"""统一超时配置(修永久卡死).

集中各阶段"单次外部调用"的总时长上限(用户拍板),并提供 httpx.Timeout 工厂。

要点:httpx 的 `timeout=标量` 只把 connect/read/write/pool 各设为 N,**没有"整次请求总时长"**;
服务端慢速吐字节时每次 read 都在 N 内返回一点 → read 永不触发 → 永久卡在 do_poll。
所以这里强制 **read 相设短**(停止吐数据即抛 ReadTimeout),总时长由 write 相 + 调用方护栏兜。
env 可覆盖各阶段总值,但被硬上限钳制,防再配出 3600 那种值。
"""

from __future__ import annotations

import os
from typing import Mapping

import httpx

CONNECT_TIMEOUT_SECONDS = 10.0

# 各阶段总时长默认(秒)——用户拍板的"单次外部调用允许上限"。
_DEFAULTS: dict[str, float] = {
    "oss": 300.0,            # OSS 上传/归档单次尝试 5min
    "video_download": 600.0,  # 视频下载 10min
    "video_llm": 600.0,       # qwen/gemini 单次判定 10min
    "crawapi": 180.0,         # 平台搜索/作者/画像 3min
    "query_llm": 120.0,       # query variant / Gate2 2min
    "pg": 30.0,               # pattern PG Gate1 30s
}
# env 覆盖也不得超过(防误配)。
_HARD_CEILING: dict[str, float] = {
    "oss": 600.0,
    "video_download": 1200.0,
    "video_llm": 1200.0,
    "crawapi": 360.0,
    "query_llm": 300.0,
    "pg": 60.0,
}
# 单次 read(两次收到数据之间)上限。OSS 按业务要求放宽到 300s。
_READ: dict[str, float] = {
    "oss": 300.0,
    "video_download": 120.0,
    "video_llm": 120.0,
    "crawapi": 60.0,
    "query_llm": 60.0,
    "pg": 30.0,
}
_ENV_KEYS: dict[str, tuple[str, ...]] = {
    "oss": ("CONTENT_AGENT_OSS_TIMEOUT_SECONDS",),
    "video_download": ("CONTENT_AGENT_VIDEO_DOWNLOAD_TIMEOUT_SECONDS",),
    "video_llm": ("CONTENT_AGENT_VIDEO_LLM_TIMEOUT_SECONDS",),
    "crawapi": ("CONTENTFIND_API_CRAWAPI_TIMEOUT_SECONDS",),
    "query_llm": ("CONTENT_AGENT_QUERY_LLM_TIMEOUT_SECONDS",),
    "pg": ("OPEN_AIGC_PG_TIMEOUT_SECONDS",),
}


def total_timeout(stage: str, env: Mapping[str, str] | None = None) -> float:
    """阶段总时长(秒):env 覆盖 → 硬上限钳制 → 默认。"""
    src = os.environ if env is None else env
    value = _DEFAULTS[stage]
    for key in _ENV_KEYS[stage]:
        raw = src.get(key)
        if raw:
            try:
                value = float(raw)
                break
            except (TypeError, ValueError):
                pass
    return min(value, _HARD_CEILING[stage])


def read_timeout(stage: str) -> float:
    return _READ[stage]


def as_httpx_timeout(
    total_seconds: float,
    *,
    read: float,
    connect: float = CONNECT_TIMEOUT_SECONDS,
) -> httpx.Timeout:
    """把一个总时长(秒)转成分段 httpx.Timeout:read 短、write=总、connect 短。"""
    total = max(float(total_seconds), 1.0)
    return httpx.Timeout(
        connect=min(connect, total),
        read=min(read, total),
        write=total,
        pool=min(connect, total),
    )


def httpx_timeout(stage: str, env: Mapping[str, str] | None = None) -> httpx.Timeout:
    """按阶段直接构造 httpx.Timeout(已含 env 覆盖 + read 短上限)。"""
    return as_httpx_timeout(total_timeout(stage, env=env), read=_READ[stage])