"""CRUD des créneaux."""

import uuid

from fastapi import APIRouter, Depends, HTTPException, Response, status
from sqlmodel import Session, select

from app.api._common import owned_or_404, replace_links, resolve_skills
from app.api.deps import get_edition
from app.api.schemas import ShiftCreate, ShiftRead, ShiftUpdate
from app.db import get_session
from app.models import Edition, Position, Shift, ShiftRequiredSkill, Skill

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


def _skill_codes(session: Session, shift_id: uuid.UUID) -> list[str]:
    return sorted(
        session.exec(
            select(Skill.code)
            .join(ShiftRequiredSkill, ShiftRequiredSkill.skill_id == Skill.id)
            .where(ShiftRequiredSkill.shift_id == shift_id)
        )
    )


def _read(session: Session, shift: Shift) -> ShiftRead:
    return ShiftRead(
        **shift.model_dump(),
        required_skill_codes=_skill_codes(session, shift.id),
    )


def _set_skills(session: Session, shift: Shift, codes: list[str]) -> None:
    skills = resolve_skills(session, shift.edition_id, codes)
    replace_links(
        session,
        ShiftRequiredSkill,
        filter_column=ShiftRequiredSkill.shift_id,
        filter_value=shift.id,
        pairs=[{"shift_id": shift.id, "skill_id": s.id} for s in skills],
    )


def _check_range(starts_at, ends_at) -> None:
    if ends_at <= starts_at:
        raise HTTPException(
            status_code=422,
            detail={"code": "shift.ends_not_after_starts"},
        )


def _require_position(
    session: Session, position_id: uuid.UUID, edition_id: uuid.UUID
) -> Position:
    position = session.get(Position, position_id)
    if position is None or position.edition_id != edition_id:
        raise HTTPException(
            status_code=422, detail={"code": "shift.position_wrong_edition"}
        )
    return position


@router.post("", response_model=ShiftRead, status_code=status.HTTP_201_CREATED)
def create_shift(
    payload: ShiftCreate,
    edition: Edition = Depends(get_edition),
    session: Session = Depends(get_session),
) -> ShiftRead:
    _check_range(payload.starts_at, payload.ends_at)
    _require_position(session, payload.position_id, edition.id)
    shift = Shift(
        edition_id=edition.id,
        **payload.model_dump(exclude={"required_skill_codes"}),
    )
    session.add(shift)
    session.flush()
    _set_skills(session, shift, payload.required_skill_codes)
    session.commit()
    session.refresh(shift)
    return _read(session, shift)


@router.get("", response_model=list[ShiftRead])
def list_shifts(
    position_id: uuid.UUID | None = None,
    edition: Edition = Depends(get_edition),
    session: Session = Depends(get_session),
) -> list[ShiftRead]:
    stmt = (
        select(Shift)
        .where(Shift.edition_id == edition.id)
        .order_by(Shift.starts_at)
    )
    if position_id is not None:
        stmt = stmt.where(Shift.position_id == position_id)
    return [_read(session, s) for s in session.exec(stmt)]


@router.get("/{shift_id}", response_model=ShiftRead)
def get_shift(
    shift_id: uuid.UUID,
    edition: Edition = Depends(get_edition),
    session: Session = Depends(get_session),
) -> ShiftRead:
    shift = owned_or_404(session.get(Shift, shift_id), edition.id)
    return _read(session, shift)


@router.patch("/{shift_id}", response_model=ShiftRead)
def update_shift(
    shift_id: uuid.UUID,
    payload: ShiftUpdate,
    edition: Edition = Depends(get_edition),
    session: Session = Depends(get_session),
) -> ShiftRead:
    shift = owned_or_404(session.get(Shift, shift_id), edition.id)
    changes = payload.model_dump(exclude_unset=True)
    skill_codes = changes.pop("required_skill_codes", None)
    if "position_id" in changes:
        _require_position(session, changes["position_id"], edition.id)
    for field, value in changes.items():
        setattr(shift, field, value)
    _check_range(shift.starts_at, shift.ends_at)
    if skill_codes is not None:
        _set_skills(session, shift, skill_codes)
    session.commit()
    session.refresh(shift)
    return _read(session, shift)


@router.delete("/{shift_id}", status_code=status.HTTP_204_NO_CONTENT)
def delete_shift(
    shift_id: uuid.UUID,
    edition: Edition = Depends(get_edition),
    session: Session = Depends(get_session),
) -> Response:
    shift = owned_or_404(session.get(Shift, shift_id), edition.id)
    session.delete(shift)
    session.commit()
    return Response(status_code=status.HTTP_204_NO_CONTENT)