"""
Tests for Message Bus

Tests cover:
- Message publishing and subscription
- Request-response pattern
- Message priority
- Local delivery (without Redis)
"""

import pytest
import asyncio
from datetime import datetime, timezone
from unittest.mock import AsyncMock, MagicMock

import sys
sys.path.insert(0, str(__file__).rsplit('/tests/', 1)[0])

from orchestrator.message_bus import (
    MessageBus,
    AgentMessage,
    MessagePriority,
    MessageType,
)


class TestAgentMessage:
    """Tests for AgentMessage dataclass"""

    def test_message_creation_defaults(self):
        """Message should have default values"""
        message = AgentMessage(
            sender="agent-1",
            receiver="agent-2",
            message_type="test",
            payload={"data": "value"}
        )

        assert message.sender == "agent-1"
        assert message.receiver == "agent-2"
        assert message.priority == MessagePriority.NORMAL
        assert message.correlation_id is not None
        assert message.timestamp is not None

    def test_message_with_priority(self):
        """Message should accept custom priority"""
        message = AgentMessage(
            sender="alert-agent",
            receiver="admin",
            message_type="critical_alert",
            payload={},
            priority=MessagePriority.CRITICAL
        )

        assert message.priority == MessagePriority.CRITICAL

    def test_message_serialization(self):
        """Message should serialize and deserialize correctly"""
        original = AgentMessage(
            sender="sender",
            receiver="receiver",
            message_type="test",
            payload={"key": "value"},
            priority=MessagePriority.HIGH
        )

        data = original.to_dict()
        restored = AgentMessage.from_dict(data)

        assert restored.sender == original.sender
        assert restored.receiver == original.receiver
        assert restored.message_type == original.message_type
        assert restored.payload == original.payload
        assert restored.priority == original.priority
        assert restored.correlation_id == original.correlation_id


class TestMessageBus:
    """Tests for MessageBus"""

    @pytest.fixture
    def bus(self):
        """Create a message bus without Redis"""
        return MessageBus(
            redis_client=None,
            db_pool=None,
            namespace="test"
        )

    @pytest.mark.asyncio
    async def test_start_stop(self, bus):
        """Bus should start and stop correctly"""
        await bus.start()
        assert bus._running is True

        await bus.stop()
        assert bus._running is False

    @pytest.mark.asyncio
    async def test_subscribe_unsubscribe(self, bus):
        """Should subscribe and unsubscribe handlers"""
        handler = AsyncMock(return_value=None)

        await bus.subscribe("agent-1", handler)
        assert "agent-1" in bus._handlers

        await bus.unsubscribe("agent-1")
        assert "agent-1" not in bus._handlers

    @pytest.mark.asyncio
    async def test_local_message_delivery(self, bus):
        """Messages should be delivered locally without Redis"""
        received = []

        async def handler(message):
            received.append(message)
            return None

        await bus.subscribe("agent-2", handler)

        message = AgentMessage(
            sender="agent-1",
            receiver="agent-2",
            message_type="test",
            payload={"data": "hello"}
        )

        await bus.publish(message)

        # Local delivery is synchronous
        assert len(received) == 1
        assert received[0].payload["data"] == "hello"

    @pytest.mark.asyncio
    async def test_request_response(self, bus):
        """Request should get response from handler"""
        async def handler(message):
            return {"result": "processed"}

        await bus.subscribe("responder", handler)

        message = AgentMessage(
            sender="requester",
            receiver="responder",
            message_type="request",
            payload={"query": "test"}
        )

        response = await bus.request(message, timeout=5.0)

        assert response["result"] == "processed"

    @pytest.mark.asyncio
    async def test_request_timeout(self, bus):
        """Request should timeout if no response"""
        async def slow_handler(message):
            await asyncio.sleep(10)
            return {"result": "too late"}

        await bus.subscribe("slow-agent", slow_handler)

        message = AgentMessage(
            sender="requester",
            receiver="slow-agent",
            message_type="request",
            payload={}
        )

        with pytest.raises(asyncio.TimeoutError):
            await bus.request(message, timeout=0.1)

    @pytest.mark.asyncio
    async def test_broadcast(self, bus):
        """Broadcast should reach all subscribers"""
        received_1 = []
        received_2 = []

        async def handler_1(message):
            received_1.append(message)
            return None

        async def handler_2(message):
            received_2.append(message)
            return None

        await bus.subscribe("agent-1", handler_1)
        await bus.subscribe("agent-2", handler_2)

        message = AgentMessage(
            sender="broadcaster",
            receiver="*",
            message_type="announcement",
            payload={"text": "Hello everyone"}
        )

        await bus.broadcast(message)

        assert len(received_1) == 1
        assert len(received_2) == 1

    def test_connected_property(self, bus):
        """Connected should reflect running state"""
        assert bus.connected is False

    def test_subscriber_count(self, bus):
        """Should track subscriber count"""
        assert bus.subscriber_count == 0


class TestMessagePriority:
    """Tests for MessagePriority enum"""

    def test_priority_ordering(self):
        """Priorities should have correct ordering"""
        assert MessagePriority.LOW.value < MessagePriority.NORMAL.value
        assert MessagePriority.NORMAL.value < MessagePriority.HIGH.value
        assert MessagePriority.HIGH.value < MessagePriority.CRITICAL.value

    def test_priority_values(self):
        """Priorities should have expected values"""
        assert MessagePriority.LOW.value == 0
        assert MessagePriority.NORMAL.value == 1
        assert MessagePriority.HIGH.value == 2
        assert MessagePriority.CRITICAL.value == 3