#!/usr/bin/env bash
set -e

# This script generates the sha256 sum of each file in the packages/ and stores them in the sha256/ directory. 
# If the sha256/ directory exists, it only prints out the names of the charts whose sha256 sums were changed
# If the sha256/ directory does not exist, it prints out the names of all charts

if ! which sha256sum > /dev/null; then
    echo "Could not find required program to compute SHA256 sums: sha256sum"
    exit 1
fi

for f in packages/*; do
    rm -rf ./sha256sum-new/$(basename -- ${f})
    mkdir -p ./sha256sum-new/$(basename -- ${f})
    find ${f} -type f | sort | xargs sha256sum > ./sha256sum-new/$(basename -- ${f})/$(basename -- ${f}).sum
done

# If there were no sha256sums in the first place, output the name of every chart
if [ ! -d sha256sum ]; then
    cp -R sha256sum-new sha256sum
    for f in packages/*; do
        echo $(basename -- ${f})
    done
fi

# For all the new sha256sums that were generated, compare them and see if the existing assets need to be rebuilt
for f in sha256sum-new/*; do
    if ! cmp -s ./sha256sum/$(basename -- ${f})/$(basename -- ${f}).sum ${f}/$(basename -- ${f}).sum; then
        echo $(basename -- ${f})
    fi
done

rm -rf ./sha256sum 2>/dev/null
mv ./sha256sum-new ./sha256sum