from django.db import models 
from django.urls import reverse
import uuid 
from datetime import date
from django.contrib.auth.models import User
from django.forms import ModelForm
from django.utils.translation import ugettext_lazy  as _
import catalog.models

class Genre(models.Model):
    name = models.CharField(max_length=200, help_text="Enter a book genre (e.g. Science Fiction, French Poetry etc.)")

    def __str__(self):
        return self.name

class Language(models.Model):
    name = models.CharField(max_length=200, help_text="Enter the book's natural language (e.g. English, French, Japanese etc.)")

    def __str__(self):
        return self.name


class Author(models.Model):
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)
    date_of_birth = models.DateField(null=True, blank=True)
    date_of_death = models.DateField('Died', null=True, blank=True)

    def get_absolute_url(self):
        return reverse('author-detail', args=[str(self.id)])

    def __str__(self):
        return '%s, %s' % (self.last_name, self.first_name)


class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey('Author', on_delete=models.SET_NULL, null=True)
    summary = models.TextField(max_length=1000, help_text="Enter a brief description of the book")
    isbn = models.CharField('ISBN',max_length=13, help_text='13 Character <a href="https://www.isbn-international.org/content/what-isbn">ISBN number</a>')
    genre = models.ManyToManyField(Genre, help_text="Select a genre for this book")
    language = models.ForeignKey('Language', on_delete=models.SET_NULL, null=True)

    def display_genre(self):
        return ', '.join([genre.name for genre in self.genre.all()[:3]])
    display_genre.short_description = 'Genre'

    def get_absolute_url(self):
        return reverse('book-detail', args=[str(self.id)])

    def __str__(self):
        return self.title


class BookInstance(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, help_text="Unique ID for this particular book across whole library")
    book = models.ForeignKey('Book', on_delete=models.SET_NULL, null=True) 
    imprint = models.CharField(max_length=200)
    due_back = models.DateField(null=True, blank=True)
    borrower = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, blank=True)

    LOAN_STATUS = (
        ('m', 'Maintenance'),
        ('o', 'On loan'),
        ('a', 'Available'),
        ('r', 'Reserved'),
    )

    status = models.CharField(max_length=1, choices=LOAN_STATUS, blank=True, default='m', help_text='Book availability')

    @property
    def is_overdue(self):
        if self.due_back and date.today() > self.due_back:
            return True
        return False


    class Meta:
        ordering = ["due_back"]
        permissions = (("can_mark_returned", "Set book as returned"),)


        def __str__(self):
            return '%s (%s)' % (self.id,self.book.title)


class Meta:
        ordering = ['last_name', 'first_name']


        def get_absolute_url(self):
            return reverse('author-detail', args=[str(self.id)])

class RenewBookModelForm(ModelForm):
    def clean_due_back(self):
        data = self.cleaned_data['due_back']
       
       # Check if a date is not in the past.
        if data < datetime.date.today():
            raise ValidationError(_('Invalid date - renewal in past'))

       # Check if a date is in the allowed range (+4 weeks from today).
        if data > datetime.date.today() + datetime.timedelta(weeks=4):
            raise ValidationError(_('Invalid date - renewal more than 4 weeks ahead'))

       # Remember to always return the cleaned data.
        return data

    class Meta:
        model = BookInstance
        fields = ['due_back']
        labels = {'due_back': _('Renewal date')}
        help_texts = {'due_back': _('Enter a date between now and 4 weeks (default 3).')}
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class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey('Author', on_delete=models.SET_NULL, null=True)
    summary = models.TextField(max_length=1000, help_text=
        'Enter a brief description of the book')
    isbn = models.CharField('ISBN', max_length=13, help_text=
        '13 Character <a href="https://www.isbn-international.org/content/what-isbn">ISBN number</a>'
        )
    genre = models.ManyToManyField(Genre, help_text=
        'Select a genre for this book')
    language = models.ForeignKey('Language', on_delete=models.SET_NULL,
        null=True)

    def display_genre(self):
        return ', '.join([genre.name for genre in self.genre.all()[:3]])
    display_genre.short_description = 'Genre'

    def get_absolute_url(self):
        return reverse('book-detail', args=[str(self.id)])

    def __str__(self):
        return self.title


class BookInstance(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, help_text=
        'Unique ID for this particular book across whole library')
    book = models.ForeignKey('Book', on_delete=models.SET_NULL, null=True)
    imprint = models.CharField(max_length=200)
    due_back = models.DateField(null=True, blank=True)
    borrower = models.ForeignKey(User, on_delete=models.SET_NULL, null=True,
        blank=True)
    LOAN_STATUS = ('m', 'Maintenance'), ('o', 'On loan'), ('a', 'Available'), (
        'r', 'Reserved')
    status = models.CharField(max_length=1, choices=LOAN_STATUS, blank=True,
        default='m', help_text='Book availability')

    @property
    def is_overdue(self):
        if self.due_back and date.today() > self.due_back:
            return True
        return False


    class Meta:
        ordering = ['due_back']
        permissions = ('can_mark_returned', 'Set book as returned'),

        def __str__(self):
            return '%s (%s)' % (self.id, self.book.title)


class Meta:
    ordering = ['last_name', 'first_name']

    def get_absolute_url(self):
        return reverse('author-detail', args=[str(self.id)])


class RenewBookModelForm(ModelForm):

    def clean_due_back(self):
        data = self.cleaned_data['due_back']
        if data < datetime.date.today():
            raise ValidationError(_('Invalid date - renewal in past'))
        if data > datetime.date.today() + datetime.timedelta(weeks=4):
            raise ValidationError(_(
                'Invalid date - renewal more than 4 weeks ahead'))
        return data


    class Meta:
        model = BookInstance
        fields = ['due_back']
        labels = {'due_back': _('Renewal date')}
        help_texts = {'due_back': _(
            'Enter a date between now and 4 weeks (default 3).')}

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class Author(models.Model):
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class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey('Author', on_delete=models.SET_NULL, null=True)
    summary = models.TextField(max_length=1000, help_text=
        'Enter a brief description of the book')
    isbn = models.CharField('ISBN', max_length=13, help_text=
        '13 Character <a href="https://www.isbn-international.org/content/what-isbn">ISBN number</a>'
        )
    genre = models.ManyToManyField(Genre, help_text=
        'Select a genre for this book')
    language = models.ForeignKey('Language', on_delete=models.SET_NULL,
        null=True)

    def display_genre(self):
        return ', '.join([genre.name for genre in self.genre.all()[:3]])
    display_genre.short_description = 'Genre'

    def get_absolute_url(self):
        return reverse('book-detail', args=[str(self.id)])

    def __str__(self):
        return self.title


class BookInstance(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, help_text=
        'Unique ID for this particular book across whole library')
    book = models.ForeignKey('Book', on_delete=models.SET_NULL, null=True)
    imprint = models.CharField(max_length=200)
    due_back = models.DateField(null=True, blank=True)
    borrower = models.ForeignKey(User, on_delete=models.SET_NULL, null=True,
        blank=True)
    LOAN_STATUS = ('m', 'Maintenance'), ('o', 'On loan'), ('a', 'Available'), (
        'r', 'Reserved')
    status = models.CharField(max_length=1, choices=LOAN_STATUS, blank=True,
        default='m', help_text='Book availability')

    @property
    def is_overdue(self):
        if self.due_back and date.today() > self.due_back:
            return True
        return False


    class Meta:
        ordering = ['due_back']
        permissions = ('can_mark_returned', 'Set book as returned'),

        def __str__(self):
            return '%s (%s)' % (self.id, self.book.title)


class Meta:
    ordering = ['last_name', 'first_name']

    def get_absolute_url(self):
        return reverse('author-detail', args=[str(self.id)])


class RenewBookModelForm(ModelForm):

    def clean_due_back(self):
        data = self.cleaned_data['due_back']
        if data < datetime.date.today():
            raise ValidationError(_('Invalid date - renewal in past'))
        if data > datetime.date.today() + datetime.timedelta(weeks=4):
            raise ValidationError(_(
                'Invalid date - renewal more than 4 weeks ahead'))
        return data


    class Meta:
        model = BookInstance
        fields = ['due_back']
        labels = {'due_back': _('Renewal date')}
        help_texts = {'due_back': _(
            'Enter a date between now and 4 weeks (default 3).')}

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class Author(models.Model):
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    def __str__(self):
        return '%s, %s' % (self.last_name, self.first_name)


class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey('Author', on_delete=models.SET_NULL, null=True)
    summary = models.TextField(max_length=1000, help_text=
        'Enter a brief description of the book')
    isbn = models.CharField('ISBN', max_length=13, help_text=
        '13 Character <a href="https://www.isbn-international.org/content/what-isbn">ISBN number</a>'
        )
    genre = models.ManyToManyField(Genre, help_text=
        'Select a genre for this book')
    language = models.ForeignKey('Language', on_delete=models.SET_NULL,
        null=True)

    def display_genre(self):
        return ', '.join([genre.name for genre in self.genre.all()[:3]])
    display_genre.short_description = 'Genre'

    def get_absolute_url(self):
        return reverse('book-detail', args=[str(self.id)])

    def __str__(self):
        return self.title


class BookInstance(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, help_text=
        'Unique ID for this particular book across whole library')
    book = models.ForeignKey('Book', on_delete=models.SET_NULL, null=True)
    imprint = models.CharField(max_length=200)
    due_back = models.DateField(null=True, blank=True)
    borrower = models.ForeignKey(User, on_delete=models.SET_NULL, null=True,
        blank=True)
    LOAN_STATUS = ('m', 'Maintenance'), ('o', 'On loan'), ('a', 'Available'), (
        'r', 'Reserved')
    status = models.CharField(max_length=1, choices=LOAN_STATUS, blank=True,
        default='m', help_text='Book availability')

    @property
    def is_overdue(self):
        if self.due_back and date.today() > self.due_back:
            return True
        return False


    class Meta:
        ordering = ['due_back']
        permissions = ('can_mark_returned', 'Set book as returned'),

        def __str__(self):
            return '%s (%s)' % (self.id, self.book.title)


class Meta:
    ordering = ['last_name', 'first_name']

    def get_absolute_url(self):
        return reverse('author-detail', args=[str(self.id)])


class RenewBookModelForm(ModelForm):

    def clean_due_back(self):
        data = self.cleaned_data['due_back']
        if data < datetime.date.today():
            raise ValidationError(_('Invalid date - renewal in past'))
        if data > datetime.date.today() + datetime.timedelta(weeks=4):
            raise ValidationError(_(
                'Invalid date - renewal more than 4 weeks ahead'))
        return data


    class Meta:
        model = BookInstance
        fields = ['due_back']
        labels = {'due_back': _('Renewal date')}
        help_texts = {'due_back': _(
            'Enter a date between now and 4 weeks (default 3).')}

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class Language(models.Model):
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    def __str__(self):
        return self.name


class Author(models.Model):
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)
    date_of_birth = models.DateField(null=True, blank=True)
    date_of_death = models.DateField('Died', null=True, blank=True)

    def get_absolute_url(self):
        return reverse('author-detail', args=[str(self.id)])

    def __str__(self):
        return '%s, %s' % (self.last_name, self.first_name)


class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey('Author', on_delete=models.SET_NULL, null=True)
    summary = models.TextField(max_length=1000, help_text=
        'Enter a brief description of the book')
    isbn = models.CharField('ISBN', max_length=13, help_text=
        '13 Character <a href="https://www.isbn-international.org/content/what-isbn">ISBN number</a>'
        )
    genre = models.ManyToManyField(Genre, help_text=
        'Select a genre for this book')
    language = models.ForeignKey('Language', on_delete=models.SET_NULL,
        null=True)

    def display_genre(self):
        return ', '.join([genre.name for genre in self.genre.all()[:3]])
    display_genre.short_description = 'Genre'

    def get_absolute_url(self):
        return reverse('book-detail', args=[str(self.id)])

    def __str__(self):
        return self.title


class BookInstance(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, help_text=
        'Unique ID for this particular book across whole library')
    book = models.ForeignKey('Book', on_delete=models.SET_NULL, null=True)
    imprint = models.CharField(max_length=200)
    due_back = models.DateField(null=True, blank=True)
    borrower = models.ForeignKey(User, on_delete=models.SET_NULL, null=True,
        blank=True)
    LOAN_STATUS = ('m', 'Maintenance'), ('o', 'On loan'), ('a', 'Available'), (
        'r', 'Reserved')
    status = models.CharField(max_length=1, choices=LOAN_STATUS, blank=True,
        default='m', help_text='Book availability')

    @property
    def is_overdue(self):
        if self.due_back and date.today() > self.due_back:
            return True
        return False


    class Meta:
        ordering = ['due_back']
        permissions = ('can_mark_returned', 'Set book as returned'),

        def __str__(self):
            return '%s (%s)' % (self.id, self.book.title)


class Meta:
    ordering = ['last_name', 'first_name']

    def get_absolute_url(self):
        return reverse('author-detail', args=[str(self.id)])


class RenewBookModelForm(ModelForm):

    def clean_due_back(self):
        data = self.cleaned_data['due_back']
        if data < datetime.date.today():
            raise ValidationError(_('Invalid date - renewal in past'))
        if data > datetime.date.today() + datetime.timedelta(weeks=4):
            raise ValidationError(_(
                'Invalid date - renewal more than 4 weeks ahead'))
        return data


    class Meta:
        model = BookInstance
        fields = ['due_back']
        labels = {'due_back': _('Renewal date')}
        help_texts = {'due_back': _(
            'Enter a date between now and 4 weeks (default 3).')}

from django.db import models 
from django.urls import reverse
import uuid 
from datetime import date
from django.contrib.auth.models import User
from django.forms import ModelForm
from django.utils.translation import ugettext_lazy  as _
import catalog.models

class Genre(models.Model):
    name = models.CharField(max_length=200, help_text="Enter a book genre (e.g. Science Fiction, French Poetry etc.)")

    def __str__(self):
        return self.name

class Language(models.Model):
    name = models.CharField(max_length=200, help_text="Enter the book's natural language (e.g. English, French, Japanese etc.)")

    def __str__(self):
        return self.name


class Author(models.Model):
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)
    date_of_birth = models.DateField(null=True, blank=True)
    date_of_death = models.DateField('Died', null=True, blank=True)

    def get_absolute_url(self):
        return reverse('author-detail', args=[str(self.id)])

    def __str__(self):
        return '%s, %s' % (self.last_name, self.first_name)


class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey('Author', on_delete=models.SET_NULL, null=True)
    summary = models.TextField(max_length=1000, help_text="Enter a brief description of the book")
    isbn = models.CharField('ISBN',max_length=13, help_text='13 Character <a href="https://www.isbn-international.org/content/what-isbn">ISBN number</a>')
    genre = models.ManyToManyField(Genre, help_text="Select a genre for this book")
    language = models.ForeignKey('Language', on_delete=models.SET_NULL, null=True)

    def display_genre(self):
        return ', '.join([genre.name for genre in self.genre.all()[:3]])
    display_genre.short_description = 'Genre'

    def get_absolute_url(self):
        return reverse('book-detail', args=[str(self.id)])

    def __str__(self):
        return self.title


class BookInstance(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, help_text="Unique ID for this particular book across whole library")
    book = models.ForeignKey('Book', on_delete=models.SET_NULL, null=True) 
    imprint = models.CharField(max_length=200)
    due_back = models.DateField(null=True, blank=True)
    borrower = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, blank=True)

    LOAN_STATUS = (
        ('m', 'Maintenance'),
        ('o', 'On loan'),
        ('a', 'Available'),
        ('r', 'Reserved'),
    )

    status = models.CharField(max_length=1, choices=LOAN_STATUS, blank=True, default='m', help_text='Book availability')

    @property
    def is_overdue(self):
        if self.due_back and date.today() > self.due_back:
            return True
        return False


    class Meta:
        ordering = ["due_back"]
        permissions = (("can_mark_returned", "Set book as returned"),)


        def __str__(self):
            return '%s (%s)' % (self.id,self.book.title)


class Meta:
        ordering = ['last_name', 'first_name']


        def get_absolute_url(self):
            return reverse('author-detail', args=[str(self.id)])

class RenewBookModelForm(ModelForm):
    def clean_due_back(self):
        data = self.cleaned_data['due_back']
       
       # Check if a date is not in the past.
        if data < datetime.date.today():
            raise ValidationError(_('Invalid date - renewal in past'))

       # Check if a date is in the allowed range (+4 weeks from today).
        if data > datetime.date.today() + datetime.timedelta(weeks=4):
            raise ValidationError(_('Invalid date - renewal more than 4 weeks ahead'))

       # Remember to always return the cleaned data.
        return data

    class Meta:
        model = BookInstance
        fields = ['due_back']
        labels = {'due_back': _('Renewal date')}
        help_texts = {'due_back': _('Enter a date between now and 4 weeks (default 3).')}