models.py 29.1 KB
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import datetime

from django.db import models
from django.db.models.signals import m2m_changed
from django.db.models import Count
from django.core.mail import EmailMessage
from django.urls import reverse
from django.utils.translation import ugettext_lazy as _
from django.utils import timezone
from django.contrib.auth.models import Group
from django.contrib.staticfiles.storage import staticfiles_storage
from django.template import Template, Context
from django.contrib.contenttypes.fields import GenericRelation
from django.conf import settings
from autoslug import AutoSlugField

from .utils import hash_name

from .videos.models import Video
from .notes.models import Note
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from .course_material.models import CourseMaterial
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import re


class Class(models.Model):
    name = models.CharField(
        max_length=255,
    )
    assistants = models.ManyToManyField(
        settings.AUTH_USER_MODEL,
        verbose_name=_('Assistants'),
        related_name='professor_classes',
        blank=True,
    )
    students = models.ManyToManyField(
        settings.AUTH_USER_MODEL,
        related_name='classes',
        blank=True,
    )
    course = models.ForeignKey(
        'Course',
        models.CASCADE,
        verbose_name=_('Course'),
    )
    user_can_certificate = models.BooleanField(
        _('Certification Allowed'),
        default=False,
    )
    user_can_certificate_even_without_progress = models.BooleanField(
        _('Certification Allowed Even Without Progress'),
        default=False,
    )

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    def __str__(self):
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        return u'%s @ %s' % (self.name, self.course)

    def get_absolute_url(self):
        return reverse('class', kwargs={'pk': self.id})

    def add_students(self, *objs):
        for obj in objs:
            try:
                c = Class.objects.get(course=self.course, students=obj)
                c.students.remove(obj)
            except Class.DoesNotExist:
                pass
            self.students.add(obj)

    def remove_students(self, *objs):
        for obj in objs:
            self.students.remove(obj)
            if CourseStudent.objects.filter(course=self.course,
                                            user=obj).exists():
                self.course.default_class.students.add(obj)

    @property
    def get_students(self):
        return CourseStudent.objects.filter(course=self.course, user__in=self.students.all()).order_by('user__first_name')


def remove_duplicate_classes(sender, instance, action, reverse, model, pk_set, **kwargs):
    """Clean the same student in twice classes."""
    # add student to default_class everytime that m2m cleans
    if action == 'pre_clear':
        default_class = instance.course.default_class
        for student in instance.students.all():
            student.classes.add(default_class)

    # garantee that student has been subscribe in only one class
    if action == 'post_add':
        try:
            for student in instance.students.all():
                classes = student.classes.filter(course=instance.course).exclude(id=instance.id)
                for classe in classes:
                    student.classes.remove(classe)

        # garantee that this block executes only when instance == Class.
        except AttributeError:
            pass


m2m_changed.connect(remove_duplicate_classes, sender=Class.students.through)


class Course(models.Model):
    STATES = (
        ('draft', _('Draft')),
        ('published', _('Published')),
    )

    slug = models.SlugField(
        _('Slug'),
        max_length=255,
        unique=True,
    )
    name = models.CharField(
        _('Name'),
        max_length=255,
        blank=True,
    )
    intro_video = models.ForeignKey(
        Video,
        models.CASCADE,
        verbose_name=_('Intro video'),
        null=True,
        blank=True,
    )
    application = models.TextField(
        _('Application'),
        blank=True,
    )
    requirement = models.TextField(
        _('Requirement'),
        blank=True,
    )
    abstract = models.TextField(
        _('Abstract'),
        blank=True,
    )
    structure = models.TextField(
        _('Structure'),
        blank=True,
    )
    workload = models.TextField(
        _('Workload'),
        blank=True,
    )
    pronatec = models.TextField(
        _('Pronatec'),
        blank=True,
    )
    status = models.CharField(
        _('Status'),
        choices=STATES,
        default=STATES[0][0],
        max_length=64,
    )
    thumbnail = models.ImageField(
        _('Thumbnail'),
        upload_to=hash_name('course_thumbnails', 'name'),
        null=True,
        blank=True,
    )
    professors = models.ManyToManyField(
        settings.AUTH_USER_MODEL,
        related_name='professorcourse_set',
        through='CourseProfessor',
    )
    authors = models.ManyToManyField(
        settings.AUTH_USER_MODEL,
        related_name='authorcourses',
        through='CourseAuthor',
    )
    students = models.ManyToManyField(
        settings.AUTH_USER_MODEL,
        related_name='studentcourse_set',
        through='CourseStudent',
    )
    home_thumbnail = models.ImageField(
        _('Home thumbnail'),
        upload_to=hash_name('home_thumbnails', 'name'),
        null=True,
        blank=True,
    )
    home_position = models.IntegerField(
        null=True,
        blank=True,
    )
    start_date = models.DateField(
        _('Start date'),
        default=None,
        blank=True,
        null=True,
    )
    home_published = models.BooleanField(
        default=False,
    )
    default_class = models.OneToOneField(
        Class,
        models.SET_NULL,
        verbose_name=_('Default Class'),
        related_name='default_course',
        null=True,
        blank=True,
    )
    min_percent_to_complete = models.IntegerField(
        default=100,
        null=True,
        blank=True,
    )

    groups = models.ManyToManyField(
        Group,
        verbose_name=_('groups'),
        blank=True,
        help_text=_('The Groups that can have access to this forum. If empty, there are no group restrictions.'),
        related_name="courses",
    )

    class Meta:
        verbose_name = _('Course')
        verbose_name_plural = _('Courses')

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    def __str__(self):
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        return self.name

    @property
    def unit_set(self):
        return Unit.objects.filter(lesson__in=self.lessons.all()).order_by('lesson')

    @property
    def public_lessons(self):
        return self.lessons.exclude(status='draft')

    def first_lesson(self):
        if self.lessons.exists():
            return self.lessons.all()[0]

    def enroll_student(self, student):
        if not Class.objects.filter(course=self, students=student).exists():
            self.default_class.students.add(student)

        if not CourseStudent.objects.filter(course=self, user=student).exists():
            CourseStudent.objects.create(course=self, user=student)

    def is_enrolled(self, user):
        return CourseStudent.objects.filter(course=self, user=user).exists()

    @property
    def thumbnail_url(self):
        return self.get_thumbnail_url()

    def get_thumbnail_url(self):
        if self.thumbnail:
            return self.thumbnail.url
        return ''

    def get_home_thumbnail_url(self):
        if self.home_thumbnail:
            return self.home_thumbnail.url
        return ''

    @property
    def has_started(self):
        if self.start_date and self.start_date <= datetime.date.today():
            return True
        else:
            return False

    def avg_lessons_users_progress(self, classes=None):
        if classes:
            student_enrolled = self.coursestudent_set.filter(
                user__classes__in=classes).count()
        else:
            student_enrolled = self.coursestudent_set.all().count()
        progress_list = []
        for lesson in self.lessons.all():
            lesson_progress = {}
            lesson_progress['name'] = lesson.name
            lesson_progress['slug'] = lesson.slug
            lesson_progress['position'] = lesson.position
            units_len = lesson.unit_count()
            # avoid zero divisfion
            if units_len and student_enrolled:
                units_done = StudentProgress.objects.exclude(
                    complete=None).filter(unit__lesson=lesson)
                if classes:
                    units_done = units_done.filter(user__classes__in=classes)
                units_done_len = units_done.count()
                lesson_progress['progress'] = 100 * units_done_len / (
                    units_len * student_enrolled)
                # lesson_progress['forum_questions'] = lesson.forum_questions.count()
                # lesson_progress['progress'] =
                # lesson_progress['finish'] = self.get_lesson_finish_time(lesson)
            else:
                lesson_progress['progress'] = 0
                # lesson_progress['finish'] = ''
            progress_list.append(lesson_progress)
        return progress_list

    def forum_answers_by_lesson(self):
        return self.user.forum_answers.values('question__lesson').annotate(
            Count('question__lesson'))

    @property
    def authors_names(self):
        professors = self.course_authors.all()
        professors_names = ''
        if professors:
            last_elem_index = len(professors) - 1
            for index, professor in enumerate(professors):
                professors_names += professor.get_name()
                if last_elem_index != index:
                    professors_names += ', '
        return professors_names

    def get_professor_role(self, user):
        try:
            cp = self.course_professors.get(user=user)
            return cp.role
        except CourseProfessor.DoesNotExist:
            return False

    def get_role_professors(self, role):
        try:
            cp_set = self.course_professors.filter(role=role)
        except CourseProfessor.DoesNotExist:
            return False

        professors = []
        for cp in cp_set:
            professors.append(cp.user)

        return iter(professors)

    def is_course_assistant(self, user):
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        if user.is_anonymous:
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            return False

        return self.get_professor_role(user) == 'assistant'
        # return role =='assistant', 'coordinator'] or user.is_superuser

    def is_assistant_or_coordinator(self, user):
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        if user.is_anonymous:
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            return False

        if user.is_staff or user.is_superuser:
            return True

        role = self.get_professor_role(user)
        return role in ['assistant', 'coordinator'] or user.is_superuser

    def is_course_coordinator(self, user):
        course_coordinators = self.get_role_professors('coordinator')

        return user.is_superuser or user.is_staff or user in course_coordinators

    def has_perm_own_all_classes(self, user):
        role = self.get_professor_role(user)
        return role == 'coordinator' or user.is_superuser

    def save(self, *args, **kwargs):
        is_new = self.pk is None

        super(Course, self).save(*args, **kwargs)

        if is_new:
            c = Class.objects.create(name=self.name, course=self)
            self.default_class = c
            self.save()
            CourseMaterial.objects.create(course=self)


class CourseStudent(models.Model):
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        models.CASCADE,
        verbose_name=_('Student'),
    )
    course = models.ForeignKey(
        Course,
        models.CASCADE,
        verbose_name=_('Course'),
    )
    start_date = models.DateTimeField(
        default=timezone.now,
    )

    class Meta:
        unique_together = (('user', 'course'),)
        ordering = ['course__start_date']

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    def __str__(self):
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        return u'{0} - {1}'.format(self.course, self.user)

    def save(self, *args, **kwargs):
        super(CourseStudent, self).save(*args, **kwargs)

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        # TODO Move this to Course Certification app, couse this app must not depend on Course Certification.
        # try:
        #     receipt = CourseCertification.objects.get(course_student=self)
        # except CourseCertification.DoesNotExist:
        #     from base64 import urlsafe_b64encode as ub64
        #     from hashlib import sha1
        #     from time import time
        #     h = ub64(sha1(str(time()) + self.user.last_name.encode('utf-8')).digest()[0:6])
        #     receipt = CourseCertification(course_student=self,
        #                                   course=self.course,
        #                                   type=CourseCertification.TYPES[0][0],
        #                                   is_valid=True, link_hash=h)
        #     receipt.save()
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    @property
    def units_done(self):
        return StudentProgress.objects.exclude(complete=None) \
            .filter(user=self.user, unit__lesson__course=self.course)

    def _plpc_course_finished(self):
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        from courses_learning_objects.models import LearningObject, Answer
        activities = LearningObject.objects\
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            .filter(unit__lesson__in=self.course.lessons
                    .filter(status='published'),
                    type='discussion')
        answers = Answer.objects\
            .filter(activity__in=activities, user=self.user)

        return self.percent_progress() > self.min_percent_to_complete() and \
               activities.count() == answers.count()

    def _course_finished(self):
        return self.percent_progress() >= \
            self.course.min_percent_to_complete

    @property
    def course_finished(self):
        return self._plpc_course_finished()

    def can_emmit_receipt(self):
        if not self.get_current_class().user_can_certificate and not self.course_finished:
            return False
        if self.get_current_class().user_can_certificate_even_without_progress and self.certificate.type == 'certificate':
            return True
        return self.course_finished

    def get_current_class(self):
        return Class.objects.get(students=self.user, course=self.course)

    def min_percent_to_complete(self):
        return self.course.min_percent_to_complete

    def reached_last_unit(self):
        try:
            last_unit_done = self.units_done.latest('complete')
            # try to get the next unit in same lesson
            next_unit = Unit.objects \
                .filter(lesson=last_unit_done.unit.lesson,
                        position__gt=last_unit_done.unit.position) \
                .order_by('position').first()

            if next_unit:
                return False
            else:
                next_lesson = self.course.lessons \
                    .filter(position__gt=last_unit_done.unit.lesson.position) \
                    .order_by('position').first()

                if next_lesson and next_lesson.first_unit():
                    return False
                else:
                    return True
        except StudentProgress.DoesNotExist:
            return False
        except AttributeError:
            pass
        return None

    def resume_next_unit(self):
        try:
            last_unit_done = self.units_done.latest('complete')
            # try to get the next unit in same lesson
            next_unit = Unit.objects.filter(lesson=last_unit_done.unit.lesson,
                                            position__gt=last_unit_done.unit.position).order_by(
                'position').first()

            if next_unit:
                return next_unit
            else:
                next_lesson = self.course.lessons.filter(
                    position__gt=last_unit_done.unit.lesson.position,
                    status='published').order_by(
                    'position').first()
                if next_lesson and next_lesson.first_unit():
                    return next_lesson.units.order_by('position').first()
                else:
                    return self.course.first_lesson().first_unit()
        except StudentProgress.DoesNotExist:
            first_lesson = self.course.first_lesson()
            if first_lesson:
                return first_lesson.first_unit()
        except AttributeError:
            pass
        return None

    def percent_progress(self):
        units_len = self.course.unit_set.count()
        if units_len <= 0:
            return 0
        units_done_len = self.units_done.count()
        return int(100.0 * units_done_len / units_len)

    def units_done_by_lesson(self, lesson):
        return StudentProgress.objects.exclude(complete=None)\
                                      .filter(user=self.user, unit__lesson=lesson)

    def get_lesson_finish_time(self, lesson):
        latest = StudentProgress.objects.exclude(complete=None).filter(user=self.user, unit__lesson=lesson).order_by('complete')
        if latest:
            return latest.latest('complete').complete
        else:
            return ''

    def percent_progress_by_lesson(self):
        """
        Returns a list with dictionaries with keys name (lesson name), slug (lesson slug) and progress (percent lesson progress, decimal)
        """
        # TODO refator to make one query to count unts done for all lessons
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        from courses_learning_objects.models import LearningObject, Answer
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        progress_list = []
        for lesson in self.course.lessons.filter(status='published'):
            lesson_progress = {}
            lesson_progress['name'] = lesson.name
            lesson_progress['slug'] = lesson.slug
            lesson_progress['position'] = lesson.position
            units_len = lesson.unit_count()
            lesson_progress['activities'] = []
            if units_len:
                units_done_len = self.units_done_by_lesson(lesson).count()
                lesson_progress['progress'] = 100 * units_done_len / units_len
                lesson_progress['finish'] = self.get_lesson_finish_time(lesson)
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                activities = LearningObject.objects.filter(unit__lesson=lesson, type='discussion')
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                i = 0
                for activity in activities:
                    i = i + 1
                    new_actv = {}
                    new_actv['name'] = 'Atividade ' + str(i)
                    new_actv['position'] = activity.unit.position
                    ans = Answer.objects.filter(activity=activity, user=self.user)
                    if ans:
                        new_actv['done'] = 'true'
                    else:
                        new_actv['done'] = 'false'
                    lesson_progress['activities'].append(new_actv)
            else:
                lesson_progress['progress'] = 0
                lesson_progress['finish'] = ''
            progress_list.append(lesson_progress)
        return progress_list

    def forum_questions_by_lesson(self):
        return self.user.forum_questions.values('lesson').annotate(Count('lesson'))

    def forum_answers_by_lesson(self):
        return self.user.forum_answers.values('question__lesson').annotate(Count('question__lesson'))


class CourseProfessor(models.Model):
    ROLES = (
        ('instructor', _('Instructor')),
        ('assistant', _('Assistant')),
        ('coordinator', _('Professor Coordinator')),
    )

    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        models.SET_NULL,
        verbose_name=_('Professor'),
        related_name='teaching_courses',
        blank=True,
        null=True
    )
    course = models.ForeignKey(
        Course,
        models.CASCADE,
        verbose_name=_('Course'),
        related_name='course_professors'
    )
    biography = models.TextField(
        _('Biography'),
        blank=True,
        null=True
    )
    role = models.CharField(_('Role'), choices=ROLES, default=ROLES[1][0], max_length=128)
    picture = models.ImageField(_('Picture'), upload_to=hash_name('bio-pictures', 'name'), blank=True, null=True)
    name = models.TextField(_('Name'), max_length=30, blank=True, null=True)
    is_course_author = models.BooleanField(default=False)

    class Meta:
        unique_together = (('user', 'course'),)
        verbose_name = _('Course Professor')
        verbose_name_plural = _('Course Professors')

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    def __str__(self):
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        return u'%s @ %s' % (self.user, self.course)

    def get_name(self):
        if self.name:
            return self.name
        elif self.user:
            return self.user.get_full_name()

    def get_biography(self):
        if self.biography:
            return self.biography
        elif self.user:
            return self.user.biography

    def get_picture_url(self):
        if self.picture:
            location = "/%s/%s" % (settings.MEDIA_URL, self.picture)
            return re.sub('/+', '/', location)
        elif self.user:
            return self.user.get_picture_thumb_url()

    def new_message(self, course, subject, message, to=[]):
        return ProfessorMessage.objects.create(subject=subject,
                                               message=message,
                                               course=course,
                                               users=to,
                                               professor=self)

    def get_current_user_classes(self):
        return Class.objects.filter(course=self.course, assistants=self.user)


class CourseAuthor(models.Model):

    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        models.SET_NULL,
        verbose_name=_('Professor'),
        related_name='authoring_courses',
        blank=True,
        null=True,
    )
    course = models.ForeignKey(
        Course,
        models.CASCADE,
        verbose_name=_('Course'),
        related_name='course_authors',
    )
    biography = models.TextField(
        _('Biography'),
        blank=True,
        null=True,
    )
    picture = models.ImageField(
        _('Picture'),
        upload_to=hash_name('bio-pictures', 'name'),
        blank=True,
        null=True,
    )
    name = models.TextField(
        _('Name'),
        max_length=30,
        blank=True,
        null=True,
    )
    position = models.IntegerField(
        default=100,
        null=True,
        blank=True,
    )

    class Meta:
        unique_together = (('user', 'course'),)
        verbose_name = _('Course Author')
        verbose_name_plural = _('Course Authors')
        ordering = ['position']

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    def __str__(self):
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        return u'%s @ %s' % (self.user, self.course)

    def get_name(self):
        if self.name:
            return self.name
        elif self.user:
            return self.user.get_full_name()
        else:
            return ''

    def get_biography(self):
        if self.biography:
            return self.biography
        elif self.user:
            return self.user.biography

    def get_picture_url(self):
        if self.picture:
            location = "/%s/%s" % (settings.MEDIA_URL, self.picture)
            return re.sub('/+', '/', location)
        elif self.user:
            return self.user.get_picture_thumb_url()


class ProfessorMessage(models.Model):
    professor = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        models.PROTECT,
        verbose_name=_('Professor')
    )
    users = models.ManyToManyField(
        settings.AUTH_USER_MODEL,
        related_name='messages',
    )
    subject = models.CharField(
        _('Subject'),
        max_length=255,
    )
    message = models.TextField(
        _('Message'),
    )
    date = models.DateTimeField(
        _('Date'),
        auto_now_add=True
    )
    course = models.ForeignKey(
        Course,
        models.CASCADE,
        verbose_name=_('Course'),
        null=True,
    )

    def send(self):
        bcc = [u.email for u in self.users.all() if u.is_active and re.match(r"(^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$)", u.email)]
        try:
            et = EmailTemplate.objects.get(name='professor-message')
        except EmailTemplate.DoesNotExist:
            et = EmailTemplate(name="professor-message", subject="{{subject}}", template="{{message|safe}}")
        subject = Template(et.subject).render(Context({'subject': self.subject}))
        message = Template(et.template).render(Context({'message': self.message}))
        email = EmailMessage(subject, message, settings.DEFAULT_FROM_EMAIL, [settings.DEFAULT_FROM_EMAIL, ], bcc)
        email.content_subtype = "html"
        return email.send()


class ProfessorMessageRead(models.Model):
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        models.CASCADE,
        verbose_name=_('Student'),
    )
    message = models.ForeignKey(
        ProfessorMessage,
        models.CASCADE,
        verbose_name=_('ProfessorMessage'),
        related_name='read_status',
    )
    is_read = models.BooleanField(default=False)

    def __str__(self):
        return self.user.username + " " + self.message.subject + " " + str(self.is_read)

    class Meta:
        unique_together = ('user', 'message')


class PositionedModel(models.Model):
    collection_name = 'pk'

    class Meta:
        abstract = True

    def save(self, *args, **kwargs):
        if not self.id:
            filters = {self.collection_name: getattr(self, self.collection_name)}
            latest = self.__class__.objects.filter(**filters) \
                .aggregate(models.Max('position')) \
                .get('position__max')

            if latest is not None:
                self.position = latest + 1

        return super(PositionedModel, self).save(*args, **kwargs)


class Lesson(PositionedModel):
    STATES = (
        ('draft', _('Draft')),
        ('published', _('Published')),
    )

    course = models.ForeignKey(
        Course,
        models.CASCADE,
        verbose_name=_('Course'),
        related_name='lessons',
    )
    desc = models.TextField(
        _('Description')
    )
    name = models.CharField(
        _('Name'),
        max_length=255,
    )
    notes = models.TextField(
        _('Notes'),
        default="",
        blank=True,
    )
    position = models.IntegerField(
        default=0,
    )
    slug = AutoSlugField(
        _('Slug'),
        populate_from='name',
        max_length=128,
        editable=False,
        unique=True,
    )
    status = models.CharField(
        _('Status'),
        choices=STATES,
        default=STATES[0][0],
        max_length=64,
    )

    collection_name = 'course'

    @property
    def is_course_last_lesson(self):
        lessons = list(self.course.public_lessons)
        return len(lessons) > 0 and self == lessons[-1]

    class Meta:
        verbose_name = _('Lesson')
        verbose_name_plural = _('Lessons')
        ordering = ['position']

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    def __str__(self):
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        return self.name

    @property
    def thumbnail(self):
        try:
            first_vid_unit = self.units.exclude(video=None).order_by('position')[0]
            thumbnail = 'http://i1.ytimg.com/vi/' + first_vid_unit.video.youtube_id + '/hqdefault.jpg'
            return thumbnail
        except IndexError:
            return staticfiles_storage.url('img/lesson-default.png')

    def activity_count(self):
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        from courses_learning_objects.models import LearningObject
        return LearningObject.objects.filter(unit__lesson=self).count()
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    def unit_count(self):
        return self.units.all().count()

    def video_count(self):
        return self.units.exclude(video=None).count()

    def is_ready(self):
        return self.status == 'published' and self.units.exists()

    def first_unit(self):
        if self.units.exists():
            try:
                return self.units.order_by('position').first()
            except AttributeError:
                return None


class Unit(PositionedModel):
    title = models.CharField(
        _('Title'),
        max_length=128,
        blank=True,
    )
    lesson = models.ForeignKey(
        Lesson,
        models.CASCADE,
        verbose_name=_('Lesson'),
        related_name='units',
    )
    video = models.ForeignKey(
        Video,
        models.SET_NULL,
        verbose_name=_('Video'),
        related_name='unit',
        null=True,
        blank=True,
    )
    side_notes = models.TextField(
        _('Side notes'),
        blank=True,
    )
    position = models.IntegerField(
        default=0,
    )
    notes = GenericRelation(
        Note,
    )
    chat_room = models.CharField(
        _('Chat Room'),
        max_length=255,
        blank=True,
        null=True,
    )

    collection_name = 'lesson'

    class Meta:
        verbose_name = _('Unit')
        verbose_name_plural = _('Units')
        ordering = ['lesson', 'position']

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    def __str__(self):
        return '{} / {} / {} - {}'.format(self.lesson.course.name, self.lesson.name, self.title, self.position)
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class StudentProgress(models.Model):
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        models.CASCADE,
        verbose_name=_('Student'),
    )
    unit = models.ForeignKey(
        Unit,
        models.CASCADE,
        verbose_name=_('Unit'),
        related_name='progress',
    )
    complete = models.DateTimeField(
        editable=True,
        null=True,
        blank=True,
    )
    last_access = models.DateTimeField(
        auto_now=True,
        editable=False,
    )

    class Meta:
        unique_together = (('user', 'unit'),)
        verbose_name = _('Student Progress')

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    def __str__(self):
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        return u'%s @ %s c: %s la: %s' % (
            self.user, self.unit, self.complete, self.last_access)


class EmailTemplate(models.Model):
    name = models.CharField(
        max_length=255,
    )
    subject = models.CharField(
        max_length=255,
    )
    template = models.TextField()