from __future__ import annotations

import re
from urllib.parse import urlsplit

from packaging.utils import canonicalize_name


SLUG_RE = re.compile(r"^[a-z0-9](?:[a-z0-9-]{0,62}[a-z0-9])?$")
DISTRIBUTION_RE = re.compile(r"^[A-Za-z0-9](?:[A-Za-z0-9._-]{0,126}[A-Za-z0-9])?$")
IMPORT_RE = re.compile(r"^[A-Za-z_][A-Za-z0-9_]{0,127}$")
SHA256_RE = re.compile(r"^[a-fA-F0-9]{64}$")

SELF_IMPORT_NAME = "netbox_plugin_store"
SELF_DISTRIBUTION_NAME = canonicalize_name("netbox-plugin-store")


class ValidationError(ValueError):
    pass


def validate_slug(value: str) -> str:
    if not isinstance(value, str) or not SLUG_RE.fullmatch(value):
        raise ValidationError("Invalid plugin slug.")
    return value


def validate_distribution_name(value: str) -> str:
    if not isinstance(value, str) or not DISTRIBUTION_RE.fullmatch(value):
        raise ValidationError("Invalid Python distribution name.")
    return value


def validate_import_name(value: str) -> str:
    if not isinstance(value, str) or not IMPORT_RE.fullmatch(value):
        raise ValidationError("Invalid Python import name.")
    return value


def validate_sha256(value: str) -> str:
    if not isinstance(value, str) or not SHA256_RE.fullmatch(value):
        raise ValidationError("Invalid SHA-256 digest.")
    return value.lower()


def ensure_not_self(package_name: str, import_name: str) -> None:
    if canonicalize_name(package_name) == SELF_DISTRIBUTION_NAME or import_name == SELF_IMPORT_NAME:
        raise ValidationError("The Plugin Store cannot manage its own lifecycle.")


def validate_public_url(value: str) -> str:
    parsed = urlsplit(value)
    if parsed.scheme not in {"https", "http"} or not parsed.hostname:
        raise ValidationError("URL must be an absolute HTTP(S) URL.")
    if parsed.username is not None or parsed.password is not None:
        raise ValidationError("URLs containing credentials are not accepted.")
    return value