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

# Copyright (c) 2010 - 2014 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a dialog to show the output of the hg diff command process.
"""

import os

from PyQt4.QtCore import pyqtSlot, QProcess, QTimer, QFileInfo, Qt
from PyQt4.QtGui import QWidget, QDialogButtonBox, QBrush, QColor, \
    QTextCursor, QLineEdit, QApplication, QCursor

from E5Gui import E5MessageBox, E5FileDialog
from E5Gui.E5Application import e5App

from .Ui_HgDiffDialog import Ui_HgDiffDialog

import Utilities
import Preferences


class HgDiffDialog(QWidget, Ui_HgDiffDialog):
    """
    Class implementing a dialog to show the output of the hg diff command
    process.
    """
    def __init__(self, vcs, parent=None):
        """
        Constructor
        
        @param vcs reference to the vcs object
        @param parent parent widget (QWidget)
        """
        super().__init__(parent)
        self.setupUi(self)
        
        self.buttonBox.button(QDialogButtonBox.Save).setEnabled(False)
        self.buttonBox.button(QDialogButtonBox.Close).setDefault(True)
        
        self.process = QProcess()
        self.vcs = vcs
        self.__hgClient = self.vcs.getClient()
        
        font = Preferences.getEditorOtherFonts("MonospacedFont")
        self.contents.setFontFamily(font.family())
        self.contents.setFontPointSize(font.pointSize())
        
        self.cNormalFormat = self.contents.currentCharFormat()
        self.cAddedFormat = self.contents.currentCharFormat()
        self.cAddedFormat.setBackground(QBrush(QColor(190, 237, 190)))
        self.cRemovedFormat = self.contents.currentCharFormat()
        self.cRemovedFormat.setBackground(QBrush(QColor(237, 190, 190)))
        self.cLineNoFormat = self.contents.currentCharFormat()
        self.cLineNoFormat.setBackground(QBrush(QColor(255, 220, 168)))
        
        self.process.finished.connect(self.__procFinished)
        self.process.readyReadStandardOutput.connect(self.__readStdout)
        self.process.readyReadStandardError.connect(self.__readStderr)
    
    def closeEvent(self, e):
        """
        Private slot implementing a close event handler.
        
        @param e close event (QCloseEvent)
        """
        if self.__hgClient:
            if self.__hgClient.isExecuting():
                self.__hgClient.cancel()
        else:
            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)
        
        e.accept()
    
    def __getVersionArg(self, version):
        """
        Private method to get a hg revision argument for the given revision.
        
        @param version revision (integer or string)
        @return version argument (string)
        """
        if version == "WORKING":
            return None
        else:
            return str(version)
    
    def start(self, fn, versions=None, bundle=None, qdiff=False):
        """
        Public slot to start the hg diff command.
        
        @param fn filename to be diffed (string)
        @param versions list of versions to be diffed (list of up to 2 strings
            or None)
        @param bundle name of a bundle file (string)
        @param qdiff flag indicating qdiff command shall be used (boolean)
        """
        self.errorGroup.hide()
        self.inputGroup.show()
        self.intercept = False
        self.filename = fn
        
        self.contents.clear()
        self.paras = 0
        
        self.filesCombo.clear()
        
        args = []
        if qdiff:
            args.append('qdiff')
            self.setWindowTitle(self.trUtf8("Patch Contents"))
        else:
            args.append('diff')
            self.vcs.addArguments(args, self.vcs.options['global'])
            self.vcs.addArguments(args, self.vcs.options['diff'])
            
            if self.vcs.hasSubrepositories():
                args.append("--subrepos")
            
            if bundle:
                args.append('--repository')
                args.append(bundle)
            elif self.vcs.bundleFile and os.path.exists(self.vcs.bundleFile):
                args.append('--repository')
                args.append(self.vcs.bundleFile)
            
            if versions is not None:
                self.raise_()
                self.activateWindow()
                
                rev1 = self.__getVersionArg(versions[0])
                rev2 = None
                if len(versions) == 2:
                    rev2 = self.__getVersionArg(versions[1])
                
                if rev1 is not None or rev2 is not None:
                    args.append('-r')
                    if rev1 is not None and rev2 is not None:
                        args.append('{0}:{1}'.format(rev1, rev2))
                    elif rev2 is None:
                        args.append(rev1)
                    elif rev1 is None:
                        args.append(':{0}'.format(rev2))
        
        if isinstance(fn, list):
            dname, fnames = self.vcs.splitPathList(fn)
            self.vcs.addArguments(args, fn)
        else:
            dname, fname = self.vcs.splitPath(fn)
            args.append(fn)
        
        self.__oldFile = ""
        self.__oldFileLine = -1
        self.__fileSeparators = []
        
        QApplication.setOverrideCursor(QCursor(Qt.WaitCursor))
        if self.__hgClient:
            self.inputGroup.setEnabled(False)
            self.inputGroup.hide()
            
            out, err = self.__hgClient.runcommand(args)
            
            if err:
                self.__showError(err)
            if out:
                for line in out.splitlines(True):
                    self.__processOutputLine(line)
                    if self.__hgClient.wasCanceled():
                        break
            
            self.__finish()
        else:
            # find the root of the repo
            repodir = dname
            while not os.path.isdir(os.path.join(repodir, self.vcs.adminDir)):
                repodir = os.path.dirname(repodir)
                if os.path.splitdrive(repodir)[1] == os.sep:
                    return
            
            self.process.kill()
            
            self.process.setWorkingDirectory(repodir)
            
            self.process.start('hg', args)
            procStarted = self.process.waitForStarted(5000)
            if not procStarted:
                QApplication.restoreOverrideCursor()
                self.inputGroup.setEnabled(False)
                self.inputGroup.hide()
                E5MessageBox.critical(
                    self,
                    self.trUtf8('Process Generation Error'),
                    self.trUtf8(
                        'The process {0} could not be started. '
                        'Ensure, that it is in the search path.'
                    ).format('hg'))
    
    def __procFinished(self, exitCode, exitStatus):
        """
        Private slot connected to the finished signal.
        
        @param exitCode exit code of the process (integer)
        @param exitStatus exit status of the process (QProcess.ExitStatus)
        """
        self.__finish()
    
    def __finish(self):
        """
        Private slot called when the process finished or the user pressed
        the button.
        """
        QApplication.restoreOverrideCursor()
        self.inputGroup.setEnabled(False)
        self.inputGroup.hide()
        
        if self.paras == 0:
            self.contents.insertPlainText(
                self.trUtf8('There is no difference.'))
            return
        
        self.buttonBox.button(QDialogButtonBox.Save).setEnabled(True)
        self.buttonBox.button(QDialogButtonBox.Close).setDefault(True)
        self.buttonBox.button(QDialogButtonBox.Close).setFocus(
            Qt.OtherFocusReason)
        
        tc = self.contents.textCursor()
        tc.movePosition(QTextCursor.Start)
        self.contents.setTextCursor(tc)
        self.contents.ensureCursorVisible()
        
        self.filesCombo.addItem(self.trUtf8("<Start>"), 0)
        self.filesCombo.addItem(self.trUtf8("<End>"), -1)
        for oldFile, newFile, pos in sorted(self.__fileSeparators):
            if oldFile != newFile:
                self.filesCombo.addItem(
                    "{0}\n{1}".format(oldFile, newFile), pos)
            else:
                self.filesCombo.addItem(oldFile, pos)
    
    def __appendText(self, txt, format):
        """
        Private method to append text to the end of the contents pane.
        
        @param txt text to insert (string)
        @param format text format to be used (QTextCharFormat)
        """
        tc = self.contents.textCursor()
        tc.movePosition(QTextCursor.End)
        self.contents.setTextCursor(tc)
        self.contents.setCurrentCharFormat(format)
        self.contents.insertPlainText(txt)
    
    def __extractFileName(self, line):
        """
        Private method to extract the file name out of a file separator line.
        
        @param line line to be processed (string)
        @return extracted file name (string)
        """
        f = line.split(None, 1)[1]
        f = f.rsplit(None, 6)[0]
        f = f.split("/", 1)[1]
        return f
    
    def __processFileLine(self, line):
        """
        Private slot to process a line giving the old/new file.
        
        @param line line to be processed (string)
        """
        if line.startswith('---'):
            self.__oldFileLine = self.paras
            self.__oldFile = self.__extractFileName(line)
        else:
            self.__fileSeparators.append(
                (self.__oldFile, self.__extractFileName(line),
                 self.__oldFileLine))
    
    def __processOutputLine(self, line):
        """
        Private method to process the lines of output.
        
        @param line output line to be processed (string)
        """
        if line.startswith("--- ") or \
           line.startswith("+++ "):
            self.__processFileLine(line)
        
        if line.startswith('+'):
            format = self.cAddedFormat
        elif line.startswith('-'):
            format = self.cRemovedFormat
        elif line.startswith('@@'):
            format = self.cLineNoFormat
        else:
            format = self.cNormalFormat
        self.__appendText(line, format)
        self.paras += 1
    
    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.
        """
        self.process.setReadChannel(QProcess.StandardOutput)
        
        while self.process.canReadLine():
            line = str(self.process.readLine(),
                       Preferences.getSystem("IOEncoding"),
                       'replace')
            self.__processOutputLine(line)
    
    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.
        """
        if self.process is not None:
            s = str(self.process.readAllStandardError(),
                    Preferences.getSystem("IOEncoding"),
                    'replace')
            self.__showError(s)
    
    def __showError(self, out):
        """
        Private slot to show some error.
        
        @param out error to be shown (string)
        """
        self.errorGroup.show()
        self.errors.insertPlainText(out)
        self.errors.ensureCursorVisible()
    
    def on_buttonBox_clicked(self, button):
        """
        Private slot called by a button of the button box clicked.
        
        @param button button that was clicked (QAbstractButton)
        """
        if button == self.buttonBox.button(QDialogButtonBox.Save):
            self.on_saveButton_clicked()
    
    @pyqtSlot(int)
    def on_filesCombo_activated(self, index):
        """
        Private slot to handle the selection of a file.
        
        @param index activated row (integer)
        """
        para = self.filesCombo.itemData(index)
        
        if para == 0:
            tc = self.contents.textCursor()
            tc.movePosition(QTextCursor.Start)
            self.contents.setTextCursor(tc)
            self.contents.ensureCursorVisible()
        elif para == -1:
            tc = self.contents.textCursor()
            tc.movePosition(QTextCursor.End)
            self.contents.setTextCursor(tc)
            self.contents.ensureCursorVisible()
        else:
            # step 1: move cursor to end
            tc = self.contents.textCursor()
            tc.movePosition(QTextCursor.End)
            self.contents.setTextCursor(tc)
            self.contents.ensureCursorVisible()
            
            # step 2: move cursor to desired line
            tc = self.contents.textCursor()
            delta = tc.blockNumber() - para
            tc.movePosition(QTextCursor.PreviousBlock, QTextCursor.MoveAnchor,
                            delta)
            self.contents.setTextCursor(tc)
            self.contents.ensureCursorVisible()
    
    @pyqtSlot()
    def on_saveButton_clicked(self):
        """
        Private slot to handle the Save button press.
        
        It saves the diff shown in the dialog to a file in the local
        filesystem.
        """
        if isinstance(self.filename, list):
            if len(self.filename) > 1:
                fname = self.vcs.splitPathList(self.filename)[0]
            else:
                dname, fname = self.vcs.splitPath(self.filename[0])
                if fname != '.':
                    fname = "{0}.diff".format(self.filename[0])
                else:
                    fname = dname
        else:
            fname = self.vcs.splitPath(self.filename)[0]
        
        fname, selectedFilter = E5FileDialog.getSaveFileNameAndFilter(
            self,
            self.trUtf8("Save Diff"),
            fname,
            self.trUtf8("Patch Files (*.diff)"),
            None,
            E5FileDialog.Options(E5FileDialog.DontConfirmOverwrite))
        
        if not fname:
            return  # user aborted
        
        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.trUtf8("Save Diff"),
                self.trUtf8("<p>The patch file <b>{0}</b> already exists."
                            " Overwrite it?</p>").format(fname),
                icon=E5MessageBox.Warning)
            if not res:
                return
        fname = Utilities.toNativeSeparators(fname)
        
        eol = e5App().getObject("Project").getEolString()
        try:
            f = open(fname, "w", encoding="utf-8", newline="")
            f.write(eol.join(self.contents.toPlainText().splitlines()))
            f.close()
        except IOError as why:
            E5MessageBox.critical(
                self, self.trUtf8('Save Diff'),
                self.trUtf8(
                    '<p>The patch file <b>{0}</b> could not be saved.'
                    '<br>Reason: {1}</p>')
                .format(fname, str(why)))
    
    def on_passwordCheckBox_toggled(self, isOn):
        """
        Private slot to handle the password checkbox toggled.
        
        @param isOn flag indicating the status of the check box (boolean)
        """
        if isOn:
            self.input.setEchoMode(QLineEdit.Password)
        else:
            self.input.setEchoMode(QLineEdit.Normal)
    
    @pyqtSlot()
    def on_sendButton_clicked(self):
        """
        Private slot to send the input to the subversion process.
        """
        input = self.input.text()
        input += os.linesep
        
        if self.passwordCheckBox.isChecked():
            self.errors.insertPlainText(os.linesep)
            self.errors.ensureCursorVisible()
        else:
            self.errors.insertPlainText(input)
            self.errors.ensureCursorVisible()
        
        self.process.write(input)
        
        self.passwordCheckBox.setChecked(False)
        self.input.clear()
    
    def on_input_returnPressed(self):
        """
        Private slot to handle the press of the return key in the input field.
        """
        self.intercept = True
        self.on_sendButton_clicked()
    
    def keyPressEvent(self, evt):
        """
        Protected slot to handle a key press event.
        
        @param evt the key press event (QKeyEvent)
        """
        if self.intercept:
            self.intercept = False
            evt.accept()
            return
        super().keyPressEvent(evt)
