import os

import click.testing
import ereuse_utils
import flask.cli

from ereuse_devicehub.config import DevicehubConfig
from ereuse_devicehub.devicehub import Devicehub


class DevicehubGroup(flask.cli.FlaskGroup):
    # todo users cannot make cli to use a custom db this way!
    CONFIG = DevicehubConfig

    def main(self, *args, **kwargs):
        # todo this should be taken as an argument for the cli
        inventory = os.environ.get('dhi')
        if not inventory:
            raise ValueError('Please do "export dhi={inventory}"')
        self.create_app = self.create_app_factory(inventory)
        return super().main(*args, **kwargs)

    @classmethod
    def create_app_factory(cls, inventory):
        return lambda: Devicehub(inventory, config=cls.CONFIG())


def get_version(ctx, param, value):
    if not value or ctx.resilient_parsing:
        return
    click.echo('Devicehub {}'.format(ereuse_utils.version('ereuse-devicehub')), color=ctx.color)
    flask.cli.get_version(ctx, param, value)


@click.option('--version',
              help='Devicehub version.',
              expose_value=False,
              callback=get_version,
              is_flag=True,
              is_eager=True)
@click.group(cls=DevicehubGroup,
             context_settings=Devicehub.cli_context_settings,
             add_version_option=False,
             help="""
            Manages the Devicehub of the inventory {}.

            Use 'export dhi=xx' to set the inventory that this CLI
            manages. For example 'export dhi=db1' and then executing
            'dh tag add' adds a tag in the db1 database. Operations
            that affect the common database (like creating an user)
            are not affected by this.
             """.format(os.environ.get('dhi')))
def cli():
    pass