"""企微群机器人通知层(消息推送 webhook,HTTP POST,无状态)。

文档:https://developer.work.weixin.qq.com/document/path/99110
凭据存 Prefect Secret Block `wecom-webhook`(值为完整 webhook URL,含 key);
本地调试可用环境变量 WECOM_WEBHOOK_URL 覆盖。
markdown 支持:1-6 级标题/加粗/链接/引用/<font color="info|comment|warning">(不支持表格);
单条 ≤4096 字节,超长自动按行分段;频率限制 20 条/分钟。

所有函数容错——发送失败只 print 警告并返回 False,绝不中断 flow(对齐 artifacts.py 风格)。
"""

from __future__ import annotations

import os

import httpx

WEBHOOK_BLOCK = "wecom-webhook"
MAX_MARKDOWN_BYTES = 4000  # 官方上限 4096,留余量
MAX_TEXT_BYTES = 2000      # text 类型上限 2048,留余量


def load_webhook_url() -> str:
    url = os.environ.get("WECOM_WEBHOOK_URL", "").strip()
    if not url:
        from prefect.blocks.system import Secret

        url = (Secret.load(WEBHOOK_BLOCK).get() or "").strip()
    if not url:
        raise ValueError(f"webhook 地址为空(Secret Block {WEBHOOK_BLOCK} 或 WECOM_WEBHOOK_URL)")
    return url


def _split_bytes(content: str, limit: int) -> list[str]:
    """按字节预算切段,优先在换行处切。"""
    if len(content.encode("utf-8")) <= limit:
        return [content]
    parts: list[str] = []
    cur = ""
    for line in content.splitlines(keepends=True):
        if cur and len((cur + line).encode("utf-8")) > limit:
            parts.append(cur)
            cur = line
        else:
            cur += line
    if cur:
        parts.append(cur)
    return parts


def _post(url: str, payload: dict) -> bool:
    resp = httpx.post(url, json=payload, timeout=15)
    try:
        data = resp.json()
    except ValueError:
        data = {}
    if resp.status_code != 200 or data.get("errcode") != 0:
        print(f"[wecom] 发送失败: HTTP {resp.status_code} {data or resp.text[:100]}")
        return False
    return True


def _send(content: str, msgtype: str, limit: int) -> bool:
    try:
        url = load_webhook_url()
        parts = _split_bytes(content, limit)
        ok = all(_post(url, {"msgtype": msgtype, msgtype: {"content": part}}) for part in parts)
        if ok and len(parts) > 1:
            print(f"[wecom] {msgtype} 已发送 ({len(parts)} 段)")
        return ok
    except Exception as err:  # noqa: BLE001
        print(f"[wecom] {msgtype} 发送失败: {err}")
        return False


def send_markdown(content: str) -> bool:
    """发送 markdown 到群(超长自动分段)。失败返回 False,不抛异常。"""
    return _send(content, "markdown", MAX_MARKDOWN_BYTES)


def send_text(content: str) -> bool:
    """发送纯文本到群。失败返回 False,不抛异常。"""
    return _send(content, "text", MAX_TEXT_BYTES)