#!/bin/bash

set -e

IGNORE_INTERNAL=0

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

script_mode=${0##*/find-lib}

case $script_mode in
	deps|provides) true;;
	*) echo "error: unknown mode $script_mode"; exit 1;;
esac

if [[ -z $1 ]]; then
	echo "${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

	case ${script_mode} in
		deps) bsdtar -C $tmpdir -xf "$1";;
		provides)bsdtar -C $tmpdir -xf "$1" --include="*.so*";;
	esac

	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
}

process_sofile() {
	# 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}" ${soobjects[@]}; then
		# libfoo.so=1-64
		echo "${soname}=${soversion}-${soarch}"
		soobjects=(${soobjects[@]} "${soname}=${soversion}-${soarch}")
	fi
}

case $script_mode in 
	deps) find_args="-perm -u+x";;
	provides) find_args="-name *.so*";;
esac

find . -type f $find_args | while read filename; do
	if [[ $script_mode = "provides" ]]; then
		# ignore if we don't have a shared object
		if ! LC_ALL=C readelf -h "$filename" 2>/dev/null | grep -q '.*Type:.*DYN (Shared object file).*'; then
			continue
		fi
	fi

	# 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

	if [[ $script_mode = "provides" ]]; then
		# get the string binaries link to: libfoo.so.1.2 -> libfoo.so.1
		sofile=$(LC_ALL=C readelf -d "$filename" 2>/dev/null | sed -n 's/.*Library soname: \[\(.*\)\].*/\1/p')
		[ -z "$sofile" ] && sofile="${filename##*/}"
		process_sofile
	elif [[ $script_mode = "deps" ]]; then
		# 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
			process_sofile
		done
	fi
done