"""
Unit tests for the SharedMemory class.
"""

import pytest
from datetime import datetime
import threading
import time

from coda.core.memory import SharedMemory, MemoryEntry


class TestSharedMemory:
    """Tests for the SharedMemory class."""
    
    @pytest.fixture
    def memory(self):
        """Create a fresh SharedMemory instance."""
        return SharedMemory()
    
    def test_store_and_retrieve(self, memory):
        """Test basic store and retrieve operations."""
        memory.store(
            key="test_key",
            value={"data": "value"},
            agent_name="TestAgent"
        )
        
        result = memory.retrieve("test_key")
        
        assert result == {"data": "value"}
    
    def test_retrieve_nonexistent(self, memory):
        """Test retrieving a non-existent key."""
        result = memory.retrieve("nonexistent")
        
        assert result is None
    
    def test_retrieve_entry(self, memory):
        """Test retrieving the full entry with metadata."""
        memory.store(
            key="test_key",
            value="test_value",
            agent_name="TestAgent",
            metadata={"extra": "info"}
        )
        
        entry = memory.retrieve_entry("test_key")
        
        assert entry is not None
        assert entry.value == "test_value"
        assert entry.agent_name == "TestAgent"
        assert entry.metadata == {"extra": "info"}
        assert isinstance(entry.timestamp, datetime)
    
    def test_get_context(self, memory):
        """Test retrieving multiple keys as context."""
        memory.store("key1", "value1", "Agent1")
        memory.store("key2", "value2", "Agent2")
        memory.store("key3", "value3", "Agent3")
        
        context = memory.get_context(["key1", "key3", "nonexistent"])
        
        assert context == {"key1": "value1", "key3": "value3"}
    
    def test_get_all(self, memory):
        """Test retrieving all stored values."""
        memory.store("key1", "value1", "Agent")
        memory.store("key2", "value2", "Agent")
        
        all_data = memory.get_all()
        
        assert all_data == {"key1": "value1", "key2": "value2"}
    
    def test_overwrite_value(self, memory):
        """Test overwriting an existing value."""
        memory.store("key", "original", "Agent")
        memory.store("key", "updated", "Agent")
        
        assert memory.retrieve("key") == "updated"
    
    def test_history_tracking(self, memory):
        """Test that history is tracked for all operations."""
        memory.store("key1", "v1", "Agent1")
        memory.store("key2", "v2", "Agent2")
        memory.store("key1", "v1_updated", "Agent1")
        
        history = memory.get_history()
        
        assert len(history) == 3
        assert history[0].key == "key1"
        assert history[1].key == "key2"
        assert history[2].value == "v1_updated"
    
    def test_history_filter_by_agent(self, memory):
        """Test filtering history by agent name."""
        memory.store("k1", "v1", "Agent1")
        memory.store("k2", "v2", "Agent2")
        memory.store("k3", "v3", "Agent1")
        
        agent1_history = memory.get_history(agent_name="Agent1")
        
        assert len(agent1_history) == 2
        assert all(e.agent_name == "Agent1" for e in agent1_history)
    
    def test_has_key(self, memory):
        """Test key existence check."""
        memory.store("exists", "value", "Agent")
        
        assert memory.has_key("exists") is True
        assert memory.has_key("not_exists") is False
    
    def test_clear(self, memory):
        """Test clearing all data."""
        memory.store("k1", "v1", "Agent")
        memory.store("k2", "v2", "Agent")
        
        memory.clear()
        
        assert memory.retrieve("k1") is None
        assert memory.retrieve("k2") is None
        assert len(memory.get_history()) == 0
    
    def test_keys(self, memory):
        """Test getting all keys."""
        memory.store("a", 1, "Agent")
        memory.store("b", 2, "Agent")
        memory.store("c", 3, "Agent")
        
        keys = memory.keys()
        
        assert set(keys) == {"a", "b", "c"}
    
    def test_thread_safety(self, memory):
        """Test that operations are thread-safe."""
        results = []
        errors = []
        
        def writer(n):
            try:
                for i in range(100):
                    memory.store(f"key_{n}_{i}", i, f"Agent{n}")
            except Exception as e:
                errors.append(e)
        
        def reader():
            try:
                for _ in range(100):
                    memory.get_all()
                    memory.keys()
            except Exception as e:
                errors.append(e)
        
        threads = [
            threading.Thread(target=writer, args=(i,))
            for i in range(3)
        ]
        threads.append(threading.Thread(target=reader))
        
        for t in threads:
            t.start()
        for t in threads:
            t.join()
        
        assert len(errors) == 0