"""
Python Code Validator for Scheduled Jobs
验证用户提交的 Python 代码安全性和语法正确性
"""
import ast
import re
from typing import Dict, List, Tuple


class PythonCodeValidator:
    """验证Python代码的安全性和有效性"""

    # 危险的内置函数和模块
    DANGEROUS_BUILTINS = {
        'eval', 'exec', 'compile', '__import__',
        'open', 'file', 'input', 'raw_input',
        'execfile', 'reload',
    }

    # 危险的模块
    DANGEROUS_MODULES = {
        'os', 'sys', 'subprocess', 'socket',
        'shutil', 'pickle', 'multiprocessing',
        'threading', 'ctypes', 'importlib',
    }

    # 允许的模块（白名单）
    ALLOWED_MODULES = {
        'asyncio', 'datetime', 'math', 'json',
        'logging', 'typing', 'collections',
        'app.services', 'app.models', 'sqlalchemy',
    }

    @staticmethod
    def validate_syntax(code: str) -> Tuple[bool, str]:
        """
        验证Python代码语法

        Returns:
            (is_valid, error_message)
        """
        try:
            ast.parse(code)
            return True, ""
        except SyntaxError as e:
            return False, f"语法错误 (第{e.lineno}行): {e.msg}"
        except Exception as e:
            return False, f"代码解析错误: {str(e)}"

    @staticmethod
    def check_dangerous_functions(code: str) -> Tuple[bool, List[str]]:
        """
        检查是否使用了危险函数

        Returns:
            (is_safe, dangerous_items)
        """
        dangerous_found = []

        try:
            tree = ast.parse(code)

            for node in ast.walk(tree):
                # 检查函数调用
                if isinstance(node, ast.Call):
                    if isinstance(node.func, ast.Name):
                        if node.func.id in PythonCodeValidator.DANGEROUS_BUILTINS:
                            dangerous_found.append(f"危险函数: {node.func.id}")

                # 检查模块导入
                elif isinstance(node, ast.Import):
                    for alias in node.names:
                        module_name = alias.name.split('.')[0]
                        if module_name in PythonCodeValidator.DANGEROUS_MODULES:
                            if not any(module_name.startswith(allowed) for allowed in PythonCodeValidator.ALLOWED_MODULES):
                                dangerous_found.append(f"危险模块导入: {alias.name}")

                elif isinstance(node, ast.ImportFrom):
                    if node.module:
                        module_name = node.module.split('.')[0]
                        if module_name in PythonCodeValidator.DANGEROUS_MODULES:
                            if not any(module_name.startswith(allowed) for allowed in PythonCodeValidator.ALLOWED_MODULES):
                                dangerous_found.append(f"危险模块导入: from {node.module}")

            return len(dangerous_found) == 0, dangerous_found

        except Exception as e:
            return False, [f"代码分析错误: {str(e)}"]

    @staticmethod
    def validate_code(code: str) -> Dict:
        """
        完整的代码验证

        Returns:
            {
                "valid": bool,
                "errors": List[str],
                "warnings": List[str]
            }
        """
        errors = []
        warnings = []

        # 1. 检查代码是否为空
        if not code or not code.strip():
            errors.append("代码不能为空")
            return {"valid": False, "errors": errors, "warnings": warnings}

        # 2. 语法验证
        syntax_valid, syntax_error = PythonCodeValidator.validate_syntax(code)
        if not syntax_valid:
            errors.append(syntax_error)
            return {"valid": False, "errors": errors, "warnings": warnings}

        # 3. 安全检查
        is_safe, dangerous_items = PythonCodeValidator.check_dangerous_functions(code)
        if not is_safe:
            errors.extend(dangerous_items)

        # 4. 检查代码长度
        if len(code) > 10000:  # 10KB limit
            warnings.append("代码过长，可能影响性能")

        # 5. 检查是否包含无限循环风险
        if re.search(r'while\s+True\s*:', code):
            warnings.append("检测到 'while True'，请确保有退出条件")

        return {
            "valid": len(errors) == 0,
            "errors": errors,
            "warnings": warnings
        }


# 导出验证器实例
code_validator = PythonCodeValidator()