import json
import click
from pathlib import Path
import logging
from logging.handlers import RotatingFileHandler
import sys
from iottb.contexts import IottbConfig

APP_NAME = 'iottb'
DB_NAME = 'iottb.db'
CFG_FILE_PATH = str(Path(click.get_app_dir(APP_NAME)).joinpath('iottb.cfg'))
CONSOLE_LOG_FORMATS = {
    0: '%(levelname)s - %(message)s',
    1: '%(levelname)s - %(module)s - %(message)s',
    2: '%(levelname)s - %(asctime)s - %(module)s - %(funcName)s - %(lineno)d - %(message)s'
}

LOGFILE_LOG_FORMAT = {
    0: '%(levelname)s - %(asctime)s - %(module)s  - %(message)s',
    1: '%(levelname)s - %(asctime)s - %(module)s - %(funcName)s - %(message)s',
    2: '%(levelname)s - %(asctime)s - %(module)s - %(funcName)s - %(lineno)d - %(message)s'
}
MAX_VERBOSITY = len(CONSOLE_LOG_FORMATS) - 1
assert len(LOGFILE_LOG_FORMAT) == len(CONSOLE_LOG_FORMATS), 'Log formats must be same size'

logger = logging.getLogger(__name__)


def setup_logging(verbosity, debug):
    """ Setup root logger for iottb """
    log_level = logging.ERROR
    handlers = []
    date_format = '%Y-%m-%d %H:%M:%S'
    if verbosity > 0:
        log_level = logging.WARNING
        if verbosity > MAX_VERBOSITY:
            verbosity = MAX_VERBOSITY
            log_level = logging.INFO
        assert verbosity <= MAX_VERBOSITY, f'Verbosity must be <= {MAX_VERBOSITY}'
        console_handler = logging.StreamHandler(sys.stdout)
        console_handler.setFormatter(logging.Formatter(CONSOLE_LOG_FORMATS[verbosity], datefmt=date_format))
        console_handler.setLevel(logging.DEBUG)  # can keep at debug since it depends on global level?
        handlers.append(console_handler)

    if debug:
        log_level = logging.DEBUG

    # Logfile logs INFO+, no debugs though
    file_handler = RotatingFileHandler(f'{APP_NAME}.log', maxBytes=10240, backupCount=5)
    file_handler.setFormatter(logging.Formatter(LOGFILE_LOG_FORMAT[verbosity], datefmt=date_format))
    file_handler.setLevel(logging.INFO)

    # finnish root logger setup
    handlers.append(file_handler)
    # Force this config to be applied to root logger
    logging.basicConfig(level=log_level, handlers=handlers, force=True)


def create_default_config(cfg_file):
    """Create default iottb config file."""
    logger.info(f'Creating default config file at {cfg_file}')
    defaults = {
        'DefaultDatabase': DB_NAME,
        'DefaultDatabasePath': str(Path.home())
    }

    try:
        cfg_file.parent.mkdir(exist_ok=True)
        with cfg_file.open('w') as config_file:
            defaults_dict = json.dumps(defaults, indent=4)
            config_file.write(defaults_dict)
    except IOError as e:
        logger.error(f"Failed to create default configuration file at {cfg_file}: {e}")
        raise RuntimeError(f"Failed to create configuration file: {e}") from e
    return defaults


def load_config(cfg_file):
    """Loads or creates default configuration from given file path."""
    logger.info("Loading iottb config file")
    if not cfg_file.is_file():
        return create_default_config(cfg_file)
    with open(cfg_file, 'r') as config_file:
        return json.load(config_file)



@click.group()
@click.option('-v', '--verbosity', count=True, type=click.IntRange(0, 3), default=0,
              help='Set verbosity')
@click.option('-d', '--debug', is_flag=True, default=False,
              help='Enable debug mode')
@click.option('--cfg-file', type=click.Path(),
              default=Path(click.get_app_dir(APP_NAME)).joinpath('iottb.cfg'),
              envvar='IOTTB_CONF_HOME', help='Path to iottb config file')
@click.pass_context
def cli(ctx, verbosity, debug, cfg_file):
    ctx.ensure_object(dict)  # Make sure context is ready for use
    logger.info("Starting execution.")
    ctx.obj['CONFIG'] = IottbConfig(cfg_file)  # Load configuration directly
    setup_logging(verbosity, debug)  # Setup logging based on the loaded configuration and other options


@click.command()
@click.option('-d', '--dest', default=str(Path.home()), type=str, help='Location to put (new) iottb database')
@click.option('--name', default=DB_NAME, type=str, help='Name of new database.')
@click.option('--update-default/ --no-update-default', default=True,
              help='If new db should be set as the new default')
@click.pass_context
def init_db(ctx, dest, name, update_default):
    logger.debug('TOP init_db')


@click.command
@click.option('--obj', '--object', type=click.Choice(['cfg', 'db', 'dev', 'cap']),
              help='Type of file to edit.')
@click.option('--file', type=click.Choice(['iottb.cfg', '']))
def edit(ctx, file, table, key, value):
    """Edit config or metadata files. TODO: Implement"""
    pass


@click.command
@click.confirmation_option(prompt="Are you certain that you want to delete the cfg file?")
def rm_cfg():
    """ Removes the cfg file from the filesystem.

        This is mostly a utility during development. Once non-standard database locations are implemented,
        deleting this would lead to iottb not being able to find them anymore.
    """
    Path(CFG_FILE_PATH).unlink()
    click.echo(f'Iottb configuration removed at {CFG_FILE_PATH}')


##################################################################################
# Add all subcommands to group here
#################################################################################
cli.add_command(init_db)
cli.add_command(rm_cfg)
cli.add_command(edit)

if __name__ == '__main__':
    cli(auto_envvar_prefix='IOTTB')