"""Tests for app.core.output_formatter.StreamFormatter."""

from __future__ import annotations

import pytest

from app.core.output_formatter import StreamFormatter
from app.schemas import WsFloatingDomain, WsStreamEnd, WsStreamStart, WsStreamText


async def _stream(*events: tuple[str, object]):
    for event in events:
        yield event


async def _collect(formatter: StreamFormatter, event_stream):
    frames = []
    async for frame in formatter.format(event_stream):
        frames.append(frame)
    return frames


@pytest.mark.asyncio
async def test_stream_formatter_text_stream() -> None:
    formatter = StreamFormatter(request_id="req-1")
    frames = await _collect(
        formatter,
        _stream(("token", "Hello"), ("token", " world")),
    )

    assert isinstance(frames[0], WsStreamStart)
    assert isinstance(frames[1], WsStreamText)
    assert frames[1].chunk == "Hello"
    assert isinstance(frames[2], WsStreamText)
    assert frames[2].chunk == " world"
    assert isinstance(frames[-1], WsStreamEnd)


@pytest.mark.asyncio
async def test_stream_formatter_floating_domain_first() -> None:
    formatter = StreamFormatter(request_id="req-2")
    frames = await _collect(
        formatter,
        _stream(
            (
                "floating_domain",
                {"type": "node", "id": "n-1", "section": None},
            ),
            ("token", "Summary"),
        ),
    )

    assert isinstance(frames[0], WsFloatingDomain)
    assert frames[0].domain.type == "node"
    assert frames[0].domain.id == "n-1"
    assert isinstance(frames[1], WsStreamStart)
    assert isinstance(frames[2], WsStreamText)
    assert frames[2].chunk == "Summary"
    assert isinstance(frames[-1], WsStreamEnd)


@pytest.mark.asyncio
async def test_stream_formatter_ignores_unknown_events() -> None:
    formatter = StreamFormatter(request_id="req-3")
    frames = await _collect(
        formatter,
        _stream(("tool_end", {"name": "x"}), ("token", "ok")),
    )

    text_frames = [f for f in frames if isinstance(f, WsStreamText)]
    assert len(text_frames) == 1
    assert text_frames[0].chunk == "ok"


@pytest.mark.asyncio
async def test_stream_formatter_empty_stream_still_brackets() -> None:
    formatter = StreamFormatter(request_id="req-4")
    frames = await _collect(formatter, _stream())

    assert len(frames) == 2
    assert isinstance(frames[0], WsStreamStart)
    assert isinstance(frames[1], WsStreamEnd)