#!/usr/bin/env python
#
# Copyright (c) 2006-2007, Hans Meine <hans_meine@gmx.net>
#  All rights reserved.
#
# This is licensed according to the new BSD license.
# Please send patches / comments, I would be happy about any feedback.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
#
# * Neither the name of the University of Hamburg nor the names of its
#   contributors may be used to endorse or promote products derived from
#   this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# (Update: I am not happy with the program's structure anymore, the
# useMime-code makes the rest quite ugly actually. :-( )

import sys, os, stat, select

mediaExtensions = [
	"jpg", "jpeg", "bmp", "png", "tif", "tiff", "jpe",
	"mpeg", "mpg", "avi", "mpe", "mov", "wmv",
	"mp3", "wav", "ogg", "aac", "mp2", "mpc", "wma",
	"pdf", "ps", "txt", "gz", "bz2", "zip", "arj",
	"doc", "xls", "ppt"]

from optparse import OptionParser

op = OptionParser(
	usage = "%prog [options] <filename> ...",
	description = "Renames files with uppercase filenames and removes executable bits from files with known media extensions.")
op.add_option("-v", "--verbose", action = "store_true", default = True,
			  dest = "verbosity", help = "verbose output (default)")
op.add_option("-q", "--quiet", action = "store_false",
			  dest = "verbosity", help = "quite mode (only errors)")
op.add_option("-m", "--mime", action = "store_true", default = False,
			  dest = "useMime", help = "use mime-output capable 'file' implementation for checking media files (default: list of extensions)")
op.add_option("-f", "--force", action = "store_true", default = False,
			  dest = "forceMode", help = "force overwriting existing files")
op.add_option("-p", "--pretend", action = "store_true", default = False,
			  dest = "pretend", help = "show actions, but do not perform them")
op.add_option("-r", "--recursive", action = "store_true", default = False,
			  dest = "recursive", help = "recurse into subdirectories")
op.add_option("-e", "--deexecall", action = "store_true", default = False,
			  dest = "deexecall", help = "remove exec bits from all regular files")
op.add_option("-a", "--renameall", action = "store_true",
			  dest = "renameAll", default = False,
			  help = "rename files without extensions, too (default: only UPPERCASE.JPG, not README for example)")
op.add_option("-i", "--irreversible", action = "store_true",
			  dest = "irreversible", default = False,
			  help = "rename really all files (even MixedCase, implies --renameall)")
options, args = op.parse_args()

if not len(args):
	sys.stderr.write("No files given - nothing to do!\n\n")
	op.print_help()

def verbose(str):
	if options.verbosity:
		sys.stdout.write(str)

# for performance reasons, "file" is called maximally once (if -m
# switch was given), on all files with exec bits:
# FIXME: check for os.sysconf("SC_ARG_MAX")
if options.useMime:
	fileargs = ["file", "-i", "-N"]
	for fn in args:
		s = os.stat(fn)
		mode = stat.S_IMODE(s[stat.ST_MODE])
		if stat.S_ISREG(s[stat.ST_MODE]) and mode & 0111:
			fileargs.append(fn)

	fileIsMedia = {}
	if len(fileargs) > 3:
		rd, wr = os.pipe()
		pid = os.fork()
		if not pid:
			os.close(rd)
			os.dup2(wr, sys.stdout.fileno())
			os.close(wr)

			os.execvp("file", fileargs)
			sys.exit(0)

		os.close(wr)
		fileInfo = ""
		while rd:
			select.select([rd], [], [])
			fileOutput = os.read(rd, 20480)
			if not fileOutput:
				break
			fileInfo += fileOutput

		res = os.waitpid(pid, 0)
		if res[1]:
			sys.stderr.write("Sub-process for 'file' with PID %d returned %d (signal %d)\n" % (res[0], res[1] / 256, res[1] & 255))
			sys.stderr.write("  Parameters were: %s\n" % (" ".join(fileargs), ))
			sys.exit(1)

		for fileInfoLine in fileInfo.split("\n"):
			fields = fileInfoLine.split(":")
			if len(fields) > 1:
				if fields[1].startswith(" image/") or \
					   fields[1].startswith(" video/") or \
					   fields[1].startswith(" text/") or \
					   fields[1].startswith(" audio/"):
					fileIsMedia[fields[0]] = mode

def lowerIfUpper(str):
	if str == str.upper():
		return str.lower()
	return str

def checkExecMediaFile(filename):
	if options.useMime:
		return fileIsMedia.has_key(filename) and fileIsMedia[filename]

	s = os.stat(filename)
	if not stat.S_ISREG(s[stat.ST_MODE]):
		return False

	mode = stat.S_IMODE(s[stat.ST_MODE]) # AND chmod'able bits
	if mode & 0111:
		if options.deexecall:
			return mode
		basepath, ext = os.path.splitext(fn)
		if ext[1:].lower() in mediaExtensions:
			return mode

	return False

chmodCount = 0
renameCount = 0
errorCount = 0

for fn in args:
	if os.path.isdir(fn):
		mode = False
	else:
		try:
			mode = checkExecMediaFile(fn)
		except OSError, e:
			if e.errno == 2: # "no such file or directory" on broken links
				continue
			raise # what else could happen?

	dir, filename = os.path.split(fn)
	basename, ext = os.path.splitext(filename)

	if options.irreversible:
		newFilename = filename.lower()
	elif not (len(ext) or options.renameAll):
		# handle exceptions like README, CHANGES, TODO, NEWS, LICENSE, INSTALL:
		newFilename = filename
	else:
		newFilename = lowerIfUpper(filename)
		if newFilename == filename:
			newFilename = basename + lowerIfUpper(ext)

	# verbose output
	if mode or (newFilename != filename):
		msg = "'%s'" % (fn, )
		if mode:
			msg += " (-exec)"
		if newFilename != filename:
			msg += " -> '%s'" % (newFilename, )
		verbose(msg + "\n")

	if mode:
		try:
			if not options.pretend:
				os.chmod(fn, mode & 07666)
			chmodCount += 1
		except OSError, e:
			sys.stderr.write(str(e)+"\n")
			errorCount += 1

	if newFilename != filename:
		lfn = os.path.join(dir, newFilename)
		if os.path.exists(lfn) and not options.forceMode:
			sys.stderr.write("WARNING: target '%s' exists! (skipping, use --force to overwrite)\n" % (lfn, ))
		else:
			try:
				if not options.pretend:
					os.rename(fn, lfn)
					fn = lfn
				renameCount += 1
			except OSError, e:
				sys.stderr.write(str(e)+"\n")
				errorCount += 1

	if os.path.isdir(fn) and options.recursive:
		for name in os.listdir(fn):
			args.append(os.path.join(fn, name))

prefix = ""
if options.pretend:
	prefix = "[PRETEND MODE] "

if chmodCount:
	verbose(prefix + "Removed executable bits from %d files.\n" % (chmodCount, ))
if renameCount:
	verbose(prefix + "Renamed %d files.\n" % (renameCount, ))
if errorCount:
	verbose("%d errors occured.\n" % (errorCount, ))