"""Summarize confirmed fall events for review, latency records and
false-alarm counting during acceptance sessions.

Reads the JSONL written by ``alerts.EventArtifactWriter``. Use it after a test
session: run some normal activity (walking, sitting, bending, picking up) and
check that no events were recorded, or read back the latency of real falls.

    python -m v1.report                      # scans artifacts/events
    python -m v1.report artifacts/events     # a source directory
    python -m v1.report .../20260721/events.jsonl
"""

import json
import sys
from pathlib import Path
from typing import Dict, List


def load_events(jsonl_path: Path) -> List[Dict]:
    path = Path(jsonl_path)
    if not path.is_file():
        return []
    events = []
    for line in path.read_text(encoding="utf-8").splitlines():
        line = line.strip()
        if line:
            events.append(json.loads(line))
    return events


def collect_jsonl(root: Path) -> List[Path]:
    """Return every events.jsonl under a source/day directory, or the file itself."""

    path = Path(root)
    if path.is_file():
        return [path]
    return sorted(path.glob("**/events.jsonl"))


def summarize(events: List[Dict]) -> Dict:
    latencies = [float(e.get("latency_seconds", 0.0)) for e in events]
    within = [lat for lat in latencies if 1.0 <= lat <= 3.0]
    return {
        "count": len(events),
        "latencies": latencies,
        "latency_in_target": len(within),
    }


def format_report(jsonl_path: Path, events: List[Dict]) -> str:
    summary = summarize(events)
    lines = [
        "{0}".format(jsonl_path),
        "  events: {0}  (latency in 1-3s: {1}/{0})".format(
            summary["count"], summary["latency_in_target"]
        ),
    ]
    for event in events:
        lines.append(
            "  {0}  track={1}  utc={2}  latency={3:.2f}s  shot={4}".format(
                event.get("event_id", "?"),
                event.get("track_id", "?"),
                event.get("confirmed_at_utc", "?"),
                float(event.get("latency_seconds", 0.0)),
                event.get("screenshot", "?"),
            )
        )
    if not events:
        lines.append("  (no confirmed events — a clean pass for negative activity)")
    return "\n".join(lines)


def main(argv=None) -> int:
    argv = list(sys.argv[1:] if argv is None else argv)
    root = Path(argv[0]) if argv else Path("artifacts/events")
    files = collect_jsonl(root)
    if not files:
        print("no events.jsonl found under {0}".format(root))
        return 0
    for jsonl_path in files:
        print(format_report(jsonl_path, load_events(jsonl_path)))
    return 0


if __name__ == "__main__":
    raise SystemExit(main())