import os, dirdiff
blocksize = 1024 * 1024

def intersect(seq1, seq2):
    return [item for item in seq1 if item in seq2]

def comparetrees(dir1, dir2, diffs, verbose = False):
	print('-' * 20)
	names1 = os.listdir(dir1)
	names2 = os.listdir(dir2)
	if not dirdiff.comparedirs(dir1, dir2, names1, names2):
		diffs.append('unique files at %s - %s' % (dir1, dir2))

	print('Comparing contents')
	common = intersect(names1, names2)
	missed = common[:]

	for name in common:
		path1 = os.path.join(dir1, name)
		path2 = os.path.join(dir2, name)
		if os.path.isfile(path1) and os.path.isfile(path2):
			missed.remove(name)
			file1 = open(path1, 'rb')
			file2 = open(path2, 'rb')
			while True:
				bytes1 = file1.read(blocksize)
				bytes2 = file2.read(blocksize)
				if (not bytes1) and (not bytes2):
					if verbose: print(name, 'matches')
					break
				if bytes1 != bytes2:
					diffs.append('files differ at %s - %s' % (path1, path2))
					print(name, 'DIFFERS')
					break
	for name in common:
		path1 = os.path.join(dir1, name)
		path2 = os.path.join(dir2, name)
		if os.path.isdir(path1) and os.path.isdir(path2):
			missed.remove(name)
			comparetrees(path1, path2, diffs, verbose)

	for name in missed:
		diffs.append('files missed at %s - %s' % (dir1, dir2, name))
		print(name, 'DIFFERS')

if __name__ == '__main__':
	dir1, dir2 = dirdiff.getargs()
	diffs = []
	comparetrees(dir1, dir2, diffs, True)
	print('=' * 40)
	if not diffs:
		print('No diffs found.')
	else:
		print('Diffs found:', len(diffs))
		for diff in diffs: print('-', diff)