#!/bin/sh
set -euo pipefail


usage() {
	echo 'Usage: symlinks FILENAME.txt'
}

FILENAME="${1:-}"
eval "$(assert-arg -- "$FILENAME" 'FILENAME.txt')"



filter() {
	awk '$1 != "" && $2 != "" && $3 == "" && $1 != "#"'
}

getdirs() {
	awk '
	n = split($1, seg, "/") {
		dir = substr($1, 1, length($1) - length(seg[n]))
		print dir
	}' | grep . | sort | uniq | sed 's/^/mkdir -p /'
}

gencommands() {
	awk '
	n = split($1, seg, "/") {
		printf "ln -fs "
		for (i = 0; i < n - 1; i++) {
			printf "../"
		}
		printf "%s %s\n", $2, $1
	}'
}

asignorelist() {
	cut -f1 | sort | uniq | sed 's|^|/|'
}



cat -- "$FILENAME" | filter | getdirs     | tee /dev/stderr | sh
cat -- "$FILENAME" | filter | gencommands | tee /dev/stderr | sh
cat -- "$FILENAME" | filter | asignorelist