from __future__ import annotations

import unittest
from tempfile import TemporaryDirectory
from unittest.mock import patch

from app import create_app
from app.config import Config
from app.email import EmailConfigurationError, send_transactional_email


class TransactionalEmailTest(unittest.TestCase):
    def create_test_app(self, temp_dir: str, *, configured: bool):
        class TestConfig(Config):
            TESTING = True
            SECRET_KEY = "test-secret"
            SECRET_KEY_GENERATED = False
            SQLALCHEMY_DATABASE_URI = f"sqlite:///{temp_dir}/test.db"
            ADMIN_PASSWORD = None
            RESEND_API_KEY = "re_test_key" if configured else ""
            RESEND_FROM_EMAIL = "no-reply@auth.example.com" if configured else ""

        return create_app(TestConfig, load_model_on_start=False)

    def test_send_requires_resend_configuration(self) -> None:
        with TemporaryDirectory() as temp_dir:
            app = self.create_test_app(temp_dir, configured=False)
            with app.app_context(), self.assertRaises(EmailConfigurationError):
                send_transactional_email(
                    to="user@example.com",
                    subject="测试",
                    html="<p>测试</p>",
                )

    @patch("app.email.resend.Emails.send", return_value={"id": "email_123"})
    def test_send_uses_configured_sender(self, send):
        with TemporaryDirectory() as temp_dir:
            app = self.create_test_app(temp_dir, configured=True)
            with app.app_context():
                result = send_transactional_email(
                    to="user@example.com",
                    subject="密码重置",
                    html="<p>重置链接</p>",
                )

        self.assertEqual(result, {"id": "email_123"})
        send.assert_called_once_with(
            {
                "from": "no-reply@auth.example.com",
                "to": ["user@example.com"],
                "subject": "密码重置",
                "html": "<p>重置链接</p>",
            }
        )


if __name__ == "__main__":
    unittest.main()