"""Tests for the alembic migration history.

The 0005 migration adds `script` and `last_build_status` columns to `overlays`,
drops the global_overlay_* tables, and wipes legacy l4d2center_maps/cedapug_maps
overlay rows. This module pins those behaviors.
"""
from pathlib import Path

import pytest
from alembic import command
from alembic.config import Config
from sqlalchemy import create_engine, inspect, text


_ALEMBIC_DIR = Path(__file__).resolve().parents[1] / "alembic"


def _alembic_config(db_url: str) -> Config:
    cfg = Config()
    cfg.set_main_option("script_location", str(_ALEMBIC_DIR))
    cfg.set_main_option("sqlalchemy.url", db_url)
    return cfg


@pytest.fixture
def db_url(tmp_path, monkeypatch):
    path = tmp_path / "alembic.db"
    url = f"sqlite:///{path}"
    monkeypatch.setenv("DATABASE_URL", url)
    yield url


def test_upgrade_0005_adds_script_columns(db_url) -> None:
    cfg = _alembic_config(db_url)

    command.upgrade(cfg, "0004_drop_legacy_external_overlay_type")

    engine = create_engine(db_url)
    with engine.begin() as conn:
        # Seed legacy global-type overlay rows that the migration must wipe.
        conn.execute(
            text(
                "INSERT INTO overlays (name, path, type, created_at, updated_at) "
                "VALUES ('legacy-l4d2center', '1', 'l4d2center_maps', "
                "'2026-01-01', '2026-01-01')"
            )
        )
        conn.execute(
            text(
                "INSERT INTO overlays (name, path, type, created_at, updated_at) "
                "VALUES ('legacy-cedapug', '2', 'cedapug_maps', "
                "'2026-01-01', '2026-01-01')"
            )
        )
        conn.execute(
            text(
                "INSERT INTO overlays (name, path, type, created_at, updated_at) "
                "VALUES ('keep-workshop', '3', 'workshop', "
                "'2026-01-01', '2026-01-01')"
            )
        )

    command.upgrade(cfg, "0005_script_overlays")

    inspector = inspect(engine)

    overlay_cols = {c["name"]: c for c in inspector.get_columns("overlays")}
    assert "script" in overlay_cols
    assert "last_build_status" in overlay_cols
    assert overlay_cols["script"]["nullable"] is False
    assert overlay_cols["last_build_status"]["nullable"] is False

    table_names = set(inspector.get_table_names())
    assert "global_overlay_sources" not in table_names
    assert "global_overlay_items" not in table_names
    assert "global_overlay_item_files" not in table_names

    with engine.connect() as conn:
        rows = conn.execute(
            text("SELECT name, type FROM overlays ORDER BY name")
        ).all()
        assert rows == [("keep-workshop", "workshop")]

        defaults = conn.execute(
            text(
                "SELECT script, last_build_status FROM overlays "
                "WHERE name = 'keep-workshop'"
            )
        ).one()
        assert defaults == ("", "")


def test_downgrade_0005_skipped() -> None:
    """Per the project convention (see 0004) destructive migrations are
    intentionally one-way; do not test or maintain a downgrade."""
    pytest.skip("0005 is one-way: globals data is gone after upgrade")