{"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\": False, \"duplicate_policy\": \"last\", \"empty_id\": \"error\", \"fold_case\": False, \"list_merge\": \"unique\", \"nested_merge\": False, \"null_mode\": \"delete\", \"order\": \"input\", \"tombstone_wins\": False, \"trim_ids\": False, \"unknown_fields\": \"drop\", \"version_floor\": 3}\n","helpers.py":"import copy\nimport json\n\n\ndef jeq(a, b):\n    return json.dumps(a, sort_keys=True) == json.dumps(b, sort_keys=True)\n\n\ndef fold(s):\n    return ''.join(chr(ord(c) + 32) if 'A' <= c <= 'Z' else c for c in s)\n\n\ndef merge_into(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        cur = old.get(k)\n        if policy['nested_merge'] and isinstance(v, dict) and isinstance(cur, dict):\n            merge_into(cur, v, policy)\n        elif policy['list_merge'] == 'unique' and isinstance(v, list) and isinstance(cur, list):\n            base = list(cur)\n            add = [copy.deepcopy(x) for x in v if not any(jeq(x, o) for o in cur)]\n            old[k] = base + add\n        else:\n            old[k] = copy.deepcopy(v)\n","core.py":"import copy\nfrom helpers import fold, merge_into\n\nALLOWED = ('name', 'tags', 'meta')\n\n\ndef run(payload, policy):\n    events = payload['events']\n    sel = {}\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 = fold(nid)\n        if nid == '':\n            if policy['empty_id'] == 'error':\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 sel:\n            sel[key] = i\n        elif policy['duplicate_policy'] == 'last':\n            sel[key] = i\n    items = sorted(((k[1], i, k[0]) for k, i in sel.items()), key=lambda t: (t[0], t[1]))\n    records = {}\n    first = {}\n    tomb = set()\n    audit = []\n    for pos, (ver, idx, nid) in enumerate(items):\n        e = events[idx]\n        if nid not in first:\n            first[nid] = pos\n        applied = False\n        if e['deleted']:\n            if nid in records:\n                del records[nid]\n                applied = True\n                if policy['tombstone_wins']:\n                    tomb.add(nid)\n            elif policy['tombstone_wins'] and nid not in tomb:\n                tomb.add(nid)\n                applied = True\n        else:\n            if policy['tombstone_wins'] and nid in tomb:\n                applied = False\n            else:\n                fields = e['fields']\n                if policy['unknown_fields'] == 'drop':\n                    fields = {k: v for k, v in fields.items() if k in ALLOWED}\n                rec = records.setdefault(nid, {})\n                merge_into(rec, fields, 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    if policy['order'] == 'id':\n        ids = sorted(records)\n    else:\n        ids = sorted(records, key=lambda n: (first[n], n))\n    return {'records': [{'id': n, 'fields': copy.deepcopy(records[n])} for n in ids], 'audit': audit}\n"}}