from io import StringIO
import sys
from unittest.mock import patch, MagicMock
import unittest
import importlib
soyaml = importlib.import_module("so-yaml")


class TestRemove(unittest.TestCase):

    def test_main_missing_input(self):
        with patch('sys.exit', new=MagicMock()) as sysmock:
            with patch('sys.stderr', new=StringIO()) as mock_stdout:
                sys.argv = ["cmd"]
                soyaml.main()
                sysmock.assert_called_once_with(1)
                self.assertIn(mock_stdout.getvalue(), "Usage:")

    def test_main_help(self):
        with patch('sys.exit', new=MagicMock()) as sysmock:
            with patch('sys.stderr', new=StringIO()) as mock_stdout:
                sys.argv = ["cmd", "help"]
                soyaml.main()
                sysmock.assert_called()
                self.assertIn(mock_stdout.getvalue(), "Usage:")

    def test_remove(self):
        filename = "/tmp/so-yaml_test-remove.yaml"
        file = open(filename, "w")
        file.write("{key1: { child1: 123, child2: abc }, key2: false}")
        file.close()

        soyaml.remove([filename, "key1"])

        file = open(filename, "r")
        actual = file.read()
        file.close()

        expected = "key2: false\n"
        self.assertEqual(actual, expected)

    def test_remove_missing_args(self):
        with patch('sys.exit', new=MagicMock()) as sysmock:
            with patch('sys.stderr', new=StringIO()) as mock_stdout:
                filename = "/tmp/so-yaml_test-remove.yaml"
                file = open(filename, "w")
                file.write("{key1: { child1: 123, child2: abc }, key2: false}")
                file.close()

                soyaml.remove([filename])

                file = open(filename, "r")
                actual = file.read()
                file.close()

                expected = "{key1: { child1: 123, child2: abc }, key2: false}"
                self.assertEqual(actual, expected)
                sysmock.assert_called_once_with(1)
                self.assertIn(mock_stdout.getvalue(), "Missing filename or key arg\n")