import pytest
from alembic.autogenerate import compare_metadata
from alembic.migration import MigrationContext
from conftest import migrate
from fastapi.testclient import TestClient
from sqlalchemy import text

from app.db.session import Base
from app.main import create_app


def test_startup_requires_migration(database):
    with pytest.raises(RuntimeError, match="alembic upgrade head"):
        with TestClient(create_app(database)):
            pass


def test_startup_rejects_previous_schema(database):
    migrate(database, "0002_catalog")
    with pytest.raises(RuntimeError, match="alembic upgrade head"):
        with TestClient(create_app(database)):
            pass


def test_upgrade_preserves_original_rows_and_repeated_upgrade(database):
    migrate(database, "0001_baseline")
    with database.begin() as connection:
        connection.execute(
            text("""INSERT INTO knowledge_items
            (title, category, content, source_url, verification_status)
            VALUES ('示例旧数据', '未分类', '原始正文', 'https://example.com/', 'verified')""")
        )
        # 模拟 create_all 建表后没有 Alembic 版本记录的旧工程。
        connection.execute(text("DELETE FROM alembic_version"))
    migrate(database)
    migrate(database)
    with database.connect() as connection:
        row = connection.execute(text("SELECT * FROM knowledge_items")).mappings().one()
        assert row["title"] == "示例旧数据" and row["content"] == "原始正文"
        assert row["collected_at"] is None
        assert row["verification_status"] == "pending"
        assert connection.scalar(text("SELECT count(*) FROM audit_events")) == 2
        assert (
            connection.scalar(text("SELECT version_num FROM alembic_version"))
            == "0003_retrieval_runs"
        )
        assert compare_metadata(MigrationContext.configure(connection), Base.metadata) == []
    migrate(database, "0001_baseline", downgrade=True)
    with database.connect() as connection:
        assert connection.scalar(text("SELECT content FROM knowledge_items")) == "原始正文"
    migrate(database)