{"files": {"main.py": "from core import run\nfrom policy import POLICY\ndef evaluate(payload):\n    return run(payload, POLICY)\n", "policy.py": "POLICY = {\"audit_all\": True, \"duplicate_policy\": \"first\", \"empty_id\": \"skip\", \"fold_case\": True, \"list_merge\": \"replace\", \"nested_merge\": True, \"null_mode\": \"ignore\", \"order\": \"id\", \"tombstone_wins\": True, \"trim_ids\": True, \"unknown_fields\": \"keep\", \"version_floor\": 2}\n", "helpers.py": "import copy\n\n\ndef ascii_fold(s):\n    return ''.join(chr(ord(c) + 32) if 'A' <= c <= 'Z' else c for c in s)\n\n\ndef merge(old, new, policy):\n    for k, v in new.items():\n        if v is None:\n            if policy['null_mode'] == 'delete':\n                old.pop(k, None)\n            continue\n        if k in old:\n            o = old[k]\n            if policy['nested_merge'] and isinstance(o, dict) and isinstance(v, dict):\n                merge(o, v, policy)\n                continue\n            if policy['list_merge'] == 'unique' and isinstance(o, list) and isinstance(v, list):\n                add = [copy.deepcopy(x) for x in v if not any(x == y for y in o)]\n                old[k] = o + add\n                continue\n        old[k] = copy.deepcopy(v)\n    return old\n", "core.py": "import copy\nfrom helpers import ascii_fold, merge\n\nKEEP = ('name', 'tags', 'meta')\n\n\ndef run(payload, policy):\n    events = payload['events']\n    chosen = {}\n    order_keys = []\n    for i, e in enumerate(events):\n        nid = e['id']\n        if policy['trim_ids']:\n            nid = nid.strip()\n        if policy['fold_case']:\n            nid = ascii_fold(nid)\n        if nid == '':\n            if policy['empty_id'] == 'raise':\n                raise ValueError('empty id')\n            continue\n        if e['version'] < policy['version_floor']:\n            continue\n        key = (nid, e['version'])\n        if key not in chosen:\n            chosen[key] = (i, e)\n            order_keys.append(key)\n        elif policy['duplicate_policy'] == 'last':\n            chosen[key] = (i, e)\n    items = [(k[1], chosen[k][0], k[0], chosen[k][1]) for k in order_keys]\n    items.sort(key=lambda t: (t[0], t[1]))\n    records = {}\n    tomb = set()\n    first_idx = {}\n    audit = []\n    for pos, (ver, oi, nid, e) in enumerate(items):\n        if nid not in first_idx:\n            first_idx[nid] = pos\n        applied = False\n        if e['deleted']:\n            if nid in tomb:\n                applied = False\n            elif nid in records:\n                del records[nid]\n                if policy['tombstone_wins']:\n                    tomb.add(nid)\n                applied = True\n            elif policy['tombstone_wins']:\n                tomb.add(nid)\n                applied = True\n        else:\n            if policy['tombstone_wins'] and nid in tomb:\n                applied = False\n            else:\n                f = e['fields']\n                if policy['unknown_fields'] == 'drop':\n                    f = {k: v for k, v in f.items() if k in KEEP}\n                rec = records.get(nid)\n                if rec is None:\n                    rec = {}\n                    records[nid] = rec\n                merge(rec, f, policy)\n                applied = True\n        if applied or policy['audit_all']:\n            audit.append('%s:%d:%s' % (nid, ver, 'applied' if applied else 'blocked'))\n    ids = list(records.keys())\n    if policy['order'] == 'id':\n        ids.sort()\n    else:\n        ids.sort(key=lambda n: (first_idx[n], n))\n    return {'records': [{'id': n, 'fields': copy.deepcopy(records[n])} for n in ids], 'audit': audit}\n"}}