import json
import subprocess

import click
from pathlib import PurePath, Path
import configparser
import logging
from logging.handlers import RotatingFileHandler
import sys

APP_NAME = 'iottb'
DB_NAME = 'iottb.db'

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."""
    assert logger is not None, 'Logger must be initialized'
    logger.info(f'Creating default config file at {cfg_file}')
    # By default, create iottb.db in user home
    defaults = {
        'DefaultDatabase': DB_NAME,
        'DatabaseLocations': {
            DB_NAME: str(Path.home() / DB_NAME)
        }
    }
    with open(cfg_file, 'w') as config_file:
        json.dump(defaults, config_file)
    return defaults


def load_config(ctx, param, value):
    """ Try to load iottb config file.
        If the file does not exist, it will be created with default values.`
        Try to load the iottb config file from the given path.
        If the file does not exist, it will be created with default values.
        The only value set is the path to the iottb.db file.
    """
    logger.info(f'Loading config from {value}')
    cfg_file = value
    if not cfg_file.is_file():
        defaults = create_default_config(cfg_file)
    else:
        defaults = json.load(cfg_file)

    ctx.obj['path']['cfg'] = cfg_file
    ctx.obj['path']['db'] = defaults['DatabaseLocations'][defaults['DefaultDatabase']]


@click.group()
@click.option('-v', '--verbosity', type=click.IntRange(0, MAX_VERBOSITY), 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', is_eager=True, callback=load_config, help='Path to iottb config file')
@click.pass_context
def main(verbosity, debug):
    setup_logging(verbosity, debug)


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