.architectures-lib

#!/usr/bin/env bash

_awkArch() {
	local version="$1"; shift
	local awkExpr="$1"; shift
	awk "$@" "/^#|^\$/ { next } $awkExpr" "$version/release-architectures"
}

dpkgArches() {
	local version="$1"; shift
	_awkArch "$version" '{ print $2 }'
}

hasBashbrewArch() {
	local version="$1"; shift
	local bashbrewArch="$1"; shift
	_awkArch "$version" 'BEGIN { exitCode = 1 } $1 == bashbrewArch { exitCode = 0 } END { exit exitCode }' -v bashbrewArch="$bashbrewArch"
}

dpkgToGoArch() {
	local version="$1"; shift
	local dpkgArch="$1"; shift
	_awkArch "$version" '$2 == dpkgArch { print $3; exit }' -v dpkgArch="$dpkgArch"
}

_generateParentRepoToArches() {
	local repo="$1"; shift
	local officialImagesUrl='https://github.com/docker-library/official-images/raw/master/library/'

	eval "declare -g -A parentRepoToArches=( $(
		find -name 'Dockerfile' -exec awk '
				toupper($1) == "FROM" && $2 !~ /^('"$repo"'|scratch|.*\/.*)(:|$)/ {
					print "'"$officialImagesUrl"'" $2
				}
			' '{}' + \
			| sort -u \
			| xargs bashbrew cat --format '[{{ .RepoName }}:{{ .TagName }}]="{{ join " " .TagEntry.Architectures }}"'
	) )"
}
_generateParentRepoToArches 'golang'

parentArches() {
	local version="$1"; shift # "1.8", etc
	local variant="$1"; shift # "", "stretch", etc

	local parent="$(awk 'toupper($1) == "FROM" { print $2 }' "$version/$variant/Dockerfile")"
	echo "${parentRepoToArches[$parent]:-}"
}
variantArches() {
	local version="$1"; shift # "1.8", etc
	local variant="$1"; shift # "", "stretch", etc

	local parentArches="$(parentArches "$version" "$variant")"

	local variantArches=()
	for arch in $parentArches; do
		if hasBashbrewArch "$version" "$arch"; then
			variantArches+=( "$arch" )
		fi
	done
	echo "${variantArches[*]}"
}