#!/bin/sh
#
# Script to initiate a merge from master into
# production branch in preparation for a release

usage() {
    echo "options"
    echo "-f|--force        ignore test failures on master"
    echo "-m                merge commit message"
    exit 1
}

echo "Preparing a branch to merge master into production branch."

while [[ $# > 0 ]]; do
    case $1 in
        -f|--force)
        FORCE=true
        ;;
        -m)
        MESSAGE="$2"
        shift
        ;;
        -l)
        LOGFILE="$2"
        shift
        ;;
        *)
        usage
        ;;
    esac
    shift
done

if [[ -z "$MESSAGE" ]]; then
    usage
fi

BRANCH=release-$(date -u +'%Y-%m-%d-%H%M%S')

if [[ -z "$LOGFILE" ]]; then
    LOGFILE="start_release.$BRANCH.log"
fi

echo "Logging to $LOGFILE"

echo "Currently in ${PWD}"

STATUS=$($(find . -name "bamboo-ctl.js") status --branch master)
if [[ "$STATUS" == *"Failed"* ]]; then
    if [[ $FORCE == true ]]; then
        echo "Master is red, but going ahead anyway!"
    else
        echo "$STATUS"
        echo
        echo "Master is red. Use --force to push anyway"

        exit 1
    fi
fi

git status >> $LOGFILE

echo "Checking out $BRANCH from production"
git checkout -b $BRANCH --no-track origin/production >> $LOGFILE
if [[ $? != 0 ]]; then
    echo "checkout $BRANCH failed"
    exit 1
fi

echo "Merging master into $BRANCH"
git merge -s recursive -X theirs origin/master -m "$MESSAGE" >> $LOGFILE
if [[ $? != 0 ]]; then
    echo "Merge failed. Exiting..."
    exit 1
fi

echo "Sanity checking branch"

SANITY=$(git diff $BRANCH..origin/master)
if [[ -n "$SANITY" ]]; then
    echo "$SANITY"
    echo
    echo "Something went wrong with the merge. Fix the diff by hand. Exiting..."
    exit 1
fi

echo "Pushing $BRANCH"
git push origin $BRANCH