import asyncio
import os
import sys
from pathlib import Path

from sqlalchemy import inspect, text
from sqlalchemy.ext.asyncio import create_async_engine

from app.db import Base

PROJECT_ROOT = Path(__file__).parents[2]


async def run_alembic(command: str, database_url: str) -> None:
    process = await asyncio.create_subprocess_exec(
        sys.executable,
        "-m",
        "alembic",
        command,
        "head" if command == "upgrade" else "base",
        cwd=PROJECT_ROOT,
        env={**os.environ, "DATABASE_URL": database_url},
    )
    assert await process.wait() == 0


async def test_migration_up_and_down(postgres_url: str) -> None:
    engine = create_async_engine(postgres_url)
    async with engine.begin() as connection:
        await connection.run_sync(Base.metadata.drop_all)
        await connection.execute(text("DROP TABLE IF EXISTS alembic_version"))
    await engine.dispose()

    await run_alembic("upgrade", postgres_url)

    engine = create_async_engine(postgres_url)
    async with engine.connect() as connection:
        tables, indexes, unique_constraints = await connection.run_sync(
            lambda sync_connection: (
                set(inspect(sync_connection).get_table_names()),
                {index["name"] for index in inspect(sync_connection).get_indexes("outbox")},
                {
                    constraint["name"]
                    for constraint in inspect(sync_connection).get_unique_constraints("payments")
                },
            )
        )
    await engine.dispose()

    assert {"payments", "outbox", "alembic_version"} <= tables
    assert {"ix_outbox_aggregate_id", "ix_outbox_published_at"} <= indexes
    assert unique_constraints

    await run_alembic("downgrade", postgres_url)

    engine = create_async_engine(postgres_url)
    async with engine.connect() as connection:
        remaining_tables = await connection.run_sync(
            lambda sync_connection: set(inspect(sync_connection).get_table_names())
        )
    await engine.dispose()

    assert "payments" not in remaining_tables
    assert "outbox" not in remaining_tables