try

#! /bin/bash
set -euo pipefail
IFS=$'\n\t'
CANONICAL="http://n2t.net/ark:/99152/p0d.json"
DATASET_URL=${DATASET:-"$CANONICAL"}

usage () {
    echo "Usage: $0 {new|without-patch|with-patch|accept} <proposed change>"
    echo
    echo "<proposed change> should be one of:"
    ls -1 changes/proposed
    echo
    exit 1
}

new () {
    mkdir -p "changes/proposed/$1"
    local add="changes/proposed/$1/constraints-added.ttl"
    local rem="changes/proposed/$1/constraints-removed.ttl"
    touch "$add"
    touch "$rem"
    if [ ! -f "fix/$1.js" ]; then
        (cat <<EOF
// Object => Promise { Array<Operation> }
module.exports = async function createPatch(o) {
  throw 'implement me'
}
EOF
        ) > "fix/$1.js"
    fi
    printf "Put new SHACL constraints in:\\n  %s\\n\\n" "$add"
    printf "Put SHACL constraints to be removed in:\\n  %s\\n\\n" "$rem"
    printf "Implement your fix in:\\n  %s\\n" "fix/$1.js"
}

validate_with_change () {
    local results
    results=$(
        ./validate - \
                   --shapes shapes \
                   --remove "changes/proposed/$1/constraints-removed.ttl" \
                   --shapes "changes/proposed/$1/constraints-added.ttl" \
                   --json
           )
    local problems
    problems=$(echo "$results" | jq -f report.jq)
    if [ "$problems" == "[]" ]
    then
        echo "No problems found."
    else
        echo "$results" | jq -f report.jq -C | less -R
    fi
}

without_patch () {
    curl -s -L "${DATASET_URL}?inline-context" | validate_with_change "$1"
}

with_patch () {
    node fix "$1" -d "$DATASET_URL" -a | validate_with_change "$1"
}

accept () {
    local dir
    if [ "$DATASET_URL" == "$CANONICAL" ]
    then
        dir="changes/accepted/$(date +%Y-%m-%d)-$1"
    else
        domain=$(echo "$DATASET_URL" | awk -F/ '{print $3}')
        dir="changes/accepted/$domain/$(date +%Y-%m-%d)-$1"
    fi
    mkdir -p "$dir"
    echo -n "Writing patch to $dir... "
    node fix "$1" -d "$DATASET_URL" > "$dir/patch.json"
    node fix "$1" -d "$DATASET_URL" -a > "$dir/data-after.json"
    curl -s -L "${DATASET_URL}?inline-context" > "$dir/data-before.json"
    echo "OK"
}

if [ "${1:-}" == "" ]; then
    usage
fi

if [ "${2:-}" == "" ]; then
    usage
fi

if [ "$1" != "new" ] && [ ! -d "changes/proposed/$2" ]; then
    usage
fi

if [ ! -L shapes ] || [ ! -e shapes ]
then
    echo "Create a symlink 'shapes' pointing to the shapes directory, e.g.:"
    echo "ln -s ../periodo-server/shapes"
    exit 1
fi

case "$1" in
    new)
        new "$2"
        ;;
    without-patch)
        without_patch "$2"
        ;;
    with-patch)
        with_patch "$2"
        ;;
    accept)
        accept "$2"
        ;;
    *)
       usage
       ;;
esac