from typing import Literal, Self
from pydantic import model_validator

from datetime import datetime

from .communication import CommunicationModel
from .submodels import ActivityPaymentInfo
from .enums import CommunicationCategory

from fiber_package.refs import SignupRefList
from fiber_package.signup.signup import SignupModel
from fiber_package.signup.util import validate_answer
from fiber_package.signup.enums import is_question_category

from fiber_package.signup.element.form_base_question import FormBaseQuestion

from fiber_package.signup.element.types import FormElementUnion, FormTextUnion

class ActivityModel(CommunicationModel):
    category: Literal[CommunicationCategory.activity]

    slug: str
    # unique short name used in the public URL

    start_time: datetime
    end_time: datetime

    payment_info: ActivityPaymentInfo | None = None

    form: list[FormElementUnion]

    signups: SignupRefList = SignupRefList([], "signup")

    # TODO: see Felt 'activiteiten' DB schema. Things like:
    # email, target group, maximal attendees ....

    @model_validator(mode='after')
    def check_end_after_start(self) -> Self:
        if self.end_time < self.start_time:
            raise ValueError("End time cannot be earlier than start time")
        return self

    def validate_signup_form(self, signup: SignupModel) -> None:
        required = set()
        answerable = set()

        question_dict: dict[str, FormBaseQuestion] = {}

        for element in self.form:
            if not is_question_category(element.category):
                continue
            # so we know it is istance of FormBaseQuestion
            answerable.add(element.name)
            if element.required:
                required.add(element.name)
            question_dict[element.name] = element

        answers = signup.answers
        for answer in answers:
            q_name = answer.question_name
            if q_name not in answerable:
                raise ValueError(
                    f"Form contains answer to "
                    f"non-existing question {q_name}."
                )
            answerable.remove(q_name)
            if answer.question_name in required:
                required.remove(q_name)

            question = question_dict[q_name]
            validate_answer(question, answer)


        if len(required) > 0:
            raise ValueError("Form does not answer all required questions.")