"""Tests for SSE switch progress feedback — Issue #5.

SSE events emitted during model switch, phase progression visible.
"""
import asyncio
import json
import pytest
from unittest.mock import patch
from httpx import Response, ASGITransport, AsyncClient

from main import app as router_app

SIDECAR_URL = "http://localhost:8081"
MAIN_PC_URL = "http://localhost:8080"
FALLBACK_URL = "http://localhost:9999"


def test_sse_format():
    """SSE events are properly formatted."""
    from main import _sse_format

    event = _sse_format("model_switching", {"phase": "stopping", "message": "Stopping..."})
    assert "event: model_switching" in event
    assert '"phase": "stopping"' in event
    assert '"message": "Stopping..."' in event


def test_sse_progress_stream_yields_events():
    """SSE progress stream yields events during switch."""
    from main import sse_progress_stream

    async def run_test():
        event = asyncio.Event()  # Not set — simulates ongoing switch
        events = []
        async for sse_chunk in sse_progress_stream(event):
            events.append(sse_chunk)
            # Stop after a few events to avoid long waits
            if len(events) >= 4:
                break

        assert len(events) >= 2
        # Verify events are SSE-formatted
        for sse in events:
            assert "event: model_switching" in sse

    asyncio.run(run_test())


def test_sse_progress_stream_completes_on_set():
    """SSE stream yields completion event when switch finishes."""
    from main import sse_progress_stream

    async def run_test():
        event = asyncio.Event()
        event.set()  # Already complete
        chunks = []
        async for sse_chunk in sse_progress_stream(event):
            chunks.append(sse_chunk)
            if len(chunks) >= 5:
                break

        assert len(chunks) >= 1
        # Should include completion event
        has_complete = any('"phase": "complete"' in c for c in chunks)
        assert has_complete

    asyncio.run(run_test())