import base64

import requests


class Utils:
    def __init__(self):
        pass
    
    def b64_decode(self, input_str):
        input_str = self.fix_padding(input_str)
        try:
            return base64.b64decode(input_str).decode('utf-8')
        except Exception as e:
            raise ValueError(f"Decoding failed: {e}")
    
    def fix_padding(self, input_str):
        padding = len(input_str) % 4
        if padding:
            input_str += "=" * (4 - padding)
        return input_str
    
    def is_accessible(self, url, headers=None):
        try:
            response = requests.head(url, headers=headers, timeout=10)
            return response.status_code in [200, 302]
        except:
            return False