#!/usr/bin/env python
"""
# OpenWRT download directory cleanup utility.
# Delete all but the very last version of the program tarballs.
#
# Copyright (c) 2010 Michael Buesch <mb@bu3sch.de>
"""

import sys
import os
import re

DEBUG = 0


def parseVer_1234(match):
	progname = match.group(1)
	progversion = (int(match.group(2)) << 64) |\
		      (int(match.group(3)) << 48) |\
		      (int(match.group(4)) << 32) |\
		      (int(match.group(5)) << 16)
	return (progname, progversion)

def parseVer_123(match):
	progname = match.group(1)
	patchlevel = match.group(5)
	if patchlevel:
		patchlevel = ord(patchlevel[0])
	else:
		patchlevel = 0
	progversion = (int(match.group(2)) << 64) |\
		      (int(match.group(3)) << 48) |\
		      (int(match.group(4)) << 32) |\
		      patchlevel
	return (progname, progversion)

def parseVer_12(match):
	progname = match.group(1)
	patchlevel = match.group(4)
	if patchlevel:
		patchlevel = ord(patchlevel[0])
	else:
		patchlevel = 0
	progversion = (int(match.group(2)) << 64) |\
		      (int(match.group(3)) << 48) |\
		      patchlevel
	return (progname, progversion)

def parseVer_r(match):
	progname = match.group(1)
	progversion = (int(match.group(2)) << 64)
	return (progname, progversion)

def parseVer_ymd(match):
	progname = match.group(1)
	progversion = (int(match.group(2)) << 64) |\
		      (int(match.group(3)) << 48) |\
		      (int(match.group(4)) << 32)
	return (progname, progversion)

extensions = (
	".tar.gz",
	".tar.bz2",
	".orig.tar.gz",
	".orig.tar.bz2",
	".zip",
	".tgz",
	".tbz",
)

versionRegex = (
	(re.compile(r"(.+)[-_](\d+)\.(\d+)\.(\d+)\.(\d+)"), parseVer_1234),	# xxx-1.2.3.4
	(re.compile(r"(.+)[-_](\d\d\d\d)-?(\d\d)-?(\d\d)"), parseVer_ymd),	# xxx-YYYY-MM-DD
	(re.compile(r"(.+)[-_](\d+)\.(\d+)\.(\d+)(\w?)"), parseVer_123),	# xxx-1.2.3a
	(re.compile(r"(.+)[-_](\d+)\.(\d+)(\w?)"), parseVer_12),		# xxx-1.2a
	(re.compile(r"(.+)[-_]r?(\d+)"), parseVer_r),				# xxx-r1111
)

blacklist = (
	re.compile(r"wl_apsta.*"),
	re.compile(r"boost.*"),
	re.compile(r".*\.fw"),
	re.compile(r".*\.arm"),
	re.compile(r".*\.bin"),
	re.compile(r"RT\d+_Firmware.*"),
)

class EntryParseError(Exception): pass

class Entry:
	def __init__(self, directory, filename):
		self.directory = directory
		self.filename = filename
		self.progname = ""

		for ext in extensions:
			if filename.endswith(ext):
				filename = filename[0:0-len(ext)]
				break
		else:
			if DEBUG:
				print "Extension did not match on", filename
			raise EntryParseError("ext")
		for (regex, parseVersion) in versionRegex:
			match = regex.match(filename)
			if match:
				(self.progname, self.version) = parseVersion(match)
				break
		else:
			if DEBUG:
				print "Version regex did not match on", filename
			raise EntryParseError("ver")

	def deleteFile(self):
		path = (self.directory + "/" + self.filename).replace("//", "/")
		print "Deleting", path
		if not DEBUG:
			os.unlink(path)

	def __eq__(self, y):
		return self.filename == y.filename

	def __ge__(self, y):
		return self.version >= y.version

def usage():
	print "OpenWRT download directory cleanup utility"
	print "Usage: " + sys.argv[0] + " path/to/dl"

def main(argv):
	if len(argv) != 2:
		usage()
		return 1
	directory = argv[1]

	# Create a directory listing and parse the file names.
	entries = []
	for filename in os.listdir(directory):
		if filename == "." or filename == "..":
			continue
		for black in blacklist:
			if black.match(filename):
				if DEBUG:
					print filename, "is blacklisted"
				break
		else:
			try:
				entries.append(Entry(directory, filename))
			except (EntryParseError), e: pass

	# Create a map of programs
	progmap = {}
	for entry in entries:
		if entry.progname in progmap.keys():
			progmap[entry.progname].append(entry)
		else:
			progmap[entry.progname] = [entry,]

	# Traverse the program map and delete everything but the last version
	for prog in progmap:
		lastVersion = None
		versions = progmap[prog]
		for version in versions:
			if lastVersion is None or version >= lastVersion:
				lastVersion = version
		if lastVersion:
			for version in versions:
				if version != lastVersion:
					version.deleteFile()
			if DEBUG:
				print "Keeping", lastVersion.filename

	return 0

if __name__ == "__main__":
	sys.exit(main(sys.argv))