import io
import email
import unittest
from email.message import Message
from email.policy import default
from test.test_email import TestEmailBase


class TestCustomMessage(TestEmailBase):

    class MyMessage(Message):
        def __init__(self, policy):
            self.check_policy = policy
            super().__init__()

    MyPolicy = TestEmailBase.policy.clone(linesep='boo')

    def test_custom_message_gets_policy_if_possible_from_string(self):
        msg = email.message_from_string("Subject: bogus\n\nmsg\n",
                                        self.MyMessage,
                                        policy=self.MyPolicy)
        self.assertIsInstance(msg, self.MyMessage)
        self.assertIs(msg.check_policy, self.MyPolicy)

    def test_custom_message_gets_policy_if_possible_from_file(self):
        source_file = io.StringIO("Subject: bogus\n\nmsg\n")
        msg = email.message_from_file(source_file,
                                      self.MyMessage,
                                      policy=self.MyPolicy)
        self.assertIsInstance(msg, self.MyMessage)
        self.assertIs(msg.check_policy, self.MyPolicy)

    # XXX add tests for other functions that take Message arg.


class TestParserBase:

    def test_only_split_on_cr_lf(self):
        # The unicode line splitter splits on unicode linebreaks, which are
        # more numerous than allowed by the email RFCs; make sure we are only
        # splitting on those two.
        msg = self.parser(
            "Next-Line: not\x85broken\r\n"
            "Null: not\x00broken\r\n"
            "Vertical-Tab: not\vbroken\r\n"
            "Form-Feed: not\fbroken\r\n"
            "File-Separator: not\x1Cbroken\r\n"
            "Group-Separator: not\x1Dbroken\r\n"
            "Record-Separator: not\x1Ebroken\r\n"
            "Line-Separator: not\u2028broken\r\n"
            "Paragraph-Separator: not\u2029broken\r\n"
            "\r\n",
            policy=default,
        )
        self.assertEqual(msg.items(), [
            ("Next-Line", "not\x85broken"),
            ("Null", "not\x00broken"),
            ("Vertical-Tab", "not\vbroken"),
            ("Form-Feed", "not\fbroken"),
            ("File-Separator", "not\x1Cbroken"),
            ("Group-Separator", "not\x1Dbroken"),
            ("Record-Separator", "not\x1Ebroken"),
            ("Line-Separator", "not\u2028broken"),
            ("Paragraph-Separator", "not\u2029broken"),
        ])
        self.assertEqual(msg.get_payload(), "")

class TestParser(TestParserBase, TestEmailBase):
    parser = staticmethod(email.message_from_string)

class TestBytesParser(TestParserBase, TestEmailBase):
    def parser(self, s, *args, **kw):
        return email.message_from_bytes(s.encode(), *args, **kw)


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