"""shares: one grant per note and person, and only the permissions the app knows

Revision ID: 0034
Revises: 0033
Create Date: 2026-10-07

Nothing wrote a share until #5174, so the table never needed these. Now the Share
dialog does:
- A unique index on (resource_type, resource_id, shared_with_user_id) where a user is
  the target, so sharing a note with someone twice updates the one grant rather than
  stacking two (the same for a group, ahead of step 15).
- A check that `permission` is `view` or `edit`.
- An index on `shared_with_user_id` for "Shared with me".

## Downgrade

Drops the indexes and the check. The rows stay.
"""
from alembic import op

revision = "0034"
down_revision = "0033"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.create_index(
        "uq_shares_resource_user",
        "shares",
        ["resource_type", "resource_id", "shared_with_user_id"],
        unique=True,
        postgresql_where="shared_with_user_id IS NOT NULL",
    )
    op.create_index(
        "uq_shares_resource_group",
        "shares",
        ["resource_type", "resource_id", "shared_with_group_id"],
        unique=True,
        postgresql_where="shared_with_group_id IS NOT NULL",
    )
    op.create_index("ix_shares_user", "shares", ["shared_with_user_id"])
    op.create_check_constraint("ck_shares_permission", "shares", "permission IN ('view', 'edit')")


def downgrade() -> None:
    op.drop_constraint("ck_shares_permission", "shares", type_="check")
    op.drop_index("ix_shares_user", table_name="shares")
    op.drop_index("uq_shares_resource_group", table_name="shares")
    op.drop_index("uq_shares_resource_user", table_name="shares")