from typing import Optional

from fastapi import APIRouter, HTTPException, Query, status
from sqlalchemy.exc import IntegrityError
from sqlmodel import Session, select

from app.db import SessionDep
from app.dependencies import CurrentUser, get_mail_template_in_organization, get_route_in_organization
from app.models.mail_template import MailTemplate, MailTemplateCreate, MailTemplatePublic, MailTemplateUpdate
from app.models.route import Route

router = APIRouter(prefix="/mail-templates", tags=["mail-templates"])


def _commit_or_conflict(session: Session) -> None:
    try:
        session.commit()
    except IntegrityError as exc:
        session.rollback()
        if "uq_mail_template_route_event" in str(getattr(exc, "orig", exc)):
            raise HTTPException(
                status_code=status.HTTP_409_CONFLICT,
                detail="A mail template for this event type already exists on this route",
            ) from exc
        raise


@router.post("", response_model=MailTemplatePublic, status_code=status.HTTP_201_CREATED)
def create_mail_template(payload: MailTemplateCreate, session: SessionDep, current_user: CurrentUser) -> MailTemplate:
    get_route_in_organization(session, payload.route_id, current_user.organization_id)
    mail_template = MailTemplate.model_validate(payload)
    session.add(mail_template)
    _commit_or_conflict(session)
    session.refresh(mail_template)
    return mail_template


@router.get("", response_model=list[MailTemplatePublic])
def list_mail_templates(
    session: SessionDep,
    current_user: CurrentUser,
    route_id: Optional[int] = None,
) -> list[MailTemplate]:
    statement = select(MailTemplate).join(Route).where(Route.organization_id == current_user.organization_id)
    if route_id is not None:
        statement = statement.where(MailTemplate.route_id == route_id)
    statement = statement.order_by(MailTemplate.id)
    return list(session.exec(statement).all())


@router.get("/{template_id}", response_model=MailTemplatePublic)
def get_mail_template(template_id: int, session: SessionDep, current_user: CurrentUser) -> MailTemplate:
    return get_mail_template_in_organization(session, template_id, current_user.organization_id)


@router.patch("/{template_id}", response_model=MailTemplatePublic)
def update_mail_template(
    template_id: int, payload: MailTemplateUpdate, session: SessionDep, current_user: CurrentUser
) -> MailTemplate:
    mail_template = get_mail_template_in_organization(session, template_id, current_user.organization_id)
    for field, value in payload.model_dump(exclude_unset=True).items():
        setattr(mail_template, field, value)
    session.add(mail_template)
    _commit_or_conflict(session)
    session.refresh(mail_template)
    return mail_template


@router.delete("/{template_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_mail_template(template_id: int, session: SessionDep, current_user: CurrentUser) -> None:
    mail_template = get_mail_template_in_organization(session, template_id, current_user.organization_id)
    session.delete(mail_template)
    session.commit()