#
# . ./build.vars and set -o errexit are assumed.
# See warning at the top of build.vars.
#

date() { command date +"${1:-${TIMESTAMP_FMT}}"; };
fetch_git() { [ -d ${1} ] && (cd ${1} && git pull origin main) || git clone ${3} ${2} ${1}; };
get_basename() { set -- $(get_name_without_slash ${1}); echo "${1##*/}"; };
get_var() { eval echo \${${1}}; }; # XXX
set_var() { eval ${1}=\"${2}\"; }; # XXX
get_name_without_slash() { while [ "x${1%/}" != "x${1}" ]; do set -- ${1%/}; done; echo ${1}; };
get_postfix_lrg() { echo "${1##*${2}}"; };
get_prefix_lrg() { echo "${1%%${2}*}"; };
get_postfix() { echo "${1#*${2}}"; };
get_prefix() { echo "${1%${2}*}"; };
match_any() { [ "x${1#*${2}*}" != "x${1}" ]; };
match_start() { [ "x${1#${2}}" != "x${1}" ]; };
push_IFS() { _IFS="${IFS}"; IFS="${1}"; };
pop_IFS() { IFS="${_IFS}"; unset _IFS; };
set_build_dir() { BUILD_DIR=${1}-${2}-${TARGET}; };
split() { push_IFS "${1}"; set -- ${2}; pop_IFS; echo "${*}"; };
unsplit() { push_IFS "${1}"; shift; set -- "${@}"; echo "${*}"; pop_IFS; };


rm_if_exists() {
	set_flag_vars_from_args "$@"; shift ${_nshift:-0};
	[ -d ${1} ] && rm -rf ${1}; [ -f ${1} ] && rm -f ${1};
	[ ${_arg_m:-0} -eq 1 ] && mkdir ${1};
	[ ${_arg_c:-0} -eq 1 ] && cd ${1};
	unset_flag_vars_from_args;
};

set_flag_vars_from_args() {
	unset _flag_vars _nshift;
	while [ ${#} -gt 1 ]; do
		if [ "x${1%[a-z]}" = "x-" ]; then
			set_var _arg_${1#-} 1;
			_flag_vars="${_flag_vars:+${_flag_vars} }_arg_${1#-}";
			: $((_nshift+=1));
		fi; shift;
	done;
};
unset_flag_vars_from_args() {
	set -- ${_flag_vars}; while [ ${#} -gt 0 ]; do
		unset ${1}; shift; done; unset _flag_vars _nshift;
};

set_env_vars() {
	_val_new="${1}"; shift;
	while [ ${#} -gt 1 ]; do
		[ -z "${_val_new}" ] && unset ${1} ||\
			export "${1}=${_val_new}"; shift;
	done; unset _val_new;
};


# Download GNU bash-style patch sets into ${2}-patches-extra and
# apply them to ${2} in the correct order.
apply_patches() {
	(rm_if_exists -m -c ${2}-patches-extra;
	wget -c -nd -np -r -R \*.htm\* -R \*.sig ${1};
	for _patch_fname in		\
			$(find . -type f -not -iname \*.sig | sort); do
		patch -b -d ../${2} -p0	\
			< ${_patch_fname};
	done; unset _patch_fname);
};

# Check whether all supplied arguments contain non-empty valid values.
check_path_vars() {
	while [ ${#} -gt 0 ]; do
		unset _val;
		if [ -z "${_val:=$(get_var "${1}")}" ]; then
			log_msg failexit "Error: variable \`${1}' is empty or unset.";
		elif match_any "${_val}" " "; then
			log_msg failexit "Error: variable \`${1}' contains one or more whitespace characters.";
		else
			shift;
		fi;
	done; unset _val;
};

# Check whether all supplied command names resolve.
check_prereqs() {
	while [ ${#} -gt 0 ]; do
		if ! command -v ${1} >/dev/null; then
			log_msg failexit "Error: missing prerequisite command \`${1}'.";
		fi; shift;
	done;
};

# Clear the environment by unsetting each exported variable except
# for those named by the caller. 
clear_env_with_except() {
	_vfilter="${*}"; _unset_cmds="$(mktemp -q)";
	export | while read _vspec; do
		set -- ${_vspec}; shift;
		if ! match_list "${_vfilter}" " "	\
				$(get_prefix_lrg ${1} =); then
			echo unset $(get_prefix_lrg ${1} =) >> ${_unset_cmds};
		fi;
	done; . "${_unset_cmds}"; rm -f "${_unset_cmds}" 2>/dev/null;
	unset _vfilter _vspec;
};

fetch() {
	wget ${WGET_ARGS} ${1};
	if [ ${#} -eq 2 ]; then
		set -- $(get_basename ${1}) "$(compare_hash $(get_basename ${1}) ${2})" ${2};
		if [ -n "${2}" ]; then
			log_msg failexit "Error: hash mismatch for URL \`${1}' (is: ${2}, should be: ${3}.)";
		fi;
	fi;
};

compare_hash() {
	# Push the output of dgst(1SSL) and the caller-supplied hash
	# value to compare the former with on the pseudo-stack and
	# shift off# all but the last two positional parameters.
	# This corresponds to the hash output and caller-supplied
	# hash values.
	set -- $(openssl dgst -sha256 ${1}) ${2}; shift $((${#}-2));
	[ "x${1}" = "x${2}" ] || echo "${1}";
};
compare_hash_manifest() {
	while [ ${#} -gt 0 ]; do
		if ! compare_hash ${1} ${2}; then
			log_msg failexit "Error: hash mismatch for patch file \`${1}'.";
		fi; shift;
	done; return 0;
};

is_build_script_done() {
	if [ -n "${ARG_BUILD_STEPS}" ]; then
		if [ "${ARG_BUILD_STEPS}" = "finish" ]\
		|| [ -z "${ARG_BUILD_STEPS#ALL}" ]; then
			return 1;	# Build
		elif ! match_list ${ARG_BUILD_STEPS} , ${1}; then
			return 0;	# Skip
		else
			return 1;	# Build
		fi;
	elif [ -f ${WORKDIR}/.${2:-$(get_basename ${SCRIPT_FNAME%.build})}.${1} ]; then
		return 0;		# Skip
	else
		return 1;		# Build
	fi;
};
set_build_script_done() {
	_script_fname=${SCRIPT_FNAME##*/};
	_done_fname=${WORKDIR}/.${_script_fname%.build};
	while [ $# -ge 1 ]; do
		if [ "x${1#-}" != "x${1}" ]; then
			rm -f ${_done_fname}.${1#-};
		else
			touch ${_done_fname}.${1};
			log_msg info "Finished build step ${1} of build script \`${_script_fname}'.";
		fi; shift;
	done;
	unset _script_fname _done_fname;
};

log_env_vars() {
	log_msg info "Variables for this build:";
	while [ ${_nvar:=0} -lt ${#} ]; do
		_arg="$(eval echo \${${_nvar}})"; _arg="${_arg%%=*}";
		if [ ${#_arg} -gt ${_arg_len_max:=0} ]; then
			_arg_len_max=${#_arg};
		fi; : $((_nvar+=1));
	done; unset _nvar _arg;
	while [ ${#} -gt 0 ]; do
		log_msg info "$(printf				\
			"%${_arg_len_max}.${_arg_len_max}s=%s"	\
			"${1%%=*}" "$(get_var ${1#*=})")";
		shift;
	done; unset _arg_len_max;
};
log_msg() {
	_lvl=${1}; shift;
	case ${_lvl} in
		failexit) printf "\033[${LOG_MSG_FAIL_COLOUR}m"; ;;
		fail) printf "\033[${LOG_MSG_FAIL_COLOUR}m"; ;;
		info) printf "\033[${LOG_MSG_INFO_COLOUR}m"; ;;
		succ) printf "\033[${LOG_MSG_SUCC_COLOUR}m"; ;;
	esac;
	if [ $# -gt 1 ]; then
		printf "==> %s %s %s\033[0m\n" "$(date "${TIMESTAMP_FMT}")" "${1}" "$*";
	else
		printf "==> %s %s\033[0m\n" "$(date "${TIMESTAMP_FMT}")" "${1}";
	fi; [ ${_lvl} = failexit ] && exit 1 || unset _lvl;
};

match_list() {
	_cmp="${3}"; push_IFS "${2}"; set -- ${1}; pop_IFS;
	while [ ${#} -gt 0 ]; do
		if [ "x${1}" = "x${_cmp}" ]; then
			unset _cmp; return 0;
		fi; shift;
	done; unset _cmp; return 1;
};

parse_args_into_vars() {
	_arg0="${1}"; _args_valid="${2}"; shift 2;
	while [ $# -gt 0 ]; do
		case "${1}" in
		--*)	_aname="${1#--}";
			if ! match_list "${_args_valid}" , "${_aname%%=*}"; then
				log_msg failexit "Unknown parameter --${_aname%%=*} specified.";
			elif match_start "${_aname}" "*="; then
				_aval="$(get_postfix "${_aname}" =)";
				_aname="$(get_prefix_lrg "${_aname}" =)";
			else
				_aval=1;
			fi;
			set_var $(echo arg_${_aname} | tr a-z- A-Z_) "${_aval}";
			shift; ;;
		*=*)	set_var "$(get_prefix_lrg "${1}" =)"\
				"$(get_postfix "${1}" =)"; shift; ;;
		*)	log_msg failexit "Invalid or unknown command line argument \`${1}'."; ;;
		esac;
	done; unset _arg0 _args_valid _aname _aval;
};

parse_with_pkg_name() {
	PKG_NAME=${1}; shift;
	while [ $# -ge 0 ]; do
		if [ "x${PKG_NAME}" = "x${1}" ]; then
			_pkg_NAME=$(echo "${PKG_NAME}" | tr a-z A-Z);
			for _vname in ${PKG_VARS}; do
				_vNAME=$(echo "${_vname}" | tr a-z A-Z);
				if [ -n "${_vval:=$(get_var PKG_${_pkg_NAME}_${_vNAME})}" ]; then
					export PKG_${_vNAME}="${_vval}";
					if [ "x${_vname#[A-Z]}" != "x${_vname}" ]; then
						export ${_vname}="${_vval}";
					fi;
				else
					unset PKG_${_vNAME};
				fi; unset _vval;
			done; unset _pkg_NAME _vname _vNAME;
			if [ -z "${PKG_URL}" ]; then
				return 1;
			else
				[ -z "${PKG_FNAME}" ] && PKG_FNAME=${PKG_URL##*/};
				[ -z "${PKG_SUBDIR}" ] && PKG_SUBDIR=${PKG_FNAME%%.tar*};
				return 0;
			fi;
		fi; shift;
	done; return 1;
};

# vim:filetype=sh