import appdirs
import argparse
import logging
import os
import pathlib
import sys

from configparser import ConfigParser
from getpass import getpass

from api import StandardNotesAPI
from sn_fuse import StandardNotesFUSE
from fuse import FUSE

OFFICIAL_SERVER_URL = 'https://sync.standardnotes.org'
DEFAULT_SYNC_SEC = 30
MINIMUM_SYNC_SEC = 5
APP_NAME = 'standardnotes-fs'

# path settings
cfg_env = os.environ.get('SN_FS_CONFIG_PATH')
CONFIG_PATH = cfg_env if cfg_env else appdirs.user_config_dir(APP_NAME)
CONFIG_FILE = pathlib.PurePath(CONFIG_PATH, APP_NAME + '.conf')

def parse_options():
    parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter)
    parser.add_argument('mountpoint', nargs='?', help='local mountpoint folder')
    parser.add_argument('--username',
                        help='Standard Notes username to log in with')
    parser.add_argument('--password',
                        help='Standard Notes password to log in with\n'
                             'NOTE: It is NOT recommended to use this option!\n'
                             '      The password may be stored in history, so\n'
                             '      use the password prompt instead.')
    parser.add_argument('-v', '--verbosity', action='count',
                        help='output verbosity -v or -vv (implies --foreground)')
    parser.add_argument('--foreground', action='store_true',
                        help='run standardnotes-fs in the foreground')
    parser.add_argument('--sync-sec', type=int, default=DEFAULT_SYNC_SEC,
                        help='how many seconds between each sync. Default: 10')
    parser.add_argument('--sync-url',
                        help='URL of Standard File sync server. Defaults to:\n'
                        ''+OFFICIAL_SERVER_URL)
    parser.add_argument('--no-config-file', action='store_true',
                        help='don\'t load or create a config file')
    parser.add_argument('--config', default=CONFIG_FILE,
                        help='specify a config file location. Defaults to:\n'
                        ''+str(CONFIG_FILE))
    parser.add_argument('--logout', action='store_true',
                        help='delete login credentials saved in config and quit')
    return parser.parse_args()

def main():
    args = parse_options()
    config = ConfigParser()
    keys = {}

    # configure logging
    if args.verbosity == 1:
        log_level = logging.INFO
    elif args.verbosity == 2:
        log_level = logging.DEBUG
    else:
        log_level = logging.CRITICAL
    logging.basicConfig(level=log_level,
                        format='%(levelname)-8s: %(message)s')
    if args.verbosity: args.foreground = True

    # figure out config file
    config_file = pathlib.Path(args.config)

    # logout and quit if wanted
    if args.logout:
        try:
            config_file.unlink()
            print('Config file deleted and logged out.')
        except OSError:
            logging.info('Already logged out.')
        sys.exit(0)

    # make sure mountpoint is specified
    if not args.mountpoint:
        print('No mountpoint specified.')
        sys.exit(1)

    # keep sync_sec above the minimum sync time
    if args.sync_sec < MINIMUM_SYNC_SEC:
        sync_sec = MINIMUM_SYNC_SEC
        print('Sync interval must be at least', MINIMUM_SYNC_SEC,
              'seconds. Using that instead.')
    else:
        sync_sec = args.sync_sec

    # load config file settings
    if not args.no_config_file:
        try:
            config_file.parent.mkdir(mode=0o0700, parents=True, exist_ok=True)
            log_msg = 'Using config directory "%s".'
            logging.info(log_msg % str(config_file.parent))
        except OSError:
            log_msg = 'Error creating config file directory "%s".'
            print(log_msg % str(config_file.parent))
            sys.exit(1)

        try:
            with config_file.open() as f:
                config.read_file(f)
                log_msg = 'Loaded config file "%s".'
                logging.info(log_msg % str(config_file))
        except OSError:
            log_msg = 'Unable to read config file "%s".'
            logging.info(log_msg % str(config_file))

    # figure out all login params
    if args.sync_url:
        sync_url = args.sync_url
    elif config.has_option('user', 'sync_url'):
        sync_url = config.get('user', 'sync_url')
    else:
        sync_url = OFFICIAL_SERVER_URL
    log_msg = 'Using sync URL "%s".'
    logging.info(log_msg % sync_url)

    if config.has_option('user', 'username') \
        and config.has_section('keys') \
        and not args.username \
        and not args.password:
            username = config.get('user', 'username')
            keys = dict(config.items('keys'))
    else:
        username = args.username if args.username else \
                   input('Please enter your Standard Notes username: ')
        password = args.password if args.password else \
                   getpass('Please enter your password (hidden): ')

    # log the user in
    try:
        sn_api = StandardNotesAPI(sync_url, username)
        if not keys:
            keys = sn_api.genKeys(password)
            del password
        sn_api.signIn(keys)
        log_msg = 'Successfully logged into account "%s".'
        logging.info(log_msg % username)
        login_success = True
    except:
        log_msg = 'Failed to log into account "%s".'
        print(log_msg % username)
        login_success = False

    # write settings back if good, clear if not
    if not args.no_config_file:
        config.read_dict(dict(user=dict(sync_url=sync_url, username=username),
                              keys=keys))
        try:
            with config_file.open(mode='w+') as f:
                if login_success:
                    config.write(f)
                    log_msg = 'Config written to file "%s".'
                    logging.info(log_msg % str(config_file))
                else:
                    log_msg = 'Clearing config file "%s".'
                    logging.info(log_msg % config_file)
            config_file.chmod(0o600)
        except OSError:
            log_msg = 'Unable to write config file "%s".'
            logging.warning(log_msg % str(config_file))

    if login_success:
        logging.info('Starting FUSE filesystem.')
        fuse = FUSE(StandardNotesFUSE(sn_api, sync_sec),
                    args.mountpoint,
                    foreground=args.foreground,
                    nothreads=True) # benefits don't outweigh the costs

    logging.info('Exiting.')

if __name__ == '__main__':
    main()