"""
Copyright OpenSearch Contributors
SPDX-License-Identifier: Apache-2.0
"""

import errno
import os
import platform
import shutil

from os.path import expanduser, exists, dirname
from configobj import ConfigObj


def config_location():
    """Return absolute conf file path according to different OS."""
    if "XDG_CONFIG_HOME" in os.environ:
        return "%s/opensearchsql-cli/" % expanduser(os.environ["XDG_CONFIG_HOME"])
    elif platform.system() == "Windows":
        # USERPROFILE is typically C:\Users\{username}
        return "%s\\AppData\\Local\\dbcli\\opensearchsql-cli\\" % os.getenv("USERPROFILE")
    else:
        return expanduser("~/.config/opensearchsql-cli/")


def _load_config(user_config, default_config=None):
    config = ConfigObj()
    config.merge(ConfigObj(default_config, interpolation=False))
    config.merge(ConfigObj(expanduser(user_config), interpolation=False, encoding="utf-8"))
    config.filename = expanduser(user_config)

    return config


def ensure_dir_exists(path):
    """
    Try to create config file in OS.

    Ignore existing destination. Raise error for other OSError, such as errno.EACCES (Permission denied),
    errno.ENOSPC (No space left on device)
    """
    parent_dir = expanduser(dirname(path))
    try:
        os.makedirs(parent_dir)
    except OSError as exc:
        if exc.errno != errno.EEXIST:
            raise


def _write_default_config(source, destination, overwrite=False):
    destination = expanduser(destination)
    if not overwrite and exists(destination):
        return

    ensure_dir_exists(destination)
    shutil.copyfile(source, destination)


# https://stackoverflow.com/questions/40193112/python-setuptools-distribute-configuration-files-to-os-specific-directories
def get_config(clirc_file=None):
    """
    Get config for opensearchsql cli.

    This config comes from either existing config in the OS, or create a config file in the OS, and write default config
    including in the package to it.
    """
    from .conf import __file__ as package_root

    package_root = os.path.dirname(package_root)

    clirc_file = clirc_file or "%sconfig" % config_location()
    default_config = os.path.join(package_root, "clirc")

    _write_default_config(default_config, clirc_file)

    return _load_config(clirc_file, default_config)