#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2018, Anaconda, Inc. and Intake contributors
# All rights reserved.
#
# The full license is in the LICENSE file, distributed with this software.
#-----------------------------------------------------------------------------

from os.path import expanduser
import logging
import os
import posixpath
import yaml
from intake.utils import yaml_load

from .utils import make_path_posix
logger = logging.getLogger('intake')

confdir = make_path_posix(
    os.getenv('INTAKE_CONF_DIR', os.path.join(expanduser('~'), '.intake')))


defaults = {
    'auth': {'cls': 'intake.auth.base.BaseAuth'},
    'port': 5000,
    'cache_dir': posixpath.join(confdir, 'cache'),
    'cache_disabled': False,
    'cache_download_progress': True,
    'logging': 'INFO',
    'catalog_path': [],
    'persist_path': posixpath.join(confdir, 'persisted'),
    'package_scan': False
}


def cfile():
    return make_path_posix(
        os.getenv('INTAKE_CONF_FILE', posixpath.join(confdir, 'conf.yaml')))


class Config(dict):
    def __init__(self, filename=None, **kwargs):
        self.filename = filename if filename is not None else cfile()
        self.reload_all()
        super().__init__(**kwargs)

    def reset(self):
        """Set conf values back to defaults"""
        self.clear()
        self.update(defaults)

    def save(self):
        """Save current configuration to file as YAML

        Uses ``.filename`` for target location
        """
        if self.filename is False:
            return
        try:
            os.makedirs(os.path.dirname(self.filename))
        except (OSError, IOError):
            pass
        with open(self.filename, 'w') as f:
            yaml.dump(dict(self), f)

    def reload_all(self):
        self.reset()
        self.load()
        self.load_env()

    def load(self, fn=None):
        """Update global config from YAML file

        If fn is None, looks in global config directory, which is either defined
        by the INTAKE_CONF_DIR env-var or is ~/.intake/ .
        """
        fn = fn or self.filename

        if os.path.isfile(fn):
            with open(fn) as f:
                try:
                    self.update(yaml_load(f))
                except Exception as e:
                    logger.warning('Failure to load config file "{fn}": {e}'
                                   ''.format(fn=fn, e=e))

    def load_env(self):
        """Analyse environment variables and update conf accordingly"""
        # environment variables take precedence over conf file
        for key, envvar in [['cache_dir', 'INTAKE_CACHE_DIR'],
                            ['catalog_path', 'INTAKE_PATH'],
                            ['persist_path', 'INTAKE_PERSIST_PATH']]:
            if envvar in os.environ:
                self[key] = make_path_posix(os.environ[envvar])
        self['catalog_path'] = intake_path_dirs(self['catalog_path'])
        for key, envvar in [['cache_disabled', 'INTAKE_DISABLE_CACHING'],
                            ['cache_download_progress', 'INTAKE_CACHE_PROGRESS']]:
            if envvar in os.environ:
                self[key] = os.environ[envvar].lower() in ['true', 't', 'y', 'yes']
        if 'INTAKE_LOG_LEVEL' in os.environ:
            self['logging'] = os.environ['INTAKE_LOG_LEVEL']


def intake_path_dirs(path):
    """Return a list of directories from the intake path.

    If a string, perhaps taken from an environment variable, then the
    list of paths will be split on the character ":" for posix of ";" for
    windows. Protocol indicators ("protocol://") will be ignored.
    """
    if isinstance(path, (list, tuple)):
        return path
    import re
    pattern = re.compile(";" if os.name == 'nt' else r"(?<!:):(?![:/])")
    return pattern.split(path)


conf = Config()
conf.reload_all()
save_conf = conf.save
load_cond = conf.load

logger.setLevel(conf['logging'].upper())
ch = logging.StreamHandler()
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - '
                              '%(filename)s:%(funcName)s:L%(lineno)d - '
                              '%(message)s')
ch.setFormatter(formatter)
logger.addHandler(ch)
logger.debug('Intake logger set to debug')