#! /usr/bin/python

import os, string, sys

# Contains an entry for each relative filename encountered in multiple 
# directory structures, with a list of directories in which it occurs.
class DirComparer : 

	def __init__( self ) :
		self.dirs = []
		self.dirnum = -1
		self.contents = {}
		
	def startNewDirectory( self, path ) :
		self.dirs.append( path )
		self.dirnum = self.dirnum + 1
		
	def addPath( self, fullpath ) :
		relpath = fullpath[ len(self.dirs[self.dirnum]): ]
		dirname = self.dirs[self.dirnum]
		if ( relpath[0] == os.sep ) :
			relpath = relpath[1:]
		if self.contents.has_key( relpath ) :
			self.contents[relpath].setInDir( dirname )
		else :
			file = File( relpath )
			file.setInDir( dirname )
			self.contents[relpath] = file
	
	def getFiles( self ) :
		return self.contents
		
class File :
	def __init__( self, relpath ) :
		self.relpath = relpath
		self.dirs = []
		
	def getPath( self ) :
		return self.relpath
		
	def setInDir( self, dirname ) :
		self.dirs.append( dirname )
		
	def isInDir( self, dirname ) :
		if dirname in self.dirs :
			return 1
		else :
			return 0

def addPath( comparer, dirname, names ) :
	for name in names :
		fullpath = os.path.join( dirname, name )
		comparer.addPath( fullpath )

def displayComparison( dir1, dir2, comparer ) :
	dir1abs = os.path.abspath( dir1 )
	dir2abs = os.path.abspath( dir2 )
	dir1only = []
	dir1newer = []
	dir2only = []
	dir2newer = []
	inbothdirs = []
	bothdirssame = []
	
	files = comparer.getFiles()
	keys = files.keys()
	keys.sort()
	
	for key in keys :
		fileobj = files[key]
		if fileobj.isInDir( dir1 ) :
			if fileobj.isInDir( dir2 ) :
				inbothdirs.append( fileobj )
			else :
				dir1only.append( fileobj )
		elif fileobj.isInDir( dir2 ) :
			dir2only.append( fileobj )

	print
	print "***************************************************"
	print "Comparing: "
	print dir1abs
	print dir2abs
	print "***************************************************"
	print
			
	for dir in [ [dir1abs, dir1only], [dir2abs, dir2only] ] :
#	for dir in [ [dir1, dir1only] ] :
		print "Files in \"%s\" only: \n" % (dir[0])
		if dir[1] == [] :
			print "     (none)"
		for fileobj in dir[1] :
			print "     " + fileobj.getPath()
		print
		
	for f in inbothdirs :
		relpath = f.getPath()
		fullpath1 = os.path.join( dir1, relpath )
		fullpath2 = os.path.join( dir2, relpath )		
		
		modtime1 = os.path.getmtime( fullpath1 )
		modtime2 = os.path.getmtime( fullpath2 )
		if  modtime1 > modtime2 :
			dir1newer.append( f )
		elif modtime2 > modtime1 :
			dir2newer.append( f )
		else :
			bothdirssame.append( f )	
	
	for dir in [ [dir1abs, dir1newer], [dir2abs, dir2newer] ] :
		print "File in \"%s\" is newer: \n" % (dir[0])
		if dir[1] == [] :
			print "     (none)"
		for fileobj in dir[1] :
			print "     " + fileobj.getPath()
		print
	
	print "Summary:\n"
	for dir in [ [dir1abs, dir1only], [dir2abs, dir2only] ] :
		print "     \"%s\" contains %d unique files." % (dir[0], len(dir[1]))
	for dir in [ [dir1abs, dir1newer], [dir2abs, dir2newer] ] :
		print "     \"%s\" contains %d newer files." % (dir[0], len(dir[1]))
	print "     Files with same modification time in both directories numbered %d." % (len(bothdirssame))
	print
	
if __name__ == '__main__' :

	comparer = DirComparer()
	try :
		dirname1 = sys.argv[1]
		dirname2 = sys.argv[2]
	except :
		print "\n   Usage:\n     compare-dirs.py dir1 dir2\n"
		print
		print """\
   Compares the contents of two different directories, telling you 
   which files are uniquely in only one of the two directories 
   and which files newer in one of the two directories.\n"""
		sys.exit(1)

		
	for dir in (dirname1, dirname2) :
		if (not os.path.exists(dir)) or (not os.path.isdir(dir)):
			print "\n     ERROR: Path \"%s\" is not a directory or does not exist.\n" % (dir)
			sys.exit(1)
			
		
	#################################
	# Here's the os.path.walk part. #
	#################################
	comparer.startNewDirectory( dirname1 )
	os.path.walk( dirname1, addPath, comparer )
	comparer.startNewDirectory( dirname2 )
	os.path.walk( dirname2, addPath, comparer )

	displayComparison( dirname1, dirname2, comparer )