dulwich/dulwich/cli.py

#
# dulwich - Simple command-line interface to Dulwich
# Copyright (C) 2008-2011 Jelmer Vernooij <jelmer@jelmer.uk>
# vim: expandtab
#
# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
# Dulwich is dual-licensed under the Apache License, Version 2.0 and the GNU
# General Public License as public by the Free Software Foundation; version 2.0
# or (at your option) any later version. You can redistribute it and/or
# modify it under the terms of either of these two licenses.
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# You should have received a copy of the licenses; if not, see
# <http://www.gnu.org/licenses/> for a copy of the GNU General Public License
# and <http://www.apache.org/licenses/LICENSE-2.0> for a copy of the Apache
# License, Version 2.0.
#

"""Simple command-line interface to Dulwich>.

This is a very simple command-line wrapper for Dulwich. It is by
no means intended to be a full-blown Git command-line interface but just
a way to test Dulwich.
"""

import argparse
import os
import signal
import sys
from pathlib import Path
from typing import TYPE_CHECKING, ClassVar, Optional

from dulwich import porcelain

from .client import GitProtocolError, get_transport_and_path
from .errors import ApplyDeltaError
from .index import Index
from .objectspec import parse_commit
from .pack import Pack, sha_to_hex
from .repo import Repo

if TYPE_CHECKING:
    pass


def signal_int(signal, frame) -> None:
    sys.exit(1)


def signal_quit(signal, frame) -> None:
    import pdb

    pdb.set_trace()


class Command:
    """A Dulwich subcommand."""

    def run(self, args) -> Optional[int]:
        """Run the command."""
        raise NotImplementedError(self.run)


class cmd_archive(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "--remote",
            type=str,
            help="Retrieve archive from specified remote repo",
        )
        parser.add_argument("committish", type=str, nargs="?")
        args = parser.parse_args(args)
        if args.remote:
            client, path = get_transport_and_path(args.remote)
            client.archive(
                path,
                args.committish,
                sys.stdout.write,
                write_error=sys.stderr.write,
            )
        else:
            # Use buffer if available (for binary output), otherwise use stdout
            outstream = getattr(sys.stdout, "buffer", sys.stdout)
            porcelain.archive(
                ".", args.committish, outstream=outstream, errstream=sys.stderr
            )


class cmd_add(Command):
    def run(self, argv) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("path", nargs="+")
        args = parser.parse_args(argv)

        # Convert '.' to None to add all files
        paths = args.path
        if len(paths) == 1 and paths[0] == ".":
            paths = None

        porcelain.add(".", paths=paths)


class cmd_rm(Command):
    def run(self, argv) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "--cached", action="store_true", help="Remove from index only"
        )
        parser.add_argument("path", type=Path, nargs="+")
        args = parser.parse_args(argv)

        porcelain.remove(".", paths=args.path, cached=args.cached)


class cmd_fetch_pack(Command):
    def run(self, argv) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("--all", action="store_true")
        parser.add_argument("location", nargs="?", type=str)
        parser.add_argument("refs", nargs="*", type=str)
        args = parser.parse_args(argv)
        client, path = get_transport_and_path(args.location)
        r = Repo(".")
        if args.all:
            determine_wants = r.object_store.determine_wants_all
        else:

            def determine_wants(refs, depth: Optional[int] = None):
                return [y.encode("utf-8") for y in args.refs if y not in r.object_store]

        client.fetch(path, r, determine_wants)


class cmd_fetch(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("location", help="Remote location to fetch from")
        args = parser.parse_args(args)
        client, path = get_transport_and_path(args.location)
        r = Repo(".")

        def progress(msg: bytes) -> None:
            sys.stdout.buffer.write(msg)

        refs = client.fetch(path, r, progress=progress)
        print("Remote refs:")
        for item in refs.items():
            print("{} -> {}".format(*item))


class cmd_for_each_ref(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("pattern", type=str, nargs="?")
        args = parser.parse_args(args)
        for sha, object_type, ref in porcelain.for_each_ref(".", args.pattern):
            print(f"{sha.decode()} {object_type.decode()}\t{ref.decode()}")


class cmd_fsck(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(args)
        for obj, msg in porcelain.fsck("."):
            print(f"{obj}: {msg}")


class cmd_log(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "--reverse",
            action="store_true",
            help="Reverse order in which entries are printed",
        )
        parser.add_argument(
            "--name-status",
            action="store_true",
            help="Print name/status for each changed file",
        )
        parser.add_argument("paths", nargs="*", help="Paths to show log for")
        args = parser.parse_args(args)

        porcelain.log(
            ".",
            paths=args.paths,
            reverse=args.reverse,
            name_status=args.name_status,
            outstream=sys.stdout,
        )


class cmd_diff(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "commit", nargs="?", default="HEAD", help="Commit to show diff for"
        )
        args = parser.parse_args(args)

        r = Repo(".")
        commit_id = (
            args.commit.encode() if isinstance(args.commit, str) else args.commit
        )
        commit = parse_commit(r, commit_id)
        parent_commit = r[commit.parents[0]]
        porcelain.diff_tree(
            r, parent_commit.tree, commit.tree, outstream=sys.stdout.buffer
        )


class cmd_dump_pack(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("filename", help="Pack file to dump")
        args = parser.parse_args(args)

        basename, _ = os.path.splitext(args.filename)
        x = Pack(basename)
        print(f"Object names checksum: {x.name()}")
        print(f"Checksum: {sha_to_hex(x.get_stored_checksum())}")
        x.check()
        print(f"Length: {len(x)}")
        for name in x:
            try:
                print(f"\t{x[name]}")
            except KeyError as k:
                print(f"\t{name}: Unable to resolve base {k}")
            except ApplyDeltaError as e:
                print(f"\t{name}: Unable to apply delta: {e!r}")


class cmd_dump_index(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("filename", help="Index file to dump")
        args = parser.parse_args(args)

        idx = Index(args.filename)

        for o in idx:
            print(o, idx[o])


class cmd_init(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "--bare", action="store_true", help="Create a bare repository"
        )
        parser.add_argument(
            "path", nargs="?", default=os.getcwd(), help="Repository path"
        )
        args = parser.parse_args(args)

        porcelain.init(args.path, bare=args.bare)


class cmd_clone(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "--bare",
            help="Whether to create a bare repository.",
            action="store_true",
        )
        parser.add_argument("--depth", type=int, help="Depth at which to fetch")
        parser.add_argument(
            "-b",
            "--branch",
            type=str,
            help="Check out branch instead of branch pointed to by remote HEAD",
        )
        parser.add_argument(
            "--refspec",
            type=str,
            help="References to fetch",
            action="append",
        )
        parser.add_argument(
            "--filter",
            dest="filter_spec",
            type=str,
            help="git-rev-list-style object filter",
        )
        parser.add_argument(
            "--protocol",
            type=int,
            help="Git protocol version to use",
        )
        parser.add_argument("source", help="Repository to clone from")
        parser.add_argument("target", nargs="?", help="Directory to clone into")
        args = parser.parse_args(args)

        try:
            porcelain.clone(
                args.source,
                args.target,
                bare=args.bare,
                depth=args.depth,
                branch=args.branch,
                refspec=args.refspec,
                filter_spec=args.filter_spec,
                protocol_version=args.protocol,
            )
        except GitProtocolError as e:
            print(f"{e}")


class cmd_commit(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("--message", "-m", required=True, help="Commit message")
        args = parser.parse_args(args)
        porcelain.commit(".", message=args.message)


class cmd_commit_tree(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("--message", "-m", required=True, help="Commit message")
        parser.add_argument("tree", help="Tree SHA to commit")
        args = parser.parse_args(args)
        porcelain.commit_tree(".", tree=args.tree, message=args.message)


class cmd_update_server_info(Command):
    def run(self, args) -> None:
        porcelain.update_server_info(".")


class cmd_symbolic_ref(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("name", help="Symbolic reference name")
        parser.add_argument("ref", nargs="?", help="Target reference")
        parser.add_argument("--force", action="store_true", help="Force update")
        args = parser.parse_args(args)

        # If ref is provided, we're setting; otherwise we're reading
        if args.ref:
            # Set symbolic reference
            from .repo import Repo

            with Repo(".") as repo:
                repo.refs.set_symbolic_ref(args.name.encode(), args.ref.encode())
        else:
            # Read symbolic reference
            from .repo import Repo

            with Repo(".") as repo:
                try:
                    target = repo.refs.read_ref(args.name.encode())
                    if target.startswith(b"ref: "):
                        print(target[5:].decode())
                    else:
                        print(target.decode())
                except KeyError:
                    print(f"fatal: ref '{args.name}' is not a symbolic ref")


class cmd_pack_refs(Command):
    def run(self, argv) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("--all", action="store_true")
        # ignored, we never prune
        parser.add_argument("--no-prune", action="store_true")

        args = parser.parse_args(argv)

        porcelain.pack_refs(".", all=args.all)


class cmd_show(Command):
    def run(self, argv) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("objectish", type=str, nargs="*")
        args = parser.parse_args(argv)
        porcelain.show(".", args.objectish or None, outstream=sys.stdout)


class cmd_diff_tree(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("old_tree", help="Old tree SHA")
        parser.add_argument("new_tree", help="New tree SHA")
        args = parser.parse_args(args)
        porcelain.diff_tree(".", args.old_tree, args.new_tree)


class cmd_rev_list(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("commits", nargs="+", help="Commit IDs to list")
        args = parser.parse_args(args)
        porcelain.rev_list(".", args.commits)


class cmd_tag(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "-a",
            "--annotated",
            help="Create an annotated tag.",
            action="store_true",
        )
        parser.add_argument(
            "-s", "--sign", help="Sign the annotated tag.", action="store_true"
        )
        parser.add_argument("tag_name", help="Name of the tag to create")
        args = parser.parse_args(args)
        porcelain.tag_create(
            ".", args.tag_name, annotated=args.annotated, sign=args.sign
        )


class cmd_repack(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(args)
        porcelain.repack(".")


class cmd_reset(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        mode_group = parser.add_mutually_exclusive_group()
        mode_group.add_argument(
            "--hard", action="store_true", help="Reset working tree and index"
        )
        mode_group.add_argument("--soft", action="store_true", help="Reset only HEAD")
        mode_group.add_argument(
            "--mixed", action="store_true", help="Reset HEAD and index"
        )
        parser.add_argument("treeish", nargs="?", help="Commit/tree to reset to")
        args = parser.parse_args(args)

        if args.hard:
            porcelain.reset(".", mode="hard", treeish=args.treeish)
        elif args.soft:
            # Soft reset: only change HEAD
            if args.treeish:
                from .repo import Repo

                with Repo(".") as repo:
                    repo.refs[b"HEAD"] = args.treeish.encode()
        elif args.mixed:
            # Mixed reset is not implemented yet
            raise NotImplementedError("Mixed reset not yet implemented")
        else:
            # Default to mixed behavior (not implemented)
            raise NotImplementedError("Mixed reset not yet implemented")


class cmd_daemon(Command):
    def run(self, args) -> None:
        from dulwich import log_utils

        from .protocol import TCP_GIT_PORT

        parser = argparse.ArgumentParser()
        parser.add_argument(
            "-l",
            "--listen_address",
            default="localhost",
            help="Binding IP address.",
        )
        parser.add_argument(
            "-p",
            "--port",
            type=int,
            default=TCP_GIT_PORT,
            help="Binding TCP port.",
        )
        parser.add_argument(
            "gitdir", nargs="?", default=".", help="Git directory to serve"
        )
        args = parser.parse_args(args)

        log_utils.default_logging_config()
        porcelain.daemon(args.gitdir, address=args.listen_address, port=args.port)


class cmd_web_daemon(Command):
    def run(self, args) -> None:
        from dulwich import log_utils

        parser = argparse.ArgumentParser()
        parser.add_argument(
            "-l",
            "--listen_address",
            default="",
            help="Binding IP address.",
        )
        parser.add_argument(
            "-p",
            "--port",
            type=int,
            default=8000,
            help="Binding TCP port.",
        )
        parser.add_argument(
            "gitdir", nargs="?", default=".", help="Git directory to serve"
        )
        args = parser.parse_args(args)

        log_utils.default_logging_config()
        porcelain.web_daemon(args.gitdir, address=args.listen_address, port=args.port)


class cmd_write_tree(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(args)
        sys.stdout.write("{}\n".format(porcelain.write_tree(".").decode()))


class cmd_receive_pack(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("gitdir", nargs="?", default=".", help="Git directory")
        args = parser.parse_args(args)
        porcelain.receive_pack(args.gitdir)


class cmd_upload_pack(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("gitdir", nargs="?", default=".", help="Git directory")
        args = parser.parse_args(args)
        porcelain.upload_pack(args.gitdir)


class cmd_status(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("gitdir", nargs="?", default=".", help="Git directory")
        args = parser.parse_args(args)
        status = porcelain.status(args.gitdir)
        if any(names for (kind, names) in status.staged.items()):
            sys.stdout.write("Changes to be committed:\n\n")
            for kind, names in status.staged.items():
                for name in names:
                    sys.stdout.write(
                        f"\t{kind}: {name.decode(sys.getfilesystemencoding())}\n"
                    )
            sys.stdout.write("\n")
        if status.unstaged:
            sys.stdout.write("Changes not staged for commit:\n\n")
            for name in status.unstaged:
                sys.stdout.write(f"\t{name.decode(sys.getfilesystemencoding())}\n")
            sys.stdout.write("\n")
        if status.untracked:
            sys.stdout.write("Untracked files:\n\n")
            for name in status.untracked:
                sys.stdout.write(f"\t{name}\n")
            sys.stdout.write("\n")


class cmd_ls_remote(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("url", help="Remote URL to list references from")
        args = parser.parse_args(args)
        refs = porcelain.ls_remote(args.url)
        for ref in sorted(refs):
            sys.stdout.write(f"{ref}\t{refs[ref]}\n")


class cmd_ls_tree(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "-r",
            "--recursive",
            action="store_true",
            help="Recursively list tree contents.",
        )
        parser.add_argument(
            "--name-only", action="store_true", help="Only display name."
        )
        parser.add_argument("treeish", nargs="?", help="Tree-ish to list")
        args = parser.parse_args(args)
        porcelain.ls_tree(
            ".",
            args.treeish,
            outstream=sys.stdout,
            recursive=args.recursive,
            name_only=args.name_only,
        )


class cmd_pack_objects(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "--stdout", action="store_true", help="Write pack to stdout"
        )
        parser.add_argument("--deltify", action="store_true", help="Create deltas")
        parser.add_argument(
            "--no-reuse-deltas", action="store_true", help="Don't reuse existing deltas"
        )
        parser.add_argument("basename", nargs="?", help="Base name for pack files")
        args = parser.parse_args(args)

        if not args.stdout and not args.basename:
            parser.error("basename required when not using --stdout")

        object_ids = [line.strip() for line in sys.stdin.readlines()]
        deltify = args.deltify
        reuse_deltas = not args.no_reuse_deltas

        if args.stdout:
            packf = getattr(sys.stdout, "buffer", sys.stdout)
            idxf = None
            close = []
        else:
            packf = open(args.basename + ".pack", "wb")
            idxf = open(args.basename + ".idx", "wb")
            close = [packf, idxf]

        porcelain.pack_objects(
            ".", object_ids, packf, idxf, deltify=deltify, reuse_deltas=reuse_deltas
        )
        for f in close:
            f.close()


class cmd_unpack_objects(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("pack_file", help="Pack file to unpack")
        args = parser.parse_args(args)

        count = porcelain.unpack_objects(args.pack_file)
        print(f"Unpacked {count} objects")


class cmd_pull(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("from_location", type=str)
        parser.add_argument("refspec", type=str, nargs="*")
        parser.add_argument("--filter", type=str, nargs=1)
        parser.add_argument("--protocol", type=int)
        args = parser.parse_args(args)
        porcelain.pull(
            ".",
            args.from_location or None,
            args.refspec or None,
            filter_spec=args.filter,
            protocol_version=args.protocol or None,
        )


class cmd_push(Command):
    def run(self, argv) -> Optional[int]:
        parser = argparse.ArgumentParser()
        parser.add_argument("-f", "--force", action="store_true", help="Force")
        parser.add_argument("to_location", type=str)
        parser.add_argument("refspec", type=str, nargs="*")
        args = parser.parse_args(argv)
        try:
            porcelain.push(
                ".", args.to_location, args.refspec or None, force=args.force
            )
        except porcelain.DivergedBranches:
            sys.stderr.write("Diverged branches; specify --force to override")
            return 1

        return None


class cmd_remote_add(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("name", help="Name of the remote")
        parser.add_argument("url", help="URL of the remote")
        args = parser.parse_args(args)
        porcelain.remote_add(".", args.name, args.url)


class SuperCommand(Command):
    subcommands: ClassVar[dict[str, type[Command]]] = {}
    default_command: ClassVar[Optional[type[Command]]] = None

    def run(self, args):
        if not args:
            if self.default_command:
                return self.default_command().run(args)
            else:
                print(
                    "Supported subcommands: {}".format(
                        ", ".join(self.subcommands.keys())
                    )
                )
                return False
        cmd = args[0]
        try:
            cmd_kls = self.subcommands[cmd]
        except KeyError:
            print(f"No such subcommand: {args[0]}")
            return False
        return cmd_kls().run(args[1:])


class cmd_remote(SuperCommand):
    subcommands: ClassVar[dict[str, type[Command]]] = {
        "add": cmd_remote_add,
    }


class cmd_submodule_list(Command):
    def run(self, argv) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(argv)
        for path, sha in porcelain.submodule_list("."):
            sys.stdout.write(f" {sha} {path}\n")


class cmd_submodule_init(Command):
    def run(self, argv) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(argv)
        porcelain.submodule_init(".")


class cmd_submodule(SuperCommand):
    subcommands: ClassVar[dict[str, type[Command]]] = {
        "init": cmd_submodule_init,
        "list": cmd_submodule_list,
    }

    default_command = cmd_submodule_list


class cmd_check_ignore(Command):
    def run(self, args):
        parser = argparse.ArgumentParser()
        parser.add_argument("paths", nargs="+", help="Paths to check")
        args = parser.parse_args(args)
        ret = 1
        for path in porcelain.check_ignore(".", args.paths):
            print(path)
            ret = 0
        return ret


class cmd_check_mailmap(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument("identities", nargs="+", help="Identities to check")
        args = parser.parse_args(args)
        for identity in args.identities:
            canonical_identity = porcelain.check_mailmap(".", identity)
            print(canonical_identity)


class cmd_branch(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "branch",
            type=str,
            help="Name of the branch",
        )
        parser.add_argument(
            "-d",
            "--delete",
            action="store_true",
            help="Delete branch",
        )
        args = parser.parse_args(args)
        if not args.branch:
            print("Usage: dulwich branch [-d] BRANCH_NAME")
            sys.exit(1)

        if args.delete:
            porcelain.branch_delete(".", name=args.branch)
        else:
            try:
                porcelain.branch_create(".", name=args.branch)
            except porcelain.Error as e:
                sys.stderr.write(f"{e}")
                sys.exit(1)


class cmd_checkout(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "target",
            type=str,
            help="Name of the branch, tag, or commit to checkout",
        )
        parser.add_argument(
            "-f",
            "--force",
            action="store_true",
            help="Force checkout",
        )
        parser.add_argument(
            "-b",
            "--new-branch",
            type=str,
            help="Create a new branch at the target and switch to it",
        )
        args = parser.parse_args(args)
        if not args.target:
            print("Usage: dulwich checkout TARGET [--force] [-b NEW_BRANCH]")
            sys.exit(1)

        try:
            porcelain.checkout(
                ".", target=args.target, force=args.force, new_branch=args.new_branch
            )
        except porcelain.CheckoutError as e:
            sys.stderr.write(f"{e}\n")
            sys.exit(1)


class cmd_stash_list(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(args)
        for i, entry in porcelain.stash_list("."):
            print("stash@{{{}}}: {}".format(i, entry.message.rstrip("\n")))


class cmd_stash_push(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(args)
        porcelain.stash_push(".")
        print("Saved working directory and index state")


class cmd_stash_pop(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(args)
        porcelain.stash_pop(".")
        print("Restored working directory and index state")


class cmd_stash(SuperCommand):
    subcommands: ClassVar[dict[str, type[Command]]] = {
        "list": cmd_stash_list,
        "pop": cmd_stash_pop,
        "push": cmd_stash_push,
    }


class cmd_ls_files(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(args)
        for name in porcelain.ls_files("."):
            print(name)


class cmd_describe(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.parse_args(args)
        print(porcelain.describe("."))


class cmd_merge(Command):
    def run(self, args) -> Optional[int]:
        parser = argparse.ArgumentParser()
        parser.add_argument("commit", type=str, help="Commit to merge")
        parser.add_argument(
            "--no-commit", action="store_true", help="Do not create a merge commit"
        )
        parser.add_argument(
            "--no-ff", action="store_true", help="Force create a merge commit"
        )
        parser.add_argument("-m", "--message", type=str, help="Merge commit message")
        args = parser.parse_args(args)

        try:
            merge_commit_id, conflicts = porcelain.merge(
                ".",
                args.commit,
                no_commit=args.no_commit,
                no_ff=args.no_ff,
                message=args.message,
            )

            if conflicts:
                print(f"Merge conflicts in {len(conflicts)} file(s):")
                for conflict_path in conflicts:
                    print(f"  {conflict_path.decode()}")
                print(
                    "\nAutomatic merge failed; fix conflicts and then commit the result."
                )
                return 1
            elif merge_commit_id is None and not args.no_commit:
                print("Already up to date.")
            elif args.no_commit:
                print("Automatic merge successful; not committing as requested.")
            else:
                print(
                    f"Merge successful. Created merge commit {merge_commit_id.decode()}"
                )
            return None
        except porcelain.Error as e:
            print(f"Error: {e}")
            return 1


class cmd_merge_tree(Command):
    def run(self, args) -> Optional[int]:
        parser = argparse.ArgumentParser(
            description="Perform a tree-level merge without touching the working directory"
        )
        parser.add_argument(
            "base_tree",
            nargs="?",
            help="The common ancestor tree (optional, defaults to empty tree)",
        )
        parser.add_argument("our_tree", help="Our side of the merge")
        parser.add_argument("their_tree", help="Their side of the merge")
        parser.add_argument(
            "-z",
            "--name-only",
            action="store_true",
            help="Output only conflict paths, null-terminated",
        )
        args = parser.parse_args(args)

        try:
            # Determine base tree - if only two args provided, base is None
            if args.base_tree is None:
                # Only two arguments provided
                base_tree = None
                our_tree = args.our_tree
                their_tree = args.their_tree
            else:
                # Three arguments provided
                base_tree = args.base_tree
                our_tree = args.our_tree
                their_tree = args.their_tree

            merged_tree_id, conflicts = porcelain.merge_tree(
                ".", base_tree, our_tree, their_tree
            )

            if args.name_only:
                # Output only conflict paths, null-terminated
                for conflict_path in conflicts:
                    sys.stdout.buffer.write(conflict_path)
                    sys.stdout.buffer.write(b"\0")
            else:
                # Output the merged tree SHA
                print(merged_tree_id.decode("ascii"))

                # Output conflict information
                if conflicts:
                    print(f"\nConflicts in {len(conflicts)} file(s):")
                    for conflict_path in conflicts:
                        print(f"  {conflict_path.decode()}")

            return None

        except porcelain.Error as e:
            print(f"Error: {e}", file=sys.stderr)
            return 1
        except KeyError as e:
            print(f"Error: Object not found: {e}", file=sys.stderr)
            return 1


class cmd_help(Command):
    def run(self, args) -> None:
        parser = argparse.ArgumentParser()
        parser.add_argument(
            "-a",
            "--all",
            action="store_true",
            help="List all commands.",
        )
        args = parser.parse_args(args)

        if args.all:
            print("Available commands:")
            for cmd in sorted(commands):
                print(f"  {cmd}")
        else:
            print(
                """\
The dulwich command line tool is currently a very basic frontend for the
Dulwich python module. For full functionality, please see the API reference.

For a list of supported commands, see 'dulwich help -a'.
"""
            )


commands = {
    "add": cmd_add,
    "archive": cmd_archive,
    "branch": cmd_branch,
    "check-ignore": cmd_check_ignore,
    "check-mailmap": cmd_check_mailmap,
    "checkout": cmd_checkout,
    "clone": cmd_clone,
    "commit": cmd_commit,
    "commit-tree": cmd_commit_tree,
    "describe": cmd_describe,
    "daemon": cmd_daemon,
    "diff": cmd_diff,
    "diff-tree": cmd_diff_tree,
    "dump-pack": cmd_dump_pack,
    "dump-index": cmd_dump_index,
    "fetch-pack": cmd_fetch_pack,
    "fetch": cmd_fetch,
    "for-each-ref": cmd_for_each_ref,
    "fsck": cmd_fsck,
    "help": cmd_help,
    "init": cmd_init,
    "log": cmd_log,
    "ls-files": cmd_ls_files,
    "ls-remote": cmd_ls_remote,
    "ls-tree": cmd_ls_tree,
    "merge": cmd_merge,
    "merge-tree": cmd_merge_tree,
    "pack-objects": cmd_pack_objects,
    "pack-refs": cmd_pack_refs,
    "pull": cmd_pull,
    "push": cmd_push,
    "receive-pack": cmd_receive_pack,
    "remote": cmd_remote,
    "repack": cmd_repack,
    "reset": cmd_reset,
    "rev-list": cmd_rev_list,
    "rm": cmd_rm,
    "show": cmd_show,
    "stash": cmd_stash,
    "status": cmd_status,
    "symbolic-ref": cmd_symbolic_ref,
    "submodule": cmd_submodule,
    "tag": cmd_tag,
    "unpack-objects": cmd_unpack_objects,
    "update-server-info": cmd_update_server_info,
    "upload-pack": cmd_upload_pack,
    "web-daemon": cmd_web_daemon,
    "write-tree": cmd_write_tree,
}


def main(argv=None):
    if argv is None:
        argv = sys.argv[1:]

    if len(argv) < 1:
        print("Usage: dulwich <{}> [OPTIONS...]".format("|".join(commands.keys())))
        return 1

    cmd = argv[0]
    try:
        cmd_kls = commands[cmd]
    except KeyError:
        print(f"No such subcommand: {cmd}")
        return 1
    # TODO(jelmer): Return non-0 on errors
    return cmd_kls().run(argv[1:])


def _main() -> None:
    if "DULWICH_PDB" in os.environ and getattr(signal, "SIGQUIT", None):
        signal.signal(signal.SIGQUIT, signal_quit)  # type: ignore
    signal.signal(signal.SIGINT, signal_int)

    sys.exit(main())


if __name__ == "__main__":
    _main()