#!/usr/bin/env bash
########################################################
#
# Prints a line with the files that can be removed
#  from PORTDIR
#
# Author: Fernando J. Pereda <ferdy AT gentoo.org>
# License: Do with it whatever you want
# Usage:
#     Execute it to retrieve a list of files that are
#      not claimed by any package installed. This list
#      may be used using bash command expansion feature:
#
#          $ sudo rm $(distfiles-cleanable)
#
########################################################
#
# Revision History:
#
#  0.1: (25 August 2005)
#    --  Initial release
#  0.2: (25 August 2005)
#    --  Fix ' ' in environment.bz2
#  0.3: (25 August 2005)
#    --  Exclude *-src directories from the list
#  0.4: (26 August 2005)
#    --  Fix excluding *-src directories (thanks Narf)
#
########################################################

# Get paths
cache_vdb_path=$(portageq vdb_path)
cache_portdir=$(portageq portdir)

# Retrieve a list of files in distfiles/
distfiles_list=$(echo ${cache_portdir}/distfiles/*)

# Now get a list of the files claimed by packages
for e in ${cache_vdb_path}/*-*/*/environment.bz2 ; do
	claimed_list="${claimed_list} $(bzcat ${e} | sed -n -e "/^AA='\?\([^']*\)'\?$/s--\1-p")"
done

#####
# The first two attempts are the 'correct' way to solve this
#   particular problem; but the third one is way faster :)
#####
##### First attempt
# Now check each file from distfiles_list to see if
#  it's in claimed_list
#for d in ${distfiles_list} ; do
#	# Is the file claimed ? If so, remove it from the list
#	[[ -z ${claimed_list##*${d}*} ]] && distfiles_list=${distfiles_list//${d}}
#done
#####
#### Second attempt
# Now remove every item in claimed_list from distfiles_list
#for d in ${claimed_list} ; do
#	distfiles_list=${distfiles_list//${d}}
#done
####

#### Third attempt (aka let's hack)
# Build a list of sed expressions: -e s/filename// for each filename in claimed_list
sed_args=$(sed -e "s~\([^ ]*\)\( \|$\)~-e s/\1// ~g" <<< ${claimed_list})
# Now call sed with that list, remove cache_portdir prefix and remove extra spaces
sed ${sed_args} \
	-e 's~[^- ]*-src\( \|$\)~~g' \
	-e "s~${cache_portdir}/distfiles.~~g" \
	-e 's~ \+~ ~g' \
	<<< ${distfiles_list}
####