# -*- coding: utf-8 -*-
"""
This program has been developed by students from the bachelor Computer Science at Utrecht
University within the Software Project course.
© Copyright Utrecht University (Department of Information and Computing Sciences)
"""

import struct
import mock
import pytest
import zmq

from robot_interface.endpoints.video_sender import VideoSender
from robot_interface.state import state
from robot_interface.core.config import settings


@pytest.fixture
def zmq_context():
    """Provide a ZMQ context."""
    yield zmq.Context()


def _patch_basics(mocker):
    """Common patches: prevent real threads, port binds, and state errors."""
    mocker.patch("robot_interface.endpoints.socket_base.zmq.Socket.bind")
    mocker.patch("robot_interface.endpoints.video_sender.threading.Thread")
    mocker.patch.object(state, "is_initialized", True)


def _patch_exit_event(mocker):
    """Make exit_event stop the loop after one iteration."""
    fake_event = mock.Mock()
    fake_event.is_set.side_effect = [False, True]
    mocker.patch.object(state, "exit_event", fake_event)


def test_no_qi_session(zmq_context, mocker):
    """Video loop should not start without a qi_session."""
    _patch_basics(mocker)
    mocker.patch.object(state, "qi_session", None)

    sender = VideoSender(zmq_context)
    sender.start_video_rcv()

    assert not hasattr(sender, "thread")


def test_video_streaming(zmq_context, mocker):
    """VideoSender should send retrieved image data."""
    _patch_basics(mocker)
    _patch_exit_event(mocker)

    # Pepper's image buffer lives at index 6
    mocker.patch.object(settings.video_config, "image_buffer", 6)

    test_width = 320
    test_height = 240
    mock_video_service = mock.Mock()
    mock_video_service.getImageRemote.return_value = [test_width, test_height, None, None, None, None, b"fake_img"]

    fake_session = mock.Mock()
    fake_session.service.return_value = mock_video_service
    mocker.patch.object(state, "qi_session", fake_session)

    mocker.patch.object(
        fake_session.service("ALVideoDevice"),
        "subscribeCamera",
        return_value="stream_name"
    )

    sender = VideoSender(zmq_context)
    send_socket = mock.Mock()
    sender.socket.send_multipart = send_socket

    sender.start_video_rcv()
    sender.video_rcv_loop(mock_video_service, "stream_name")

    send_socket.assert_called_with([
    struct.pack('<I', 320),
    struct.pack('<I', 240),
    b"fake_img"
])


def test_video_receive_error(zmq_context, mocker):
    """Errors retrieving images should not call send()."""
    _patch_basics(mocker)
    _patch_exit_event(mocker)

    mock_video_service = mock.Mock()
    mock_video_service.getImageRemote.side_effect = Exception("boom")

    fake_session = mock.Mock()
    fake_session.service.return_value = mock_video_service
    mocker.patch.object(state, "qi_session", fake_session)

    mocker.patch.object(
        fake_session.service("ALVideoDevice"),
        "subscribeCamera",
        return_value="stream_name"
    )

    sender = VideoSender(zmq_context)
    send_socket = mock.Mock()
    sender.socket.send_multipart = send_socket

    sender.start_video_rcv()
    sender.video_rcv_loop(mock_video_service, "stream_name")

    send_socket.assert_not_called()

def test_video_loop_keyboard_interrupt(zmq_context, mocker):
    """Video loop should handle KeyboardInterrupt gracefully and unsubscribe."""
    _patch_basics(mocker)
    _patch_exit_event(mocker)
    
    # We mock the video service to raise KeyboardInterrupt when accessed
    mock_video_service = mock.Mock()
    mock_video_service.getImageRemote.side_effect = KeyboardInterrupt
    
    # Mock logging to verify the specific interrupt message is logged
    mock_logger = mocker.patch("robot_interface.endpoints.video_sender.logging")

    sender = VideoSender(zmq_context)
    
    # Execute the loop
    sender.video_rcv_loop(mock_video_service, "stream_name")

    # Verify the 'finally' block executed (unsubscribe)
    mock_video_service.unsubscribe.assert_called_with("stream_name")
    mock_logger.info.assert_any_call("Unsubscribed from video stream.")