from flask_wtf import FlaskForm
from werkzeug.utils import secure_filename
from wtforms import (
    FileField,
    StringField,
    SubmitField,
    ValidationError,
    IntegerField
)
from wtforms.validators import DataRequired, Length


class AddCorpusFileForm(FlaskForm):
    '''
    Form to add a .vrt corpus file to the current corpus.
    '''
    # Required fields
    author = StringField('Author', validators=[DataRequired(), Length(1, 255)])
    file = FileField('File', validators=[DataRequired()])
    publishing_year = IntegerField('Publishing year',
                                   validators=[DataRequired()])
    title = StringField('Title', validators=[DataRequired(), Length(1, 255)])
    # Optional fields
    address = StringField('Adress', validators=[Length(0, 255)])
    booktitle = StringField('Booktitle', validators=[Length(0, 255)])
    chapter = StringField('Chapter', validators=[Length(0, 255)])
    editor = StringField('Editor', validators=[Length(0, 255)])
    institution = StringField('Institution', validators=[Length(0, 255)])
    journal = StringField('Journal', validators=[Length(0, 255)])
    pages = StringField('Pages', validators=[Length(0, 255)])
    publisher = StringField('Publisher', validators=[Length(0, 255)])
    school = StringField('School', validators=[Length(0, 255)])
    submit = SubmitField()

    def __init__(self, corpus, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.corpus = corpus

    def validate_file(self, field):
        if not field.data.filename.lower().endswith('.vrt'):
            raise ValidationError('File does not have an approved extension: '
                                  '.vrt')
        field.data.filename = secure_filename(field.data.filename)
        for corpus_file in self.corpus.files:
            if field.data.filename == corpus_file.filename:
                raise ValidationError('File already registered to corpus.')


class EditCorpusFileForm(FlaskForm):
    '''
    Form to edit meta data of one corpus file.
    '''
    # Required fields
    author = StringField('Author', validators=[DataRequired(), Length(1, 255)])
    publishing_year = IntegerField('Publishing year',
                                   validators=[DataRequired()])
    title = StringField('Title', validators=[DataRequired(), Length(1, 255)])
    # Optional fields
    address = StringField('Adress', validators=[Length(0, 255)])
    booktitle = StringField('Booktitle', validators=[Length(0, 255)])
    chapter = StringField('Chapter', validators=[Length(0, 255)])
    editor = StringField('Editor', validators=[Length(0, 255)])
    institution = StringField('Institution', validators=[Length(0, 255)])
    journal = StringField('Journal', validators=[Length(0, 255)])
    pages = StringField('Pages', validators=[Length(0, 255)])
    publisher = StringField('Publisher', validators=[Length(0, 255)])
    school = StringField('School', validators=[Length(0, 255)])
    submit = SubmitField()


class AddCorpusForm(FlaskForm):
    '''
    Form to add a a new corpus.
    '''
    description = StringField('Description',
                              validators=[DataRequired(), Length(1, 255)])
    submit = SubmitField()
    title = StringField('Title', validators=[DataRequired(), Length(1, 32)])


class ImportCorpusForm(FlaskForm):
    '''
    Form to import a corpus.
    '''
    description = StringField('Description',
                              validators=[DataRequired(), Length(1, 255)])
    file = FileField('File', validators=[DataRequired()])
    submit = SubmitField()
    title = StringField('Title', validators=[DataRequired(), Length(1, 32)])

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    def validate_file(self, field):
        if not field.data.filename.lower().endswith('.zip'):
            raise ValidationError('File does not have an approved extension: '
                                  '.zip')
        field.data.filename = secure_filename(field.data.filename)