"""Regression checks for Lambda routing without AWS credentials or calls."""
import importlib.util
from pathlib import Path
import sys
import types
import unittest
from unittest.mock import Mock, patch


class InfrastructureTests(unittest.TestCase):
    def setUp(self):
        fake_boto3 = types.ModuleType("boto3")
        fake_boto3.client = Mock()
        path = Path(__file__).resolve().parents[1] / "src/lambdas/aws_infrastructure/aws_infrastructure.py"
        spec = importlib.util.spec_from_file_location("infrastructure_under_test", path)
        self.module = importlib.util.module_from_spec(spec)
        with patch.dict(sys.modules, {"boto3": fake_boto3}):
            spec.loader.exec_module(self.module)
        self.module.ec2 = Mock()
        self.module.lambda_client = Mock()

    def test_lambda_operations_route_to_lambda_api(self):
        for operation in ("listar_lambdas", "listar", "list"):
            with self.subTest(operation=operation):
                self.module.lambda_client.reset_mock()
                self.module.lambda_client.list_functions.return_value = {
                    "Functions": [{"FunctionName": "demo-function", "Runtime": "python3.14"}]
                }
                result = self.module.lambda_handler({"operation": operation}, None)
                self.assertEqual(result["count"], 1)
                self.assertEqual(result["functions"][0]["functionName"], "demo-function")
                self.module.lambda_client.list_functions.assert_called_once_with()
                self.module.ec2.describe_instances.assert_not_called()

    def test_ec2_default_and_explicit_operation_are_preserved(self):
        for event in ({}, {"operation": "listar_ec2"}):
            with self.subTest(event=event):
                self.module.ec2.reset_mock()
                self.module.ec2.describe_instances.return_value = {"Reservations": []}
                self.assertEqual(self.module.lambda_handler(event, None), {"count": 0, "instances": []})
                self.module.ec2.describe_instances.assert_called_once_with()
                self.module.lambda_client.list_functions.assert_not_called()

    def test_unknown_operation_does_not_call_aws(self):
        result = self.module.lambda_handler({"operation": "delete"}, None)
        self.assertEqual(result, {"error": "Operacion no soportada", "operation": "delete"})
        self.module.ec2.describe_instances.assert_not_called()
        self.module.lambda_client.list_functions.assert_not_called()


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