## vim:ft=zsh
## reverse tabbing, useful in the prompt
## Copyright (C) 2008, 2009 by Daniel Friesel <derf@finalrewind.org>
## License: WTFPL <http://sam.zoy.org/wtfpl>

setopt localoptions
setopt rc_quotes null_glob

typeset -i lastfull=0
typeset -i short=0
typeset -i tilde=0
typeset -i named=0
typeset IFS=$'\n'

if zstyle -t ':prompt:rtab' fish; then
	lastfull=1
	short=1
	tilde=1
fi
if zstyle -t ':prompt:rtab' nameddirs; then
	tilde=1
	named=1
fi
zstyle -t ':prompt:rtab' last && lastfull=1
zstyle -t ':prompt:rtab' short && short=1
zstyle -t ':prompt:rtab' tilde && tilde=1

while [[ ${1} == -* ]]; do
	case ${1} in
		-f|--fish)
			lastfull=1
			short=1
			tilde=1
		;;
		-h|--help)
			print 'Usage: rtab [-f -l -s -t] [directory]'
			print ' -f, --fish      fish-simulation, like -l -s -t'
			print ' -l, --last      Print the last directory''s full name'
			print ' -s, --short     Truncate directory names to the first character'
			print ' -t, --tilde     Substitute ~ for the home directory'
			print ' -T, --nameddirs Substitute named directories as well'
			print 'The long options can also be set via zstyle, like'
			print '  zstyle :prompt:rtab fish yes'
			return 0
		;;
		-l|--last) lastfull=1 ;;
		-s|--short) short=1 ;;
		-t|--tilde) tilde=1 ;;
		-T|--nameddirs)
			tilde=1
			named=1
		;;
		-|--)
			shift
			break
		;;
	esac
	shift
done

typeset -a tree expn
typeset result part dir=${1-${PWD}}
typeset -i i

[[ -d ${dir} ]] || return 0

if (( named )) {
	for part in ${(k)nameddirs}; {
		[[ ${dir} == ${nameddirs[$part]}(/*|) ]] && dir=${dir/${nameddirs[$part]}/\~${part}}
	}
}
(( tilde )) && dir=${dir/#${HOME}/\~}
tree=(${(s:/:)dir})
(
	# Start either in the currrent named directory or in /
	if [[ ${tree[1]} == \~* ]] {
		cd -q ${~tree[1]}
		result=${tree[1]}
		shift tree
	} else {
		cd -q /
	}
	for dir in ${tree}; {
		if (( lastfull && ${#tree} == 1 )) {
			result+="/${tree}"
			break
		}

		# required for the until loop
		expn=(a b)
		part=''
		i=0
		until [[ (( ${#expn} == 1 )) || ${dir} == ${expn} || ${i} -gt 99 ]]  do
			(( i++ ))
			part+=${dir[$i]}
			expn=($(echo ${part}*(-/)))
			# Never show a single . as directory
			if [[ ${i} == 1 && ${dir[$i]} == . ]] {
				expn=(a b)
			} elif [[ ${short} == 1 ]] {
				break
			}
		done
		result+="/${part}"
		cd -q ${dir}
		shift tree
	}
	echo ${result:-/}
)