#!/usr/bin/env python3
"""Consult one decision with its private scoped credential, never execute its plan."""
import argparse
import hashlib
import json
from pathlib import Path
import re
from control import Client


def endpoint(cfg, suffix=''):
    decision_id=cfg.get('decision_id')
    if not isinstance(decision_id,str) or not re.fullmatch(r'[A-Za-z0-9_.:-]{1,128}',decision_id):
        raise ValueError('Invalid bound decision')
    return '/api/decisions/'+decision_id+suffix


def execute(cfg,action,payload=None):
    client=Client(cfg['control'])
    if action=='show':return client.call(endpoint(cfg))
    if action=='history':return client.call(endpoint(cfg,'/history'))
    if action=='edit':
        if not isinstance(payload,dict) or 'expected_revision' not in payload or not payload.get('reason'):
            raise ValueError('Edit requires current revision and reason')
        return client.call(endpoint(cfg),payload,'PATCH')
    if action=='ask':
        if not isinstance(payload,dict) or not payload.get('question'):
            raise ValueError('A factual question is required')
        key=payload.get('idempotency_key') or 'fact-'+hashlib.sha256(
            json.dumps(payload,sort_keys=True,ensure_ascii=True).encode()).hexdigest()[:32]
        return client.call(endpoint(cfg,'/facts'),{**payload,'idempotency_key':key})
    raise ValueError('Unsupported consultation action')


def main():
    parser=argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--config',required=True)
    parser.add_argument('action',choices=['show','history','edit','ask'])
    parser.add_argument('--payload-file')
    parser.add_argument('--question')
    args=parser.parse_args()
    cfg=json.loads(Path(args.config).read_text(encoding='utf-8-sig'))
    payload=json.loads(Path(args.payload_file).read_text(encoding='utf-8-sig')) if args.payload_file else None
    if args.question:payload={'question':args.question}
    print(json.dumps(execute(cfg,args.action,payload),ensure_ascii=True))


if __name__=='__main__':main()