"""Tests for the optional MJPEG web viewer (stdlib only -- no cv2 / hardware).

Binds an ephemeral localhost port, hits each route, and checks the framing.
"""

from __future__ import annotations

import time
import urllib.request

import pytest

from gowelcome.web import MjpegServer

# A minimal valid JPEG (SOI ... EOI) used as the stub frame.
_FAKE_JPEG = bytes.fromhex("ffd8ffe000104a46494600010100000100010000ffd9")


@pytest.fixture()
def server():
    srv = MjpegServer(lambda: _FAKE_JPEG, host="127.0.0.1", port=0, fps=30)
    srv.start()
    time.sleep(0.2)
    try:
        yield srv
    finally:
        srv.stop()


def _get(port: int, path: str, n: int | None = None):
    resp = urllib.request.urlopen(f"http://127.0.0.1:{port}{path}", timeout=3)
    return resp.status, resp.headers.get("Content-Type"), (resp.read(n) if n else resp.read())


def test_healthz(server):
    status, ctype, body = _get(server.port, "/healthz")
    assert status == 200
    assert body == b"ok"


def test_index_embeds_stream(server):
    status, ctype, body = _get(server.port, "/")
    assert status == 200
    assert "text/html" in ctype
    assert b"/stream.mjpg" in body


def test_snapshot_returns_jpeg(server):
    status, ctype, body = _get(server.port, "/snapshot.jpg")
    assert status == 200
    assert ctype == "image/jpeg"
    assert body[:2] == b"\xff\xd8"  # JPEG SOI


def test_stream_is_multipart_mjpeg(server):
    resp = urllib.request.urlopen(f"http://127.0.0.1:{server.port}/stream.mjpg", timeout=3)
    assert "multipart/x-mixed-replace" in resp.headers.get("Content-Type", "")
    chunk = resp.read(400)
    resp.close()
    assert b"--gowelcomeframe" in chunk
    assert b"image/jpeg" in chunk


def test_unknown_path_404(server):
    with pytest.raises(urllib.error.HTTPError) as exc:
        _get(server.port, "/nope")
    assert exc.value.code == 404


def test_stop_is_idempotent(server):
    server.stop()
    server.stop()  # must not raise