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

'''
Task Coach - Your friendly task manager
Copyright (C) 2004-2016 Task Coach developers <developers@taskcoach.org>

Task Coach is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Task Coach is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
'''

from taskcoachlib import meta, persistence, patterns, operating_system
from taskcoachlib.i18n import _
import lockfile
from taskcoachlib.widgets import GetPassword
from taskcoachlib.workarounds import ExceptionAsUnicode
from taskcoachlib.gui.dialog import BackupManagerDialog
import wx
import os
import gc
import sys
import codecs
import traceback

try:
    from taskcoachlib.syncml import sync
except ImportError:  # pragma: no cover
    # Unsupported platform.
    pass


class IOController(object): 
    ''' IOController is responsible for opening, closing, loading,
    saving, and exporting files. It also presents the necessary dialogs
    to let the user specify what file to load/save/etc. '''

    def __init__(self, taskFile, messageCallback, settings, splash=None): 
        super(IOController, self).__init__()
        self.__taskFile = taskFile
        self.__messageCallback = messageCallback
        self.__settings = settings
        self.__splash = splash
        defaultPath = os.path.expanduser('~')
        self.__tskFileSaveDialogOpts = {'default_path': defaultPath, 
            'default_extension': 'tsk', 'wildcard': 
            _('%s files (*.tsk)|*.tsk|All files (*.*)|*') % meta.name}
        self.__tskFileOpenDialogOpts = {'default_path': defaultPath, 
            'default_extension': 'tsk', 'wildcard': 
            _('%s files (*.tsk)|*.tsk|Backup files (*.tsk.bak)|*.tsk.bak|'
              'All files (*.*)|*') % meta.name}
        self.__icsFileDialogOpts = {'default_path': defaultPath, 
            'default_extension': 'ics', 'wildcard': 
            _('iCalendar files (*.ics)|*.ics|All files (*.*)|*')}
        self.__htmlFileDialogOpts = {'default_path': defaultPath, 
            'default_extension': 'html', 'wildcard': 
            _('HTML files (*.html)|*.html|All files (*.*)|*')}
        self.__csvFileDialogOpts = {'default_path': defaultPath,
            'default_extension': 'csv', 'wildcard': 
            _('CSV files (*.csv)|*.csv|Text files (*.txt)|*.txt|'
              'All files (*.*)|*')}
        self.__todotxtFileDialogOpts = {'default_path': defaultPath,
            'default_extension': 'txt', 'wildcard':
            _('Todo.txt files (*.txt)|*.txt|All files (*.*)|*')}
        self.__errorMessageOptions = dict(caption=_('%s file error') % \
                                          meta.name, style=wx.ICON_ERROR)

    def syncMLConfig(self):
        return self.__taskFile.syncMLConfig()

    def setSyncMLConfig(self, config):
        self.__taskFile.setSyncMLConfig(config)

    def needSave(self):
        return self.__taskFile.needSave()

    def changedOnDisk(self):
        return self.__taskFile.changedOnDisk()

    def hasDeletedItems(self):
        return bool([task for task in self.__taskFile.tasks() if task.isDeleted()] + \
                    [note for note in self.__taskFile.notes() if note.isDeleted()])

    def purgeDeletedItems(self):
        self.__taskFile.tasks().removeItems([task for task in self.__taskFile.tasks() if task.isDeleted()])
        self.__taskFile.notes().removeItems([note for note in self.__taskFile.notes() if note.isDeleted()])

    def openAfterStart(self, commandLineArgs):
        ''' Open either the file specified on the command line, or the file
            the user was working on previously, or none at all. '''
        if commandLineArgs:
            filename = commandLineArgs[0].decode(sys.getfilesystemencoding())
        else:
            filename = self.__settings.get('file', 'lastfile')
        if filename:
            # Use CallAfter so that the main window is opened first and any 
            # error messages are shown on top of it
            wx.CallAfter(self.open, filename)
            
    def open(self, filename=None, showerror=wx.MessageBox, 
             fileExists=os.path.exists, breakLock=False, lock=True):
        if self.__taskFile.needSave():
            if not self.__saveUnsavedChanges():
                return
        if not filename:
            filename = self.__askUserForFile(_('Open'), 
                                             self.__tskFileOpenDialogOpts)
        if not filename:
            return
        self.__updateDefaultPath(filename)
        if fileExists(filename):
            self.__closeUnconditionally()
            self.__addRecentFile(filename)
            try:
                try:
                    self.__taskFile.load(filename, lock=lock, 
                                         breakLock=breakLock)
                except:
                    # Need to destroy splash screen first because it may 
                    # interfere with dialogs we show later on Mac OS X
                    if self.__splash:
                        self.__splash.Destroy()
                    raise
            except lockfile.LockTimeout:
                if breakLock:
                    if self.__askOpenUnlocked(filename): 
                        self.open(filename, showerror, lock=False)
                elif self.__askBreakLock(filename):
                    self.open(filename, showerror, breakLock=True)
                else:
                    return
            except lockfile.LockFailed:
                if self.__askOpenUnlocked(filename): 
                    self.open(filename, showerror, lock=False)
                else:
                    return
            except persistence.xml.reader.XMLReaderTooNewException:
                self.__showTooNewErrorMessage(filename, showerror)
                return
            except Exception:
                self.__showGenericErrorMessage(filename, showerror, showBackups=True)
                return
            self.__messageCallback(_('Loaded %(nrtasks)d tasks from '
                 '%(filename)s') % dict(nrtasks=len(self.__taskFile.tasks()), 
                                        filename=self.__taskFile.filename()))
        else:
            errorMessage = _("Cannot open %s because it doesn't exist") % filename
            # Use CallAfter on Mac OS X because otherwise the app will hang:
            if operating_system.isMac():
                wx.CallAfter(showerror, errorMessage, **self.__errorMessageOptions)
            else:
                showerror(errorMessage, **self.__errorMessageOptions)
            self.__removeRecentFile(filename)
            
    def merge(self, filename=None, showerror=wx.MessageBox):
        if not filename:
            filename = self.__askUserForFile(_('Merge'), 
                                             self.__tskFileOpenDialogOpts)
        if filename:
            try:
                self.__taskFile.merge(filename)
            except lockfile.LockTimeout:
                showerror(_('Cannot open %(filename)s\nbecause it is locked.') % \
                          dict(filename=filename),
                          **self.__errorMessageOptions)
                return
            except persistence.xml.reader.XMLReaderTooNewException:
                self.__showTooNewErrorMessage(filename, showerror)
                return
            except Exception:
                self.__showGenericErrorMessage(filename, showerror)
                return
            self.__messageCallback(_('Merged %(filename)s') % \
                                   dict(filename=filename))
            self.__addRecentFile(filename)

    def save(self, showerror=wx.MessageBox):
        if self.__taskFile.filename():
            if self._saveSave(self.__taskFile, showerror):
                return True
            else:
                return self.saveas(showerror=showerror)
        elif not self.__taskFile.isEmpty():
            return self.saveas(showerror=showerror)  # Ask for filename
        else:
            return False

    def mergeDiskChanges(self):
        self.__taskFile.mergeDiskChanges()

    def saveas(self, filename=None, showerror=wx.MessageBox, 
               fileExists=os.path.exists):
        if not filename:
            filename = self.__askUserForFile(_('Save as'), 
                self.__tskFileSaveDialogOpts,
                flag=wx.FD_SAVE | wx.FD_OVERWRITE_PROMPT, fileExists=fileExists)
            if not filename:
                return False  # User didn't enter a filename, cancel save
        if self._saveSave(self.__taskFile, showerror, filename):
            return True
        else:
            return self.saveas(showerror=showerror)  # Try again

    def saveselection(self, tasks, filename=None, showerror=wx.MessageBox,
                      TaskFileClass=persistence.TaskFile, 
                      fileExists=os.path.exists):
        if not filename:
            filename = self.__askUserForFile(_('Save selection'),
                self.__tskFileSaveDialogOpts, 
                flag=wx.FD_SAVE | wx.FD_OVERWRITE_PROMPT, fileExists=fileExists)
            if not filename:
                return False  # User didn't enter a filename, cancel save
        selectionFile = self._createSelectionFile(tasks, TaskFileClass)
        if self._saveSave(selectionFile, showerror, filename):
            return True
        else:
            return self.saveselection(tasks, showerror=showerror, 
                                      TaskFileClass=TaskFileClass)  # Try again
            
    def _createSelectionFile(self, tasks, TaskFileClass):
        selectionFile = TaskFileClass()
        # Add the selected tasks:
        selectionFile.tasks().extend(tasks)
        # Include categories used by the selected tasks:
        allCategories = set()
        for task in tasks:
            allCategories.update(task.categories())
        # Also include parents of used categories, recursively:
        for category in allCategories.copy():
            allCategories.update(category.ancestors())
        selectionFile.categories().extend(allCategories)
        return selectionFile
    
    def _saveSave(self, taskFile, showerror, filename=None):
        ''' Save the file and show an error message if saving fails. '''
        try:
            if filename:
                taskFile.saveas(filename)
            else:
                filename = taskFile.filename()
                taskFile.save()
            self.__showSaveMessage(taskFile)
            self.__addRecentFile(filename)
            return True
        except lockfile.LockTimeout:
            errorMessage = _('Cannot save %s\nIt is locked by another instance '
                             'of %s.\n') % (filename, meta.name)
            showerror(errorMessage, **self.__errorMessageOptions)
            return False
        except (OSError, IOError, lockfile.LockFailed), reason:
            errorMessage = _('Cannot save %s\n%s') % (filename, 
                           ExceptionAsUnicode(reason))
            showerror(errorMessage, **self.__errorMessageOptions)
            return False
        
    def saveastemplate(self, task):
        templates = persistence.TemplateList(self.__settings.pathToTemplatesDir())
        templates.addTemplate(task)
        templates.save()

    def importTemplate(self, showerror=wx.MessageBox):
        filename = self.__askUserForFile(_('Import template'),
            fileDialogOpts={'default_extension': 'tsktmpl', 
                            'wildcard': _('%s template files (*.tsktmpl)|'
                                          '*.tsktmpl') % meta.name})
        if filename:
            templates = persistence.TemplateList(self.__settings.pathToTemplatesDir())
            try:
                templates.copyTemplate(filename)
            except Exception, reason:  # pylint: disable=W0703
                errorMessage = _('Cannot import template %s\n%s') % (filename, 
                               ExceptionAsUnicode(reason))
                showerror(errorMessage, **self.__errorMessageOptions)
            
    def close(self, force=False):
        if self.__taskFile.needSave():
            if force:
                # No user interaction, since we're forced to close right now.
                if self.__taskFile.filename():
                    self._saveSave(self.__taskFile, 
                                   lambda *args, **kwargs: None)
                else:
                    pass  # No filename, we cannot ask, give up...
            else:
                if not self.__saveUnsavedChanges():
                    return False
        self.__closeUnconditionally()
        return True
    
    def export(self, title, fileDialogOpts, writerClass, viewer, selectionOnly, 
               openfile=codecs.open, showerror=wx.MessageBox, filename=None, 
               fileExists=os.path.exists, **kwargs):
        filename = filename or self.__askUserForFile(title, fileDialogOpts, 
            flag=wx.FD_SAVE | wx.FD_OVERWRITE_PROMPT, fileExists=fileExists)
        if filename:
            fd = self.__openFileForWriting(filename, openfile, showerror)
            if fd is None:
                return False
            count = writerClass(fd, filename).write(viewer, self.__settings, 
                                                    selectionOnly, **kwargs)
            fd.close()
            self.__messageCallback(_('Exported %(count)d items to '
                                     '%(filename)s') % dict(count=count, 
                                                            filename=filename))
            return True
        else:
            return False

    def exportAsHTML(self, viewer, selectionOnly=False, separateCSS=False,
                     columns=None, openfile=codecs.open, 
                     showerror=wx.MessageBox, filename=None, 
                     fileExists=os.path.exists):
        return self.export(_('Export as HTML'), self.__htmlFileDialogOpts, 
            persistence.HTMLWriter, viewer, selectionOnly, openfile, showerror, 
            filename, fileExists, separateCSS=separateCSS, columns=columns)

    def exportAsCSV(self, viewer, selectionOnly=False, 
                    separateDateAndTimeColumns=False, columns=None,
                    fileExists=os.path.exists):
        return self.export(_('Export as CSV'), self.__csvFileDialogOpts, 
            persistence.CSVWriter, viewer, selectionOnly, 
            separateDateAndTimeColumns=separateDateAndTimeColumns, 
            columns=columns, fileExists=fileExists)
        
    def exportAsICalendar(self, viewer, selectionOnly=False, 
                          fileExists=os.path.exists):
        return self.export(_('Export as iCalendar'),
            self.__icsFileDialogOpts, persistence.iCalendarWriter, viewer, 
            selectionOnly, fileExists=fileExists)
        
    def exportAsTodoTxt(self, viewer, selectionOnly=False,
                        fileExists=os.path.exists):
        return self.export(_('Export as Todo.txt'),
            self.__todotxtFileDialogOpts, persistence.TodoTxtWriter, viewer,
            selectionOnly, fileExists=fileExists)

    def importCSV(self, **kwargs):
        persistence.CSVReader(self.__taskFile.tasks(),
                              self.__taskFile.categories()).read(**kwargs)
                              
    def importTodoTxt(self, filename):
        persistence.TodoTxtReader(self.__taskFile.tasks(),
                                  self.__taskFile.categories()).read(filename)

    def synchronize(self):
        doReset = False
        while True:
            password = GetPassword('Task Coach', 'SyncML', reset=doReset)
            if not password:
                break

            synchronizer = sync.Synchronizer(self.__syncReport,
                                         self.__taskFile, password)
            try:
                synchronizer.synchronize()
            except sync.AuthenticationFailure:
                doReset = True
            else:
                self.__messageCallback(_('Finished synchronization'))
                break
            finally:
                synchronizer.Destroy()

    def filename(self):
        return self.__taskFile.filename()

    def __syncReport(self, msg):
        wx.MessageBox(msg, _('Synchronization status'), 
                      style=wx.OK | wx.ICON_ERROR)

    def __openFileForWriting(self, filename, openfile, showerror, mode='w', 
                             encoding='utf-8'):
        try:
            return openfile(filename, mode, encoding)
        except IOError, reason:
            errorMessage = _('Cannot open %s\n%s') % (filename, 
                           ExceptionAsUnicode(reason))
            showerror(errorMessage, **self.__errorMessageOptions)
            return None
        
    def __addRecentFile(self, fileName):
        recentFiles = self.__settings.getlist('file', 'recentfiles')
        if fileName in recentFiles:
            recentFiles.remove(fileName)
        recentFiles.insert(0, fileName)
        maximumNumberOfRecentFiles = self.__settings.getint('file', 
                                                            'maxrecentfiles')
        recentFiles = recentFiles[:maximumNumberOfRecentFiles]
        self.__settings.setlist('file', 'recentfiles', recentFiles)
        
    def __removeRecentFile(self, fileName):
        recentFiles = self.__settings.getlist('file', 'recentfiles')
        if fileName in recentFiles:
            recentFiles.remove(fileName)
            self.__settings.setlist('file', 'recentfiles', recentFiles)
        
    def __askUserForFile(self, title, fileDialogOpts, flag=wx.FD_OPEN, 
                         fileExists=os.path.exists):
        filename = wx.FileSelector(title, flags=flag, 
                                   **fileDialogOpts)  # pylint: disable=W0142
        if filename and (flag & wx.FD_SAVE):
            # On Ubuntu, the default extension is not added automatically to
            # a filename typed by the user. Add the extension if necessary.
            extension = os.path.extsep + fileDialogOpts['default_extension']
            if not filename.endswith(extension):
                filename += extension
                if fileExists(filename):
                    return self.__askUserForOverwriteConfirmation(filename, title, 
                                                                  fileDialogOpts)
        return filename
    
    def __askUserForOverwriteConfirmation(self, filename, title, 
                                          fileDialogOpts):
        result = wx.MessageBox(_('A file named %s already exists.\n'
                                 'Do you want to replace it?') % filename,
            title, 
            style=wx.YES_NO | wx.CANCEL | wx.ICON_QUESTION | wx.NO_DEFAULT)
        if result == wx.YES:
            extensions = { 'Todo.txt': '.txt' }
            for auto in set(self.__settings.getlist('file', 'autoimport') + self.__settings.getlist('file', 'autoexport')):
                autoName = os.path.splitext(filename)[0] + extensions[auto]
                if os.path.exists(autoName):
                    os.remove(autoName)
                if os.path.exists(autoName + '-meta'):
                    os.remove(autoName + '-meta')
            return filename
        elif result == wx.NO:
            return self.__askUserForFile(title, fileDialogOpts, 
                                         flag=wx.FD_SAVE | \
                                              wx.FD_OVERWRITE_PROMPT)
        else:
            return None

    def __saveUnsavedChanges(self):
        result = wx.MessageBox(_('You have unsaved changes.\n'
            'Save before closing?'), _('%s: save changes?') % meta.name,
            style=wx.YES_NO | wx.CANCEL | wx.ICON_QUESTION | wx.YES_DEFAULT)
        if result == wx.YES:
            if not self.save():
                return False
        elif result == wx.CANCEL:
            return False
        return True
    
    def __askBreakLock(self, filename):
        result = wx.MessageBox(_('''Cannot open %s because it is locked.

This means either that another instance of TaskCoach
is running and has this file opened, or that a previous
instance of Task Coach crashed. If no other instance is
running, you can safely break the lock.

Break the lock?''') % filename,
            _('%s: file locked') % meta.name,
            style=wx.YES_NO | wx.ICON_QUESTION | wx.NO_DEFAULT)
        return result == wx.YES
    
    def __askOpenUnlocked(self, filename):
        result = wx.MessageBox(_('Cannot acquire a lock because locking is not '
            'supported\non the location of %s.\n'
            'Open %s unlocked?') % (filename, filename), 
             _('%s: file locked') % meta.name,
            style=wx.YES_NO | wx.ICON_QUESTION | wx.NO_DEFAULT)
        return result == wx.YES
    
    def __closeUnconditionally(self):
        self.__messageCallback(_('Closed %s') % self.__taskFile.filename())
        self.__taskFile.close()
        patterns.CommandHistory().clear()
        gc.collect()

    def __showSaveMessage(self, savedFile):    
        self.__messageCallback(_('Saved %(nrtasks)d tasks to %(filename)s') % \
            {'nrtasks': len(savedFile.tasks()), 
             'filename': savedFile.filename()})
        
    def __showTooNewErrorMessage(self, filename, showerror):
        showerror(_('Cannot open %(filename)s\n'
                    'because it was created by a newer version of %(name)s.\n'
                    'Please upgrade %(name)s.') % \
            dict(filename=filename, name=meta.name),
            **self.__errorMessageOptions)
        
    def __showGenericErrorMessage(self, filename, showerror, showBackups=False):
        sys.stderr.write(''.join(traceback.format_exception(*sys.exc_info())))
        limitedException = ''.join(traceback.format_exception(*sys.exc_info(), 
                                                              limit=10))
        message = _('Error while reading %s:\n') % filename + \
                    limitedException
        man = persistence.BackupManifest(self.__settings)
        if showBackups and man.hasBackups(filename):
            message += u'\n' + _('The backup manager will now open to allow you to restore\nan older version of this file.')
        showerror(message, **self.__errorMessageOptions)

        if showBackups and man.hasBackups(filename):
            dlg = BackupManagerDialog(None, self.__settings, filename)
            try:
                if dlg.ShowModal() == wx.ID_OK:
                    wx.CallAfter(self.open, dlg.restoredFilename())
            finally:
                dlg.Destroy()

    def __updateDefaultPath(self, filename):
        for options in [self.__tskFileOpenDialogOpts, 
                        self.__tskFileSaveDialogOpts,
                        self.__csvFileDialogOpts,
                        self.__icsFileDialogOpts, 
                        self.__htmlFileDialogOpts]:
            options['default_path'] = os.path.dirname(filename)