"""余额获取：模板渲染 → HTTP 请求（带重试）→ JSON 路径提取。"""

from __future__ import annotations

import json
import logging
import re
import time
from dataclasses import dataclass

import requests

logger = logging.getLogger("monitor.fetcher")

PLACEHOLDER = "{{apiKey}}"
_TOKEN_RE = re.compile(r"([^.\[]+)|\[(\d+)\]")


@dataclass
class FetchResult:
    """一次拉取的结果。"""

    ok: bool
    balance: float | None = None
    auth_error: bool = False
    status_code: int | None = None
    error: str = ""


def render_template(text: str, api_key: str) -> str:
    """把模板中的 {{apiKey}} 替换为账号密钥。"""
    return text.replace(PLACEHOLDER, api_key)


def extract_balance(data: object, path: str) -> float:
    """按点路径/数组索引提取余额，如 data.balance、data[0].balance、$.data[0].balance。

    取到的值必须是数字或可转数字的字符串，否则抛 ValueError。
    """
    p = path.strip()
    if p.startswith("$"):
        p = p[1:]
    cur: object = data
    for key, idx in _TOKEN_RE.findall(p):
        if key:
            if not isinstance(cur, dict) or key not in cur:
                raise ValueError(f"路径不存在: {path}（在 {key!r} 处）")
            cur = cur[key]
        if idx != "":
            n = int(idx)
            if not isinstance(cur, list) or n >= len(cur):
                raise ValueError(f"数组索引越界: {path}（索引 {n}）")
            cur = cur[n]
    if isinstance(cur, bool) or not isinstance(cur, (int, float, str)):
        raise ValueError(f"余额不是数字: {path} -> {cur!r}")
    try:
        return float(cur)
    except (TypeError, ValueError):
        raise ValueError(f"余额不是数字: {path} -> {cur!r}")


def _build_request(platform: dict, api_key: str) -> tuple[str, dict, str | None]:
    url = render_template(platform["url"], api_key)
    headers_raw = platform.get("headers") or {}
    if isinstance(headers_raw, str):
        headers_raw = json.loads(headers_raw) if headers_raw.strip() else {}
    headers = json.loads(render_template(json.dumps(headers_raw), api_key))
    body = None
    if platform["method"] == "POST" and platform.get("body"):
        body = render_template(platform["body"], api_key)
        if not any(k.lower() == "content-type" for k in headers):
            headers["Content-Type"] = "application/json"
    return url, headers, body


def fetch_balance(platform: dict, api_key: str, retry_count: int, timeout: int) -> FetchResult:
    """执行一次余额拉取。

    策略：
    - 401/403 → auth_error（不重试，由调用方禁用账号并通知）
    - 其他 4xx → 直接失败（配置问题，不重试）
    - 网络异常 / 5xx → 重试 retry_count 次，间隔 2s
    - JSON 解析/路径提取失败 → 直接失败
    """
    url, headers, body = _build_request(platform, api_key)
    method = platform["method"]
    attempts = retry_count + 1
    for attempt in range(attempts):
        try:
            if method == "GET":
                resp = requests.get(url, headers=headers, timeout=timeout)
            else:
                resp = requests.post(url, headers=headers, data=body, timeout=timeout)
        except requests.RequestException as exc:
            logger.warning("请求异常(%s/%s) %s: %s", attempt + 1, attempts, url, exc)
            if attempt < attempts - 1:
                time.sleep(2)
            continue
        if resp.status_code in (401, 403):
            # 认证失败可能是瞬时的（key 刚生效/风控），先按重试次数再确认，仍失败才判定
            if attempt < attempts - 1:
                logger.warning("认证失败(%s/%s) %s status=%s，重试确认", attempt + 1, attempts, url, resp.status_code)
                time.sleep(1)
                continue
            return FetchResult(ok=False, auth_error=True, status_code=resp.status_code,
                               error=f"HTTP {resp.status_code}（认证失败）")
        if resp.status_code >= 500:
            logger.warning("服务端错误(%s/%s) %s status=%s", attempt + 1, attempts, url, resp.status_code)
            if attempt < attempts - 1:
                time.sleep(2)
            continue
        if resp.status_code >= 400:
            return FetchResult(ok=False, status_code=resp.status_code,
                               error=f"HTTP {resp.status_code}: {resp.text[:120]}")
        try:
            data = resp.json()
        except ValueError:
            return FetchResult(ok=False, status_code=resp.status_code,
                               error="响应不是合法 JSON")
        try:
            balance = extract_balance(data, platform["balance_path"])
        except ValueError as exc:
            return FetchResult(ok=False, status_code=resp.status_code, error=str(exc))
        return FetchResult(ok=True, balance=balance, status_code=resp.status_code)
    return FetchResult(ok=False, error=f"网络错误，重试 {retry_count} 次后仍失败")