from wtforms import Form, StringField, validators
from wtforms.fields.choices import SelectMultipleField, RadioField
from wtforms.fields.numeric import IntegerField
from wtforms.widgets.core import CheckboxInput, ListWidget, Input


def validate_therapy_types(form, field):
    """
    Validate form input for given therapy types (mapping in input field)
    :param form: required by calling method
    :param field: data field for validation (therapy types)
    :return:
    """

    # Given choices by the data source
    valid_choices = {"A", "S", "T", "V"}
    # All of them in arbitrary sets are allowed
    if not all(choice in valid_choices for choice in field.data):
        raise validators.ValidationError("Invalid value in therapy types selection.")


def validate_therapy_phone_times(form, field):
    """
    Validate number of weeks for therapy phone times search.
    :param form: required by calling method
    :param field: data field for validation (therapy phone times in weeks)
    :return:
    """
    # Weeks from 1 to 4
    valid_choices = {1, 2, 3, 4}
    # Check for given data at all -> at least 1 week necessary
    if not field.data:
        raise validators.ValidationError("Please select at least one option.")
    # All of them in arbitrary sets are allowed
    if not all(choice in valid_choices for choice in field.data):
        raise validators.ValidationError("Invalid value in therapy phone types selection.")


class RangeInput(Input):
    """
    Define a range as input type to use HTML element form-range
    """
    input_type = "range"


class SearchForm(Form):
    """
    Search Form to search with several parameters and constraints for doctors/therapists with phone times
    """

    # Match location as string or plz with arbitrary length
    location = StringField("Standort/PLZ", validators=[validators.InputRequired(), validators.Length(min=2, max=50),
                                                       validators.Regexp("^[a-zA-ZäöüßÄÖÜẞ0-9]+$")])
    # Define a distance as range input to limit the search area
    therapy_distance = IntegerField(
        "Distanz",
        widget=RangeInput(),
        default=25,
        validators=[validators.InputRequired(), validators.NumberRange(min=0, max=50)]
    )
    # Define several therapy types (all of them possible to search for)
    therapy_type = SelectMultipleField("Therapieverfahren", choices=[
        ("A", "Analytische Psychotherapie"),
        ("S", "Systemische Therapie"),
        ("T", "Tiefenpsychologisch fundierte Psychotherapie"),
        ("V", "Verhaltenstherapie")], option_widget=CheckboxInput(), widget=ListWidget(prefix_label=False),
                                       validators=[validate_therapy_types])
    # Distinction between adults/children & youth as radio button
    therapy_age_range = RadioField("Altersgruppe", choices=[
        ("E", "Erwachsene"),
        ("K", "Kinder und Jugendliche")], validators=[validators.InputRequired(), validators.any_of(["E", "K"])])
    # Distinction between available therapy types
    therapy_setting = RadioField("Therapiesetting", choices=[
        ("E", "Einzeltherapie"),
        ("G", "Gruppentherapie")], validators=[validators.InputRequired(), validators.any_of(["E", "G"])])
    # TODO: find a better name for label
    # Choose for how many weeks to show phone times
    amount_of_weeks = IntegerField(
        # Rest of the label rendered by the frontend (even though not perfect solution)
        "Telefonzeiten für die ",
        widget=RangeInput(),
        default=1,
        validators=[validators.InputRequired(), validators.NumberRange(min=1, max=4)]
    )