#! /bin/env python3
# encoding: utf-8

# library imports
import fnmatch
import glob
import os
import over
import re
import sys
import time

# --------------------------------------------------

prefix = over.core.textui.prefix
_print = over.core.textui.Output('Find Orphans')

# --------------------------------------------------
# Functions

# --------------------------------------------------
# Classes

# --------------------------------------------------

if __name__ == '__main__':
	main = over.core.app.Main('Find Orphans', None, 'AWARE-Overwatch Joint Software License')
	main.add_option('filter', 'str', ['/home/*', '/var/*', '*.pyc', '/lib*/modules/*', '*.pyo', '/usr/share/mime/*', '/usr/local/*'], 'Shell globs that should be filtered out.', plural=True)
	main.add_option('null-separated', 'bool', False, 'Output each filename separated with a null character. Otherwise use a newline.', short_name='0')
	main.add_option('output', 'bool', True, 'Output filenames to stdout. Otherwise just counts them.')
	main.add_help('Description', ['Finds files on Gentoo systems that aren\'t owned by any installed package and lists them.'])
	main.enable_help('h')
	main.parse()
	
	if not main.targets:
		_print('specify at least one directory to work on, e.g. \'/\'', prefix.fail)
		main.exit(silent=True)
	
	# --------------------------------------------------
	# Create a list of all files
	
	all_files = set()
	threads = [] # {proc, output_buffer}
	
	for root in main.targets:
		proc = over.core.cmd.Command('find', root, '-type', 'f', '-print0')
		proc.run()
		threads.append({'proc': proc, 'output_buffer': [], 'root': root})
	
	_print('gathering a list of all files using %d processes' %(len(threads)), prefix.start)
	
	while True:
		at_least_one_lives = False
		
		for thread in threads:
			tmp = thread['proc'].get_output()
			
			if not tmp is None:
				thread['output_buffer'].append(tmp)
				at_least_one_lives = True
		
		if at_least_one_lives:
			time.sleep(.25)
		else:
			break
	
	_print('post-processing file list')
	
	for thread in threads:
		output = b''.join(thread['output_buffer']).decode('utf-8')
		all_files.update(os.path.normpath(os.path.join(os.path.abspath(thread['root']), f)) for f in output.split('\x00') if f)
	
	_print('found %d files' %(len(all_files)), prefix.done)
	
	# --------------------------------------------------
	# create a list of owned files
	
	_print('gathering a list of files owned by installed packages', prefix.start)
	
	owned_files = set()
	
	for contents_filename in glob.glob('/var/db/pkg/*/*/CONTENTS'):
		owned_files.update(re.findall('obj (.+) [0-9a-f]+ \d+', open(contents_filename).read()))
	
	unowned_files = all_files - owned_files
	
	_print('found %d owned files' %(len(owned_files)), prefix.done)
	_print('there are %d unowned files' %(len(unowned_files)))
	
	# --------------------------------------------------
	# apply filters
	
	_print('applying filters', prefix.start)
	
	unowned_files_ignored = set()
	
	for filter in main.cfg.filter:
		unowned_files_ignored.update(fnmatch.filter(unowned_files, filter))
	
	files_to_output = unowned_files - unowned_files_ignored
	
	_print('found §y%d unowned files§/' %(len(files_to_output)), prefix.done)
	
	# --------------------------------------------------
	# output
	
	if main.cfg.output:
		joiner = '\x00' if main.cfg.null_separated else '\n'
		print(joiner.join(sorted(files_to_output)))