"""Tests for tools/code_execution_tool.py - Security-critical module.

This module executes arbitrary code and requires comprehensive security testing.
"""

import pytest
from unittest.mock import patch, MagicMock
from types import SimpleNamespace

# Import will fail if module doesn't exist - that's expected
try:
    from tools.code_execution_tool import (
        execute_code,
        validate_code_safety,
        CodeExecutionError,
        ResourceLimitExceeded,
    )
    HAS_MODULE = True
except ImportError:
    HAS_MODULE = False


pytestmark = [
    pytest.mark.skipif(not HAS_MODULE, reason="code_execution_tool module not found"),
    pytest.mark.security,  # Mark as security test
]


class TestValidateCodeSafety:
    """Tests for code safety validation."""

    def test_blocks_dangerous_imports(self):
        """Should block imports of dangerous modules."""
        dangerous_code = """
import os
os.system('rm -rf /')
"""
        with pytest.raises(CodeExecutionError) as exc_info:
            validate_code_safety(dangerous_code)
        assert "dangerous import" in str(exc_info.value).lower()

    def test_blocks_subprocess(self):
        """Should block subprocess module usage."""
        code = """
import subprocess
subprocess.run(['ls', '-la'])
"""
        with pytest.raises(CodeExecutionError):
            validate_code_safety(code)

    def test_blocks_compile_eval(self):
        """Should block compile() and eval() usage."""
        code = "eval('__import__(\"os\").system(\"ls\")')"
        with pytest.raises(CodeExecutionError):
            validate_code_safety(code)

    def test_blocks_file_operations(self):
        """Should block direct file operations."""
        code = """
with open('/etc/passwd', 'r') as f:
    data = f.read()
"""
        with pytest.raises(CodeExecutionError):
            validate_code_safety(code)

    def test_allows_safe_code(self):
        """Should allow safe code execution."""
        safe_code = """
def factorial(n):
    if n <= 1:
        return 1
    return n * factorial(n - 1)

result = factorial(5)
"""
        # Should not raise
        validate_code_safety(safe_code)

    def test_blocks_network_access(self):
        """Should block network-related imports."""
        code = """
import socket
s = socket.socket()
"""
        with pytest.raises(CodeExecutionError):
            validate_code_safety(code)


class TestExecuteCode:
    """Tests for code execution with sandboxing."""

    def test_executes_simple_code(self):
        """Should execute simple code and return result."""
        code = "result = 2 + 2"
        result = execute_code(code)
        assert result["success"] is True
        assert result.get("variables", {}).get("result") == 4

    def test_handles_syntax_errors(self):
        """Should gracefully handle syntax errors."""
        code = "def broken("
        result = execute_code(code)
        assert result["success"] is False
        assert "syntax" in result.get("error", "").lower()

    def test_handles_runtime_errors(self):
        """Should gracefully handle runtime errors."""
        code = "1 / 0"
        result = execute_code(code)
        assert result["success"] is False
        assert "zero" in result.get("error", "").lower()

    def test_enforces_timeout(self):
        """Should enforce execution timeout."""
        code = """
import time
time.sleep(100)  # Long sleep
"""
        with pytest.raises(ResourceLimitExceeded):
            execute_code(code, timeout=1)

    def test_enforces_memory_limit(self):
        """Should enforce memory usage limit."""
        code = """
# Try to allocate large amount of memory
huge_list = [0] * (100 * 1024 * 1024)  # 100M integers
"""
        with pytest.raises(ResourceLimitExceeded):
            execute_code(code, memory_limit_mb=10)

    def test_restricts_available_modules(self):
        """Should only allow whitelisted modules."""
        code = """
import math
result = math.sqrt(16)
"""
        result = execute_code(code, allowed_modules=["math"])
        assert result["success"] is True

    def test_captures_stdout(self):
        """Should capture stdout from executed code."""
        code = """
print("Hello, World!")
print("Second line")
"""
        result = execute_code(code)
        assert result["success"] is True
        assert "Hello, World!" in result.get("stdout", "")
        assert "Second line" in result.get("stdout", "")

    def test_captures_stderr(self):
        """Should capture stderr from executed code."""
        code = """
import sys
print("Error message", file=sys.stderr)
"""
        result = execute_code(code)
        assert "Error message" in result.get("stderr", "")


class TestResourceLimits:
    """Tests for resource limit enforcement."""

    def test_cpu_time_limit(self):
        """Should limit CPU time usage."""
        code = """
# CPU-intensive calculation
for i in range(10000000):
    pass
"""
        with pytest.raises(ResourceLimitExceeded):
            execute_code(code, cpu_time_limit=0.1)

    def test_output_size_limit(self):
        """Should limit output size."""
        code = """
# Generate large output
print("x" * (10 * 1024 * 1024))  # 10MB of output
"""
        with pytest.raises(ResourceLimitExceeded):
            execute_code(code, max_output_size=1024)


class TestSecurityScenarios:
    """Security-focused test scenarios."""

    def test_prevents_shell_injection(self):
        """Should prevent shell command injection."""
        malicious_code = """
__import__('os').system('cat /etc/passwd')
"""
        with pytest.raises(CodeExecutionError):
            validate_code_safety(malicious_code)

    def test_prevents_import_builtins_abuse(self):
        """Should prevent __builtins__ abuse."""
        code = """
__builtins__['__import__']('os').system('ls')
"""
        with pytest.raises(CodeExecutionError):
            validate_code_safety(code)

    def test_isolates_globals(self):
        """Should isolate global namespace between executions."""
        code1 = "x = 42"
        execute_code(code1)
        
        code2 = "result = x + 1"  # Should not have access to x
        result = execute_code(code2)
        assert result["success"] is False  # NameError expected

    def test_prevents_infinite_recursion(self):
        """Should prevent/recover from infinite recursion."""
        code = """
def recurse():
    return recurse()
recurse()
"""
        with pytest.raises(ResourceLimitExceeded):
            execute_code(code, max_recursion_depth=100)