diagram_type":
                self.__showInvalidDataMessage(filename, linenum)
                return False
            try:
                self.__diagramType = int(value.strip().split(None, 1)[0])
            except ValueError:
                self.__showInvalidDataMessage(filename, linenum)
                return False
            self.scene.clear()
            self.builder = self.__diagramBuilder(self.__diagramType, "")
            
            # step 3: extract scene size
            linenum += 1
            key, value = lines[linenum].split(": ", 1)
            if key.strip() != "scene_size":
                self.__showInvalidDataMessage(filename, linenum)
                return False
            try:
                width, height = [float(v.strip()) for v in value.split(";")]
            except ValueError:
                self.__showInvalidDataMessage(filename, linenum)
                return False
            self.umlView.setSceneSize(width, height)
            
            # step 4: extract builder data if available
            linenum += 1
            key, value = lines[linenum].split(": ", 1)
            if key.strip() == "builder_data":
                ok = self.builder.parsePersistenceData(version, value)
                if not ok:
                    self.__showInvalidDataMessage(filename, linenum)
                    return False
                linenum += 1
            
            # step 5: extract the graphics items
            ok, vlinenum = self.umlView.parsePersistenceData(
                version, lines[linenum:])
            if not ok:
                self.__showInvalidDataMessage(filename, linenum + vlinenum)
                return False
        
        except IndexError:
            self.__showInvalidDataMessage(filename)
            return False
        
        # everything worked fine, so remember the file name and set the
        # window title
        self.setWindowTitle(self.__diagramTypeString())
        self.__fileName = filename
        
        return True
    
    def __showInvalidDataMessage(self, filename, linenum=-1):
        """
        Private slot to show a message dialog indicating an invalid data file.
        
        @param filename name of the file containing the invalid data (string)
        @param linenum number of the invalid line (integer)
        """
        if linenum < 0:
            msg = self.tr("""<p>The file <b>{0}</b> does not contain"""
                          """ valid data.</p>""").format(filename)
        else:
            msg = self.tr("""<p>The file <b>{0}</b> does not contain"""
                          """ valid data.</p><p>Invalid line: {1}</p>"""
                          ).format(filename, linenum + 1)
        E5MessageBox.critical(self, self.tr("Load Diagram"), msg)
