"""authentik expression Policy Models"""
from django.db import models
from django.utils.translation import gettext as _
from rest_framework.serializers import BaseSerializer

from authentik.policies.expression.evaluator import PolicyEvaluator
from authentik.policies.models import Policy
from authentik.policies.types import PolicyRequest, PolicyResult


class ExpressionPolicy(Policy):
    """Execute arbitrary Python code to implement custom checks and validation."""

    expression = models.TextField()

    @property
    def serializer(self) -> BaseSerializer:
        from authentik.policies.expression.api import ExpressionPolicySerializer

        return ExpressionPolicySerializer

    @property
    def component(self) -> str:
        return "ak-policy-expression-form"

    def passes(self, request: PolicyRequest) -> PolicyResult:
        """Evaluate and render expression. Returns PolicyResult(false) on error."""
        evaluator = PolicyEvaluator(self.name)
        evaluator.policy = self
        evaluator.set_policy_request(request)
        return evaluator.evaluate(self.expression)

    def save(self, *args, **kwargs):
        evaluator = PolicyEvaluator(self.name)
        evaluator.policy = self
        evaluator.validate(self.expression)
        return super().save(*args, **kwargs)

    class Meta:

        verbose_name = _("Expression Policy")
        verbose_name_plural = _("Expression Policies")