# -*- coding: utf-8 -*-
"""HTTP 客户端与响应体收窄工具。

（自 music_api.py 拆出，行为与原实现一致。）
"""

import asyncio
from typing import Any

from core import aiohttp_compat as requests  # 异步 HTTP 垫片（requests 同形 API）

from .constants import (
    APIConstants,
)
from .errors import (
    APIException,
)


def _ensure_dict(result: Any, msg: str) -> dict[str, Any]:
    """上游 200 但返回 null/数组等非 dict 体（风控/抖动）时统一前置校验"""
    if isinstance(result, dict):
        return result
    raise APIException(msg)


def _as_dict(v: Any) -> dict[str, Any]:
    """上游嵌套字段类型不稳定（dict / None / 列表都真实出现过）：非 dict 一律回落空 dict。

    收窄成显式函数，避免满屏 `x if isinstance(x, dict) else {}` 三元式——
    那种写法读起来累，且把字段来自 `user.get(...)`（类型 Any|None）时的收窄责任
    散落在各处，容易被后来的改动改漏。
    """
    return v if isinstance(v, dict) else {}


class HTTPClient:
    """HTTP客户端类"""

    @staticmethod
    async def post_request(url: str, params: str, cookies: dict[str, str]) -> str:
        """发送POST请求并返回文本响应。
        网络异常/5xx 做一次 1 秒退避重试（全站 API 调用此前零重试，
        上游抖动即整首失败）；4xx（429/460 风控）不重试——立即重试会加剧风控。"""
        headers = {
            'User-Agent': APIConstants.USER_AGENT,
            'Referer': APIConstants.REFERER,
        }

        request_cookies = APIConstants.DEFAULT_COOKIES.copy()
        request_cookies.update(cookies)

        last_err = None
        for attempt in range(2):
            try:
                response = await requests.post(url, headers=headers, cookies=request_cookies,
                                         data={"params": params}, timeout=30)
                if response.status_code >= 500 and attempt == 0:
                    await asyncio.sleep(1.0)
                    continue
                response.raise_for_status()
                if len(response.content) > _MAX_UPSTREAM_JSON_BYTES:
                    raise APIException("上游响应体异常（超过大小上限）")
                return response.text
            except requests.HTTPError as e:
                # 4xx（429/460 风控）不重试——原实现 HTTPError 落入
                # 下方 RequestException 分支被重试一次，与 意图相反
                raise APIException(f"HTTP请求失败: {e}") from e
            except requests.RequestException as e:
                last_err = e
                if attempt == 0:
                    await asyncio.sleep(1.0)
                    continue
        raise APIException(f"HTTP请求失败: {last_err}")

    @staticmethod
    async def post_request_full(url: str, params: str, cookies: dict[str, str]) -> requests.Response:
        """发送POST请求并返回完整响应对象（同 post_request 的有界重试）"""
        headers = {
            'User-Agent': APIConstants.USER_AGENT,
            'Referer': APIConstants.REFERER,
        }

        request_cookies = APIConstants.DEFAULT_COOKIES.copy()
        request_cookies.update(cookies)

        last_err = None
        for attempt in range(2):
            try:
                response = await requests.post(url, headers=headers, cookies=request_cookies,
                                         data={"params": params}, timeout=30)
                if response.status_code >= 500 and attempt == 0:
                    await asyncio.sleep(1.0)
                    continue
                response.raise_for_status()
                if len(response.content) > _MAX_UPSTREAM_JSON_BYTES:
                    raise APIException("上游响应体异常（超过大小上限）")
                return response
            except requests.HTTPError as e:
                # 4xx 不重试（同上）
                raise APIException(f"HTTP请求失败: {e}") from e
            except requests.RequestException as e:
                last_err = e
                if attempt == 0:
                    await asyncio.sleep(1.0)
                    continue
        raise APIException(f"HTTP请求失败: {last_err}")


# 上游 JSON 响应体上限——requests 已全量入内存，此处拦截的是
# 异常/被劫持上游的超大 body 进入后续 .json() 解析与传播（音频/封面已有字节预算）
_MAX_UPSTREAM_JSON_BYTES = 8 * 1024 * 1024