"""sync: server-ingestion columns on the event logs

Revision ID: 20260728_sync_synced_at
Revises: 20260728_user_settings
Create Date: 2026-07-28 11:00:00.000000

Adds ``synced_at`` to ``likes`` and ``play_history`` — the server-side ingestion
time used as the delta-sync ordering key (distinct from the event time
``created_at``/``played_at``, which a sync push preserves from the client even
when the event happened offline earlier). Existing rows are backfilled from
their event time so a first sync after upgrade behaves sensibly.
"""

from __future__ import annotations

from collections.abc import Sequence

import sqlalchemy as sa
from alembic import op

revision: str = "20260728_sync_synced_at"
down_revision: str | None = "20260728_user_settings"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    op.add_column(
        "likes",
        sa.Column(
            "synced_at",
            sa.DateTime(timezone=True),
            server_default=sa.text("now()"),
            nullable=False,
        ),
    )
    op.execute("UPDATE likes SET synced_at = created_at")
    op.create_index(op.f("ix_likes_synced_at"), "likes", ["synced_at"])

    op.add_column(
        "play_history",
        sa.Column(
            "synced_at",
            sa.DateTime(timezone=True),
            server_default=sa.text("now()"),
            nullable=False,
        ),
    )
    op.execute("UPDATE play_history SET synced_at = played_at")
    op.create_index(op.f("ix_play_history_synced_at"), "play_history", ["synced_at"])


def downgrade() -> None:
    op.drop_index(op.f("ix_play_history_synced_at"), table_name="play_history")
    op.drop_column("play_history", "synced_at")
    op.drop_index(op.f("ix_likes_synced_at"), table_name="likes")
    op.drop_column("likes", "synced_at")