"""Publish the weekly retro (AGENTIC-WP-0010 T02).

The retro is published to the State Hub as a **read model** — a progress event of
``event_type=coding_retro`` whose ``detail`` carries the structured report. This is
exactly how ``daily-triage-report`` surfaces, and it is what activity-core's
``coding_retro`` resolver (ACTIVITY-WP-0008) reads. A local JSON + markdown report
is always written; the hub publish is best-effort and **degrades gracefully** when
the hub is unreachable.
"""

from __future__ import annotations

import json
import os
import urllib.request
from typing import Callable, Optional

DEFAULT_HUB = "http://127.0.0.1:8000"


def render_markdown(report: dict) -> str:
    w = report.get("window", {})
    lines = [
        f"# Weekly Coding Retro  ({w.get('since', '')[:10]} → {w.get('until', '')[:10]})",
        f"_{report.get('n_sessions', 0)} real sessions · generated {report.get('generated_at', '')}_",
        "",
        "## Top improvement suggestions (cross-flavor first, ≤3 per repo)",
    ]
    if not report.get("suggestions"):
        lines.append("- (no recurring problems above threshold this week)")
    for s in report.get("suggestions", []):
        flag = " [CROSS-FLAVOR]" if s.get("cross_flavor") else ""
        lines.append(f"- **{s['repo']}** ({s['priority']}, score={s['score']}){flag}: "
                     f"{s['title']} — {s['recommendation']}")
    m = report.get("measure", {})
    lines += ["", "## Fleet snapshot",
              f"- infra-overhead median: {m.get('infra_overhead_share_median')}",
              f"- error rate: {m.get('error_rate')}  ·  schema-thrash: {m.get('schema_thrash_sessions')}",
              f"- success rate: {m.get('success_rate')}  ·  tokens p50: {m.get('tokens_p50')}"]
    return "\n".join(lines)


def write_local(report: dict, json_path: str, md_path: Optional[str] = None) -> None:
    os.makedirs(os.path.dirname(json_path) or ".", exist_ok=True)
    with open(json_path, "w", encoding="utf-8") as fh:
        json.dump(report, fh, indent=2, sort_keys=True)
        fh.write("\n")
    if md_path:
        with open(md_path, "w", encoding="utf-8") as fh:
            fh.write(render_markdown(report))
            fh.write("\n")


def _http_post(url: str, payload: dict) -> None:
    req = urllib.request.Request(url, data=json.dumps(payload).encode(),
                                 headers={"Content-Type": "application/json"}, method="POST")
    with urllib.request.urlopen(req, timeout=10) as r:
        r.read()


def publish_to_hub(report: dict, *, base_url: str = DEFAULT_HUB,
                   poster: Optional[Callable[[str, dict], None]] = None) -> bool:
    """POST the retro as an event_type=coding_retro progress event. Best-effort."""
    poster = poster or _http_post
    n = report.get("n_sessions", 0)
    k = len(report.get("suggestions", []))
    payload = {
        "event_type": "coding_retro",
        "author": "helix-forge",
        "summary": f"Weekly coding retro: {k} ranked suggestions across "
                   f"{report.get('window', {}).get('days', 7)} days ({n} sessions).",
        "detail": report,
    }
    try:
        poster(f"{base_url.rstrip('/')}/progress/", payload)
        return True
    except Exception:
        return False