#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# Copyright (C) 2019 Daniel Borkmann <daniel@iogearbox.net>
# Copyright (C) 2020 Jakub Kicinski <kuba@kernel.org>

# Pull from a pull request in patchwork, add a commit message
# based on the contents of the tag or the email if tag was empty.
# Optionally, compare if the patches on the branch are identical
# to what's posted on the mailing list.

source $(dirname $0)/lib.sh

usage()
{
  cat <<-EOF
  usage: pw-pull [-p PULL] [-s SERIES] [-c] [-P PULL_URL] [-T] [-h]
EOF
  exit
}

get_cover_tags()
{
  [ -z "$cover_tags" ] && return

  # first arg is JSON either of cover or of the pull
  local json="$1"

  clink=$(echo "$json" | jq -r '.url')
  link=$(curl -s "$clink" | jq -r '.comments')
  [ "$link" == "null" ] && return

  echo -ne "$(curl -s $link | jq -r '.[].content')" |
      sed -n '/^\(Ack\|Review\|Test\)ed-[Bb]y:/p'
}

pull=""
pull_url=""
cover=""
cover_tags="y"
series=""
series_branch="tmp"
head_old=$(git rev-parse --verify HEAD)
while true; do
  case "$1" in
    -p | --pull ) pull="$2"; shift 2 ;;
    -s | --series ) series="$2"; shift 2 ;;
    -c | --pull-from-cover ) cover="y"; shift ;;
    -P | --pull-url ) pull_url="$2"; shift 2 ;;
    -T | --no-cover-tags) cover_tags=""; shift ;;
    -h | --help ) usage; break ;;
    -- ) shift; break ;;
    * )  break ;;
  esac
done
[ -z "$pull" ] && [ -z "$cover" ] && [ -z "$pull_url" ] && usage
[ ! -z "$pull" ] && [ ! -z "$cover" ]    && usage
[ ! -z "$pull" ] && [ ! -z "$pull_url" ] && usage

srv=$(git config --get pw.server)
srv=${srv%/} # strip trailing slash

target=$(git branch --show-current)

if [ ! -z "$pull" ]; then
  pull_json=$(curl -s $srv/patches/$pull/)

  pull_url=$(echo "$pull_json" | jq -r '.pull_url')
  pull_author=$(echo "$pull_json" | jq -r '.submitter.name')
  pull_subject=$(echo "$pull_json" |
		   jq -r '.name' |
		   sed -e 's/\[.*\] *//')
  pull_msgid=$(echo "$pull_json" | jq -r '.msgid' | tr -d '<>')
  json=$pull_json
elif [ ! -z "$cover" ]; then
  series_json=$(curl -s $srv/series/$series/)

  pull_author=$(echo "$series_json" | jq -r '.submitter.name')
  pull_subject=$(echo "$series_json" |
		   jq -r '.name' |
		   sed -e 's/\[.*\] *//')
  pull_msgid=$(echo "$series_json" | jq -r '.cover_letter.msgid' | tr -d '<>')

  cover_id=$(echo "$series_json" | jq -r '.cover_letter.id')
  cover_json=$(curl -s $srv/covers/$cover_id/)

  pull_msg=$(echo "$pull" |
		   jq -r '.content' |
		   awk 'BEGIN {e=0}
                        /^---/ {e=1}
                        /^Please consider/ {e=1}
                        {if(!e) print}')

  if [ -z "$pull_url" ]; then
    pull_url=$(echo "$cover_json" |
		 jq -r '.content' |
		 awk '/^.+$/                      { if (n) {n=0; print} }
		      /and are available in the git repository at:/ {n=1}')
    pull_url=$(echo $pull_url)
  fi

  if [ -z "$pull_url" ]; then
    echo "Unable to parse out pull URL"
    exit 1
  fi

  json=$cover_json
fi

tags="$(get_cover_tags "$json")"
# Download the series from ML and make a local branch
if [ ! -z "$series" ]; then
    mbox_from_series $series
    git checkout -b $series_branch
    git am -3 mbox.i
    rm -f mbox.i
    git checkout "$target"
fi

git pull --stat --log --no-edit --no-ff $pull_url
if [ $? -ne 0 ]; then
    bold "Waiting for conflict resolution..."
    while git status | head -9 | grep "conflicts" >/dev/null; do
	sleep 0.25
    done
fi

merge_header=$(git show --format="%s" --no-patch)
merge_body=$(git show --format="%b" --no-patch)

# count lines until "* tag", ignore empty and gpg output
significant_lines=$(echo -e "$merge_body" |
			awk 'BEGIN {c=0; e=0}
			     /^\* (tag|git|https|'"'"')/ {e=1}
			     /^[^#]/ { if(!e) c++}
			     END {print c}')

if [ "$significant_lines" -le 1 ]; then
    # Construct the message from email body if tag is empty
    pull_msg=$(echo "$json" |
		   jq -r '.content' |
		   awk 'BEGIN {e=0}
                        /^---/ {e=1}
                        /^The following changes since commit/ {e=1}
                        /^The following are changes since commit/ {e=1}
                        /^Please consider/ {e=1}
                        /^Please, pull these changes/ {e=1}
                        {if(!e) print}')

    git commit --amend --signoff -F- <<EOF
$merge_header

$pull_author says:

====================
$pull_subject

$pull_msg

$merge_body
====================

$tags
Link: https://lore.kernel.org/r/$pull_msgid
EOF
else
    # Tag has info in it, just use that
    git commit --amend --signoff -F- <<EOF
$merge_header

$pull_author says:

====================
$merge_body
====================

$tags
Link: https://lore.kernel.org/r/$pull_msgid
EOF
fi

if [ ! -z "$series" ]; then
    if git diff "$target"..$series_branch --exit-code; then
	echo -e '\e[0;32mSeries matches PR\e[0m'
    else
	echo -e '\n\n\e[1;31mSeries differs!!\e[0m\n'
    fi
    git branch -D $series_branch
fi

git commit --amend

# Checks
head_new=$(git rev-parse --verify HEAD)
pw-check -s $head_old -e $head_new