#!/bin/bash

set -e

IGNORE_INTERNAL=0

if [[ $1 = "--ignore-internal" ]]; then
	IGNORE_INTERNAL=1
	shift
fi

if [[ -z $1 ]]; then
	echo "$(basename "$0") [options] <package file|extracted package dir>"
	echo "Options:"
	echo "    --ignore-internal   ignore internal libraries"
	exit 1
fi


cleanup() {
	if [[ $tmpdir ]]; then
		rm -rf $tmpdir;
	fi
}

if [[ -d $1 ]]; then
	cd $1
else
	tmpdir=$(mktemp -d /tmp/find-sodeps.XXXXXXX)
	trap "cleanup" EXIT INT TERM

	tar -C $tmpdir -xf "$1"

	cd $tmpdir
fi

in_array() {
	local needle=$1; shift
	[[ -z $1 ]] && return 1 # Not Found
	local item
	for item in "$@"; do
	[[ $item = $needle ]] && return 0 # Found
	done
	return 1 # Not Found
}

find . -type f -perm -u+x | while read filename; do
	# get architecture of the file; if soarch is empty it's not an ELF binary
	soarch=$(LC_ALL=C readelf -h "$filename" 2>/dev/null | sed -n 's/.*Class.*ELF\(32\|64\)/\1/p')
	[ -n "$soarch" ] || continue
	# process all libraries needed by the binary
	for sofile in $(LC_ALL=C readelf -d "$filename" 2>/dev/null | sed -nr 's/.*Shared library: \[(.*)\].*/\1/p')
	do
		# extract the library name: libfoo.so
		soname="${sofile%%\.so\.*}.so"
		# extract the major version: 1
		soversion="${sofile##*\.so\.}"
		if [[ "$soversion" = "$sofile" ]] && (($IGNORE_INTERNAL)); then
			continue
		fi
		if ! in_array "${soname}=${soversion}-${soarch}" ${sodepends[@]}; then
			# libfoo.so=1-64
			echo "${soname}=${soversion}-${soarch}"
			sodepends=(${sodepends[@]} "${soname}=${soversion}-${soarch}")
		fi
	done
done