#! /bin/bash

function usage {
    echo "Usage: pick-to-branch [<id>] <branch>
    Cherry-pick a commit on the given release target branch.
    If this is not the current branch, the current branch and its state are preserved.

    The commit can be given in the form of a branch name.
    If no <id> arg is given, use the commit id of the HEAD of the master.
    The <branch> arg must match a release branch or start with 'm' for master.
    A release branch may be given simply as 102, 110, 111, 30, 31."
}

case $# in
2)
    id=$1
    b=$2
    ;;
1)
    id=`git show -s --format="%H" master`
    b=$1
    ;;
*)
    usage
    exit 1
    ;;
esac


case $b in
*1*0*2*)
    branch=OpenSSL_1_0_2-stable
    ;;
*1*1*0*)
    branch=OpenSSL_1_1_0-stable
    ;;
*1*1*1*)
    branch=OpenSSL_1_1_1-stable
    ;;
*3*0*)
    branch=openssl-3.0
    ;;
*3*1*)
    branch=openssl-3.1
    ;;
m*)
    branch=master
    ;;
*)
    echo Unknown release target branch \'$b\'
    exit 1
    ;;
esac

echo "Commit to chery-pick is $id:"
git show $id | head -n 5
echo
echo "Target branch is: $branch"
echo "Are both of these correct?"

while true
do
    echo -n "Enter 'y'/'yes' to continue or 'n'/'no' to abort: "
    read x
    x="`echo $x | tr A-Z a-z`"
    if [ "$x" = "y" -o "$x" = "yes" -o "$x" = "n" -o "$x" = "no" ]
    then
        break
    fi
done

if [ "$x" = "n" -o "$x" = "no" ]
then
    exit 1
fi


ORIG_REF=`git rev-parse --abbrev-ref HEAD` # usually this will be 'master'
if [ "$branch" != "$ORIG_REF" ]; then
    STASH_OUT=`git stash`
fi

function cleanup {
    rv=$?
    echo # make sure to enter new line, needed, e.g., after Ctrl-C
    [ $rv -ne 0 ] && echo -e "pick-to-branch failed"
    if [ "$CHERRYPICKING" == 1 ] ; then
        git cherry-pick --abort 2>/dev/null || true
    fi
    if [ "$branch" != "$ORIG_REF" ]; then
        echo Returning to previous branch $ORIG_REF
        git checkout -q $ORIG_REF
        if [ "$STASH_OUT" != "No local changes to save" ]; then
            git stash pop -q # restore original state, pruning any leftover commits added locally
        fi
    fi
}
set -o errexit
trap 'cleanup' EXIT

git checkout --quiet master
git checkout $branch
git pull --ff-only
CHERRYPICKING=1
git cherry-pick -e -x $id || (git cherry-pick --abort; exit 1)
CHERRYPICKING=

while true
do
    echo -n "Enter 'y'/'yes' to push or 'n'/'no' to abort: "
    read x
    x="`echo $x | tr A-Z a-z`"
    if [ "$x" = "y" -o "$x" = "yes" -o "$x" = "n" -o "$x" = "no" ]
    then
        break
    fi
done

if [ "$x" = "y" -o "$x" = "yes" ]
then
    git push
else
    git reset --hard @~1
fi