import hashlib
import json
from json import JSONDecodeError
import os
from pathlib import Path
from typing import cast

import requests
from requests import RequestException

REQUEST_TIMEOUT = 15.0


def as_int(value: object, default: int) -> int:
    if isinstance(value, bool):
        return default
    if isinstance(value, int):
        return value
    if isinstance(value, str):
        try:
            return int(value.strip())
        except ValueError:
            return default
    return default


def as_float(value: object, default: float | None = None) -> float | None:
    return float(value) if isinstance(value, (int, float)) else default


def as_str(value: object, default: str = "") -> str:
    return str(value) if isinstance(value, (str, int, float)) else default


def as_dict(value: object) -> dict[str, object]:
    return cast(dict[str, object], value) if isinstance(value, dict) else {}


def as_list(value: object) -> list[object]:
    return cast(list[object], value) if isinstance(value, list) else []


class HttpError(Exception):
    NO_CODE = 0

    def __init__(self, status_code: int, body: object) -> None:
        self.status_code = status_code
        self.body = body
        super().__init__(f"HTTP {status_code}")


def _cache_path(url: str) -> Path:
    cdir = Path(os.getenv("CACHE_DIR", ".cached"))
    cdir.mkdir(parents=True, exist_ok=True)
    url_hash = hashlib.sha256(url.encode("utf-8")).hexdigest()[:16]
    path = cdir / f"{url_hash}.json"
    return path


def fetch_text(url: str) -> str:
    path = _cache_path(url)
    try:
        if path.exists():
            return path.read_text(encoding="utf-8")
    except OSError:
        pass

    try:
        resp = requests.get(url, timeout=REQUEST_TIMEOUT)
    except RequestException as e:
        raise HttpError(HttpError.NO_CODE, str(e)) from e

    if resp.status_code != 200:
        try:
            body: object = resp.json()
        except ValueError:
            body = resp.text
        raise HttpError(resp.status_code, body)

    content = resp.text
    try:
        path.write_text(content, encoding="utf-8")
    except OSError:
        pass
    return content


def fetch_json(url: str) -> object:
    raw = fetch_text(url)
    try:
        return json.loads(raw)
    except JSONDecodeError as exc:
        raise HttpError(HttpError.NO_CODE, f"invalid JSON: {raw[:200]!r}") from exc