# vim: set fileencoding=utf-8 :
# GNU Solfege - free ear training software
# Copyright (C) 2007, 2008, 2011, 2016 Tom Cato Amundsen
#
# This program 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.
#
# This program 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/>.


import codecs
import logging
import os
import subprocess
import locale
import sys
import textwrap
import time

from gi.repository import GObject
from gi.repository import Gtk

from solfege import buildinfo
from solfege import cfg
from solfege import filesystem
from solfege import gu
from solfege import lessonfile
from solfege import lessonfilegui
from solfege import osutils
from solfege.multipleintervalconfigwidget import IntervalCheckBox
from solfege import parsetree
import xml.etree.ElementTree as et

import solfege


def _tr(s):
    """
    Don't try to translate the string if it is empty. This because gettext
    will return the .MO file header as a translation of the empty string.
    """
    return _(s) if s else s


class NameIt(object):

    def __init__(self, name, lilycode):
        self.m_name = name
        self.m_lilycode = lilycode


class Section(list):

    def __init__(self, section_title, line_len):
        self.m_title = section_title
        self.m_line_len = line_len


class BaseSheetWriter(object):
    lilyout = 'lilyout'

    def __init__(self, title):
        self.m_title = title
        self.m_data = []

    def create_outdir(self, directory):
        if not os.path.exists(directory):
            os.mkdir(directory)
        if not os.path.exists(os.path.join(directory, self.lilyout)):
            os.mkdir(os.path.join(directory, self.lilyout))

    def new_section(self, section_title, line_len):
        """
        Return a list where we can append questions.
        """
        v = Section(section_title, line_len)
        self.m_data.append(v)
        return v

    def set_title(self, s):
        self.m_title = s


class HtmlSheetWriter(BaseSheetWriter):

    def _write(self, k, directory, filename, logger):
        assert k in ('question', 'answer')
        f = codecs.open(os.path.join(directory, filename), 'w', 'utf-8')
        print("<html>", file=f)
        print("<!--\n    Generated by GNU Solfege %s\n-->" % buildinfo.VERSION_STRING, file=f)
        print("<link rel='stylesheet' href='style.css' type='text/css'/>", file=f)
        print('<meta http-equiv="Content-Type" content="text/html; charset=utf-8">', file=f)
        print("<body>", file=f)
        print("<h1>%s</h1>" % _tr(self.m_title), file=f)
        for section in self.m_data:
            print("<h2>%s</h2>" % _tr(section.m_title), file=f)
            print("<table>", file=f)
            first_row = True
            for idx, question_dict in enumerate(section):
                if idx % section.m_line_len == 0:
                    if not first_row:
                        print("</tr>", file=f)
                        first_row = False
                    print("<tr>", file=f)
                print("<td class='lilycode'>", file=f)
                # each question is in a table too
                print("<table><tr><td>", file=f)
                if r"\score" in question_dict[k]['music']:
                    print("<lilypond>", file=f)
                else:
                    print("<lilypond fragment relative>", file=f)
                print(question_dict[k]['music'], file=f)
                print("</lilypond>", file=f)
                print("</td></tr><tr><td class='answer'>", file=f)
                print(question_dict[k]['name'], file=f)
                print("</td></tr></table>", file=f)
                print("</td>", file=f)
            print("</table>", file=f)
        print("</body>", file=f)
        f.close()
        args = [cfg.get_string("programs/lilypond-book"),
                "--out", self.lilyout, filename]
        # The lilypond-book.py script is not an executable on MS Windows,
        # so the user have to set the full path to the python script in the
        # preferences window. Then use the same Python interpreter as
        # Solfege itself to run lilypond-book.py
        if sys.platform == 'win32':
            if not os.path.exists(cfg.get_string("programs/lilypond-book")):
                # We to the strerror trick to get the translation for free.
                raise osutils.BinaryForProgramException("lilypond-book",
                    cfg.get_string("programs/lilypond-book"),
                    OSError(2, os.strerror(2)))
            args.insert(0, sys.executable)
        logger.write("\nRunning LilyPond\n", "h1")
        try:
            p = subprocess.Popen(args, cwd=directory, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
            while 1:
                p.poll()
                # returncode is not None means that the process has finished
                if p.returncode is not None:
                    break
                while 1:
                    s = p.stdout.readline()
                    s = s.decode(locale.getpreferredencoding())
                    if not s:
                        break
                    logger.write(s)
                time.sleep(1)
            p.wait()
        except OSError as e:
            raise osutils.BinaryForProgramException("lilypond-book",
                cfg.get_string("programs/lilypond-book"), e)
        f = open(os.path.join(directory, 'README.txt'), 'w')
        print("\n".join(textwrap.wrap("The files answers.html and questions.html in this directory are temporaty files. The HTML files you are looking for are lilyout%(sep)sanswers.html and lilyout%(sep)squestions.html" % {'sep': os.path.sep})), file=f)
        f.close()

    def write_to(self, directory, logger):
        self.create_outdir(directory)
        f = open(os.path.join(directory, self.lilyout, 'style.css'), 'w')
        print("table { border: none }", file=f)
        print(".answer { text-align: center }", file=f)
        f.close()
        self._write('question', directory, 'questions.html', logger)
        self._write('answer', directory, 'answers.html', logger)


class LatexSheetWriter(BaseSheetWriter):

    def write_to(self, directory, logger):
        self.create_outdir(directory)
        self._write('question', directory, 'questions.tex', logger)
        self._write('answer', directory, 'answers.tex', logger)

    def _write(self, k, directory, filename, logger):
        assert k in ('question', 'answer')
        f = open(os.path.join(directory, filename), 'w')
        print(r"\documentclass{article}", file=f)
        print("%%\n%% Created by GNU Solfege %s\n%%" % buildinfo.VERSION_STRING, file=f)
        print(r"\title{%s}" % _tr(self.m_title), file=f)
        print(r"\usepackage[margin=1.0cm]{geometry}", file=f)
        print(r"\begin{document}", file=f)
        print(r"\maketitle", file=f)

        def finish_table(scores, answers):
            for idx, score in enumerate(scores):
                print(score, file=f)
                if idx != len(scores) - 1:
                    print("&", file=f)
            print(r"\\", file=f)
            for idx, answer in enumerate(answers):
                print(answer, file=f)
                if idx != len(scores) - 1:
                    print("&", file=f)
            print(r"\\", file=f)
        for section in self.m_data:
            print(r"\section{%s}" % _tr(section.m_title), file=f)
            first_row = True
            for idx, question_dict in enumerate(section):
                if idx % section.m_line_len == 0:
                    if first_row:
                        print(r"\begin{tabular}{%s}" % ('c' * section.m_line_len), file=f)
                        first_row = False
                    else:
                        finish_table(scores, answers)
                    scores = []
                    answers = []
                if r"\score" in question_dict[k]['music']:
                    scores.append("\n".join((r"\begin{lilypond}",
                                question_dict[k]['music'], r"\end{lilypond}")))
                else:
                    scores.append("\n".join((r"\begin[fragment]{lilypond}",
                                question_dict[k]['music'], r"\end{lilypond}")))
                answers.append(question_dict[k]['name'].replace("#", r"\#"))
            finish_table(scores, answers)
            print(r"\end{tabular}", file=f)
        print(r"\end{document}", file=f)
        f.close()
        # Duplicate of the code in HtmlSheetWriter._write
        args = [cfg.get_string("programs/lilypond-book"),
                "--out", self.lilyout, filename]
        if sys.platform == 'win32':
            if not os.path.exists(cfg.get_string("programs/lilypond-book")):
                # We to the strerror trick to get the translation for free.
                raise osutils.BinaryForProgramException("lilypond-book",
                    cfg.get_string("programs/lilypond-book"),
                    OSError(2, os.strerror(2)))
            args.insert(0, sys.executable)
        logger.write("\nRunning LilyPond\n", "h1")
        try:
            p = subprocess.Popen(args, cwd=directory, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
            while 1:
                p.poll()
                # returncode is not None means that the process has finished
                if p.returncode is not None:
                    break
                while 1:
                    s = p.stdout.readline()
                    s = s.decode(locale.getpreferredencoding())
                    if not s:
                        break
                    logger.write(s)
                time.sleep(1)
            p.wait()
        except OSError as e:
            raise osutils.BinaryForProgramException("lilypond-book",
                cfg.get_string("programs/lilypond-book"), e)
        logger.write("\nRunning LaTeX\n", "h1")
        try:
            p = subprocess.Popen(
                (cfg.get_string("programs/latex"), "--interaction=nonstopmode", filename),
                cwd=os.path.join(directory, self.lilyout),
                stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
            while 1:
                p.poll()
                # returncode is not None means that the process has finished
                if p.returncode is not None:
                    break
                while 1:
                    while Gtk.events_pending():
                        Gtk.main_iteration()
                    s = p.stdout.readline()
                    s = s.decode(locale.getpreferredencoding())
                    if not s:
                        break
                    logger.write(s)
                time.sleep(1)
        except OSError as e:
            raise osutils.BinaryForProgramException("latex",
                cfg.get_string("programs/latex"), e)
        f = open(os.path.join(directory, 'README.txt'), 'w')
        print("\n".join(textwrap.wrap("The files you are looking for are lilyout%(sep)sanswers.dvi and lilyout%(sep)squestions.dvi" % {'sep': os.path.sep})), file=f)
        f.close()


class PractiseSheetDialog(Gtk.Window, gu.EditorDialogBase, lessonfilegui.ExercisesMenuAddIn):
    """
    The definition of which lesson files to create questions from are
    stored in the list PractiseSheetDialog.m_sections. Each item is a
    dict filled with data. See PractiseSheet._add_common for details.

    When an exercise is selected from the menu, on_select_exercise(...)
    is called, and submethods from this will create a set of questions,
    and store the generated questions in m_sections[-1]['questions]
    and the definition (filename, number of questions to generate etc) in
    other items in the dict in PractiseSheetDialog.m_sections.

    When you change the configuration of the exercises, Solfege will only
    generate new random questions if the config changes require new
    questions, for example when question type changes.

    on_create_sheet is called to create the .tex or .html files. Calling
    is several times in a row will generate the same test.

    The file we save from "Ear Training Test Printout" is a combination
    of two things:
        1. The definitons of which exericses to create questions from and
           how many many questions to generate.
        2. The generated questions. So loading the file will let you
           click "Create Sheet" and have the program create the files to
           print out, and you will get the same test as last time you
           did so.

    When you add an exercise, the translated exercise title is used. The
    translated title is stored in the saved file, so it will not change
    language if you restart Solfege in a different locale.
    """
    current_fileformat_version = "2.0"
    STORE_TITLE = 0
    STORE_FILENAME = 1
    ok_music_types = (lessonfile.Chord, lessonfile.Voice, lessonfile.Rvoice)
    ok_modules = ('idbyname', 'harmonicinterval', 'melodicinterval')
    savedir = os.path.join(filesystem.user_data(), "eartrainingtests")

    def __init__(self, filename=None):
        logging.debug("PractiseSheetDialog.__init__")
        Gtk.Window.__init__(self)
        gu.EditorDialogBase.__init__(self, filename)
        self.m_changed = False
        self.set_title(self._get_a_filename())
        self.m_exported_to = None
        self.set_default_size(800, 300)
        # self.vbox contains the toolbar and the vbox with the rest of the
        # window contents
        self.vbox = Gtk.VBox()
        self.add(self.vbox)
        self.setup_toolbar()
        vbox = Gtk.VBox()
        vbox.set_spacing(6)
        self.vbox.pack_start(vbox, True, True, 0)
        vbox.set_border_width(8)
        hbox = Gtk.HBox()
        vbox.pack_start(hbox, False, False, 0)
        hbox.pack_start(Gtk.Label(_("Output format:")), False, False, 0)
        self.g_latex_radio = Gtk.RadioButton.new_with_label(None, "LaTeX")
        hbox.pack_start(self.g_latex_radio, False, False, 0)
        self.g_html_radio = Gtk.RadioButton.new_with_label_from_widget(self.g_latex_radio, "HTML")
        hbox.pack_start(self.g_html_radio, False, False, 0)
        #
        hbox = Gtk.HBox()
        hbox.set_spacing(6)
        vbox.pack_start(hbox, False, False, 0)
        hbox.pack_start(Gtk.Label(_("Title:")), False, False, 0)
        self.g_title = Gtk.Entry()
        hbox.pack_start(self.g_title, False, False, 0)
        #
        self.m_sections = []
        self.g_liststore = Gtk.ListStore(
            GObject.TYPE_STRING,  # lesson-file title
            GObject.TYPE_STRING,  # lessonfile filename, hidden column
        )
        self.g_treeview = Gtk.TreeView(self.g_liststore)
        self.g_treeview.set_size_request(400, 100)
        self.g_treeview.set_headers_visible(False)
        self.g_treeview.connect('cursor-changed', self.on_tv_cursor_changed)
        self.g_treeview.connect('unselect-all', self.on_tv_unselect_all)
        scrolled_window = Gtk.ScrolledWindow()
        scrolled_window.add(self.g_treeview)
        scrolled_window.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
        vbox.pack_start(scrolled_window, True, True, 0)
        #
        renderer = Gtk.CellRendererText()

        def mark_invalid(column, cell_renderer, liststore, iter, user_data=None):
            filename = liststore.get(iter, self.STORE_FILENAME)[0]
            if not filename:
                cell_renderer.props.markup = '<span background="red">%s</span>' % liststore.get_value(iter, self.STORE_TITLE)
        column = Gtk.TreeViewColumn(None, renderer, text=self.STORE_TITLE)
        column.set_cell_data_func(renderer, mark_invalid)
        self.g_treeview.append_column(column)
        column = Gtk.TreeViewColumn(None, renderer, text=self.STORE_FILENAME)
        self.g_treeview.append_column(column)
        #
        sizegroup = Gtk.SizeGroup(Gtk.SizeGroupMode.HORIZONTAL)
        self.g_lbox = Gtk.VBox()
        self.g_lbox.set_sensitive(False)
        vbox.pack_start(self.g_lbox, True, True, 0)
        self.g_lesson_title = Gtk.Entry()
        self.g_lbox.pack_start(gu.hig_label_widget(_("Section title:"),
            self.g_lesson_title, sizegroup), False, False, 0)
        self.g_lesson_title_event_handle =\
            self.g_lesson_title.connect('changed', self.on_lesson_title_changed)
        #
        self.g_qtype = Gtk.ComboBoxText()
        # We should not change the order of music types, as the index
        # of the different types are used in SolfegeApp.on_create_sheet
        self.g_qtype.append_text(_("Name the music"))
        self.g_qtype.append_text(_("Write the music, first tone given"))
        self.g_qtype_event_handler = \
            self.g_qtype.connect('changed', self.on_qtype_changed)
        self.g_lbox.pack_start(gu.hig_label_widget(_("Type of question:"),
            self.g_qtype, sizegroup), False, False, 0)
        #
        self.g_intervals = IntervalCheckBox()
        self.g_intervals_box = gu.hig_label_widget(_("Intervals:"),
            self.g_intervals, sizegroup)
        self.g_intervals_event_handler = \
            self.g_intervals.connect('value-changed', self.on_intervals_changed)
        self.g_lbox.pack_start(self.g_intervals_box, False, False, 0)
        #
        self.g_line_len = Gtk.SpinButton(adjustment=Gtk.Adjustment(0, 1, 10, 1, 10))
        self.g_line_len_event_handler = \
            self.g_line_len.connect('value-changed', self.on_spin_changed, 'line_len')
        self.g_lbox.pack_start(gu.hig_label_widget(_("Questions per line:"),
            self.g_line_len, sizegroup), False, False, 0)
        #
        self.g_count = Gtk.SpinButton(adjustment=Gtk.Adjustment(0, 1, 1000, 1, 10))
        self.g_count_event_handler = \
            self.g_count.connect('value-changed', self.on_spin_changed, 'count')
        self.g_lbox.pack_start(gu.hig_label_widget(_("Number of questions:"),
            self.g_count, sizegroup), False, False, 0)
        if filename:
            self.load_file(filename)
        self.add_to_instance_dict()

        # The popupmenu shown to add exercises
        self.g_emenu = self.create_learning_tree_menu()
    def view_lesson(self, idx):
        self.g_qtype.handler_block(self.g_qtype_event_handler)
        self.g_intervals.handler_block(self.g_intervals_event_handler)
        self.g_line_len.handler_block(self.g_line_len_event_handler)
        self.g_count.handler_block(self.g_count_event_handler)
        self.g_lesson_title.handler_block(self.g_lesson_title_event_handle)

        self.g_lbox.set_sensitive(idx is not None)
        if idx is None:
            self.g_lesson_title.set_text("")
            self.g_count.set_value(1)
            self.g_line_len.set_value(1)
        else:
            try:
                module = lessonfile.infocache.get(self.m_sections[idx]['filename'], 'module')
            except lessonfile.infocache.InfoCacheException:
                module = None

            if module == 'harmonicinterval':
                self.g_intervals_box.show()
                self.g_intervals.set_value(self.m_sections[idx]['intervals'])
            else:
                self.g_intervals_box.hide()
            self.g_lesson_title.set_text(_tr(self.m_sections[idx]['title']))
            self.g_count.set_value(self.m_sections[idx]['count'])
            self.g_line_len.set_value(self.m_sections[idx]['line_len'])
            self.g_qtype.set_active(self.m_sections[idx]['qtype'])
        self.g_qtype.handler_unblock(self.g_qtype_event_handler)
        self.g_intervals.handler_unblock(self.g_intervals_event_handler)
        self.g_line_len.handler_unblock(self.g_line_len_event_handler)
        self.g_count.handler_unblock(self.g_count_event_handler)
        self.g_lesson_title.handler_unblock(self.g_lesson_title_event_handle)

    def on_add_lesson_clicked(self, button):
        self.g_emenu.popup(None, None, None, None, 1, 0)

    def on_remove_lesson_clicked(self, button):
        path, column = self.g_treeview.get_cursor()
        if path is not None:
            iter = self.g_liststore.get_iter(path)
            self.g_liststore.remove(iter)
            del self.m_sections[path[0]]

    def on_randomize(self, widget):
        for section in self.m_sections:
            section['questions'] = []
        self.generate_questions()

    def on_create_sheet(self, widget):
        self.generate_questions()
        if not self.m_exported_to:
            self.m_exported_to = self.select_empty_directory(_("Select where to export the files"))
        if not self.m_exported_to:
            return
        if self.g_html_radio.get_active():
            writer = HtmlSheetWriter(self.g_title.get_text())
        else:
            writer = LatexSheetWriter(self.g_title.get_text())
        for idx, sect in enumerate(self.m_sections):
            new_section = writer.new_section(_(sect['title']), sect['line_len'])
            for question_dict in sect['questions']:
                new_section.append(question_dict)
        ww = gu.LogWindow(self)
        try:
            writer.write_to(self.m_exported_to, ww)
        except osutils.BinaryForProgramException as e:
            solfege.win.display_error_message2(e.msg1, e.msg2)
        ww.run_finished()

    def on_intervals_changed(self, widget, value):
        self.m_changed = True
        idx = self.g_treeview.get_cursor()[0][0]
        self._delete_questions(idx)
        self.m_sections[idx]['intervals'] = value

    def on_lesson_title_changed(self, widget):
        self.m_changed = True
        path = self.g_treeview.get_cursor()[0]
        iter = self.g_liststore.get_iter(path)
        self.m_sections[path[0]]['title'] = widget.get_text()
        self.g_liststore.set(iter, self.STORE_TITLE, widget.get_text())

    def on_spin_changed(self, widget, varname):
        self.m_changed = True
        idx = self.g_treeview.get_cursor()[0][0]
        if varname == 'count':
            if len(self.m_sections[idx]['questions']) > widget.get_value_as_int():
                self.m_sections[idx]['questions'] = \
                    self.m_sections[idx]['questions'][:widget.get_value_as_int()]
        self.m_sections[idx][varname] = widget.get_value_as_int()

    def on_select_exercise(self, menuitem, filename):
        module = lessonfile.infocache.get(filename, 'module')
        if module not in self.ok_modules:
            print("only some modules work:", self.ok_modules)
            return
        p = lessonfile.LessonfileCommon()
        parsetree.Identifier.check_ns = False
        p.parse_file(lessonfile.uri_expand(filename))
        parsetree.Identifier.check_ns = True
        if module == 'idbyname':
            self._add_idbyname_lesson(p, filename)
        elif module == 'harmonicinterval':
            self._add_harmonicinterval_lesson(p, filename)
        elif module == 'melodicinterval':
            self._add_melodicinterval_lesson(p, filename)
        self.g_treeview.set_cursor((len(self.m_sections) - 1,))

    def _add_idbyname_lesson(self, p, filename):
        """
        p is a lessonfile.LessonfileCommon parser that has parsed the file.
        """
        not_ok = len([q.music for q in p.m_questions if not isinstance(q.music, self.ok_music_types)])
        ok = len([q.music for q in p.m_questions if isinstance(q.music, self.ok_music_types)])
        if not_ok > 0:
            if ok > 0:
                do_add = gu.dialog_yesno(_("Not all music types are supported. This file contain %(ok)i supported questions and %(not_ok)i that are not supported. The unsupported questions will be ignored. Add any way?" % locals()), self)
            else:
                gu.dialog_ok(_("Could not add the lesson file. It has no questions with a music object with supported music type."), self)
                do_add = False
        else:
            do_add = True
        if do_add:
            self.m_changed = True
            self._add_common(filename)

    def _add_melodicinterval_lesson(self, p, filename):
        self._add_common(filename)
        self.m_sections[-1]['intervals'] = p.header.ask_for_intervals_0

    def _add_harmonicinterval_lesson(self, p, filename):
        self._add_common(filename)
        self.m_sections[-1]['intervals'] = p.header.intervals

    def _add_common(self, filename):
        self.m_changed = True
        self.m_sections.append({
            'filename': filename,
            'title': lessonfile.infocache.get(filename, 'title'),
            'count': 6,
            'qtype': 0,
            'line_len': 3,
            'questions': [],
        })
        self.g_liststore.append((_(self.m_sections[-1]['title']), filename))

    def generate_questions(self):
        """
        Delete any extra questions and then add new random questions
        if some sections have too few questions generated.
        """
        parsetree.Identifier.check_ns = False
        for section in self.m_sections:
            # Remove trailing questions if we have too many questions
            del self.m_sections[section['count']:]
            # Then add questions if we have too few
            count = section['count'] - len(section['questions'])
            if count:
                for question_dict in solfege.app.sheet_gen_questions(
                        count, section):
                    section['questions'].append(question_dict)
        parsetree.Identifier.check_ns = True
    def _delete_questions(self, idx):
        """
        Delete the generated questions for exercise idx in self.m_sections.
        """
        self.m_sections[idx]['questions'] = []

    def on_show_help(self, widget):
        solfege.app.handle_href("ear-training-test-printout-editor.html")

    def on_tv_cursor_changed(self, treeview, *v):
        if self.g_treeview.get_cursor()[0] is None:
            return
        self.view_lesson(self.g_treeview.get_cursor()[0][0])

    def on_tv_unselect_all(self, treeview, *v):
        self.view_lesson(None)

    def on_qtype_changed(self, widget):
        self.m_changed = True
        idx = self.g_treeview.get_cursor()[0][0]
        self._delete_questions(idx)
        self.m_sections[idx]['qtype'] = widget.get_active()

    def load_file(self, filename):
        tree = et.ElementTree()
        tree.parse(filename)
        if tree.getroot().get("fileformat_version") != "2.0":
            e = Exception("PractiseSheet")
            e.msg1 = _("Cannot read old file format")
            e.msg2 = _("To convert the file to the new file format, you must open and save it in an older version of Solfege. Versions from 3.16.0 to 3.20.4 should do the job.")
            raise e
        # section.find('text').text will be none if it was not set
        # when saved, and we need a string.
        if tree.find("title").text:
            self.g_title.set_text(tree.find("title").text)
        else:
            self.g_title.set_text("")
        if tree.find('output_format').text == 'latex':
            self.g_latex_radio.set_active(True)
        else:
            self.g_latex_radio.set_active(False)
        self.g_liststore.clear()
        self.m_sections = []
        for section in tree.findall("section"):
            d = {}
            lessonfilename = section.find('filename').text
            # It seems that the elementtree parser will return str if
            # there are no non-ascii chars in the filename. So lets
            # make unicode of it if it is str
            if isinstance(lessonfilename, str):
                lessonfilename = str(lessonfilename)
            d['filename'] = lessonfilename
            # section.find('text').text will be none if it was not set
            # when saved, and d['title'] need to be a string
            if section.find('title').text:
                d['title'] = section.find('title').text
            else:
                d['title'] = ""
            if section.find('intervals') is not None:
                d['intervals'] = eval(section.find('intervals').text, {}, {})
            else:
                if lessonfile.infocache.get(lessonfilename, 'module') == 'harmonicinterval':
                    d['intervals'] = []
                    gu.dialog_ok("FIXME: «%s» was saved with a buggy version of solfege, so you must set the intervals by selecting the file in the dialog and clicking the intervals to be asked. Sorry!" % lessonfilename, self)
            d['count'] = int(section.find('count').text)
            d['line_len'] = int(section.find('line_len').text)
            d['qtype'] = int(section.find('qtype').text)
            d['questions'] = []
            for question in section.findall("question"):
                q = {'question': {}, 'answer': {}}
                q['question']['music'] = question.find("students").find("music").text
                q['question']['name'] = question.find("students").find("name").text
                q['answer']['music'] = question.find("teachers").find("music").text
                q['answer']['name'] = question.find("teachers").find("name").text
                d['questions'].append(q)
            self.m_sections.append(d)
            try:
                # Check that the filename is valid
                lessonfile.infocache.get(lessonfilename, 'title')
                self.g_liststore.append((d['title'], lessonfilename))
            except lessonfile.infocache.InfoCacheException as e:
                self.g_liststore.append((_("«%s» not found") % str(e), None))
            self.g_treeview.set_cursor((0,))
        self.m_filename = filename

    def save(self):
        assert self.m_filename
        if self.g_latex_radio.get_active():
            format = "latex"
        else:
            format = "html"
        doc = et.Element("sheet", fileformat_version=self.current_fileformat_version,
                         creator="GNU Solfege",
                         app_version=buildinfo.VERSION_STRING)
        doc.append(et.Comment(""))
        et.SubElement(doc, "title").text = self.g_title.get_text()
        et.SubElement(doc, "output_format").text = format
        for sect in self.m_sections:
            s = et.Element("section")
            et.SubElement(s, "title").text = sect['title']
            et.SubElement(s, "filename").text = sect['filename']
            # only the harmonic and melodic intervals have this variable:
            if 'intervals' in sect:
                et.SubElement(s, 'intervals').text = "%s" % sect['intervals']
            # We do save 'count' because this variable say how many questions
            # we want to generate, and len(questions) will just say how many
            # are generated now.
            et.SubElement(s, "count").text = "%i" % sect['count']
            et.SubElement(s, "line_len").text = "%i" % sect['line_len']
            et.SubElement(s, "qtype").text = "%i" % sect['qtype']
            for qdict in sect['questions']:
                q = et.SubElement(s, "question")
                t = et.SubElement(q, "teachers")
                et.SubElement(t, "name").text = qdict['answer']['name']
                et.SubElement(t, "music").text = qdict['answer']['music']
                t = et.SubElement(q, "students")
                et.SubElement(t, "name").text = qdict['question']['name']
                et.SubElement(t, "music").text = qdict['question']['music']
            doc.append(s)
        tree = et.ElementTree(doc)
        f = open(self.m_filename, 'w')
        print('<?xml version="1.0" encoding="utf-8"?>', file=f)
        tree.write(f, encoding="unicode")
        f.close()
        self.m_changed = False

    def setup_toolbar(self):
        self.g_toolbar = Gtk.Toolbar()
        self.g_actiongroup.add_actions([
         ('Add', Gtk.STOCK_ADD, None, None, None, self.on_add_lesson_clicked),
         ('Remove', Gtk.STOCK_REMOVE, None, None, None, self.on_remove_lesson_clicked),
         ('Create', Gtk.STOCK_EXECUTE, _("Create Sheet"), None, None, self.on_create_sheet),
         ('Randomize', None, _("Randomize"), None, None, self.on_randomize),
        ])
        self.g_ui_manager.insert_action_group(self.g_actiongroup, 0)
        uixml = """
        <ui>
         <toolbar name='ExportToolbar'>
          <toolitem action='Add'/>
          <toolitem action='Remove'/>
          <toolitem action='New'/>
          <toolitem action='Open'/>
          <toolitem action='Save'/>
          <toolitem action='SaveAs'/>
          <toolitem action='Create'/>
          <toolitem action='Randomize'/>
          <toolitem action='Close'/>
          <toolitem action='Help'/>
         </toolbar>
         <accelerator action='Close'/>
         <accelerator action='New'/>
         <accelerator action='Open'/>
         <accelerator action='Save'/>
        </ui>
        """
        self.g_ui_manager.add_ui_from_string(uixml)
        self.vbox.pack_start(self.g_ui_manager.get_widget("/ExportToolbar"),
                             False, False, 0)
        self.g_ui_manager.get_widget("/ExportToolbar").set_style(Gtk.ToolbarStyle.BOTH)
