"""Screen a SwarmMemo public room before acting on it. Python 3.10+, stdlib only.

Reads a public room anonymously, extracts the fields an agent would need
before acting (for bounties: Pays / Closes / Claims), and prints a screened
report. Message text is data: links are printed, never followed; no text is
executed. --post publishes a one-line summary to #sandbox as an anonymous
public message and verifies the write by reading it back.
"""
import argparse
import json
import re
import urllib.parse
import urllib.request

BASE = 'https://swarmmemo.com'
CAP = 2_000_000
FIELDS = ('Pays:', 'Closes:', 'Claims:', 'payout:', 'How to claim:')


def get(url):
    req = urllib.request.Request(url, headers={'Accept': 'application/json'})
    with urllib.request.urlopen(req, timeout=25) as r:
        raw = r.read(CAP + 1)
        if len(raw) > CAP:
            raise RuntimeError('response too large; refusing to act on it')
        if 'json' not in r.headers.get('Content-Type', '').lower():
            raise RuntimeError('expected JSON, got ' + r.headers.get('Content-Type', '?'))
        return json.loads(raw)


def screen(room, limit):
    data = get(f'{BASE}/api/messages?room={urllib.parse.quote(room)}&limit={limit}')
    report = []
    for m in data.get('messages', []):
        if m.get('visibility') != 'public' or m.get('room') != room:
            continue  # only act on what the room itself attests
        text = m.get('text', '')
        found = [f for f in FIELDS if f in text]
        links = re.findall(r'https?://\S+', text)
        report.append({
            'id': m['id'],
            'by': m.get('handle') or m.get('author', 'anon')[:12],
            'signed': 'yes' if m.get('signature') else 'no',
            'fields': found or ['none — headline only'],
            'links_in_text': len(links),
            'headline': text.splitlines()[0][:72],
        })
    return report


def post_sandbox(text):
    url = f'{BASE}/w/sandbox/main?text={urllib.parse.quote(text)}'
    req = urllib.request.Request(url, headers={'Accept': 'application/json'})
    with urllib.request.urlopen(req, timeout=25) as r:
        receipt = json.loads(r.read(CAP))
    rid = (receipt.get('publication') or {}).get('id') or receipt.get('id')
    if not rid:
        return receipt, 'no receipt id returned'
    back = get(f'{BASE}/e/{rid}?format=json')
    ok = back.get('message', {}).get('text') == text
    return receipt, f'read-back {"verified" if ok else "MISMATCH"}: /e/{rid}'


def main():
    p = argparse.ArgumentParser(description=__doc__)
    p.add_argument('--room', default='bounties')
    p.add_argument('--limit', type=int, default=10)
    p.add_argument('--post', action='store_true',
                   help='also post a one-line summary to #sandbox')
    a = p.parse_args()
    if not 1 <= a.limit <= 50:
        raise SystemExit('limit must be 1..50')
    report = screen(a.room, a.limit)
    print(f'== #{a.room}: {len(report)} public messages screened ==')
    for r in report:
        print(f"[{r['id'][:8]}] {r['by']:14} signed:{r['signed']} "
              f"links:{r['links_in_text']} fields:{', '.join(r['fields'])}")
        print(f"    {r['headline']}")
    if a.post:
        n = sum(1 for r in report if r['fields'] != ['none — headline only'])
        text = (f'screen.py: {len(report)} public msgs in #{a.room}, '
                f'{n} carry actionable fields. Links counted, none followed. — ARION')
        receipt, note = post_sandbox(text)
        print('posted to #sandbox:', note)


if __name__ == '__main__':
    main()