eryao/backend/alembic/versions/20260411_0004_add_notifications_tables.py

"""add notifications and user_notifications tables

Revision ID: 20260411_0004
Revises: 20260411_0003
Create Date: 2026-04-11 12:00:00
"""

from typing import Sequence, Union

from alembic import op
import sqlalchemy as sa
from sqlalchemy.dialects import postgresql

revision: str = "20260411_0004"
down_revision: Union[str, Sequence[str], None] = "20260411_0003"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.create_table(
        "notifications",
        sa.Column(
            "id", sa.UUID(), server_default=sa.text("gen_random_uuid()"), nullable=False
        ),
        sa.Column(
            "type",
            sa.String(length=32),
            server_default=sa.text("'system'"),
            nullable=False,
        ),
        sa.Column("title", sa.Text(), nullable=False),
        sa.Column("body", sa.Text(), nullable=False),
        sa.Column(
            "payload",
            postgresql.JSONB(astext_type=sa.Text()),
            server_default=sa.text("'{}'::jsonb"),
            nullable=False,
        ),
        sa.Column(
            "status",
            sa.String(length=16),
            server_default=sa.text("'published'"),
            nullable=False,
        ),
        sa.Column("published_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("revoked_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column(
            "created_at",
            sa.DateTime(timezone=True),
            server_default=sa.text("now()"),
            nullable=False,
        ),
        sa.Column(
            "updated_at",
            sa.DateTime(timezone=True),
            server_default=sa.text("now()"),
            nullable=False,
        ),
        sa.Column("deleted_at", sa.DateTime(timezone=True), nullable=True),
        sa.CheckConstraint(
            "status IN ('draft', 'published', 'revoked')",
            name="ck_notifications_status",
        ),
        sa.CheckConstraint(
            "jsonb_typeof(payload) = 'object'",
            name="ck_notifications_payload_object",
        ),
        sa.PrimaryKeyConstraint("id"),
    )
    op.create_index(
        "ix_notifications_status_created_at",
        "notifications",
        ["status", sa.text("created_at DESC")],
    )
    op.create_index(
        "ix_notifications_published_at",
        "notifications",
        [sa.text("published_at DESC")],
    )
    _enable_rls("notifications")

    op.create_table(
        "user_notifications",
        sa.Column(
            "id", sa.UUID(), server_default=sa.text("gen_random_uuid()"), nullable=False
        ),
        sa.Column("user_id", sa.UUID(), nullable=False),
        sa.Column("notification_id", sa.UUID(), nullable=False),
        sa.Column(
            "is_read", sa.Boolean(), server_default=sa.text("false"), nullable=False
        ),
        sa.Column("read_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column(
            "created_at",
            sa.DateTime(timezone=True),
            server_default=sa.text("now()"),
            nullable=False,
        ),
        sa.Column(
            "updated_at",
            sa.DateTime(timezone=True),
            server_default=sa.text("now()"),
            nullable=False,
        ),
        sa.ForeignKeyConstraint(["user_id"], ["auth.users.id"], ondelete="CASCADE"),
        sa.ForeignKeyConstraint(
            ["notification_id"], ["notifications.id"], ondelete="CASCADE"
        ),
        sa.PrimaryKeyConstraint("id"),
        sa.UniqueConstraint(
            "user_id", "notification_id", name="uq_user_notifications_user_notification"
        ),
    )
    op.create_index(
        "ix_user_notifications_user_created_at",
        "user_notifications",
        ["user_id", sa.text("created_at DESC")],
    )
    op.create_index(
        "ix_user_notifications_user_unread",
        "user_notifications",
        ["user_id", "is_read"],
    )
    _enable_rls("user_notifications")


def downgrade() -> None:
    _drop_rls("user_notifications")
    op.drop_index("ix_user_notifications_user_unread", table_name="user_notifications")
    op.drop_index(
        "ix_user_notifications_user_created_at", table_name="user_notifications"
    )
    op.drop_table("user_notifications")

    _drop_rls("notifications")
    op.drop_index("ix_notifications_published_at", table_name="notifications")
    op.drop_index("ix_notifications_status_created_at", table_name="notifications")
    op.drop_table("notifications")


def _enable_rls(table_name: str) -> None:
    for role in ["anon", "authenticated"]:
        for action in ["select", "insert", "update", "delete"]:
            op.execute(
                f"DROP POLICY IF EXISTS {role}_{action}_{table_name} ON {table_name}"
            )
    op.execute(f"ALTER TABLE {table_name} ENABLE ROW LEVEL SECURITY")
    for role in ["anon", "authenticated"]:
        op.execute(
            f"CREATE POLICY {role}_select_{table_name} ON {table_name} FOR SELECT TO {role} USING (false)"
        )
        op.execute(
            f"CREATE POLICY {role}_insert_{table_name} ON {table_name} FOR INSERT TO {role} WITH CHECK (false)"
        )
        op.execute(
            f"CREATE POLICY {role}_update_{table_name} ON {table_name} FOR UPDATE TO {role} USING (false) WITH CHECK (false)"
        )
        op.execute(
            f"CREATE POLICY {role}_delete_{table_name} ON {table_name} FOR DELETE TO {role} USING (false)"
        )


def _drop_rls(table_name: str) -> None:
    for role in ["anon", "authenticated"]:
        for action in ["select", "insert", "update", "delete"]:
            op.execute(
                f"DROP POLICY IF EXISTS {role}_{action}_{table_name} ON {table_name}"
            )
    op.execute(f"ALTER TABLE {table_name} DISABLE ROW LEVEL SECURITY")