"""Selected counters from existing authenticated APIs, without traffic records."""
from __future__ import annotations

import json
import time


def traffic_analytics_snapshot(rust, timeout=2):
    """Read global analytics queue loss; never retain paths, IPs or user agents.

    queue_dropped is process-global even when the API's vhost query is used.
    recorded_requests is asynchronous analytics work, not an HTTP success count.
    Call outside a timed load interval so this control-plane read is not charged
    to the request path being measured.
    """
    status, _, body = rust.admin("/api/traffic", timeout=timeout)
    if status != 200:
        raise RuntimeError(f"traffic analytics counter capture failed: HTTP {status}")
    payload = json.loads(body)
    if not isinstance(payload, dict) or payload.get("scope") != "*" or payload.get("since") != "process_start":
        raise RuntimeError("traffic analytics requires the global process-start scope")
    analytics = payload.get("analytics")
    if not isinstance(analytics, dict) or analytics.get("scope") != "*":
        raise RuntimeError("traffic analytics response lacks the global queue view")
    data = analytics.get("data")
    if not isinstance(data, dict):
        raise RuntimeError("traffic analytics response lacks the recorded counters")
    values = {"queue_capacity": analytics.get("queue_capacity"),
              "queue_dropped": analytics.get("queue_dropped"),
              "recorded_requests": data.get("requests")}
    if any(type(value) is not int or value < 0 for value in values.values()) or not values["queue_capacity"]:
        raise RuntimeError("traffic analytics queue counters are absent or malformed")
    return {"endpoint": "/api/traffic", "scope": "*", "since": "process_start",
            "pid": rust.process.pid, "observed_monotonic": time.monotonic(), **values}


def traffic_analytics_delta(before, after):
    """Keep telemetry loss separate from failed HTTP requests and log rotation."""
    for key in ["pid", "endpoint", "scope", "since", "queue_capacity"]:
        if before[key] != after[key]:
            raise RuntimeError(f"traffic analytics identity changed during capture: {key}")
    result = {"queue_dropped_delta": after["queue_dropped"] - before["queue_dropped"],
              "recorded_requests_delta": after["recorded_requests"] - before["recorded_requests"],
              "interval_seconds": after["observed_monotonic"] - before["observed_monotonic"]}
    if any(value < 0 for value in result.values()):
        raise RuntimeError("traffic analytics counters or clock reset during capture")
    return result