"""user field matcher models"""
import re

from django.db import models
from django.utils.translation import gettext as _
from structlog import get_logger

from passbook.core.models import Policy
from passbook.policies.struct import PolicyRequest, PolicyResult

LOGGER = get_logger()


class FieldMatcherPolicy(Policy):
    """Policy which checks if a field of the User model matches/doesn't match a
    certain pattern"""

    MATCH_STARTSWITH = "startswith"
    MATCH_ENDSWITH = "endswith"
    MATCH_CONTAINS = "contains"
    MATCH_REGEXP = "regexp"
    MATCH_EXACT = "exact"

    MATCHES = (
        (MATCH_STARTSWITH, _("Starts with")),
        (MATCH_ENDSWITH, _("Ends with")),
        (MATCH_CONTAINS, _("Contains")),
        (MATCH_REGEXP, _("Regexp")),
        (MATCH_EXACT, _("Exact")),
    )

    USER_FIELDS = (
        ("username", _("Username"),),
        ("name", _("Name"),),
        ("email", _("E-Mail"),),
        ("is_staff", _("Is staff"),),
        ("is_active", _("Is active"),),
        ("data_joined", _("Date joined"),),
    )

    user_field = models.TextField(choices=USER_FIELDS)
    match_action = models.CharField(max_length=50, choices=MATCHES)
    value = models.TextField()

    form = "passbook.policies.matcher.forms.FieldMatcherPolicyForm"

    def __str__(self):
        description = (
            f"{self.name}, user.{self.user_field} {self.match_action} '{self.value}'"
        )
        if self.name:
            description = f"{self.name}: {description}"
        return description

    def passes(self, request: PolicyRequest) -> PolicyResult:
        """Check if user instance passes this role"""
        if not hasattr(request.user, self.user_field):
            raise ValueError("Field does not exist")
        user_field_value = getattr(request.user, self.user_field, None)
        LOGGER.debug(
            "Checking field",
            value=user_field_value,
            action=self.match_action,
            should_be=self.value,
        )
        passes = False
        if self.match_action == FieldMatcherPolicy.MATCH_STARTSWITH:
            passes = user_field_value.startswith(self.value)
        if self.match_action == FieldMatcherPolicy.MATCH_ENDSWITH:
            passes = user_field_value.endswith(self.value)
        if self.match_action == FieldMatcherPolicy.MATCH_CONTAINS:
            passes = self.value in user_field_value
        if self.match_action == FieldMatcherPolicy.MATCH_REGEXP:
            pattern = re.compile(self.value)
            passes = bool(pattern.match(user_field_value))
        if self.match_action == FieldMatcherPolicy.MATCH_EXACT:
            passes = user_field_value == self.value
        return PolicyResult(passes)

    class Meta:

        verbose_name = _("Field matcher Policy")
        verbose_name_plural = _("Field matcher Policies")