import argparse
from dataclasses import asdict
import json
from pathlib import Path
from .core import ClockError
from .client import Clock, FileTrust
from .authority import Authority, Server


def main():
    parser = argparse.ArgumentParser(description='Authenticated application time; never changes OS time')
    commands = parser.add_subparsers(dest='command', required=True)
    read = commands.add_parser('read'); read.add_argument('--trust', required=True)
    serve = commands.add_parser('serve'); serve.add_argument('--config', required=True)
    health = commands.add_parser('health-export'); health.add_argument('--policy', required=True); health.add_argument('--output', required=True)
    args = parser.parse_args()
    try:
        if args.command == 'read':
            print(json.dumps(asdict(Clock(FileTrust(args.trust)).read())))
        elif args.command == 'health-export':
            from .health import collect, write_health
            write_health(args.output, collect(json.loads(Path(args.policy).read_text())))
        else:
            config = json.loads(Path(args.config).read_text())
            # Private host pilot: external exposure belongs to the deployment owner.
            Server(('127.0.0.1', config.get('port', 8787)), Authority(config)).serve_forever()
    except (ClockError, OSError, ValueError, KeyError):
        parser.exit(1, 'Railiance time unavailable or untrusted.\n')