#!/bin/sh

__BASE="${SHP_BASE:-"$PWD"}"
export _INCDIR="${SHP_INCDIR:-"${__BASE}/include"}"
export _BUILDDIR="${SHP_BUILDDIR:-"${__BASE}/build"}"
export _SRCDIR="${SHP_SRCDIR:-"${__BASE}/src"}"
export _NL="
"

# process an html formatted file either given or from stdin and output to stdout
# if a file is given, stdin is free to be used by any shp files it encounters
__process_shp() {
	__SHLVL=$((__SHLVL + 1))
	eval '__SH_FLAG'$__SHLVL'=""
	__LINE_EXEC_'$__SHLVL'=""
	while IFS= read -r __LINE'$__SHLVL'; do
		if [ -z "$__SH_FLAG'$__SHLVL'" ]; then
			case "$__LINE'$__SHLVL'" in
				*"<?shp"*)
					printf "%s" "${__LINE'$__SHLVL'%%<\?shp*}"
					__LINE'$__SHLVL'="${__LINE'$__SHLVL'#*<\?shp}"
					__SH_FLAG'$__SHLVL'=1
					;;
				*) echo "$__LINE'$__SHLVL'" ;;
			esac
		fi
		if [ -n "$__SH_FLAG'$__SHLVL'" ]; then
			__LINE_EXEC_'$__SHLVL'="$__LINE_EXEC_'$__SHLVL'$_NL$__LINE'$__SHLVL'"
			case "$__LINE'$__SHLVL'" in
				*"?>"*)
					eval "${__LINE_EXEC_'$__SHLVL'%%\?>*}"
					printf "%s" "${__LINE'$__SHLVL'#*\?>}"
					__SH_FLAG'$__SHLVL'=""
					__LINE_EXEC_'$__SHLVL'=""
					;;
				*) ;;
			esac
		fi
	done '"${1:+"< \"\$1\""}"'
	[ $__SH_FLAG'$__SHLVL' ] && eval "$__LINE_EXEC_'$__SHLVL'"'
	__SHLVL=$((__SHLVL - 1))
}
__SHLVL=0

# lowdown wrapper function
__lowdown() {
	lowdown --html-no-owasp --html-no-skiphtml --html-no-escapehtml --html-no-num-ent "$@" | \
		sed -E '
		s/&[lr]squo;/\&apos;/g
		s/&ndash;/--/g
		s/&[lr]dquo;/\&quot;/g
		'
}

# process a pure markdown file
# uses a special file in _INCDIR, `markdown-template.sh` to create the html
__process_md() {
	eval ' {
		set_md_metadata
		__process_shp "$_INCDIR"/_markdown-template.shp
	}'"${1:+"< \"\$1\""}"
}

# to call when including a markdown file because we don't want to *process* the whole thing
__include_md() {
	eval ' {
		set_md_metadata
		__lowdown
	}'"${1:+"< \"\$1\""}"
}

# standard library
include() {
	# if the path contains a slash, then treat it as-is
	# else, try getting it from $_INCDIR
	case "$1" in
		*/*.md) __include_md "$1" ;;
		*.md) __include_md "$_INCDIR"/"$1" ;;
		*/*) __process_shp "$1" ;;
		*) __process_shp "$_INCDIR"/"$1" ;;
	esac
}

# set markdown metadata either given or from stdin
# why do we have this big eval here--why not use /dev/stdin?
# using /dev/stdin makes the input behave Very Weirdly, I can't really explain
# what is going on but it just doesn't work how one would expect
# this eval prevents a lengthy if-else statement
# I adapted this method to all other stuff that either accepts stdin or an argument
# for maximum portability, I guess. even though every relevant unix has /dev/stdin
# I guess it's paranoia for the accidentally swallowing stdin thing as well. whatever
set_md_metadata() {
	eval ' {
		# if 1st line isnt all -, skip setting metadata
		IFS= read -r __first
		case "$__first" in
			*[!-]*) return ;;
		esac

		while IFS=" =" read -r __key __val; do
			case "$__key" in
				*[!-]*) eval "$__key=\$__val" ;;
				*) return ;;
			esac
		done
	} '"${1:+"< \"\$1\""}"
}

# good for inputs without many chars to escape
# so most titles, strings, etc.
# this is why it only accepts an argument and not stdin
escape() {
	__ESC_STR=$*
	# do this first to not create an infinite loop
	while :; do
		case "$__ESC_STR" in
			*\&*) __ESC_STR_INT="${__ESC_STR%%&*}&amp;"; __ESC_STR="${__ESC_STR#*&}" ;;
			*) __ESC_STR_INT="$__ESC_STR_INT$__ESC_STR"; break ;;
		esac
	done
	__ESC_STR=$__ESC_STR_INT
	while :; do
		case "$__ESC_STR" in
			*\<*) __ESC_STR="${__ESC_STR%<*}&lt;${__ESC_STR##*<}" ;;
			*\>*) __ESC_STR="${__ESC_STR%>*}&gt;${__ESC_STR##*>}" ;;
			*\"*) __ESC_STR="${__ESC_STR%\"*}&quot;${__ESC_STR##*\"}" ;;
			*\'*) __ESC_STR="${__ESC_STR%\'*}&apos;${__ESC_STR##*\'}" ;;
			*) break;
		esac
	done
	printf '%s\n' "$__ESC_STR"
}

# good for large inputs with lots of chars to escape
# this means mostly full files, entire posts for putting in content for a feed
escapepipe() {
	sed -e 's/&/\&amp;/g' -e 's/</\&lt;/g' -e 's/>/\&gt;/g' -e 's/"/\&quot;/g' -e "s/'/\\&apos;/g"
}

# build folder structure
find "$_SRCDIR" -type d -exec sh -c 'for d; do mkdir -p "$_BUILDDIR"/"${d#"$_SRCDIR"}"; done' sh {} +

# it's parallel time baby
# hopefully portable enough to not be an issue
__THREADS="$(nproc 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || getconf _NPROCESSORS_ONLN 2>/dev/null)"
[ $? -ne 0 ] \
	&& echo 'unable to find number of cores! defaulting to 1 thread unless otherwise specified...' >&2 \
	&& __THREADS=1

# make a parallel fifo/file descriptor we need
__fifo_para="$(mktemp -u -t "shpbuild.XXXXXX")"
mkfifo "$__fifo_para"
exec 9<>"$__fifo_para"
rm -f "$__fifo_para"
while [ "$__THREADS" -gt 0 ]; do
	printf "\n" >&9 # start with THREADS amount of lines in fd 9 for later
	__THREADS="$((__THREADS - 1))"
done

# read each line from fd 9, launch new program for each line
# print a line after program finished such that another one can take its place
__run_in_parallel() {
	read -r __ <&9
	{
		"$@"
		printf '\n' >&9
	} &
}

while IFS= read -r _FILE; do
	cd "${_FILE%/*}"
	export _OUTFILE="$_BUILDDIR/${_FILE#"$_SRCDIR/"}"
	case "${_FILE##*/}" in
		*.[hH][tT][mM][lL]|*.[sS][hH][pP]) ( __run_in_parallel __process_shp "$_FILE" ) > "${_OUTFILE%.*}.html" ;;
		*.[mM][dD]) ( __run_in_parallel __process_md "$_FILE" ) > "${_OUTFILE%.*}.html" ;;
		*.[sS][hH]) ( __run_in_parallel . "$_FILE" ) ;; # don't autocopy. this is for code :)
		*) __run_in_parallel cp -p "$_FILE" "$_OUTFILE" ;;
	esac
done <<-EOF
	$(find "$_SRCDIR" -type f)
EOF

[ -f "$_INCDIR/_postbuild.sh" ] && . "$_INCDIR/_postbuild.sh"