#!/usr/bin/env python3
# MATT-POCOCK-GRILLING-QUESTION-HOOK v2
"""Claude Code hook: attach the AskUserQuestion policy when grilling starts.

Registered for two events by install-question-tools.sh:
  PostToolUse (matcher "Skill")  fires when Claude loads a grilling skill,
                                 including grilling called by grill-me,
                                 grill-with-docs, wayfinder, triage, etc.
  UserPromptSubmit               fires when the user types /grilling or
                                 /loop-me (typed slash commands do not go
                                 through the Skill tool).

It never blocks or edits anything. It only adds context. Any error exits 0
silently so a broken hook can never interrupt a session.
Usage: python3 grilling-question-hook.py /absolute/path/grilling-question-tools.md
"""
import json
import re
import sys

SKILLS = ('grilling', 'grill-me', 'grill-with-docs', 'loop-me')
# /grill-me and /grill-with-docs always call the Skill tool for "grilling", so
# PostToolUse already covers them; matching them here would inject twice.
TYPED = ('grilling', 'loop-me')
SLASH = re.compile(r'^/(?:[\w.-]+:)?(%s)(?=\s|$)' % '|'.join(map(re.escape, TYPED)))
MAX_POLICY = 32768


def skill_name(value):
    # Plugin installs namespace skills, e.g. "mattpocock-skills:grilling".
    return value.strip().rsplit(':', 1)[-1] if isinstance(value, str) else ''


def triggered(event):
    name = event.get('hook_event_name')
    if name == 'PostToolUse' and event.get('tool_name') == 'Skill':
        tool_input = event.get('tool_input')
        if isinstance(tool_input, dict) and skill_name(tool_input.get('skill')) in SKILLS:
            return name
    if name == 'UserPromptSubmit':
        prompt = event.get('prompt')
        if isinstance(prompt, str) and SLASH.match(prompt.lstrip()):
            return name
    return None


def main():
    if len(sys.argv) != 2:
        return
    event = json.load(sys.stdin)
    if not isinstance(event, dict):
        return
    name = triggered(event)
    if not name:
        return
    with open(sys.argv[1], 'rb') as stream:
        policy = stream.read(MAX_POLICY + 1).decode('utf-8')
    if len(policy) > MAX_POLICY or 'MATT-POCOCK-GRILLING-QUESTION-POLICY' not in policy:
        print('Grilling question policy missing or invalid: %s' % sys.argv[1], file=sys.stderr)
        return
    context = ('A Matt Pocock grilling flow is active. Deliver its questions with '
               'AskUserQuestion as this policy describes; everything else in the '
               'flow is unchanged.\n\n' + policy.strip() + '\n')
    json.dump({'hookSpecificOutput': {'hookEventName': name, 'additionalContext': context}},
              sys.stdout)


if __name__ == '__main__':
    try:
        main()
    except Exception as error:  # Never break the session.
        print('Grilling question hook skipped: %s' % error, file=sys.stderr)
    sys.exit(0)