import argparse
import dynamic_inventory


class Script(object):
    def __init__(self, environment_path):
        config = dynamic_inventory.Config(environment_path)
        self.inventory = dynamic_inventory.Inventory(config)

    def execute(self):
        args = self._parse_args()
        if args.host is None:
            self._do_list()
        else:
            self._do_host(args.host)

    def _parse_args(self):
        p = argparse.ArgumentParser(description='Produce Ansible inventory')
        p.add_argument(
            '--list', action='store_true', default=True,
            help='List all hosts')
        p.add_argument(
            '--host', action='store',
            help='Show variable for a single host')
        return p.parse_args()

    def _do_list(self):
        data = self.inventory.groups.copy()
        data["_meta"] = {"hostvars": self.inventory.nodes}
        print(dynamic_inventory.convert_to_json(data))

    def _do_host(self, name):
        print(dynamic_inventory.convert_to_json(self.inventory.nodes[name]))