# -*- coding: utf-8 -*-
# Copyright (C) 2012 Anaconda, Inc
# SPDX-License-Identifier: BSD-3-Clause
from __future__ import absolute_import, print_function

from argparse import RawDescriptionHelpFormatter

from conda.base.context import context, determine_target_prefix, env_name
from conda.cli.conda_argparse import add_parser_json, add_parser_prefix
from conda.cli.common import stdout_json

from ..env import from_environment

description = """
Export a given environment
"""

example = """
examples:
    conda env export
    conda env export --file SOME_FILE
"""


def configure_parser(sub_parsers):
    p = sub_parsers.add_parser(
        'export',
        formatter_class=RawDescriptionHelpFormatter,
        description=description,
        help=description,
        epilog=example,
    )

    p.add_argument(
        '-c', '--channel',
        action='append',
        help='Additional channel to include in the export'
    )

    p.add_argument(
        "--override-channels",
        action="store_true",
        help="Do not include .condarc channels",
    )
    add_parser_prefix(p)

    p.add_argument(
        '-f', '--file',
        default=None,
        required=False
    )

    p.add_argument(
        '--no-builds',
        default=False,
        action='store_true',
        required=False,
        help='Remove build specification from dependencies'
    )

    p.add_argument(
        '--ignore-channels',
        default=False,
        action='store_true',
        required=False,
        help='Do not include channel names with package names.')
    add_parser_json(p)

    p.add_argument(
        '--from-history',
        default=False,
        action='store_true',
        required=False,
        help='Build environment spec from explicit specs in history'
    )
    p.set_defaults(func='.main_export.execute')


# TODO Make this aware of channels that were used to install packages
def execute(args, parser):
    prefix = determine_target_prefix(context, args)
    env = from_environment(
        env_name(prefix),
        prefix,
        no_builds=args.no_builds,
        ignore_channels=args.ignore_channels,
        from_history=args.from_history,
    )

    if args.override_channels:
        env.remove_channels()

    if args.channel is not None:
        env.add_channels(args.channel)

    if args.file is None:
        stdout_json(env.to_dict()) if args.json else print(env.to_yaml(), end='')
    else:
        fp = open(args.file, 'wb')
        env.to_dict(stream=fp) if args.json else env.to_yaml(stream=fp)
        fp.close()