#!/usr/bin/env -S python3 -B
#
# SPDX-License-Identifier: Apache-2.0
# Copyright (C) 2018 IBM Corp.
#
# Push changes to Gerrit, automatically adding reviewers to the patches by
# parsing the OpenBMC-style MAINTAINERS file in the root of the repository (if
# it exists).

from obmc import maintainers
from obmc.reviewlist import ReviewList
from typing import cast, Callable, List, Optional
import argparse
import os
import sh  # type: ignore
import sys

git: Callable[..., str] = sh.git.bake()


def get_reviewers(
    root: Optional[str] = None, mname: str = "MAINTAINERS"
) -> ReviewList:

    if not root:
        root = git("rev-parse", "--show-toplevel").strip()

    mfile = os.path.join(root, mname)
    if os.path.exists(mfile):
        return maintainers.get_reviewers(mfile)

    return ReviewList()


def gerrit_refspec_args(
    maintainers: Optional[List[str]] = None,
    reviewers: Optional[List[str]] = None,
    topic: str = None,
) -> str:
    argl: List[str] = []
    if maintainers:
        argl.extend("r={}".format(addr) for addr in maintainers)
    if reviewers:
        argl.extend("cc={}".format(addr) for addr in reviewers)
    if topic:
        argl.append("topic={}".format(topic))
    return ",".join(argl)


def decorate_refspec(refspec: str, topic: str) -> str:
    revlist = get_reviewers()
    gargs = gerrit_refspec_args(revlist.maintainers, revlist.reviewers, topic)
    if not gargs:
        return refspec
    if "%" in refspec:
        return "{},{}".format(refspec, gargs)
    return "{}%{}".format(refspec, gargs)


def do_push(args: argparse.Namespace) -> None:
    git(
        "push",
        args.remote,
        decorate_refspec(args.refspec, args.topic),
        _in=sys.stdin,
        _out=sys.stdout,
        _err=sys.stderr,
    )


def do_reviewers(args: argparse.Namespace) -> None:
    revlist = get_reviewers()
    print(gerrit_refspec_args(revlist.maintainers, revlist.reviewers))


parser = argparse.ArgumentParser()
subbies = parser.add_subparsers(dest="subcommand")
subbies.required = True

push = subbies.add_parser("push", help="Push changes to Gerrit with reviewers")
push.add_argument("remote")
push.add_argument("refspec")
push.add_argument("topic", nargs="?", default=None)
push.set_defaults(func=do_push)

reviewers = subbies.add_parser("reviewers", help="Get the reviewer list.")
reviewers.set_defaults(func=do_reviewers)

args = parser.parse_args()
args.func(args)