"""Real PostgreSQL tests, isolated in a fresh schema for every test."""

import os
from pathlib import Path
from uuid import uuid4

import pytest
from alembic import command
from alembic.config import Config
from fastapi.testclient import TestClient
from sqlalchemy import create_engine, text
from sqlalchemy.engine import make_url
from sqlalchemy.orm import sessionmaker

from app.db.session import get_db
from app.main import create_app
from app.models.auth import User
from app.services.auth import PASSWORD_HASHER

BACKEND = Path(__file__).resolve().parents[1]


def migrate(engine, revision="head", *, downgrade=False):
    config = Config(str(BACKEND / "alembic.ini"))
    with engine.begin() as connection:
        config.attributes["connection"] = connection
        (command.downgrade if downgrade else command.upgrade)(config, revision)


@pytest.fixture(scope="session")
def postgres_url(tmp_path_factory):
    url = os.environ.get("TEST_DATABASE_URL")
    server = None
    if not url:
        try:
            import pgserver
        except ImportError:
            pytest.fail("请设置 TEST_DATABASE_URL，或安装可选的本机测试依赖 pgserver")
        server = pgserver.get_server(tmp_path_factory.mktemp("postgres"), cleanup_mode="stop")
        url = server.get_uri().replace("postgresql://", "postgresql+psycopg://", 1)
    if not url.startswith("postgresql+psycopg://"):
        pytest.fail("TEST_DATABASE_URL 必须使用 postgresql+psycopg://")
    bootstrap = create_engine(url)
    with bootstrap.begin() as connection:
        connection.execute(text("CREATE EXTENSION IF NOT EXISTS vector WITH SCHEMA public"))
    bootstrap.dispose()
    yield url
    if server:
        server.cleanup()


@pytest.fixture
def database(postgres_url):
    schema = "test_" + uuid4().hex
    admin = create_engine(postgres_url)
    with admin.begin() as connection:
        connection.execute(text(f'CREATE SCHEMA "{schema}"'))
    # 不包含 public，防止误操作已有业务表。
    url = make_url(postgres_url).update_query_dict({"options": f"-csearch_path={schema}"})
    engine = create_engine(url)
    yield engine
    engine.dispose()
    with admin.begin() as connection:
        connection.execute(text(f'DROP SCHEMA "{schema}" CASCADE'))
    admin.dispose()


@pytest.fixture
def migrated_database(database):
    migrate(database)
    return database


@pytest.fixture
def anonymous_client(migrated_database):
    app = create_app(migrated_database)
    factory = sessionmaker(bind=migrated_database)

    def test_session():
        with factory() as session:
            try:
                yield session
            except Exception:
                session.rollback()
                raise

    app.dependency_overrides[get_db] = test_session
    with TestClient(app, base_url="https://testserver") as client:
        client.headers["Origin"] = "http://localhost:5173"
        yield client


@pytest.fixture
def client(anonymous_client, migrated_database):
    with sessionmaker(bind=migrated_database)() as db:
        db.add(
            User(
                username="test_admin",
                password_hash=PASSWORD_HASHER.hash("test-password-123"),
                role="admin",
            )
        )
        db.commit()
    response = anonymous_client.post(
        "/api/auth/login", json={"username": "test_admin", "password": "test-password-123"}
    )
    assert response.status_code == 200, response.text
    anonymous_client.headers["X-CSRF-Token"] = response.json()["csrf_token"]
    return anonymous_client