"""CRUD des bénévoles. La suppression est un effacement complet (RGPD).

L'email n'est pas unique : plusieurs bénévoles peuvent en partager un même
(couple, famille) — voir `app/models/domain.py:Volunteer`."""

import uuid

from fastapi import APIRouter, Depends, HTTPException, Response, status
from sqlalchemy.orm import aliased
from sqlmodel import Session, select

from app.api._common import (
    owned_or_404,
    replace_links,
    resolve_owned_ids,
    set_artists,
    set_wished_positions,
)
from app.api.deps import get_edition
from app.api.schemas import (
    VolunteerCreate,
    VolunteerPlanningEntry,
    VolunteerRead,
    VolunteerUpdate,
)
from app.auth.deps import (
    current_account_in_edition,
    require_coordinator,
    require_staff,
)
from app.db import get_session
from app.models import (
    Account,
    Artist,
    Assignment,
    Edition,
    Position,
    Role,
    Shift,
    Volunteer,
    VolunteerArtist,
    VolunteerCompanionWish,
    VolunteerPositionWish,
)

router = APIRouter(
    prefix="/editions/{edition_id}/volunteers", tags=["volunteers"]
)


def _ensure_can_read(account: Account, volunteer_id: uuid.UUID) -> None:
    if account.role in (Role.COORDINATOR, Role.LEAD):
        return
    if account.volunteer_id == volunteer_id:
        return
    raise HTTPException(status_code=403, detail={"code": "error.forbidden"})


def _artist_ids(session: Session, volunteer_id: uuid.UUID) -> list[uuid.UUID]:
    return list(
        session.exec(
            select(Artist.id)
            .join(VolunteerArtist, VolunteerArtist.artist_id == Artist.id)
            .where(VolunteerArtist.volunteer_id == volunteer_id)
            .order_by(Artist.performance_date, Artist.name)
        )
    )


def _wished_position_ids(
    session: Session, volunteer_id: uuid.UUID
) -> list[uuid.UUID]:
    return list(
        session.exec(
            select(Position.id)
            .join(
                VolunteerPositionWish,
                VolunteerPositionWish.position_id == Position.id,
            )
            .where(VolunteerPositionWish.volunteer_id == volunteer_id)
            .order_by(Position.name)
        )
    )


def _companion_ids(session: Session, volunteer_id: uuid.UUID) -> list[uuid.UUID]:
    return list(
        session.exec(
            select(Volunteer.id)
            .join(
                VolunteerCompanionWish,
                VolunteerCompanionWish.companion_id == Volunteer.id,
            )
            .where(VolunteerCompanionWish.volunteer_id == volunteer_id)
            .order_by(Volunteer.last_name, Volunteer.first_name)
        )
    )


def _read(session: Session, volunteer: Volunteer) -> VolunteerRead:
    return VolunteerRead(
        **volunteer.model_dump(
            exclude={"photo", "photo_content_type", "fee_checkout_id"}
        ),
        artist_ids=_artist_ids(session, volunteer.id),
        wished_position_ids=_wished_position_ids(session, volunteer.id),
        wished_companion_ids=_companion_ids(session, volunteer.id),
        has_photo=volunteer.photo is not None,
    )


def _set_companions(
    session: Session, volunteer: Volunteer, companion_ids: list[uuid.UUID]
) -> None:
    ids = resolve_owned_ids(
        session, Volunteer, volunteer.edition_id, companion_ids, "volunteer.unknown"
    )
    if volunteer.id in ids:
        raise HTTPException(
            status_code=422, detail={"code": "volunteer.cannot_wish_self"}
        )
    replace_links(
        session,
        VolunteerCompanionWish,
        filter_column=VolunteerCompanionWish.volunteer_id,
        filter_value=volunteer.id,
        pairs=[
            {"volunteer_id": volunteer.id, "companion_id": cid} for cid in ids
        ],
    )


@router.post("", response_model=VolunteerRead, status_code=status.HTTP_201_CREATED)
def create_volunteer(
    payload: VolunteerCreate,
    edition: Edition = Depends(get_edition),
    _guard: Account = Depends(require_coordinator),
    session: Session = Depends(get_session),
) -> VolunteerRead:
    payload.first_name = payload.first_name.title()
    payload.last_name = payload.last_name.title()
    volunteer = Volunteer(
        edition_id=edition.id,
        **payload.model_dump(
            exclude={"artist_ids", "wished_position_ids", "wished_companion_ids"}
        ),
    )
    session.add(volunteer)
    session.flush()
    set_artists(session, volunteer, payload.artist_ids)
    set_wished_positions(session, volunteer, payload.wished_position_ids)
    _set_companions(session, volunteer, payload.wished_companion_ids)
    session.commit()
    session.refresh(volunteer)
    return _read(session, volunteer)


@router.get("", response_model=list[VolunteerRead])
def list_volunteers(
    edition: Edition = Depends(get_edition),
    _guard: Account = Depends(require_staff),
    session: Session = Depends(get_session),
) -> list[VolunteerRead]:
    volunteers = session.exec(
        select(Volunteer)
        .where(Volunteer.edition_id == edition.id)
        .order_by(Volunteer.last_name, Volunteer.first_name)
    )
    return [_read(session, v) for v in volunteers]


@router.get("/{volunteer_id}", response_model=VolunteerRead)
def get_volunteer(
    volunteer_id: uuid.UUID,
    edition: Edition = Depends(get_edition),
    account: Account = Depends(current_account_in_edition),
    session: Session = Depends(get_session),
) -> VolunteerRead:
    _ensure_can_read(account, volunteer_id)
    volunteer = owned_or_404(session.get(Volunteer, volunteer_id), edition.id)
    return _read(session, volunteer)


@router.get("/{volunteer_id}/planning", response_model=list[VolunteerPlanningEntry])
def get_volunteer_planning(
    volunteer_id: uuid.UUID,
    edition: Edition = Depends(get_edition),
    account: Account = Depends(current_account_in_edition),
    session: Session = Depends(get_session),
) -> list[VolunteerPlanningEntry]:
    """Planning enrichi (poste, lieu, référent + téléphone à contacter) d'un
    bénévole — permet à l'écran bénévole (`/mobile-benevole`) d'afficher ces
    infos sans jamais donner à un compte VOLUNTEER un accès en lecture aux
    postes/créneaux de toute l'édition (réservé à COORDINATOR/LEAD)."""
    _ensure_can_read(account, volunteer_id)
    owned_or_404(session.get(Volunteer, volunteer_id), edition.id)

    Referent = aliased(Volunteer)
    rows = session.exec(
        select(Assignment, Shift, Position, Referent)
        .join(Shift, Shift.id == Assignment.shift_id)
        .join(Position, Position.id == Shift.position_id)
        .join(Account, Account.id == Position.lead_account_id, isouter=True)
        .join(Referent, Referent.id == Account.volunteer_id, isouter=True)
        .where(
            Assignment.volunteer_id == volunteer_id,
            Assignment.edition_id == edition.id,
        )
        .order_by(Shift.starts_at)
    ).all()

    return [
        VolunteerPlanningEntry(
            assignment_id=a.id,
            shift_id=s.id,
            starts_at=s.starts_at,
            ends_at=s.ends_at,
            position_name=p.name,
            position_location=p.location,
            referent_name=f"{r.first_name} {r.last_name}" if r else None,
            referent_phone=r.phone if r else None,
        )
        for a, s, p, r in rows
    ]


@router.get("/{volunteer_id}/photo")
def get_volunteer_photo(
    volunteer_id: uuid.UUID,
    edition: Edition = Depends(get_edition),
    account: Account = Depends(current_account_in_edition),
    session: Session = Depends(get_session),
) -> Response:
    """Photo transmise par le bénévole via le formulaire public
    (`app/api/forms.py`) — COORDINATION/RÉFÉRENT (ex. écran référent, en
    face du nom de chaque membre de l'équipe) ou le bénévole lui-même (écran
    bénévole)."""
    _ensure_can_read(account, volunteer_id)
    volunteer = owned_or_404(session.get(Volunteer, volunteer_id), edition.id)
    if volunteer.photo is None:
        raise HTTPException(status_code=404, detail={"code": "error.not_found"})
    return Response(
        content=volunteer.photo,
        media_type=volunteer.photo_content_type or "application/octet-stream",
    )


@router.patch("/{volunteer_id}", response_model=VolunteerRead)
def update_volunteer(
    volunteer_id: uuid.UUID,
    payload: VolunteerUpdate,
    edition: Edition = Depends(get_edition),
    _guard: Account = Depends(require_coordinator),
    session: Session = Depends(get_session),
) -> VolunteerRead:
    volunteer = owned_or_404(session.get(Volunteer, volunteer_id), edition.id)
    changes = payload.model_dump(exclude_unset=True)
    artist_ids = changes.pop("artist_ids", None)
    wished_position_ids = changes.pop("wished_position_ids", None)
    wished_companion_ids = changes.pop("wished_companion_ids", None)
    for field, value in changes.items():
        setattr(volunteer, field, value)
    session.flush()
    if artist_ids is not None:
        set_artists(session, volunteer, artist_ids)
    if wished_position_ids is not None:
        set_wished_positions(session, volunteer, wished_position_ids)
    if wished_companion_ids is not None:
        _set_companions(session, volunteer, wished_companion_ids)
    session.commit()
    session.refresh(volunteer)
    return _read(session, volunteer)


@router.delete("/{volunteer_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_volunteer(
    volunteer_id: uuid.UUID,
    edition: Edition = Depends(get_edition),
    _guard: Account = Depends(require_coordinator),
    session: Session = Depends(get_session),
) -> Response:
    volunteer = owned_or_404(session.get(Volunteer, volunteer_id), edition.id)
    # Effacement complet : la cascade base supprime disponibilités,
    # affectations, vœux et compte éventuel.
    session.delete(volunteer)
    session.commit()
    return Response(status_code=status.HTTP_204_NO_CONTENT)