"""Vœu de bénévole : être affecté avec tel(s) autre(s) bénévole(s)

Revision ID: 0010_companion_wish
Revises: 0009_volunteer_email_not_unique
Create Date: 2026-09-15

Table `volunteer_companion_wish` : de 0 à N vœux par bénévole, à sens unique
(A peut souhaiter B sans que B ne le souhaite en retour). Le solveur (section
4 de CLAUDE.md) favorise un candidat dont l'un des compagnons souhaités est
déjà affecté au créneau.
"""

from collections.abc import Sequence

import sqlalchemy as sa
from alembic import op

revision: str = "0010_companion_wish"
down_revision: str | None = "0009_volunteer_email_not_unique"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    op.create_table(
        "volunteer_companion_wish",
        sa.Column("volunteer_id", sa.Uuid(), nullable=False),
        sa.Column("companion_id", sa.Uuid(), nullable=False),
        sa.CheckConstraint(
            "volunteer_id <> companion_id", name="ck_companion_wish_not_self"
        ),
        sa.ForeignKeyConstraint(["companion_id"], ["volunteer.id"], ondelete="CASCADE"),
        sa.ForeignKeyConstraint(["volunteer_id"], ["volunteer.id"], ondelete="CASCADE"),
        sa.PrimaryKeyConstraint("volunteer_id", "companion_id"),
    )


def downgrade() -> None:
    op.drop_table("volunteer_companion_wish")