"""per-user notification inbox (phase 1)

Revision ID: 0017_notifications
Revises: 0016_video_maintenance
Create Date: 2026-06-18

Adds the durable, server-backed per-user notification table behind the inbox module. The
JSON payload column is named `data` (SQLAlchemy's declarative Base reserves `metadata`).
First producer is the maintenance job's batched "videos removed" notice. Coexists with the
existing client-side transient bell.
"""
from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op

revision: str = "0017_notifications"
down_revision: Union[str, None] = "0016_video_maintenance"
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.Integer(), primary_key=True),
        sa.Column(
            "user_id",
            sa.Integer(),
            sa.ForeignKey("users.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column("type", sa.String(length=32), nullable=False),
        sa.Column("title", sa.String(length=255), nullable=False),
        sa.Column("body", sa.Text(), nullable=True),
        sa.Column("data", sa.JSON(), nullable=True),
        sa.Column("read", sa.Boolean(), nullable=False, server_default="false"),
        sa.Column("dismissed", sa.Boolean(), nullable=False, server_default="false"),
        sa.Column(
            "created_at", sa.DateTime(timezone=True), server_default=sa.func.now()
        ),
    )
    op.create_index("ix_notifications_user_id", "notifications", ["user_id"])
    op.create_index("ix_notifications_type", "notifications", ["type"])
    op.create_index("ix_notifications_read", "notifications", ["read"])
    op.create_index("ix_notifications_created_at", "notifications", ["created_at"])
    # Fast unread-badge count + inbox listing per user.
    op.create_index(
        "ix_notifications_user_read", "notifications", ["user_id", "read"]
    )


def downgrade() -> None:
    op.drop_index("ix_notifications_user_read", table_name="notifications")
    op.drop_index("ix_notifications_created_at", table_name="notifications")
    op.drop_index("ix_notifications_read", table_name="notifications")
    op.drop_index("ix_notifications_type", table_name="notifications")
    op.drop_index("ix_notifications_user_id", table_name="notifications")
    op.drop_table("notifications")