import src.forms.exceptions as exceptions
import src.messages as messages
from sqlalchemy import func
from sqlmodel import Session, select
from src import models


def get_all(
    session: Session,
    seasons: list[str],
    productors: list[str],
    current_season: bool,
    user: models.User = None
) -> list[models.FormPublic]:
    statement = select(models.Form)
    if user:
        statement = statement .join(
            models.Productor,
            models.Form.productor_id == models.Productor.id) .where(
            models.Productor.type.in_(
                [
                    r.name for r in user.roles])) .distinct()
    if len(seasons) > 0:
        statement = statement.where(models.Form.season.in_(seasons))
    if len(productors) > 0:
        statement = statement.join(
            models.Productor).where(
            models.Productor.name.in_(productors))
    if not user:
        statement = statement.where(models.Form.visible)
    if current_season:
        subquery = (
            select(
                models.Productor.type,
                func.max(models.Form.start).label("max_start")
            )
            .join(models.Form)
            .group_by(models.Productor.type)
            .subquery()
        )
        statement = select(models.Form)\
            .join(models.Productor)\
            .join(subquery,
                  (models.Productor.type == subquery.c.type) &
                  (models.Form.start == subquery.c.max_start)
                  )
        if not user:
            statement = statement.where(models.Form.visible)
        return session.exec(statement.order_by(models.Form.name)).all()
    return session.exec(statement.order_by(models.Form.name)).all()


def get_one(session: Session, form_id: int) -> models.FormPublic:
    return session.get(models.Form, form_id)


def create_one(session: Session, form: models.FormCreate) -> models.FormPublic:
    if not form:
        raise exceptions.FormCreateError(
            messages.Messages.invalid_input(
                'form', 'input cannot be None'))
    if not session.get(models.Productor, form.productor_id):
        raise exceptions.ProductorNotFoundError(
            messages.Messages.not_found('productor'))
    if not session.get(models.User, form.referer_id):
        raise exceptions.UserNotFoundError(messages.Messages.not_found('user'))
    form_create = form.model_dump(exclude_unset=True)
    new_form = models.Form(**form_create)
    session.add(new_form)
    session.commit()
    session.refresh(new_form)
    return new_form


def update_one(
        session: Session,
        _id: int,
        form: models.FormUpdate) -> models.FormPublic:
    statement = select(models.Form).where(models.Form.id == _id)
    result = session.exec(statement)
    new_form = result.first()
    if not new_form:
        raise exceptions.FormNotFoundError(messages.Messages.not_found('form'))
    if form.productor_id and not session.get(
            models.Productor, form.productor_id):
        raise exceptions.ProductorNotFoundError(
            messages.Messages.not_found('productor'))
    if form.referer_id and not session.get(models.User, form.referer_id):
        raise exceptions.UserNotFoundError(messages.Messages.not_found('user'))
    form_updates = form.model_dump(exclude_unset=True)
    for key, value in form_updates.items():
        setattr(new_form, key, value)
    session.add(new_form)
    session.commit()
    session.refresh(new_form)
    return new_form


def delete_one(session: Session, _id: int) -> models.FormPublic:
    statement = select(models.Form).where(models.Form.id == _id)
    result = session.exec(statement)
    form = result.first()
    if not form:
        raise exceptions.FormNotFoundError(messages.Messages.not_found('form'))
    result = models.FormPublic.model_validate(form)
    session.delete(form)
    session.commit()
    return result


def is_allowed(
    session: Session, 
    user: models.User, 
    _id: int = None, 
    form: models.FormCreate = None
) -> bool:
    if not _id:
        statement = (
            select(models.Productor)
            .where(models.Productor.id == form.productor_id)
        )
        productor = session.exec(statement).first()
        return productor.type in [r.name for r in user.roles]
    statement = (
        select(models.Form)
        .join(
            models.Productor,
            models.Form.productor_id == models.Productor.id
        )
        .where(models.Form.id == _id)
        .where(
            models.Productor.type.in_(
                [r.name for r in user.roles]
            )
        )
        .distinct()
    )
    return len(session.exec(statement).all()) > 0