#!/usr/bin/env bash

usage() {
    local error="$1"

    cat >&2 <<EOF
Usage:
  $0 BRANCH PULL_REQUEST

Synopsis:
  Useful script for merging a GitHub pull request with a custom merge commit
  message.

  Strips "origin" from branch names in title.

Example:
  $0 origin/philip/jael-fix 1953

  Yields:

  Merge branch 'philip/jael-fix' (#1953)

  * origin/philip/jael-fix:
    jael: process all ships in %full update

  Signed-off-by: Jared Tobin <jared@tlon.io>

Error:
  -> $error
EOF

    exit 1
}

args="$@"

if [[ -z "$args" ]]; then
    usage "No arguments specified."
fi

REV=$1
PR=$2

TARGET=$(echo $REV | sed s_origin/__)

MERGE_MSG="Merge branch '$TARGET' (#$PR)"

git merge --no-ff --signoff --log -m "$MERGE_MSG" $REV