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

function remove_timestamp_from_diff {
	prefix="[-\+]\{3\}"
	filename_format="packages\/$(basename -- ${f})\/[^[:space:]]*"
	# https://www.gnu.org/software/diffutils/manual/html_node/Example-Unified.html#Example-Unified
	# Example timestamp: 2002-02-21 23:30:39.942229878 -0800
	date="[[:digit:]]\{4\}-[[:digit:]]\{2\}-[[:digit:]]\{2\}"
	time="[[:digit:]]\{2\}:[[:digit:]]\{2\}:[[:digit:]]\{2\}.[[:digit:]]\{9\}"
	timezone="[-\+][[:digit:]]\{4\}"
	timestamp_format="${date}[[:space:]]${time}[[:space:]]${timezone}"
	sed -i.bak "s/\(${prefix} ${filename_format}\)[[:space:]]${timestamp_format}/\1/g" ${f}/$(basename -- ${f}).patch
	rm ${f}/$(basename -- ${f}).patch.bak
}

for f in packages/*; do
	if [[ -f ${f}/package.yaml ]]; then
		if [[ -z $CHART || $CHART == $(basename -- ${f}) ]]; then
			url=$(cat ${f}/package.yaml | yq r - url)
			if [[ -z ${url} ]]; then
				continue
			fi
			subdirectory=$(cat ${f}/package.yaml | yq r - subdirectory)
			type=$(cat ${f}/package.yaml | yq r - type)
			commit=$(cat ${f}/package.yaml | yq r - commit)
			fields=$(echo ${subdirectory} | awk -F'/' '{print NF}')
			if [[ $fields -eq '0' ]]; then
				fields='1'
			fi
			if [[ $type == 'git' ]]; then
				mkdir -p /tmp/tmp-charts
				git clone --depth=1 --no-tags $url /tmp/tmp-charts
				pwd=$(pwd)
				cd /tmp/tmp-charts
				git fetch origin $commit
				git checkout $commit
				cd $pwd
				cp -r /tmp/tmp-charts/${subdirectory} ${f}/charts-original
				rm -rf /tmp/tmp-charts
			else
				mkdir -p ${f}/charts-original
				curl -sLf ${url} | tar xvzf - -C ${f}/charts-original --strip ${fields} ${subdirectory} > /dev/null 2>&1
			fi
			if [[ -f ${f}/charts/requirements.yaml ]]; then
				i=0
				while ! [[ -z $(yq r ${f}/charts/requirements.yaml "dependencies[${i}]") ]]; do
					subchart=$(yq r ${f}/charts/requirements.yaml "dependencies[${i}].name" | head -n 1)
					version=$(yq r ${f}/charts/requirements.yaml "dependencies[${i}].version" | head -n 1)
					helm_repo=$(yq r ${f}/charts/requirements.yaml "dependencies[${i}].repository" | head -n 1)
					# Remove trailing slash
					[[ ${helm_repo} == */ ]] && helm_repo=${helm_repo%/}
					if [[ ${helm_repo} == file://* ]] || [[ ${version} == *'*'* ]]; then
						# Subchart is tracked locally; patches will not be tracked
						rm -rf ${f}/charts-original/charts/${subchart}
						((i=i+1))
						continue
					fi
					# Subchart is tracked in remote Helm repo with a fixed version number; we grab the download URL and get the local chart archive
					download_url=$(curl -sLf ${helm_repo}/index.yaml | cat | yq r - "entries.${subchart}.(version == ${version}).urls[0]")
					if [[ -z ${download_url} ]]; then
						echo "Failed to get download URL for ${subchart} at version ${version} from index.yaml at ${helm_repo}"
						exit 1
					fi
					echo "Comparing current changes to ${subchart}-${version} against upstream found at ${download_url}"
					curl -sLf ${download_url} | tar xvzf - -C ${f}/charts-original/charts > /dev/null 2>&1
					((i=i+1))
				done
			fi
			if [[ -d ${f}/charts ]]; then
				split_crds=$(cat ${f}/package.yaml | yq r - generateCRDChart.enabled)
				if [[ "${split_crds}" == "true" ]]; then
					./scripts/clean-crds ${f}
				fi
				diff -x *.tgz -x *.lock -uNr ${f}/charts-original ${f}/charts > ${f}/$(basename -- ${f}).patch || true
				if ! [[ -s ${f}/$(basename -- ${f}).patch ]]; then
					# If no changes exist in patch then remove it
					rm ${f}/$(basename -- ${f}).patch
				fi
				if [[ -f ${f}/$(basename -- ${f}).patch ]]; then
					remove_timestamp_from_diff
				fi
				if [[ "${split_crds}" == "true" ]]; then
					./scripts/prepare-crds ${f}
				fi
			fi
			rm -rf ${f}/charts-original
		fi
  fi
done