import json

import click
from pathlib import Path
import logging
import re

from iottb import definitions
from iottb.contexts import DeviceMetadata, IottbConfig
from iottb.definitions import CFG_FILE_PATH

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.option('--dev', '--device-name', type=str, required=True,
              help='The name of the device to be added. If this string contains spaces or other special characters \
              normalization is performed to derive a canonical name')
@click.option('--db', '--database', type=click.Path(exists=True, file_okay=False, dir_okay=True, path_type=Path),
              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.
    """
    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
        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'Could not find a database.')
        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()}')


# @click.command('add-device', help='Add a device to a database')
# @click.option('-d', '--dev', '--device-name', type=str, required=True,
#               help='The name of the device to be added. If this string contains spaces or other special characters \
#                    normalization is performed to derive a canonical name')
# @click.option('--db', '--database', type=click.Path(exists=True, file_okay=False, dir_okay=True, path_type=Path),
#               envvar='IOTTB_DB', show_envvar=True,
#               help='Name of 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')
# # @click.option('-m', '--model', default="", help='Model of the device')
# # @click.option('--manufacturer', default="", help='Manufacturer of the device')
# # @click.option('--firmware-version', default="", help='Current firmware version of the device')
# # @click.option('--device-type', default="", help='Type of the device')
# # @click.option('-i', '--interfaces', default="", help='Supported interfaces of the device')
# # @click.option('--apps', '--companion-applications', default="", help='Companion applications of the device')
# # @click.option('--desc', '--description', default="", help='Description of the device')
# @click.pass_context
# def add_device_inactive(ctx, 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.
#     """
#     logger.info('add-device invoked')
#     config = ctx.obj['CONFIG']
#     logger.debug(f'{str(config)}')
#     database = None
#     # Setep1: Determine the current db
#     if db:
#         db_path = str(config.get_database_path)
#         database = str(config.get_full_default_path())
#         logger.debug(f'database: {database}. variable type: {type(database)}')
#         click.echo(f'No db specified, using default database')
#     if not Path(database).is_dir():
#         logger.warning(f'No database at {database}')
#         click.echo(f'Could not find a database.')
#         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"')
#         exit()
#
#     # Step 2: Check if device already exists
#     if guided:
#         add_device_guided(ctx, dev, database)
#     else:
#         device_metadata = DeviceMetadata(device_name=dev)
#         device_metadata.print_attributes()
#         click.echo('TODO: Unguided device add path')
#
#     logger.info(f'Device {dev} added.')


def normalize_device_name(name):
    """Normalizes the device name to get a shorter representation which is easier to use at the command line.

        This function derives a device name which can be more easily specified at the command line.
        The first two occurrences of white space are turned into a dash, the rest of the name is dropped.
        Name should be an ASCII string.
    """
    logger.info(f'Normalizing name {name}')
    chars_to_replace = definitions.REPLACEMENT_SET_CANONICAL_DEVICE_NAMES
    pattern = re.compile('|'.join(re.escape(char) for char in chars_to_replace))
    norm_name = pattern.sub('-', name, count=2)
    logger.debug(f'Name after first subst: {norm_name}')
    norm_name = pattern.sub('', norm_name)
    logger.debug(f'Fully normalized name: {norm_name}')
    return norm_name