import pytest
import threading
from ea_chatbot.utils.vfs import safe_vfs_copy

def test_safe_vfs_copy_success():
    """Test standard success case."""
    vfs = {
        "test.csv": {"content": "data", "metadata": {"type": "csv"}},
        "num": 42
    }
    copied = safe_vfs_copy(vfs)
    assert copied == vfs
    assert copied is not vfs
    assert copied["test.csv"] is not vfs["test.csv"]

def test_safe_vfs_copy_handles_non_copyable():
    """Test replacing uncopyable objects with error placeholders."""
    # A threading.Lock is famously uncopyable
    lock = threading.Lock()
    
    vfs = {
        "safe_file": "important data",
        "unsafe_lock": lock
    }
    
    copied = safe_vfs_copy(vfs)
    
    # Safe one remains
    assert copied["safe_file"] == "important data"
    
    # Unsafe one is REPLACED with an error dict
    assert isinstance(copied["unsafe_lock"], dict)
    assert "content" in copied["unsafe_lock"]
    assert "ERROR" in copied["unsafe_lock"]["content"]
    assert copied["unsafe_lock"]["metadata"]["type"] == "error"
    assert "lock" in str(copied["unsafe_lock"]["metadata"]["error"]).lower()
    
    # Original is unchanged (it was a lock)
    assert vfs["unsafe_lock"] is lock

def test_safe_vfs_copy_preserves_nested_copyable():
    """Test deepcopy still works for complex but copyable objects."""
    vfs = {
        "data": {"a": [1, 2, 3], "b": {"c": True}}
    }
    copied = safe_vfs_copy(vfs)
    assert copied["data"]["a"] == [1, 2, 3]
    assert copied["data"]["a"] is not vfs["data"]["a"]