"""
Tests for error propagation chains.

Tests cover:
- Error propagation between components
- Concurrent request handling
"""

from unittest.mock import Mock
import threading
import time


class TestErrorPropagationChains:
    """Tests for error propagation between components."""

    def test_error_propagation_llm_to_service(self):
        """LLM errors propagate to service layer."""
        llm_error = ConnectionError("LLM service unavailable")

        service_error = None
        try:
            raise llm_error
        except ConnectionError as e:
            service_error = {
                "source": "llm",
                "message": str(e),
                "recoverable": True,
            }

        assert service_error["source"] == "llm"

    def test_error_propagation_search_to_service(self):
        """Search errors propagate to service layer."""
        search_error = TimeoutError("Search timeout")

        service_error = None
        try:
            raise search_error
        except TimeoutError as e:
            service_error = {
                "source": "search",
                "message": str(e),
                "recoverable": True,
            }

        assert service_error["source"] == "search"

    def test_error_propagation_database_to_service(self):
        """Database errors propagate to service layer."""
        db_error = Exception("Database connection failed")

        service_error = None
        try:
            raise db_error
        except Exception as e:
            service_error = {
                "source": "database",
                "message": str(e),
                "recoverable": False,
            }

        assert service_error["source"] == "database"
        assert not service_error["recoverable"]

    def test_error_propagation_queue_to_service(self):
        """Queue errors propagate to service layer."""
        queue_error = Exception("Queue processing failed")

        service_error = None
        try:
            raise queue_error
        except Exception as e:
            service_error = {
                "source": "queue",
                "message": str(e),
            }

        assert service_error["source"] == "queue"

    def test_error_propagation_socket_to_service(self):
        """Socket errors propagate to service layer."""
        socket_error = ConnectionError("Socket disconnected")

        service_error = None
        try:
            raise socket_error
        except ConnectionError as e:
            service_error = {
                "source": "socket",
                "message": str(e),
            }

        assert service_error["source"] == "socket"

    def test_error_propagation_file_to_service(self):
        """File system errors propagate to service layer."""
        file_error = IOError("File not found")

        service_error = None
        try:
            raise file_error
        except IOError as e:
            service_error = {
                "source": "filesystem",
                "message": str(e),
            }

        assert service_error["source"] == "filesystem"

    def test_error_propagation_settings_to_service(self):
        """Settings errors propagate to service layer."""
        settings_error = ValueError("Invalid setting value")

        service_error = None
        try:
            raise settings_error
        except ValueError as e:
            service_error = {
                "source": "settings",
                "message": str(e),
            }

        assert service_error["source"] == "settings"

    def test_error_propagation_cache_to_service(self):
        """Cache errors propagate to service layer."""
        cache_error = Exception("Cache miss")

        service_error = None
        try:
            raise cache_error
        except Exception as e:
            service_error = {
                "source": "cache",
                "message": str(e),
                "recoverable": True,
            }

        assert service_error["source"] == "cache"
        assert service_error["recoverable"]

    def test_error_propagation_nested_errors(self):
        """Nested errors preserve chain."""
        original_error = ConnectionError("Original error")

        try:
            try:
                raise original_error
            except ConnectionError as e:
                raise RuntimeError(f"Wrapped: {e}") from e
        except RuntimeError as e:
            error_chain = {
                "outer": str(e),
                "inner": str(e.__cause__),
            }

        assert "Wrapped" in error_chain["outer"]
        assert "Original" in error_chain["inner"]

    def test_error_propagation_error_transformation(self):
        """Errors are transformed for API response."""
        internal_error = Exception("Internal error details")

        def transform_error(error):
            return {
                "status": "error",
                "message": "An error occurred",
                "code": 500,
            }

        api_response = transform_error(internal_error)

        assert api_response["status"] == "error"
        assert "Internal" not in api_response["message"]

    def test_error_propagation_logging(self):
        """Errors are logged during propagation."""
        logged_errors = []

        def log_error(error, context):
            logged_errors.append(
                {
                    "error": str(error),
                    "context": context,
                }
            )

        try:
            raise ValueError("Test error")
        except ValueError as e:
            log_error(e, {"phase": "analysis"})

        assert len(logged_errors) == 1
        assert logged_errors[0]["context"]["phase"] == "analysis"

    def test_error_propagation_notification(self):
        """Errors trigger notifications."""
        notifications = []

        def notify_error(error, severity):
            notifications.append(
                {
                    "error": str(error),
                    "severity": severity,
                }
            )

        try:
            raise Exception("Critical error")
        except Exception as e:
            notify_error(e, "critical")

        assert len(notifications) == 1
        assert notifications[0]["severity"] == "critical"


class TestConcurrentRequestHandling:
    """Tests for concurrent request handling."""

    def test_concurrent_research_requests(self):
        """Concurrent research requests are handled."""
        results = {}
        lock = threading.Lock()

        def process_request(request_id):
            time.sleep(0.01)
            with lock:
                results[request_id] = {"status": "completed"}

        threads = [
            threading.Thread(target=process_request, args=(f"req_{i}",))
            for i in range(5)
        ]

        for t in threads:
            t.start()
        for t in threads:
            t.join()

        assert len(results) == 5

    def test_concurrent_settings_updates(self):
        """Concurrent settings updates are handled."""
        settings = {"value": 0}
        lock = threading.Lock()

        def update_setting(new_value):
            with lock:
                settings["value"] = new_value

        threads = [
            threading.Thread(target=update_setting, args=(i,))
            for i in range(10)
        ]

        for t in threads:
            t.start()
        for t in threads:
            t.join()

        # One of the values should win
        assert settings["value"] in range(10)

    def test_concurrent_database_access(self):
        """Concurrent database access is safe."""
        db = {}
        lock = threading.Lock()
        errors = []

        def db_operation(key, value):
            try:
                with lock:
                    db[key] = value
                    _ = db[key]
            except Exception as e:
                errors.append(e)

        threads = [
            threading.Thread(target=db_operation, args=(f"key_{i}", i))
            for i in range(10)
        ]

        for t in threads:
            t.start()
        for t in threads:
            t.join()

        assert len(errors) == 0
        assert len(db) == 10

    def test_concurrent_cache_access(self):
        """Concurrent cache access is safe."""
        cache = {}
        lock = threading.Lock()

        def cache_operation(key, value):
            with lock:
                if key not in cache:
                    cache[key] = value
                return cache.get(key)

        threads = [
            threading.Thread(target=cache_operation, args=("shared_key", i))
            for i in range(10)
        ]

        for t in threads:
            t.start()
        for t in threads:
            t.join()

        # First value should be preserved
        assert cache["shared_key"] in range(10)

    def test_concurrent_queue_operations(self):
        """Concurrent queue operations are safe."""
        import queue

        q = queue.Queue()
        results = []
        lock = threading.Lock()

        def producer(item):
            q.put(item)

        def consumer():
            while not q.empty():
                try:
                    item = q.get_nowait()
                    with lock:
                        results.append(item)
                except queue.Empty:
                    break

        # Add items
        for i in range(10):
            producer(i)

        # Consume concurrently
        threads = [threading.Thread(target=consumer) for _ in range(3)]
        for t in threads:
            t.start()
        for t in threads:
            t.join()

        assert len(results) == 10

    def test_concurrent_socket_emissions(self):
        """Concurrent socket emissions are handled."""
        emissions = []
        lock = threading.Lock()

        def emit(event, data):
            with lock:
                emissions.append({"event": event, "data": data})

        threads = [
            threading.Thread(target=emit, args=(f"event_{i}", {"id": i}))
            for i in range(10)
        ]

        for t in threads:
            t.start()
        for t in threads:
            t.join()

        assert len(emissions) == 10

    def test_concurrent_resource_cleanup(self):
        """Concurrent resource cleanup is safe."""
        resources = {f"resource_{i}": Mock() for i in range(5)}
        cleaned = []
        lock = threading.Lock()

        def cleanup(resource_id):
            with lock:
                if resource_id in resources:
                    del resources[resource_id]
                    cleaned.append(resource_id)

        threads = [
            threading.Thread(target=cleanup, args=(f"resource_{i}",))
            for i in range(5)
        ]

        for t in threads:
            t.start()
        for t in threads:
            t.join()

        assert len(cleaned) == 5
        assert len(resources) == 0

    def test_concurrent_error_handling(self):
        """Concurrent error handling is safe."""
        errors = []
        lock = threading.Lock()

        def operation_with_error(op_id):
            try:
                if op_id % 2 == 0:
                    raise ValueError(f"Error in op {op_id}")
            except ValueError as e:
                with lock:
                    errors.append(str(e))

        threads = [
            threading.Thread(target=operation_with_error, args=(i,))
            for i in range(10)
        ]

        for t in threads:
            t.start()
        for t in threads:
            t.join()

        assert len(errors) == 5  # Even numbers cause errors


class TestErrorRecovery:
    """Tests for error recovery mechanisms."""

    def test_retry_with_backoff(self):
        """Retry with exponential backoff works."""
        attempts = 0
        max_attempts = 3
        success = False

        while attempts < max_attempts and not success:
            try:
                if attempts < 2:
                    raise ConnectionError("Temporary failure")
                success = True
            except ConnectionError:
                attempts += 1
                # Would sleep with backoff in real code

        assert success
        assert attempts == 2

    def test_circuit_breaker_pattern(self):
        """Circuit breaker prevents repeated failures."""
        failures = 0
        failure_threshold = 3
        circuit_open = False

        def call_service():
            nonlocal failures, circuit_open
            if circuit_open:
                raise Exception("Circuit open")
            try:
                raise Exception("Service failed")
            except Exception:
                failures += 1
                if failures >= failure_threshold:
                    circuit_open = True
                raise

        for _ in range(5):
            try:
                call_service()
            except Exception:
                pass

        assert circuit_open
        assert failures == 3

    def test_fallback_on_error(self):
        """Fallback is used on error."""

        def primary_operation():
            raise Exception("Primary failed")

        def fallback_operation():
            return "fallback_result"

        try:
            result = primary_operation()
        except Exception:
            result = fallback_operation()

        assert result == "fallback_result"

    def test_partial_result_preservation(self):
        """Partial results are preserved on error."""
        results = []

        for i in range(5):
            try:
                if i == 3:
                    raise Exception("Failed at step 3")
                results.append(f"result_{i}")
            except Exception:
                break

        assert len(results) == 3
        assert results[-1] == "result_2"

    def test_graceful_degradation(self):
        """System degrades gracefully on partial failure."""
        services = {
            "primary": {"available": False},
            "secondary": {"available": True},
            "tertiary": {"available": True},
        }

        def get_available_service():
            for name, service in services.items():
                if service["available"]:
                    return name
            return None

        service = get_available_service()

        assert service == "secondary"


class TestErrorContextPreservation:
    """Tests for error context preservation."""

    def test_error_context_preserved(self):
        """Error context is preserved through layers."""

        def inner_operation():
            raise ValueError("Inner error")

        def outer_operation():
            try:
                inner_operation()
            except ValueError as e:
                raise RuntimeError("Outer error") from e

        context = None
        try:
            outer_operation()
        except RuntimeError as e:
            context = {
                "outer": str(e),
                "inner": str(e.__cause__),
            }

        assert "Outer" in context["outer"]
        assert "Inner" in context["inner"]

    def test_error_metadata_attached(self):
        """Error metadata is attached."""

        class ErrorWithMetadata(Exception):
            def __init__(self, message, metadata):
                super().__init__(message)
                self.metadata = metadata

        try:
            raise ErrorWithMetadata(
                "Error occurred", {"phase": "analysis", "query": "test"}
            )
        except ErrorWithMetadata as e:
            metadata = e.metadata

        assert metadata["phase"] == "analysis"

    def test_error_stack_trace_captured(self):
        """Stack trace is captured."""
        import traceback

        captured_trace = None
        try:
            raise Exception("Test error")
        except Exception:
            captured_trace = traceback.format_exc()

        assert "Test error" in captured_trace
        assert "Traceback" in captured_trace
