124 lines
4.3 KiB
Python
124 lines
4.3 KiB
Python
from __future__ import annotations
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import hashlib
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import json
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import time
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import urllib.parse
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import urllib.request
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from dataclasses import dataclass
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from datetime import datetime, timedelta, timezone
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from typing import Any
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@dataclass
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class Token:
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access_token: str
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expires_at: float
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@dataclass
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class StreamUrlResult:
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url: str
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timings: dict[str, float]
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class CapacityApiClient:
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def __init__(
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self,
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base_url: str,
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app_id: str,
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app_secret: str,
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account: str,
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method: str,
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timeout: int = 20,
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):
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self.base_url = base_url.rstrip("/")
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self.app_id = app_id
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self.app_secret = app_secret
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self.account = account
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self.method = method
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self.timeout = timeout
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self.token: Token | None = None
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def get_stream_url(self, device_num: str) -> str:
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return self.get_stream_url_details(device_num).url
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def get_stream_url_details(self, device_num: str) -> StreamUrlResult:
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timings: dict[str, float] = {}
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started = time.monotonic()
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access_token = self._get_access_token(timings)
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timings["token_ms"] = round((time.monotonic() - started) * 1000, 2)
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started = time.monotonic()
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business_params = {
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"account": self.account,
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"deviceNum": device_num,
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"isSubStream": 0,
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"networkType": 1,
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"urlType": 1,
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}
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# 接口文档要求业务参数整体放进 params JSON 字符串后再参与签名。
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params = {
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"accessToken": access_token,
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"appId": self.app_id,
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"method": self.method,
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"params": json.dumps(business_params, ensure_ascii=False, separators=(",", ":")),
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"timestamp": self._timestamp(),
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"v": "1.0.0",
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}
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params["sign"] = self._sign(params)
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timings["sign_ms"] = round((time.monotonic() - started) * 1000, 2)
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started = time.monotonic()
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data = self._get_json(f"{self.base_url}/rest", params)
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timings["stream_url_ms"] = round((time.monotonic() - started) * 1000, 2)
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if data.get("errorCode") != "0":
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raise RuntimeError(data.get("errorMsg") or f"播放地址接口返回错误 {data.get('errorCode')}")
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payload = data.get("data") or {}
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stream_url = payload.get("rtspUrl") or payload.get("rtspUri")
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if not stream_url:
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raise RuntimeError("播放地址接口未返回 RTSP 地址")
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return StreamUrlResult(stream_url, timings)
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def _get_access_token(self, timings: dict[str, float] | None = None) -> str:
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if self.token and time.time() < self.token.expires_at - 300:
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if timings is not None:
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timings["token_cache"] = 1
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return self.token.access_token
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data = self._get_json(
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f"{self.base_url}/oauth/token",
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{
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"grantType": "client_credential",
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"appId": self.app_id,
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"appSecret": self.app_secret,
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},
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)
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if data.get("errorCode") != "0":
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raise RuntimeError(data.get("errorMsg") or f"获取 accessToken 失败 {data.get('errorCode')}")
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payload = data.get("data") or {}
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access_token = payload.get("accessToken")
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if not access_token:
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raise RuntimeError("token 接口未返回 accessToken")
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self.token = Token(
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access_token=access_token,
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expires_at=time.time() + int(payload.get("expiresIn") or 604800),
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)
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return access_token
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def _get_json(self, url: str, params: dict[str, Any]) -> dict[str, Any]:
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query = urllib.parse.urlencode(params)
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with urllib.request.urlopen(f"{url}?{query}", timeout=self.timeout) as response:
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body = response.read().decode("utf-8")
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return json.loads(body)
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def _sign(self, params: dict[str, Any]) -> str:
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# 签名规则：appSecret + 按 ASCII key 排序后的 key/value + appSecret。
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raw = self.app_secret + "".join(f"{key}{params[key]}" for key in sorted(params)) + self.app_secret
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return hashlib.md5(raw.encode("utf-8")).hexdigest().upper()
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@staticmethod
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def _timestamp() -> str:
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return datetime.now(timezone(timedelta(hours=8))).strftime("%Y-%m-%d %H:%M:%S")
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