"""
Tests for Alembic async support and env - AC3, AC5, and migration integration (M3).
"""

import asyncio
import os
import subprocess
import sys
from pathlib import Path
import pytest


# Project root (parent of tests/)
PROJECT_ROOT = Path(__file__).resolve().parent.parent


class TestAlembicAsyncConfig:
    """AC3: Alembic configured for async migrations."""

    def test_env_has_async_migrations_runner(self):
        """run_async_migrations and run_migrations_online exist and are callable."""
        # Load project's alembic/env.py (not the alembic package) and inspect
        env_py = PROJECT_ROOT / "alembic" / "env.py"
        assert env_py.exists(), "alembic/env.py not found"
        code = """
import asyncio
import sys
import importlib.util
sys.path.insert(0, %r)
spec = importlib.util.spec_from_file_location("env", %r)
e = importlib.util.module_from_spec(spec)
# Avoid running migrations on load: spec.loader.exec_module(e) would run env
# So we only check that the file defines the symbols (compile + ast or exec with mock)
with open(%r) as f:
    src = f.read()
assert "run_async_migrations" in src and "async def run_async_migrations" in src
assert "run_migrations_online" in src and "asyncio.run" in src
assert "create_async_engine" in src
print("ok")
""" % (str(PROJECT_ROOT), str(env_py), str(env_py))
        result = subprocess.run(
            [sys.executable, "-c", code],
            cwd=PROJECT_ROOT,
            env=os.environ.copy(),
            capture_output=True,
            text=True,
            timeout=15,
        )
        assert result.returncode == 0, (result.stderr or result.stdout or "subprocess failed")
        assert "ok" in (result.stdout or "")

    def test_env_uses_convert_to_async_url(self):
        """Alembic env uses shared convert_to_async_url for async URL."""
        from database.utils import convert_to_async_url

        # Just ensure the helper is used by env (env imports it)
        assert callable(convert_to_async_url)
        assert "asyncpg" in convert_to_async_url("postgresql://localhost/db")
        assert "aiosqlite" in convert_to_async_url("sqlite:///./foo.db")


class TestSecretsFromEnvironment:
    """AC5: All secrets (e.g. DATABASE_URL) loaded from environment."""

    def test_alembic_env_reads_database_url_from_env(self):
        """Alembic env.py reads DATABASE_URL from os.getenv."""
        env_py = PROJECT_ROOT / "alembic" / "env.py"
        code = """
with open(%r) as f:
    src = f.read()
assert "os.getenv" in src and "DATABASE_URL" in src
assert "SQLITE_PATH" in src or "sqlite" in src.lower()
print("ok")
""" % str(env_py)
        result = subprocess.run(
            [sys.executable, "-c", code],
            cwd=PROJECT_ROOT,
            env=os.environ.copy(),
            capture_output=True,
            text=True,
            timeout=15,
        )
        assert result.returncode == 0, (result.stderr or result.stdout or "subprocess failed")

    def test_connection_module_uses_env_for_url(self):
        """database.connection uses os.getenv for DATABASE_URL."""
        import database.connection as conn_module

        # The module reads DATABASE_URL at import time
        assert hasattr(conn_module, "DATABASE_URL")
        assert isinstance(conn_module.DATABASE_URL, str) or conn_module.DATABASE_URL == ""


class TestAlembicMigrationIntegration:
    """M3: Integration test - alembic upgrade head and downgrade -1."""

    @pytest.fixture
    def temp_db_env(self, tmp_path):
        """Set env to use a temp SQLite file for migrations (absolute path)."""
        db_file = tmp_path / "test_migration.db"
        # SQLite needs absolute path when cwd differs; use 3 slashes + abs path
        url = "sqlite:///" + str(db_file.resolve()).replace("\\", "/")
        env = os.environ.copy()
        env["DATABASE_URL"] = url
        return env

    def test_alembic_upgrade_head_succeeds(self, temp_db_env):
        """Task 6.1: alembic upgrade head runs successfully."""
        result = subprocess.run(
            [sys.executable, "-m", "alembic", "upgrade", "head"],
            cwd=PROJECT_ROOT,
            env=temp_db_env,
            capture_output=True,
            text=True,
            timeout=30,
        )
        assert result.returncode == 0, (
            f"alembic upgrade head failed: {result.stderr or result.stdout}"
        )

    def test_alembic_downgrade_one_succeeds(self, temp_db_env):
        """Task 6.2: alembic downgrade -1 runs after upgrade."""
        # First upgrade to head
        subprocess.run(
            [sys.executable, "-m", "alembic", "upgrade", "head"],
            cwd=PROJECT_ROOT,
            env=temp_db_env,
            capture_output=True,
            timeout=30,
        )
        # Then downgrade one revision
        result = subprocess.run(
            [sys.executable, "-m", "alembic", "downgrade", "-1"],
            cwd=PROJECT_ROOT,
            env=temp_db_env,
            capture_output=True,
            text=True,
            timeout=30,
        )
        assert result.returncode == 0, (
            f"alembic downgrade -1 failed: {result.stderr or result.stdout}"
        )