#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""A/B：JSON motor/send vs ESF1 快发（HTTP send_raw / 持久 TCP）软件段延迟。

需要：tools/ecat ecat_native 已运行（总线可不必在 OP，未连接时会报未连接但仍计时）。

用法:
  python scripts/check_esf_latency.py
  python scripts/check_esf_latency.py --n 40
"""
from __future__ import annotations

import argparse
import json
import os
import socket
import statistics
import struct
import sys
import time
import urllib.request

sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
from esp32_server import pack_esf, unpack_fsok  # noqa: E402

PAGE = os.environ.get("DCU_PAGE_BASE", "http://127.0.0.1:2625")
ECAT = PAGE + "/ecat/api"


def http(url, data: bytes, ctype="application/json", timeout=5.0):
    req = urllib.request.Request(
        url, data=data,
        headers={"Content-Type": ctype, "Accept": "application/json"},
        method="POST",
    )
    t0 = time.perf_counter()
    try:
        with urllib.request.urlopen(req, timeout=timeout) as r:
            body = r.read()
        ms = (time.perf_counter() - t0) * 1000.0
        try:
            return ms, json.loads(body.decode("utf-8", "replace") or "{}")
        except Exception:
            return ms, {"_raw_len": len(body)}
    except Exception as e:
        return (time.perf_counter() - t0) * 1000.0, {"ok": False, "error": str(e)}


def pct(xs, p):
    if not xs:
        return None
    xs = sorted(xs)
    k = max(0, min(len(xs) - 1, int(round((p / 100.0) * (len(xs) - 1)))))
    return xs[k]


def main() -> int:
    ap = argparse.ArgumentParser()
    ap.add_argument("--n", type=int, default=30)
    args = ap.parse_args()

    frame = {"ch": 2, "id": 0x00030200, "dlc": 32,
             "data": "02" + "00" * 29 + "000000"}  # 静止 CMD
    frames = [frame]
    esf = pack_esf(frames)
    js = json.dumps({"frames": frames}, ensure_ascii=False, separators=(",", ":")).encode("utf-8")

    ms_h, health = http(ECAT + "/native/health", b"{}")
    print(f"health {ms_h:.2f}ms {json.dumps(health, ensure_ascii=False)[:200]}")
    fsp = int(health.get("fast_send_port") or 0)
    print(f"fast_send_port={fsp}")

    json_ms, raw_ms = [], []
    for _ in range(args.n):
        ms, _ = http(ECAT + "/motor/send", js)
        json_ms.append(ms)
        ms, _ = http(ECAT + "/motor/send_raw", esf, "application/octet-stream")
        raw_ms.append(ms)

    tcp_ms = []
    if fsp > 0:
        sock = socket.create_connection(("127.0.0.1", fsp), timeout=None)
        sock.settimeout(2.0)
        try:
            sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
        except Exception:
            pass
        for _ in range(args.n):
            t0 = time.perf_counter()
            sock.sendall(esf)
            resp = b""
            while len(resp) < 8:
                c = sock.recv(8 - len(resp))
                if not c:
                    raise OSError("closed")
                resp += c
            tcp_ms.append((time.perf_counter() - t0) * 1000.0)
            r = unpack_fsok(resp)
            if not r.get("ok") and not tcp_ms:
                print("TCP 快发 ok=false", r)
        sock.close()

    def show(name, xs):
        if not xs:
            print(f"{name}: (skip)")
            return
        print(f"{name}: n={len(xs)} mean={statistics.mean(xs):.3f}ms "
              f"p50={pct(xs,50):.3f} p90={pct(xs,90):.3f} min={min(xs):.3f} max={max(xs):.3f}")

    show("JSON  motor/send   ", json_ms)
    show("HTTP  send_raw     ", raw_ms)
    show("TCP   fast_send    ", tcp_ms)
    print("口径：HTTP 客户端侧 POST 往返（含本机代理时）；不含浏览器 JS/pywebview hop。")
    return 0


if __name__ == "__main__":
    sys.exit(main())