"""
Tests for SessionID Pool Service (T-021, T-022)
"""

import pytest
from unittest.mock import AsyncMock, patch, MagicMock
import httpx

from app.services.session_pool import (
    SessionPool,
    session_pool,
    get_session_with_retry,
)


class TestSessionPool:
    """Tests for SessionPool class."""

    async def test_refresh_success(self):
        """Test successful session pool refresh."""
        pool = SessionPool()

        mock_response = MagicMock()
        mock_response.status_code = 200
        mock_response.json.return_value = {
            "data": [
                {"sessionid": "session_001", "user": "test1"},
                {"sessionid": "session_002", "user": "test2"},
                {"sessionid": "session_003", "user": "test3"},
            ]
        }

        mock_client = AsyncMock()
        mock_client.get.return_value = mock_response
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            result = await pool.refresh()

            assert result is True
            assert pool.size == 3
            assert not pool.is_empty

    async def test_refresh_empty_data(self):
        """Test refresh with empty data array."""
        pool = SessionPool()

        mock_response = MagicMock()
        mock_response.status_code = 200
        mock_response.json.return_value = {"data": []}

        mock_client = AsyncMock()
        mock_client.get.return_value = mock_response
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            result = await pool.refresh()

            assert result is False
            assert pool.size == 0

    async def test_refresh_api_error(self):
        """Test refresh with API error."""
        pool = SessionPool()

        mock_response = MagicMock()
        mock_response.status_code = 500

        mock_client = AsyncMock()
        mock_client.get.return_value = mock_response
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            result = await pool.refresh()

            assert result is False

    async def test_refresh_timeout(self):
        """Test refresh with timeout."""
        pool = SessionPool()

        mock_client = AsyncMock()
        mock_client.get.side_effect = httpx.TimeoutException("Timeout")
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            result = await pool.refresh()

            assert result is False

    async def test_refresh_request_error(self):
        """Test refresh with request error."""
        pool = SessionPool()

        mock_client = AsyncMock()
        mock_client.get.side_effect = httpx.RequestError("Connection failed")
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            result = await pool.refresh()

            assert result is False

    async def test_refresh_unexpected_error(self):
        """Test refresh with unexpected error."""
        pool = SessionPool()

        mock_client = AsyncMock()
        mock_client.get.side_effect = ValueError("Unexpected")
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            result = await pool.refresh()

            assert result is False

    async def test_refresh_with_auth_header(self):
        """Test that refresh includes Authorization header."""
        pool = SessionPool()

        mock_response = MagicMock()
        mock_response.status_code = 200
        mock_response.json.return_value = {"data": [{"sessionid": "test"}]}

        mock_client = AsyncMock()
        mock_client.get.return_value = mock_response
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            with patch("app.services.session_pool.settings") as mock_settings:
                mock_settings.YUNTU_API_TOKEN = "test_token"
                mock_settings.YUNTU_API_TIMEOUT = 10.0
                mock_settings.BRAND_API_BASE_URL = "https://api.test.com"

                await pool.refresh()

                mock_client.get.assert_called_once()
                call_args = mock_client.get.call_args
                assert "headers" in call_args.kwargs
                assert call_args.kwargs["headers"]["Authorization"] == "Bearer test_token"

    def test_get_random_from_pool(self):
        """Test getting random session from pool."""
        pool = SessionPool()
        pool._sessions = ["session_1", "session_2", "session_3"]

        session = pool.get_random()

        assert session in pool._sessions

    def test_get_random_from_empty_pool(self):
        """Test getting random session from empty pool."""
        pool = SessionPool()

        session = pool.get_random()

        assert session is None

    def test_remove_session(self):
        """Test removing a session from pool."""
        pool = SessionPool()
        pool._sessions = ["session_1", "session_2", "session_3"]

        pool.remove("session_2")

        assert pool.size == 2
        assert "session_2" not in pool._sessions

    def test_remove_nonexistent_session(self):
        """Test removing a session that doesn't exist."""
        pool = SessionPool()
        pool._sessions = ["session_1"]

        # Should not raise
        pool.remove("nonexistent")

        assert pool.size == 1

    def test_size_property(self):
        """Test size property."""
        pool = SessionPool()
        assert pool.size == 0

        pool._sessions = ["a", "b"]
        assert pool.size == 2

    def test_is_empty_property(self):
        """Test is_empty property."""
        pool = SessionPool()
        assert pool.is_empty is True

        pool._sessions = ["a"]
        assert pool.is_empty is False


class TestGetSessionWithRetry:
    """Tests for get_session_with_retry function (T-022)."""

    async def test_get_session_success(self):
        """Test successful session retrieval."""
        with patch.object(session_pool, "_sessions", ["session_1", "session_2"]):
            result = await get_session_with_retry()

            assert result in ["session_1", "session_2"]

    async def test_get_session_refresh_on_empty(self):
        """Test that pool is refreshed when empty."""
        with patch.object(session_pool, "_sessions", []):
            with patch.object(session_pool, "refresh") as mock_refresh:
                mock_refresh.return_value = True

                # After refresh, pool should have sessions
                async def refresh_side_effect():
                    session_pool._sessions.append("new_session")
                    return True

                mock_refresh.side_effect = refresh_side_effect

                result = await get_session_with_retry()

                assert mock_refresh.called
                assert result == "new_session"

    async def test_get_session_retry_on_refresh_failure(self):
        """Test retry behavior when refresh fails."""
        original_sessions = session_pool._sessions.copy()

        try:
            session_pool._sessions = []

            with patch.object(session_pool, "refresh") as mock_refresh:
                mock_refresh.return_value = False

                result = await get_session_with_retry(max_retries=3)

                assert result is None
                assert mock_refresh.call_count == 3
        finally:
            session_pool._sessions = original_sessions

    async def test_get_session_max_retries(self):
        """Test max retries limit."""
        original_sessions = session_pool._sessions.copy()

        try:
            session_pool._sessions = []

            with patch.object(session_pool, "refresh") as mock_refresh:
                mock_refresh.return_value = False

                result = await get_session_with_retry(max_retries=5)

                assert result is None
                assert mock_refresh.call_count == 5
        finally:
            session_pool._sessions = original_sessions


class TestSessionPoolIntegration:
    """Integration tests for session pool."""

    async def test_refresh_filters_invalid_items(self):
        """Test that refresh filters out invalid items."""
        pool = SessionPool()

        mock_response = MagicMock()
        mock_response.status_code = 200
        mock_response.json.return_value = {
            "data": [
                {"sessionid": "valid_session"},
                {"no_sessionid": "missing"},
                None,
                {"sessionid": ""},  # Empty string should be filtered
                {"sessionid": "another_valid"},
            ]
        }

        mock_client = AsyncMock()
        mock_client.get.return_value = mock_response
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            result = await pool.refresh()

            assert result is True
            assert pool.size == 2
            assert "valid_session" in pool._sessions
            assert "another_valid" in pool._sessions

    async def test_refresh_handles_non_dict_data(self):
        """Test refresh with non-dict response."""
        pool = SessionPool()

        mock_response = MagicMock()
        mock_response.status_code = 200
        mock_response.json.return_value = ["not", "a", "dict"]

        mock_client = AsyncMock()
        mock_client.get.return_value = mock_response
        mock_client.__aenter__.return_value = mock_client
        mock_client.__aexit__.return_value = None

        with patch("httpx.AsyncClient", return_value=mock_client):
            result = await pool.refresh()

            assert result is False