# Copyright (C) 2012 Anaconda, Inc
# SPDX-License-Identifier: BSD-3-Clause
"""CLI implementation for `conda-env create`.

Creates new conda environments with the specified packages.
"""

from argparse import (
    ArgumentParser,
    Namespace,
    _SubParsersAction,
)
from pathlib import Path

from .. import CondaError
from ..cli.main_config import set_keys
from ..common.configuration import DEFAULT_CONDARC_FILENAME
from ..notices import notices


def configure_parser(sub_parsers: _SubParsersAction, **kwargs) -> ArgumentParser:
    from ..auxlib.ish import dals
    from .helpers import (
        add_output_and_prompt_options,
        add_parser_default_packages,
        add_parser_environment_specifier,
        add_parser_networking,
        add_parser_platform,
        add_parser_prefix,
        add_parser_solver,
    )

    summary = "Create an environment based on an environment definition file."
    description = dals(
        f"""
        {summary}

        If using an environment.yml file (the default), you can name the
        environment in the first line of the file with 'name: envname' or
        you can specify the environment name in the CLI command using the
        -n/--name argument. The name specified in the CLI will override
        the name specified in the environment.yml file.

        Unless you are in the directory containing the environment definition
        file, use -f to specify the file path of the environment definition
        file you want to use.

        """
    )
    epilog = dals(
        """
        Examples::

            conda env create
            conda env create -n envname
            conda env create folder/envname
            conda env create -f /path/to/environment.yml
            conda env create -f /path/to/requirements.txt -n envname
            conda env create -f /path/to/requirements.txt -p /home/user/envname

        """
    )

    p = sub_parsers.add_parser(
        "create",
        help=summary,
        description=description,
        epilog=epilog,
        **kwargs,
    )
    p.add_argument(
        "-f",
        "--file",
        action="store",
        help="Environment definition file (default: environment.yml)",
        default="environment.yml",
    )

    # Add name and prefix args
    add_parser_prefix(p)

    # Add networking args
    add_parser_networking(p)

    # Add environment spec plugin args
    add_parser_environment_specifier(p)

    add_parser_default_packages(p)
    add_output_and_prompt_options(p)
    add_parser_solver(p)
    add_parser_platform(p)

    p.set_defaults(func="conda.cli.main_env_create.execute")

    return p


@notices
def execute(args: Namespace, parser: ArgumentParser) -> int:
    from ..auxlib.ish import dals
    from ..base.context import context, determine_target_prefix
    from ..common.serialize import json
    from ..core.prefix_data import PrefixData
    from ..env.env import print_result
    from ..env.installers.base import get_installer
    from ..exceptions import CondaEnvException, InvalidInstaller
    from ..gateways.disk.delete import rm_rf
    from .common import validate_file_exists

    # validate incoming arguments
    validate_file_exists(args.file)

    # detect the file format and get the env representation
    spec_hook = context.plugin_manager.get_environment_specifier(
        source=args.file,
        name=context.environment_specifier,
    )
    spec = spec_hook.environment_spec(args.file)
    env = spec.env

    # FIXME conda code currently requires args to have a name or prefix
    # don't overwrite name if it's given. gh-254
    if args.prefix is None and args.name is None:
        if env.name is None:  # requirements.txt won't populate Environment.name
            msg = dals(
                """
                Unable to create environment
                Please re-run this command with one of the following options:
                * Provide an environment name via --name or -n
                * Provide a path on disk via --prefix or -p
                """
            )
            raise CondaEnvException(msg)
        args.name = env.name

    prefix = determine_target_prefix(context, args)
    prefix_data = PrefixData(prefix)

    if args.yes and not prefix_data.is_base() and prefix_data.exists():
        rm_rf(prefix)

    prefix_data.validate_path()
    prefix_data.validate_name()

    # TODO, add capability
    # common.ensure_override_channels_requires_channel(args)
    # channel_urls = args.channel or ()

    result = {"conda": None, "pip": None}

    args_packages = (
        context.create_default_packages if not args.no_default_packages else []
    )

    if args.dry_run:
        installer_type = "conda"
        installer = get_installer(installer_type)

        pkg_specs = [*env.requested_packages, *args_packages]

        solved_env = installer.dry_run(pkg_specs, args, env)
        if args.json:
            print(json.dumps(solved_env.to_dict()))
        else:
            print(solved_env.to_yaml(), end="")

    else:
        if args_packages:
            installer_type = "conda"
            installer = get_installer(installer_type)
            result[installer_type] = installer.install(prefix, args_packages, args, env)

        # install conda packages
        installer_type = "conda"
        installer = get_installer(installer_type)
        result[installer_type] = installer.install(
            prefix, env.requested_packages, args, env
        )

        # install all other external packages
        for installer_type, pkg_specs in env.external_packages.items():
            try:
                installer = get_installer(installer_type)
                result[installer_type] = installer.install(prefix, pkg_specs, args, env)
            except InvalidInstaller:
                raise CondaError(
                    dals(
                        f"""
                        Unable to install package for {installer_type}.

                        Please double check and ensure your dependencies file has
                        the correct spelling. You might also try installing the
                        conda-env-{installer_type} package to see if provides
                        the required installer.
                        """
                    )
                )

        if context.subdir != context._native_subdir():
            set_keys(
                ("subdir", context.subdir),
                path=Path(prefix, DEFAULT_CONDARC_FILENAME),
            )

        if env.variables:
            prefix_data.set_environment_env_vars(env.variables)

        prefix_data.set_nonadmin()
        print_result(args, prefix, result)

    return 0