Source code for carlogtt_python_library.utils.validators

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# MODULE DETAILS
# This section provides metadata about the module, including its
# creation date, author, copyright information, and a brief description
# of the module's purpose and functionality.
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# src/carlogtt_python_library/utils/validators.py
# Created 10/2/23 - 9:25 AM UK Time (London) by carlogtt

"""
This module provides a set of functions and utilities for data
validation. It offers various validators to ensure the correctness and
integrity of different types of data inputs.
"""

# ======================================================================
# EXCEPTIONS
# This section documents any exceptions made or code quality rules.
# These exceptions may be necessary due to specific coding requirements
# or to bypass false positives.
# ======================================================================
#

# ======================================================================
# IMPORTS
# Importing required libraries and modules for the application.
# ======================================================================

# Standard Library Imports
import logging
import re
import string

# END IMPORTS
# ======================================================================


# List of public names in the module
__all__ = [
    'InputValidator',
]

# Setting up logger for current module
module_logger = logging.getLogger(__name__)

# Type aliases
#




class InputValidator:
    """
    A collection of input validation methods for strings, usernames,
    and passwords. All methods raise ValueError on invalid inputs.
    """



    def validate_non_empty_strings(self, **strings: str) -> dict[str, str]:
        """
        Return a non-empty string without whitespace at the beginning
        and end of the string.
        """

        strings_validated = {}

        for string_name, string_value in strings.items():
            if string_value:
                string_value = string_value.strip()

                # Match any non-whitespace character
                pattern = r'\S'
                non_whitespace_character_found = bool(re.search(pattern, string_value))

                if non_whitespace_character_found:
                    strings_validated[string_name] = string_value

                else:
                    raise ValueError(f"{string_name!r} cannot be empty.")

        return strings_validated




    def validate_username_requirements(self, username_to_validate: str) -> str:
        """
        Check if username requirements are met and return a non-empty
        string without whitespace at the beginning and end of the
        string.
        """

        if not username_to_validate:
            raise ValueError("Username cannot be empty")

        else:
            username = username_to_validate.strip()

            for ch in username:
                if not ch.isalnum():
                    raise ValueError("Username contains invalid characters.")

            if len(username) < 5 or len(username) > 16:
                raise ValueError(
                    "Username must be at least 5 characters and maximum 16 characters long."
                )

        return username




    def validate_password_requirements(self, password_to_validate: str) -> str:
        """
        Check if password requirements are met and return a non-empty
        string without whitespace at the beginning and end of the
        string.
        """

        if not password_to_validate:
            raise ValueError("Password cannot be empty.")

        else:
            password = password_to_validate.strip()

            if len(password) < 12:
                raise ValueError("Password must be at least 12 characters long.")

            magic_string_check = {"lower": 0, "upper": 0, "digit": 0, "special": 0}

            for ch in password:
                if ch in string.ascii_lowercase:
                    magic_string_check['lower'] += 1

                elif ch in string.ascii_uppercase:
                    magic_string_check['upper'] += 1

                elif ch in string.digits:
                    magic_string_check['digit'] += 1

                elif ch in string.punctuation:
                    magic_string_check['special'] += 1

                else:
                    raise ValueError(f"Password contains invalid character: {ch!r}")

            for i in magic_string_check.values():
                if i == 0:
                    raise ValueError("Password does not meet the minimum requirements.")

        return password