"""Projector view (public read-only):
  - snapshot endpoint returns the expected shape
  - leaderboard never carries student_ids (privacy)
  - WS client receives a projector_state message on connect
  - state changes (open question, submit, close) push fresh snapshots
"""

from __future__ import annotations

import pytest
from starlette.websockets import WebSocketDisconnect

from conftest import admin_login, join_student


def test_projector_snapshot_includes_required_fields(client, sid):
    join_student(client, sid, "s1", "Alice")
    response = client.get(f"/api/session/{sid}/projector")
    assert response.status_code == 200
    body = response.json()
    assert body["type"] == "projector_state"
    assert body["state"] == "lobby"
    assert body["sid"] == sid
    assert body["participant_count"] == 1
    assert "qr_url" in body and body["qr_url"].startswith("data:image/svg+xml")
    assert "join_url" in body
    assert body["pool_meta"]["question_count"] >= 1
    assert "score_distribution" in body
    assert "leaderboard" in body


def test_projector_leaderboard_redacts_student_ids(client, sid):
    """The /admin board carries student_ids; the public projector
    leaderboard must NOT — student_id namespace is private."""
    join_student(client, sid, "s1", "Alice")
    join_student(client, sid, "s2", "Bob")
    rooms = client.app.state.rooms
    client.portal.call(rooms.open_question, sid, 0, 5)
    client.portal.call(rooms.submit_answer, sid, "s1", 0, "B")
    client.portal.call(rooms.close_question, sid)

    snapshot = client.get(f"/api/session/{sid}/projector").json()
    for row in snapshot["leaderboard"]:
        assert "student_id" not in row, "projector leaderboard leaks student_ids"


def test_projector_ws_pushes_snapshot_on_state_change(client, sid):
    join_student(client, sid, "s1", "Alice")
    admin_login(client)
    with client.websocket_connect(f"/ws/projector/{sid}") as ws:
        initial = ws.receive_json()
        assert initial["type"] == "projector_state"
        assert initial["state"] == "lobby"

        # Trigger a state change via the room manager directly.
        rooms = client.app.state.rooms
        client.portal.call(rooms.open_question, sid, 0, 5)
        push = ws.receive_json()
        assert push["type"] == "projector_state"
        assert push["state"] == "question_open"
        assert push["question"] is not None
        assert push["question"]["idx"] == 0


def test_projector_404_for_unknown_sid(client):
    assert client.get("/api/session/UNKNOWN/projector").status_code == 404
    with pytest.raises(WebSocketDisconnect) as exc:
        with client.websocket_connect("/ws/projector/UNKNOWN"):
            pass
    assert exc.value.code == 4001


def test_projector_page_redirects_when_no_sid(client, sid):
    response = client.get("/projector/", follow_redirects=False)
    assert response.status_code == 302
    assert response.headers["location"].endswith(f"sid={sid}")