import asyncio
import json
import os
import subprocess
import sys
from uuid import uuid4

import pytest
from sqlalchemy import text
from sqlalchemy.ext.asyncio import create_async_engine

from app.db import engine as configured_engine


@pytest.mark.skipif(not os.getenv("TEST_POSTGRES"), reason="Set TEST_POSTGRES=1 for isolated database migration test")
def test_upgrade_existing_versions_and_downgrade():
    async def check():
        name = "migration_test_" + uuid4().hex
        admin = create_async_engine(configured_engine.url, isolation_level="AUTOCOMMIT")
        test_url = configured_engine.url.set(database=name)
        env = {**os.environ, "DATABASE_URL": test_url.render_as_string(hide_password=False)}
        async def alembic(*args):
            proc = await asyncio.to_thread(subprocess.run, [sys.executable, "-m", "alembic", *args], env=env, capture_output=True, text=True)
            assert proc.returncode == 0, proc.stderr
        async with admin.connect() as conn:
            await conn.execute(text(f'CREATE DATABASE "{name}"'))
        test_engine = create_async_engine(test_url)
        try:
            await alembic("upgrade", "0002")
            async with test_engine.begin() as conn:
                await conn.execute(text("INSERT INTO games(id,title,description,tags,engine) VALUES(1,'Old','','{}','renpy')"))
                await conn.execute(text("INSERT INTO game_versions(id,game_id,name,description,status,progress,size_bytes,manifest) VALUES(1,1,'Original','','ready','',0,CAST(:m AS jsonb)),(2,1,'Legacy mod','','ready','',0,CAST(:m AS jsonb))"), {"m": json.dumps({"format": "pgvn/1", "files": {}})})
                await conn.execute(text("UPDATE game_versions SET parent_id=1,kind='mod' WHERE id=2"))
            await alembic("upgrade", "head")
            async with test_engine.connect() as conn:
                rows = (await conn.execute(text("SELECT revision_id,base_revision_id FROM game_versions"))).all()
                assert len(rows) == 2 and all(r[0] and r[1] is None for r in rows)
                assert await conn.scalar(text("SELECT count(*) FROM revisions")) == 2
            await alembic("downgrade", "0002")
            await alembic("upgrade", "head")
        finally:
            await test_engine.dispose()
            async with admin.connect() as conn:
                await conn.execute(text(f'DROP DATABASE "{name}" WITH (FORCE)'))
            await admin.dispose()
    asyncio.run(check())