"""Tests for trajectory_compressor AsyncOpenAI event loop binding.

The AsyncOpenAI client was created once at __init__ time and stored as an
instance attribute. When process_directory() calls asyncio.run() — which
creates and closes a fresh event loop — the client's internal httpx
transport remains bound to the now-closed loop. A second call to
process_directory() would fail with "Event loop is closed".

The fix creates the AsyncOpenAI client lazily via _get_async_client() so
each asyncio.run() gets a client bound to the current loop.
"""

import types
from unittest.mock import MagicMock, patch

import pytest


class TestAsyncClientLazyCreation:
    """trajectory_compressor.py — _get_async_client()"""

    def test_async_client_none_after_init(self):
        """async_client should be None after __init__ (not eagerly created)."""
        from trajectory_compressor import TrajectoryCompressor

        comp = TrajectoryCompressor.__new__(TrajectoryCompressor)
        comp.config = MagicMock()
        comp.config.base_url = "https://api.example.com/v1"
        comp.config.api_key_env = "TEST_API_KEY"
        comp._use_call_llm = False
        comp.async_client = None
        comp._async_client_api_key = "test-key"

        assert comp.async_client is None

    def test_get_async_client_creates_new_client(self):
        """_get_async_client() should create a fresh AsyncOpenAI instance."""
        from trajectory_compressor import TrajectoryCompressor

        comp = TrajectoryCompressor.__new__(TrajectoryCompressor)
        comp.config = MagicMock()
        comp.config.base_url = "https://api.example.com/v1"
        comp._async_client_api_key = "test-key"
        comp.async_client = None

        mock_async_openai = MagicMock()
        with patch("openai.AsyncOpenAI", mock_async_openai):
            client = comp._get_async_client()

        mock_async_openai.assert_called_once_with(
            api_key="test-key",
            base_url="https://api.example.com/v1",
        )
        assert comp.async_client is not None

    def test_get_async_client_creates_fresh_each_call(self):
        """Each call to _get_async_client() creates a NEW client instance,
        so it binds to the current event loop."""
        from trajectory_compressor import TrajectoryCompressor

        comp = TrajectoryCompressor.__new__(TrajectoryCompressor)
        comp.config = MagicMock()
        comp.config.base_url = "https://api.example.com/v1"
        comp._async_client_api_key = "test-key"
        comp.async_client = None

        call_count = 0
        instances = []

        def mock_constructor(**kwargs):
            nonlocal call_count
            call_count += 1
            instance = MagicMock()
            instances.append(instance)
            return instance

        with patch("openai.AsyncOpenAI", side_effect=mock_constructor):
            client1 = comp._get_async_client()
            client2 = comp._get_async_client()

        # Should have created two separate instances
        assert call_count == 2
        assert instances[0] is not instances[1]


class TestSourceLineVerification:
    """Verify the actual source has the lazy pattern applied."""

    @staticmethod
    def _read_file() -> str:
        import os
        base = os.path.dirname(os.path.dirname(__file__))
        with open(os.path.join(base, "trajectory_compressor.py")) as f:
            return f.read()

    def test_no_eager_async_openai_in_init(self):
        """__init__ should NOT create AsyncOpenAI eagerly."""
        src = self._read_file()
        # The old pattern: self.async_client = AsyncOpenAI(...) in _init_summarizer
        # should not exist — only self.async_client = None
        lines = src.split("\n")
        for i, line in enumerate(lines, 1):
            if "self.async_client = AsyncOpenAI(" in line and "_get_async_client" not in lines[max(0,i-3):i+1]:
                # Allow it inside _get_async_client method
                # Check if we're inside _get_async_client by looking at context
                context = "\n".join(lines[max(0,i-20):i+1])
                if "_get_async_client" not in context:
                    pytest.fail(
                        f"Line {i}: AsyncOpenAI created eagerly outside _get_async_client()"
                    )

    def test_get_async_client_method_exists(self):
        """_get_async_client method should exist."""
        src = self._read_file()
        assert "def _get_async_client(self)" in src
