"""Regression coverage for clients disconnecting while responses are sent."""

from email.message import Message
import errno
import io
from pathlib import Path
import time
import unittest
from unittest.mock import Mock, patch

from primethai.auth import AuthConfig
from primethai.webui import _handler_factory


class DashboardDisconnectTests(unittest.TestCase):
    def make_handler(self, writer):
        handler_type = _handler_factory(
            (), Path("reports"), "2026-01-01", 10_000,
            AuthConfig("test", "test", b"test-secret"),
        )
        handler = handler_type.__new__(handler_type)
        handler.client_address = ("127.0.0.1", 12345)
        handler.command = "GET"
        handler.path = "/api/portfolio"
        handler.requestline = "GET /api/portfolio HTTP/1.1"
        handler.request_version = "HTTP/1.1"
        handler.headers = Message()
        handler.wfile = writer
        handler.close_connection = False
        handler._request_started_at = time.perf_counter()
        handler._authenticated = Mock(return_value=True)
        handler.log_message = Mock()
        handler._request_log = Mock()
        handler.send_response = Mock(wraps=handler.send_response)
        return handler

    def test_portfolio_disconnect_does_not_attempt_a_second_response(self):
        for error_type in (BrokenPipeError, ConnectionResetError, ConnectionAbortedError):
            for failing_write in (1, 2):  # Header flush or response body.
                with self.subTest(error=error_type, failing_write=failing_write):
                    writer = Mock()
                    writer.write.side_effect = (
                        [error_type(errno.EPIPE, "connection closed")]
                        if failing_write == 1
                        else [100, error_type(errno.ECONNRESET, "connection closed")]
                    )
                    handler = self.make_handler(writer)
                    with patch("primethai.webui._portfolio_data", return_value={"cash": 100}):
                        handler.do_GET()
                    handler.send_response.assert_called_once_with(200)
                    self.assertTrue(handler.close_connection)
                    self.assertEqual(handler._request_log.call_args.args, ("client_disconnected",))

    def test_redirect_handles_closed_connection(self):
        writer = Mock()
        writer.write.side_effect = BrokenPipeError(errno.EPIPE, "connection closed")
        handler = self.make_handler(writer)
        handler._redirect("/login")
        handler.send_response.assert_called_once_with(303)
        self.assertTrue(handler.close_connection)

    def test_success_and_actual_portfolio_failure_remain_distinct(self):
        for failed in (False, True):
            with self.subTest(failed=failed):
                handler = self.make_handler(io.BytesIO())
                with patch("primethai.webui._portfolio_data", return_value={"cash": 100},
                           side_effect=ValueError("invalid portfolio") if failed else None):
                    handler.do_GET()
                handler.send_response.assert_called_once_with(500 if failed else 200)
                response = handler.wfile.getvalue()
                self.assertIn(b"invalid portfolio" if failed else b'"cash": 100', response)
                self.assertFalse(handler.close_connection)
                if failed:
                    self.assertEqual(handler._request_log.call_args.args, ("portfolio_failed",))


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