tests/test_monitoring.py

"""
Monitoring Feature Tests
모니터링 기능 테스트

@changelog
- v1.0.0 (2026-01-25): 초기 구현
  - 메트릭 엔드포인트 테스트
  - 요청 추적 테스트
  - 에러 추적 테스트
"""
import pytest
import time
import asyncio
from unittest.mock import MagicMock, patch
from fastapi import FastAPI, HTTPException
from fastapi.testclient import TestClient
from starlette.middleware.base import BaseHTTPMiddleware


# ==============================================================================
# MetricsCollector Tests
# ==============================================================================

class TestMetricsCollector:
    """메트릭 수집기 테스트"""

    def test_singleton_pattern(self):
        """싱글톤 패턴 검증"""
        from routers.health import MetricsCollector

        collector1 = MetricsCollector()
        collector2 = MetricsCollector()

        assert collector1 is collector2

    def test_record_request(self):
        """요청 메트릭 기록 테스트"""
        from routers.health import MetricsCollector

        collector = MetricsCollector()
        initial_count = collector.total_requests

        collector.record_request(
            method="GET",
            path="/test",
            status_code=200,
            duration_ms=50.0,
            request_id="test-123"
        )

        assert collector.total_requests == initial_count + 1
        assert 200 in collector.status_code_counts

    def test_record_error(self):
        """에러 기록 테스트"""
        from routers.health import MetricsCollector

        collector = MetricsCollector()

        collector.record_error(
            request_id="test-error-123",
            endpoint="/test",
            method="POST",
            status_code=500,
            error_type="ValueError",
            error_message="Test error",
            stack_trace="at test.py:10"
        )

        recent_errors = collector.get_recent_errors(limit=10)
        assert len(recent_errors) > 0

        # 가장 최근 에러 확인
        latest_error = recent_errors[0]
        assert latest_error["request_id"] == "test-error-123"
        assert latest_error["error_type"] == "ValueError"

    def test_error_rate_calculation(self):
        """에러율 계산 테스트"""
        from routers.health import MetricsCollector

        collector = MetricsCollector()

        # 테스트용 요청 기록 (성공 8개, 에러 2개)
        for i in range(8):
            collector.record_request(
                method="GET",
                path=f"/test/{i}",
                status_code=200,
                duration_ms=10.0
            )

        for i in range(2):
            collector.record_request(
                method="GET",
                path=f"/error/{i}",
                status_code=500,
                duration_ms=10.0
            )

        # 에러율 확인 (전체 기준이므로 초기값에 따라 다름)
        summary = collector.get_metrics_summary()
        assert "error_rate_percent" in summary
        assert summary["total_errors"] >= 2

    def test_prometheus_metrics_format(self):
        """Prometheus 메트릭 포맷 테스트"""
        from routers.health import MetricsCollector

        collector = MetricsCollector()
        prometheus_output = collector.get_prometheus_metrics()

        # Prometheus 포맷 검증
        assert "# HELP" in prometheus_output
        assert "# TYPE" in prometheus_output
        assert "aewol_replay_requests_total" in prometheus_output
        assert "aewol_replay_errors_total" in prometheus_output
        assert "aewol_replay_response_time_ms" in prometheus_output

    def test_active_connections_tracking(self):
        """활성 연결 수 추적 테스트"""
        from routers.health import MetricsCollector

        collector = MetricsCollector()
        initial = collector.active_connections

        collector.increment_active_connections()
        assert collector.active_connections == initial + 1

        collector.decrement_active_connections()
        assert collector.active_connections == initial

        # 음수가 되지 않는지 확인
        for _ in range(10):
            collector.decrement_active_connections()
        assert collector.active_connections >= 0


# ==============================================================================
# Request Tracking Tests
# ==============================================================================

class TestRequestTracking:
    """요청 추적 테스트"""

    def test_get_request_id(self):
        """요청 ID 조회 테스트"""
        from middleware.request_tracking import get_request_id, request_id_var

        # 초기값은 None
        assert get_request_id() is None

        # 설정 후 조회
        request_id_var.set("test-request-id")
        assert get_request_id() == "test-request-id"

        # 정리
        request_id_var.set(None)

    def test_get_request_context(self):
        """요청 컨텍스트 조회 테스트"""
        from middleware.request_tracking import get_request_context, request_context_var

        # 초기값은 빈 딕셔너리
        assert get_request_context() == {}

        # 설정 후 조회
        test_context = {"method": "GET", "path": "/test"}
        request_context_var.set(test_context)
        assert get_request_context() == test_context

        # 정리
        request_context_var.set({})


# ==============================================================================
# JSONFormatter Tests
# ==============================================================================

class TestJSONFormatter:
    """JSON 포매터 테스트"""

    def test_basic_format(self):
        """기본 포맷 테스트"""
        import json
        import logging
        from utils.logging_config import JSONFormatter

        formatter = JSONFormatter(include_request_id=False)
        record = logging.LogRecord(
            name="test",
            level=logging.INFO,
            pathname="test.py",
            lineno=10,
            msg="Test message",
            args=(),
            exc_info=None
        )

        output = formatter.format(record)
        parsed = json.loads(output)

        assert parsed["level"] == "INFO"
        assert parsed["message"] == "Test message"
        assert parsed["logger"] == "test"
        assert "timestamp" in parsed

    def test_exception_format(self):
        """예외 포맷 테스트"""
        import json
        import logging
        import sys
        from utils.logging_config import JSONFormatter

        formatter = JSONFormatter()

        try:
            raise ValueError("Test error")
        except ValueError:
            exc_info = sys.exc_info()

        record = logging.LogRecord(
            name="test",
            level=logging.ERROR,
            pathname="test.py",
            lineno=10,
            msg="Error occurred",
            args=(),
            exc_info=exc_info
        )

        output = formatter.format(record)
        parsed = json.loads(output)

        assert "exception" in parsed
        assert parsed["exception"]["type"] == "ValueError"
        assert "Test error" in parsed["exception"]["message"]
        assert "traceback" in parsed["exception"]


# ==============================================================================
# Error Tracking Tests
# ==============================================================================

class TestErrorTracking:
    """에러 추적 테스트"""

    def test_log_error_with_context(self):
        """컨텍스트 포함 에러 로깅 테스트"""
        import logging
        from utils.logging_config import log_error_with_context

        logger = logging.getLogger("test_error")

        try:
            raise ValueError("Test error for logging")
        except ValueError as e:
            # 로깅이 에러 없이 수행되는지 확인
            log_error_with_context(
                logger,
                e,
                endpoint="/api/test",
                method="POST",
                user_id="user-123",
                params={"key": "value", "password": "secret"}
            )

    def test_error_tracker_context_manager(self):
        """ErrorTracker 컨텍스트 매니저 테스트"""
        import logging
        from utils.logging_config import ErrorTracker

        logger = logging.getLogger("test_tracker")

        # 에러 발생 시 로깅 후 재발생
        with pytest.raises(ValueError):
            with ErrorTracker(logger, endpoint="/test", reraise=True):
                raise ValueError("Test error")

        # 에러 억제
        with ErrorTracker(logger, endpoint="/test", reraise=False):
            raise ValueError("Suppressed error")
        # 여기 도달하면 에러가 억제된 것


# ==============================================================================
# Integration Tests (API Endpoints)
# ==============================================================================

class TestMetricsEndpoints:
    """메트릭 API 엔드포인트 테스트"""

    @pytest.fixture
    def client(self):
        """테스트 클라이언트 생성"""
        from server import app
        return TestClient(app)

    def test_health_metrics_endpoint(self, client):
        """GET /health/metrics 테스트"""
        response = client.get("/health/metrics")

        assert response.status_code == 200

        data = response.json()
        assert "uptime_seconds" in data
        assert "total_requests" in data
        assert "total_errors" in data
        assert "error_rate_percent" in data
        assert "avg_response_time_ms" in data
        assert "active_connections" in data
        assert "status_code_distribution" in data
        assert "top_endpoints" in data

    def test_prometheus_metrics_endpoint(self, client):
        """GET /health/metrics/prometheus 테스트"""
        response = client.get("/health/metrics/prometheus")

        assert response.status_code == 200
        assert response.headers["content-type"].startswith("text/plain")

        content = response.text
        assert "aewol_replay_requests_total" in content
        assert "# HELP" in content
        assert "# TYPE" in content

    def test_health_errors_endpoint(self, client):
        """GET /health/errors 테스트"""
        response = client.get("/health/errors")

        assert response.status_code == 200

        data = response.json()
        assert "count" in data
        assert "errors" in data
        assert isinstance(data["errors"], list)

    def test_health_errors_limit(self, client):
        """GET /health/errors?limit=10 테스트"""
        response = client.get("/health/errors?limit=10")

        assert response.status_code == 200

        data = response.json()
        assert data["count"] <= 10

    def test_request_id_header(self, client):
        """X-Request-ID 헤더 테스트"""
        # 요청 ID 없이 요청
        response = client.get("/health")

        assert response.status_code == 200
        assert "X-Request-ID" in response.headers

        # 요청 ID 지정하여 요청
        custom_id = "custom-test-id-12345"
        response = client.get("/health", headers={"X-Request-ID": custom_id})

        assert response.status_code == 200
        assert response.headers["X-Request-ID"] == custom_id

    def test_response_time_header(self, client):
        """X-Response-Time 헤더 테스트"""
        response = client.get("/health")

        assert response.status_code == 200
        assert "X-Response-Time" in response.headers
        assert "ms" in response.headers["X-Response-Time"]


# ==============================================================================
# Run Tests
# ==============================================================================

if __name__ == "__main__":
    pytest.main([__file__, "-v"])