"""
The tool to check the availability or syntax of domain, IP or URL.

::


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Provides the subdomain syntax checker.

Author:
    Nissar Chababy, @funilrys, contactTATAfunilrysTODTODcom

Special thanks:
    https://pyfunceble.github.io/#/special-thanks

Contributors:
    https://pyfunceble.github.io/#/contributors

Project link:
    https://github.com/funilrys/PyFunceble

Project documentation:
    https://docs.pyfunceble.com

Project homepage:
    https://pyfunceble.github.io/

License:
::


    Copyright 2017, 2018, 2019, 2020, 2022, 2023, 2024, 2025 Nissar Chababy

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        https://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
"""

from PyFunceble.checker.syntax.domain_base import DomainSyntaxCheckerBase


class SubDomainSyntaxChecker(DomainSyntaxCheckerBase):
    """
    Provides an interface to check the syntax of a subdomain.

    :param str subject:
        Optional, The subject to work with.
    """

    # pylint: disable=line-too-long
    REGEX_VALID_SUBDOMAIN: str = (
        r"^(?=.{0,253}$)(([a-z0-9_][a-z0-9-_]{0,61}[a-z0-9_-]|[a-z0-9])\.)+((?=.*)([a-z0-9][a-z0-9-]{0,61}[a-z0-9](?:\.)?|[a-z0-9](?:\.)?))$"
    )

    @DomainSyntaxCheckerBase.ensure_subject_is_given
    def is_valid(self) -> bool:
        """
        Validate the given subject if exists.
        """

        extension = self.get_extension()

        if (
            not extension
            or extension not in self.iana_dataset
            and extension not in self.SPECIAL_USE_DOMAIN_NAMES_EXTENSIONS
        ):
            return False

        subject_without_extension = self.idna_subject[: self.last_point_index]
        subject_without_suffix, suffix = self.get_subject_without_suffix(
            self.idna_subject, extension
        )

        if subject_without_suffix:
            if suffix.count(".") >= 2:
                return self.regex_helper.set_regex(self.REGEX_VALID_SUBDOMAIN).match(
                    subject_without_extension, return_match=False
                )

            if "." in subject_without_suffix:
                return self.regex_helper.set_regex(self.REGEX_VALID_SUBDOMAIN).match(
                    self.idna_subject, return_match=False
                )

            return False

        if "." in subject_without_extension:
            return self.regex_helper.set_regex(self.REGEX_VALID_SUBDOMAIN).match(
                subject_without_extension, return_match=False
            )

        return False
