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

# Copyright (c) 2014 - 2019 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a dialog to show the stashes.
"""


import os

from PyQt5.QtCore import pyqtSlot, Qt, QPoint, QProcess, QTimer
from PyQt5.QtGui import QCursor
from PyQt5.QtWidgets import (
    QWidget, QDialogButtonBox, QTreeWidgetItem, QAbstractButton, QMenu,
    QHeaderView, QApplication, QLineEdit
)

from E5Gui import E5MessageBox

from .Ui_GitStashBrowserDialog import Ui_GitStashBrowserDialog

import Preferences
from Globals import strToQByteArray


class GitStashBrowserDialog(QWidget, Ui_GitStashBrowserDialog):
    """
    Class implementing a dialog to show the stashes.
    """
    NameColumn = 0
    DateColumn = 1
    MessageColumn = 2
    
    Separator = "@@||@@"
    
    TotalStatisticsRole = Qt.UserRole
    FileStatisticsRole = Qt.UserRole + 1
    
    def __init__(self, vcs, parent=None):
        """
        Constructor
        
        @param vcs reference to the vcs object
        @param parent reference to the parent widget (QWidget)
        """
        super(GitStashBrowserDialog, self).__init__(parent)
        self.setupUi(self)
        
        self.buttonBox.button(QDialogButtonBox.Close).setEnabled(False)
        self.buttonBox.button(QDialogButtonBox.Cancel).setDefault(True)
        
        self.__position = QPoint()
        
        self.__fileStatisticsRole = Qt.UserRole
        self.__totalStatisticsRole = Qt.UserRole + 1
        
        self.stashList.header().setSortIndicator(0, Qt.AscendingOrder)
        
        self.refreshButton = self.buttonBox.addButton(
            self.tr("&Refresh"), QDialogButtonBox.ActionRole)
        self.refreshButton.setToolTip(
            self.tr("Press to refresh the list of stashes"))
        self.refreshButton.setEnabled(False)
        
        self.vcs = vcs
        self.__resetUI()
        
        self.__ioEncoding = Preferences.getSystem("IOEncoding")
        
        self.process = QProcess()
        self.process.finished.connect(self.__procFinished)
        self.process.readyReadStandardOutput.connect(self.__readStdout)
        self.process.readyReadStandardError.connect(self.__readStderr)
        
        self.__contextMenu = QMenu()
        self.__differencesAct = self.__contextMenu.addAction(
            self.tr("Show"), self.__showPatch)
        self.__contextMenu.addSeparator()
        self.__applyAct = self.__contextMenu.addAction(
            self.tr("Restore && Keep"), self.__apply)
        self.__popAct = self.__contextMenu.addAction(
            self.tr("Restore && Delete"), self.__pop)
        self.__contextMenu.addSeparator()
        self.__branchAct = self.__contextMenu.addAction(
            self.tr("Create Branch"), self.__branch)
        self.__contextMenu.addSeparator()
        self.__dropAct = self.__contextMenu.addAction(
            self.tr("Delete"), self.__drop)
        self.__clearAct = self.__contextMenu.addAction(
            self.tr("Delete All"), self.__clear)
    
    def closeEvent(self, e):
        """
        Protected slot implementing a close event handler.
        
        @param e close event (QCloseEvent)
        """
        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.__position = self.pos()
        
        e.accept()
    
    def show(self):
        """
        Public slot to show the dialog.
        """
        if not self.__position.isNull():
            self.move(self.__position)
        self.__resetUI()
        
        super(GitStashBrowserDialog, self).show()
    
    def __resetUI(self):
        """
        Private method to reset the user interface.
        """
        self.stashList.clear()
    
    def __resizeColumnsStashes(self):
        """
        Private method to resize the shelve list columns.
        """
        self.stashList.header().resizeSections(QHeaderView.ResizeToContents)
        self.stashList.header().setStretchLastSection(True)
    
    def __generateStashEntry(self, name, date, message):
        """
        Private method to generate the stash items.
        
        @param name name of the stash (string)
        @param date date the stash was created (string)
        @param message stash message (string)
        """
        QTreeWidgetItem(self.stashList, [name, date, message])
    
    def __getStashEntries(self):
        """
        Private method to retrieve the list of stashes.
        """
        self.buttonBox.button(QDialogButtonBox.Close).setEnabled(False)
        self.buttonBox.button(QDialogButtonBox.Cancel).setEnabled(True)
        self.buttonBox.button(QDialogButtonBox.Cancel).setDefault(True)
        
        self.inputGroup.setEnabled(True)
        self.inputGroup.show()
        self.refreshButton.setEnabled(False)
        
        QApplication.setOverrideCursor(QCursor(Qt.WaitCursor))
        QApplication.processEvents()
        
        self.buf = []
        self.errors.clear()
        self.intercept = False
        
        args = self.vcs.initCommand("stash")
        args.append("list")
        args.append("--format=format:%gd{0}%ai{0}%gs%n".format(self.Separator))
        
        self.process.kill()
        
        self.process.setWorkingDirectory(self.repodir)
        
        self.inputGroup.setEnabled(True)
        self.inputGroup.show()
        
        self.process.start('git', args)
        procStarted = self.process.waitForStarted(5000)
        if not procStarted:
            self.inputGroup.setEnabled(False)
            self.inputGroup.hide()
            E5MessageBox.critical(
                self,
                self.tr('Process Generation Error'),
                self.tr(
                    'The process {0} could not be started. '
                    'Ensure, that it is in the search path.'
                ).format('git'))
    
    def start(self, projectDir):
        """
        Public slot to start the git stash command.
        
        @param projectDir name of the project directory (string)
        """
        self.errorGroup.hide()
        QApplication.processEvents()
        
        self.__projectDir = projectDir
        
        # find the root of the repo
        self.repodir = self.__projectDir
        while not os.path.isdir(os.path.join(self.repodir, self.vcs.adminDir)):
            self.repodir = os.path.dirname(self.repodir)
            if os.path.splitdrive(self.repodir)[1] == os.sep:
                return
        
        self.activateWindow()
        self.raise_()
        
        self.stashList.clear()
        self.__started = True
        self.__getStashEntries()
    
    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.__processBuffer()
        self.__finish()
    
    def __finish(self):
        """
        Private slot called when the process finished or the user pressed
        the button.
        """
        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)
        
        QApplication.restoreOverrideCursor()
        
        self.buttonBox.button(QDialogButtonBox.Close).setEnabled(True)
        self.buttonBox.button(QDialogButtonBox.Cancel).setEnabled(False)
        self.buttonBox.button(QDialogButtonBox.Close).setDefault(True)
        
        self.inputGroup.setEnabled(False)
        self.inputGroup.hide()
        self.refreshButton.setEnabled(True)
    
    def __processBuffer(self):
        """
        Private method to process the buffered output of the git stash command.
        """
        for line in self.buf:
            name, date, message = line.split(self.Separator)
            date = date.strip().rsplit(":", 1)[0]
            self.__generateStashEntry(name, date, message.strip())
        
        self.__resizeColumnsStashes()
        
        if self.__started:
            self.stashList.setCurrentItem(self.stashList.topLevelItem(0))
            self.__started = False
    
    def __readStdout(self):
        """
        Private slot to handle the readyReadStandardOutput signal.
        
        It reads the output of the process and inserts it into a buffer.
        """
        self.process.setReadChannel(QProcess.StandardOutput)
        
        while self.process.canReadLine():
            line = str(self.process.readLine(), self.__ioEncoding,
                       'replace').strip()
            if line:
                self.buf.append(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(),
                    self.__ioEncoding, 'replace')
            self.errorGroup.show()
            self.errors.insertPlainText(s)
            self.errors.ensureCursorVisible()
    
    @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 (QAbstractButton)
        """
        if button == self.buttonBox.button(QDialogButtonBox.Close):
            self.close()
        elif button == self.buttonBox.button(QDialogButtonBox.Cancel):
            self.cancelled = True
            self.__finish()
        elif button == self.refreshButton:
            self.on_refreshButton_clicked()
    
    @pyqtSlot(QTreeWidgetItem, QTreeWidgetItem)
    def on_stashList_currentItemChanged(self, current, previous):
        """
        Private slot called, when the current item of the stash list changes.
        
        @param current reference to the new current item (QTreeWidgetItem)
        @param previous reference to the old current item (QTreeWidgetItem)
        """
        self.statisticsList.clear()
        self.filesLabel.setText("")
        self.insertionsLabel.setText("")
        self.deletionsLabel.setText("")
        
        if current:
            if current.data(0, self.TotalStatisticsRole) is None:
                args = self.vcs.initCommand("stash")
                args.append("show")
                args.append('--numstat')
                args.append(current.text(self.NameColumn))
                
                output = ""
                process = QProcess()
                process.setWorkingDirectory(self.repodir)
                process.start('git', args)
                procStarted = process.waitForStarted(5000)
                if procStarted:
                    finished = process.waitForFinished(30000)
                    if finished and process.exitCode() == 0:
                        output = str(process.readAllStandardOutput(),
                                     Preferences.getSystem("IOEncoding"),
                                     'replace')
                
                if output:
                    totals = {"files": 0, "additions": 0, "deletions": 0}
                    fileData = []
                    for line in output.splitlines():
                        additions, deletions, name = (
                            line.strip().split(None, 2)
                        )
                        totals["files"] += 1
                        if additions != "-":
                            totals["additions"] += int(additions)
                        if deletions != "-":
                            totals["deletions"] += int(deletions)
                        fileData.append({
                            "file": name,
                            "total": ("-" if additions == "-" else
                                      str(int(additions) + int(deletions))),
                            "added": additions,
                            "deleted": deletions
                        })
                    current.setData(0, self.TotalStatisticsRole, totals)
                    current.setData(0, self.FileStatisticsRole, fileData)
                else:
                    return
            
            for dataDict in current.data(0, self.FileStatisticsRole):
                QTreeWidgetItem(self.statisticsList, [
                    dataDict["file"], dataDict["total"],
                    dataDict["added"], dataDict["deleted"]])
            self.statisticsList.header().resizeSections(
                QHeaderView.ResizeToContents)
            self.statisticsList.header().setStretchLastSection(True)
            
            totals = current.data(0, self.TotalStatisticsRole)
            self.filesLabel.setText(
                self.tr("%n file(s) changed", None, totals["files"]))
            self.insertionsLabel.setText(
                self.tr("%n line(s) inserted", None, int(totals["additions"])))
            self.deletionsLabel.setText(
                self.tr("%n line(s) deleted", None, int(totals["deletions"])))
    
    @pyqtSlot(QPoint)
    def on_stashList_customContextMenuRequested(self, pos):
        """
        Private slot to show the context menu of the stash list.
        
        @param pos position of the mouse pointer (QPoint)
        """
        enable = len(self.stashList.selectedItems()) == 1
        self.__differencesAct.setEnabled(enable)
        self.__applyAct.setEnabled(enable)
        self.__popAct.setEnabled(enable)
        self.__branchAct.setEnabled(enable)
        self.__dropAct.setEnabled(enable)
        self.__clearAct.setEnabled(self.stashList.topLevelItemCount() > 0)
        
        self.__contextMenu.popup(self.mapToGlobal(pos))
    
    @pyqtSlot()
    def on_refreshButton_clicked(self):
        """
        Private slot to refresh the list of shelves.
        """
        self.start(self.__projectDir)
    
    @pyqtSlot()
    def on_sendButton_clicked(self):
        """
        Private slot to send the input to the git process.
        """
        inputTxt = self.input.text()
        inputTxt += os.linesep
        
        if self.passwordCheckBox.isChecked():
            self.errors.insertPlainText(os.linesep)
            self.errors.ensureCursorVisible()
        else:
            self.errors.insertPlainText(inputTxt)
            self.errors.ensureCursorVisible()
        self.errorGroup.show()
        
        self.process.write(strToQByteArray(inputTxt))
        
        self.passwordCheckBox.setChecked(False)
        self.input.clear()
    
    @pyqtSlot()
    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()
    
    @pyqtSlot(bool)
    def on_passwordCheckBox_toggled(self, checked):
        """
        Private slot to handle the password checkbox toggled.
        
        @param checked flag indicating the status of the check box (boolean)
        """
        if checked:
            self.input.setEchoMode(QLineEdit.Password)
        else:
            self.input.setEchoMode(QLineEdit.Normal)
    
    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(GitStashBrowserDialog, self).keyPressEvent(evt)
    
    def __showPatch(self):
        """
        Private slot to show the contents of the selected stash.
        """
        stashName = self.stashList.selectedItems()[0].text(self.NameColumn)
        self.vcs.gitStashShowPatch(self.__projectDir, stashName)
    
    def __apply(self):
        """
        Private slot to apply the selected stash but keep it.
        """
        stashName = self.stashList.selectedItems()[0].text(self.NameColumn)
        self.vcs.gitStashApply(self.__projectDir, stashName)
    
    def __pop(self):
        """
        Private slot to apply the selected stash and delete it.
        """
        stashName = self.stashList.selectedItems()[0].text(self.NameColumn)
        self.vcs.gitStashPop(self.__projectDir, stashName)
        self.on_refreshButton_clicked()
    
    def __branch(self):
        """
        Private slot to create a branch from the selected stash.
        """
        stashName = self.stashList.selectedItems()[0].text(self.NameColumn)
        self.vcs.gitStashBranch(self.__projectDir, stashName)
        self.on_refreshButton_clicked()
    
    def __drop(self):
        """
        Private slot to delete the selected stash.
        """
        stashName = self.stashList.selectedItems()[0].text(self.NameColumn)
        res = self.vcs.gitStashDrop(self.__projectDir, stashName)
        if res:
            self.on_refreshButton_clicked()
    
    def __clear(self):
        """
        Private slot to delete all stashes.
        """
        res = self.vcs.gitStashClear(self.__projectDir)
        if res:
            self.on_refreshButton_clicked()
