wepeeter

#!/bin/sh -e
#
# Usage: wepeeter [-cdps] REPEATS FILE...
#
# Makes REPEATS-many directories within a subdirectory (named weepeets) 
# of the current directory containing symlinks to the specified files.
#
# The main use of this is to give higher weight to preferred files when 
# passing a directory to a media player, e.g., your favorite songs get 
# played more often.
#
# If REPEATS is 0 then the number of repeats will be chosen 
# interactively per-file with the option to preview each file with a 
# user-specified program. The -p argument can be used to specify the 
# previewer program non-interactively.
#
# The -c argument runs wepeeter on each non-hidden file newer than the 
# wepeets directory, then updates the mtime on the wepeets directory if 
# successful.
#
# The -p argument allows a previewer to be specified, e.g., -p mpv
#
# The -s argument shows broken symlinks.
#
# The -d argument deletes broken symlinks.
#

unset -v since_change clean_dead previewer show_dead
while getopts 'cdp:s' o; do
	case "$o" in
		c) since_change=1 ;;
		d) clean_dead=1 ;;
		p) previewer="$OPTARG" ;;
		s) show_dead=1 ;;
		#h) help; exit 0 ;;
		#*) help; exit 1 ;;
	esac
done
shift $((OPTIND-1))

if [ "$clean_dead" ] || [ "$show_dead" ]; then
	for l in wepeets/*/*; do
		if [ -L "$l" ] && ! [ -f "$(realpath "$l" 2>/dev/null)" ]; then
			if [ "$clean_dead" ]; then
				rm "$l"
			else
				printf '%s\n' "$l"
			fi
		fi
	done
	exit 0
fi

wepeet() {
	repeats="${1:?}"
	shift 1
	test "${1:?}"

	# remove existing symlinks for the specified files
	for dir in wepeets/*/; do
		case "$dir" in "wepeets/*/") break;; esac
		for file; do
			rm -f "$dir/$(basename "$file")"
		done
		# remove wepeet directories if they're empty
		rmdir "$dir" 2> /dev/null || :
	done

	i=1
	while [ "$i" -le "$repeats" ]; do
		mkdir -p "wepeets/wepeet-${i}"
		for file; do
			# prefix relative paths with ../../
			case "$file" in /*) ;; *) file="../../$file" ;; esac
			ln -sf "$file" "wepeets/wepeet-${i}/"
		done
		i=$((i+1))
	done
}

if [ "$since_change" ]; then
	if [ ! -d ./wepeets/ ]; then
		echo "No wepeets directory found despite -c (run wepeeter normally first)" >&2
		exit 1
	fi

	find . -type f -newer ./wepeets/ ! -path '*/.*' -exec $0 ${previewer:+-p $previewer} 0 {} +
	touch ./wepeets/
	exit
fi

if [ "${1:?}" -eq 0 ]; then
	if [ ! "$previewer" ]; then
		echo 'Program for previewing files (leave blank to disable previews): ' >&2
		read -r previewer
	fi

	shift 1
	for file; do
		unset -v repeats
		while [ ! "$repeats" ]; do
			if [ "$previewer" ]; then
				( set -f; $previewer "$file"; )
			fi
			echo "Number of repeats for $file (leave blank to preview again): " >&2
			read -r repeats
			if [ "$repeats" ] && ! [ "$repeats" -ge 0 ]; then
				unset -v repeats
			fi
		done
		wepeet "$repeats" "$file"
	done
else
	wepeet "$@"
fi