import argparse
import csv
import gzip
import sys


def domains(path):
    with gzip.open(path, "rt", encoding="utf-8") as source:
        for line in source:
            domain = line.strip().lower().rstrip(".")
            if domain:
                yield domain

import datetime
import json

parser = argparse.ArgumentParser(description="Build bounded domain evidence for an AI agent")
parser.add_argument("file")
parser.add_argument("--keyword", required=True)
parser.add_argument("--observation-date", required=True)
parser.add_argument("--limit", type=int, default=20)
args = parser.parse_args()
if not 1 <= args.limit <= 100:
    parser.error("limit must be between 1 and 100")
try:
    date = datetime.date.fromisoformat(args.observation_date).isoformat()
except ValueError:
    parser.error("observation-date must be YYYY-MM-DD")
matches = []
for domain in domains(args.file):
    if args.keyword.lower() in domain:
        matches.append(domain)
        if len(matches) == args.limit:
            break
print(json.dumps({"source_file": args.file, "observation_date": date,
                  "meaning": "newly observed names, not verified registrations",
                  "selection": "first matching names in file order",
                  "limit": args.limit, "domains": matches}, indent=2))