'''
Open a rez-configured shell, possibly interactive.
'''
from __future__ import print_function


def setup_parser(parser, completions=False):
    from argparse import SUPPRESS
    from rez.config import config
    from rez.system import system
    from rez.shells import get_shell_types
    import os

    shells = get_shell_types()

    parser.add_argument(
        "--shell", dest="shell", type=str, choices=shells,
        default=config.default_shell or system.shell,
        help="target shell type (default: %(default)s)")
    parser.add_argument(
        "--rcfile", type=str,
        help="source this file instead of the target shell's standard startup "
        "scripts, if possible")
    parser.add_argument(
        "--norc", action="store_true",
        help="skip loading of startup scripts")
    command_action = parser.add_argument(
        "-c", "--command", type=str,
        help="read commands from string. Alternatively, list command arguments "
        "after a '--'")
    parser.add_argument(
        "-s", "--stdin", action="store_true",
        help="read commands from standard input")
    parser.add_argument(
        "--ni", "--no-implicit", dest="no_implicit",
        action="store_true",
        help="don't add implicit packages to the request")
    parser.add_argument(
        "--nl", "--no-local", dest="no_local", action="store_true",
        help="don't load local packages")
    parser.add_argument(
        "-b", "--build", action="store_true",
        help="create a build environment")
    parser.add_argument(
        "--paths", type=str, default=None,
        help="set package search path (use %r separator)" % os.pathsep)
    parser.add_argument(
        "-t", "--time", type=str,
        help="ignore packages released after the given time. Supported formats "
        "are: epoch time (eg 1393014494), or relative time (eg -10s, -5m, "
        "-0.5h, -10d)")
    parser.add_argument(
        "--max-fails", type=int, default=-1, dest="max_fails",
        metavar='N',
        help="abort if the number of failed configuration attempts exceeds N")
    parser.add_argument(
        "--time-limit", type=int, default=-1,
        dest="time_limit", metavar='SECS',
        help="abort if the resolve time exceeds SECS")
    parser.add_argument(
        "-o", "--output", type=str, metavar="FILE",
        help="store the context into an rxt file, instead of starting an "
        "interactive shell. Note that this will also store a failed resolve. "
        "If you use the special value '-', the context is written to stdout.")
    input_action = parser.add_argument(
        "-i", "--input", type=str, metavar="FILE",
        help="use a previously saved context. Resolve settings, such as PKG, "
        "--ni etc are ignored in this case")
    parser.add_argument(
        "--exclude", type=str, nargs='+', metavar="RULE",
        help="add package exclusion filters, eg '*.beta'. Note that these are "
        "added to the globally configured exclusions")
    parser.add_argument(
        "--include", type=str, nargs='+', metavar="RULE",
        help="add package inclusion filters, eg 'mypkg', 'boost-*'. Note that "
        "these are added to the globally configured inclusions")
    parser.add_argument(
        "--no-filters", dest="no_filters", action="store_true",
        help="turn off package filters. Note that any filters specified with "
        "--exclude/--include are still applied")
    parser.add_argument(
        "-p", "--patch", action="store_true",
        help="patch the current context to create a new context")
    parser.add_argument(
        "--strict", action="store_true",
        help="strict patching. Ignored if --patch is not present")
    parser.add_argument(
        "--patch-rank", type=int, metavar="N", default=0,
        help="patch rank. Ignored if --patch is not present")
    parser.add_argument(
        "--no-cache", dest="no_cache", action="store_true",
        help="do not fetch cached resolves")
    parser.add_argument(
        "-q", "--quiet", action="store_true",
        help="run in quiet mode (hides welcome message)")
    parser.add_argument(
        "--fail-graph", action="store_true",
        help="if the build environment fails to resolve due to a conflict, "
        "display the resolve graph as an image.")
    parser.add_argument(
        "--new-session", action="store_true",
        help="start the shell in a new process group")
    parser.add_argument(
        "--detached", action="store_true",
        help="open a separate terminal")
    parser.add_argument(
        "--no-passive", action="store_true",
        help="only print actions that affect the solve (has an effect only "
        "when verbosity is enabled)")
    parser.add_argument(
        "--stats", action="store_true",
        help="print advanced solver stats")
    parser.add_argument(
        "--no-pkg-cache", action="store_true",
        help="Disable package caching")
    parser.add_argument(
        "--pre-command", type=str, help=SUPPRESS)
    PKG_action = parser.add_argument(
        "PKG", type=str, nargs='*',
        help='packages to use in the target environment')
    extra_0_action = parser.add_argument(  # args after --
        "--N0", dest="extra_0", nargs='*',
        help=SUPPRESS)

    if completions:
        from rez.cli._complete_util import PackageCompleter, FilesCompleter, \
            ExecutablesCompleter, AndCompleter, SequencedCompleter
        command_action.completer = AndCompleter(ExecutablesCompleter, FilesCompleter())
        input_action.completer = FilesCompleter(dirs=False, file_patterns=["*.rxt"])
        PKG_action.completer = PackageCompleter
        extra_0_action.completer = SequencedCompleter(
            "extra_0", ExecutablesCompleter, FilesCompleter())


def command(opts, parser, extra_arg_groups=None):
    from rez.resolved_context import ResolvedContext
    from rez.resolver import ResolverStatus
    from rez.package_filter import PackageFilterList, Rule
    from rez.utils.formatting import get_epoch_time_from_str
    from rez.config import config
    import select
    import sys
    import os
    import os.path

    command = opts.command
    if extra_arg_groups:
        if opts.command:
            parser.error("argument --command: not allowed with arguments after '--'")
        command = extra_arg_groups[0] or None

    context = None
    request = opts.PKG
    t = get_epoch_time_from_str(opts.time) if opts.time else None

    if opts.paths is None:
        pkg_paths = (config.nonlocal_packages_path
                     if opts.no_local else None)
    else:
        pkg_paths = opts.paths.split(os.pathsep)
        pkg_paths = [os.path.expanduser(x) for x in pkg_paths if x]

    if opts.input:
        if opts.PKG and not opts.patch:
            parser.error("Cannot use --input and provide PKG(s), unless patching.")

        context = ResolvedContext.load(opts.input)

    if opts.patch:
        if context is None:
            from rez.status import status
            context = status.context
            if context is None:
                print("cannot patch: not in a context", file=sys.stderr)
                sys.exit(1)

        # modify the request in terms of the given patch request
        request = context.get_patched_request(request,
                                              strict=opts.strict,
                                              rank=opts.patch_rank)
        context = None

    if context is None:
        # create package filters
        if opts.no_filters:
            package_filter = PackageFilterList()
        else:
            package_filter = PackageFilterList.singleton.copy()

        for rule_str in (opts.exclude or []):
            rule = Rule.parse_rule(rule_str)
            package_filter.add_exclusion(rule)

        for rule_str in (opts.include or []):
            rule = Rule.parse_rule(rule_str)
            package_filter.add_inclusion(rule)

        # perform the resolve
        context = ResolvedContext(
            package_requests=request,
            timestamp=t,
            package_paths=pkg_paths,
            building=opts.build,
            package_filter=package_filter,
            add_implicit_packages=(not opts.no_implicit),
            verbosity=opts.verbose,
            max_fails=opts.max_fails,
            time_limit=opts.time_limit,
            caching=(not opts.no_cache),
            suppress_passive=opts.no_passive,
            print_stats=opts.stats,
            package_caching=(not opts.no_pkg_cache)
        )

    success = (context.status == ResolverStatus.solved)

    if not success:
        context.print_info(buf=sys.stderr)
        if opts.fail_graph:
            if context.graph:
                from rez.utils.graph_utils import view_graph
                g = context.graph(as_dot=True)
                view_graph(g)
            else:
                print("the failed resolve context did not generate a graph.",
                      file=sys.stderr)

    if opts.output:
        if opts.output == '-':  # print to stdout
            context.write_to_buffer(sys.stdout)
        else:
            context.save(opts.output)
        sys.exit(0 if success else 1)

    if not success:
        sys.exit(1)

    # generally shells will behave as though the '-s' flag was not present when
    # no stdin is available. So here we replicate this behaviour.
    try:
        if opts.stdin and not select.select([sys.stdin], [], [], 0.0)[0]:
            opts.stdin = False
    except select.error:
        pass  # because windows

    quiet = opts.quiet or bool(command)
    returncode, _, _ = context.execute_shell(
        shell=opts.shell,
        rcfile=opts.rcfile,
        norc=opts.norc,
        command=command,
        stdin=opts.stdin,
        quiet=quiet,
        start_new_session=opts.new_session,
        detached=opts.detached,
        pre_command=opts.pre_command,
        block=True)

    sys.exit(returncode)


# Copyright 2013-2016 Allan Johns.
#
# This library is free software: you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation, either
# version 3 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
