import json

import click
from pathlib import Path
import logging
import re

from iottb import definitions
from iottb.models.device_metadata import DeviceMetadata
from iottb.models.iottb_config import IottbConfig
from iottb.definitions import CFG_FILE_PATH, TB_ECHO_STYLES

logger = logging.getLogger(__name__)


def add_device_guided(ctx, cn, db):
    click.echo('TODO: Implement')
    logger.info('Adding device interactively')
    # logger.debug(f'Parameters: {params}. value: {value}')


@click.command('add-device', help='Add a device to a database')
@click.argument('device', type=str, required=True)
@click.option('--db', '--database', type=click.Path(exists=True, file_okay=False, dir_okay=True),
              envvar='IOTTB_DB', show_envvar=True,
              help='Database in which to add this device. If not specified use default from config.')
@click.option('--guided', is_flag=True, default=False, show_default=True, envvar='IOTTB_GUIDED_ADD', show_envvar=True,
              help='Add device interactively')
def add_device(dev, db, guided):
    """Add a new device to a database

        Device name must be supplied unless in an interactive setup. 
        Database is taken from config by default.
        If this device name contains spaces or other special characters normalization is performed to derive a canonical name.
    """
    logger.info('add-device invoked')

    # Step 1: Load Config
    # Dependency: Config file must exist
    config = IottbConfig(Path(CFG_FILE_PATH))
    logger.debug(f'Config loaded: {config}')

    # Step 2: Load database
    # dependency: Database folder must exist
    if db:
        database = db
        path = config.db_path_dict[database]
        logger.debug(f'Resolved (path, db) {path}, {database}')
    else:
        path = config.default_db_location
        database = config.default_database
        logger.debug(f'Default (path, db) {path}, {database}')
    click.secho(f'Using database {database}')
    full_db_path = Path(path) / database
    if not full_db_path.is_dir():
        logger.warning(f'No database at {database}')
        click.echo(f'No database found at {full_db_path}', lvl='w')
        click.echo(
            f'You need to initialize the testbed before before you add devices!')
        click.echo(
            f'To initialize the testbed in the default location run "iottb init-db"')
        click.echo('Exiting...')
        exit()

    # Step 3: Check if device already exists in database
    # dependency: DeviceMetadata object
    device_metadata = DeviceMetadata(device_name=dev)
    device_dir = full_db_path / device_metadata.canonical_name

    # Check if device is already registered
    if device_dir.exists():
        logger.warning(f'Device directory {device_dir} already exists.')
        click.echo(f'Device {dev} already exists in the database.')
        click.echo('Exiting...')
        exit()
    try:
        device_dir.mkdir()
    except OSError as e:
        logger.error(f'Error trying to create device {e}')
        click.echo('Exiting...')
        exit()

    # Step 4: Save metadata into device_dir
    metadata_path = device_dir / definitions.DEVICE_METADATA_FILE_NAME
    with metadata_path.open('w') as metadata_file:
        json.dump(device_metadata.__dict__, metadata_file, indent=4)
    click.echo(f'Successfully added device {dev} to database')
    logger.debug(f'Added device {dev} to database {
                 database}. Full path of metadata {metadata_path}')
    logger.info(f'Metadata for {dev} {device_metadata.print_attributes()}')