"""Validated HTTP helpers for release tooling."""

from __future__ import annotations

import urllib.parse
import urllib.request
from dataclasses import dataclass
from typing import Mapping


DEFAULT_MAX_RESPONSE_BYTES = 16 * 1024 * 1024


@dataclass(frozen=True, slots=True)
class HttpFetchResponse:
    status: int
    headers: dict[str, str]
    body: bytes

    def text(self, encoding: str = "utf-8") -> str:
        return self.body.decode(encoding)


def validate_http_url(value: str, *, label: str = "URL") -> str:
    parsed = urllib.parse.urlparse(str(value).strip())
    if parsed.scheme not in {"http", "https"} or not parsed.netloc:
        raise ValueError(f"{label} must be an absolute HTTP(S) URL.")
    if parsed.username or parsed.password:
        raise ValueError(f"{label} must not include embedded credentials.")
    return urllib.parse.urlunparse(parsed)


def fetch_http(
    url: str,
    *,
    timeout: float,
    label: str = "URL",
    method: str = "GET",
    headers: Mapping[str, str] | None = None,
    max_response_bytes: int = DEFAULT_MAX_RESPONSE_BYTES,
) -> HttpFetchResponse:
    if max_response_bytes <= 0:
        raise ValueError("max_response_bytes must be positive.")
    request = urllib.request.Request(
        validate_http_url(url, label=label),
        headers=dict(headers or {}),
        method=method,
    )
    with urllib.request.urlopen(request, timeout=timeout) as response:  # noqa: S310 - URL is validated by validate_http_url.  # nosec B310  # nosemgrep: python.lang.security.audit.dynamic-urllib-use-detected.dynamic-urllib-use-detected
        raw_length = response.headers.get("Content-Length")
        if raw_length is not None:
            try:
                declared_length = int(raw_length)
            except (TypeError, ValueError):
                declared_length = None
            if declared_length is not None and declared_length > max_response_bytes:
                raise ValueError(f"{label} response exceeds the configured size limit.")
        body = response.read(max_response_bytes + 1)
        if len(body) > max_response_bytes:
            raise ValueError(f"{label} response exceeds the configured size limit.")
        return HttpFetchResponse(
            status=int(getattr(response, "status", 0)),
            headers=dict(response.headers.items()),
            body=body,
        )