#!/usr/bin/env python3
"""AI Crawler Index — classify a user-agent string.
curl -s https://www.pathwren.workers.dev/snippet/python-classify.txt -o classify.py

Loads the index once, answers in O(number of crawlers) per call, no dependencies.
Refresh agents.json on whatever schedule you like; the shape never changes.
"""
import json, re, urllib.request

INDEX = "https://www.pathwren.workers.dev/data/agents.json"


def load(url=INDEX):
    with urllib.request.urlopen(url, timeout=20) as r:
        return json.load(r)["crawlers"]


class Classifier:
    def __init__(self, crawlers=None):
        self.crawlers = crawlers or load()
        self.rx = [(re.compile(re.escape(c["user_agent_substring"]), re.I), c)
                   for c in self.crawlers
                   if not c["user_agent_substring"].startswith("(")]

    def __call__(self, ua: str):
        """Return the matching record, or None for anything unrecognised."""
        for rx, c in self.rx:
            if rx.search(ua or ""):
                return c
        return None


if __name__ == "__main__":
    import sys
    c = Classifier()
    for line in (sys.argv[1:] or sys.stdin):
        hit = c(line.strip())
        print(f"{hit['name']}\t{hit['category']}\t{hit['operator']}" if hit
              else "-\tunknown\t-")