def split_as_size(arr,size):return arr[:size],arr[size:]

class IPS:
	MAGIC = b'\x50\x41\x54\x43\x48'
	END = b'\x45\x4f\x46'
	@classmethod
	def create_from_stream(cls,stream):
		return cls.create_from_bytes(stream.read())
	@classmethod
	def create_from_bytes(cls,byte_array):
		def extract_chunk(arr):
			offset,arr=split_as_size(arr,3)
			size,arr=split_as_size(arr,2)
			data,arr=split_as_size(arr,int.from_bytes(size))
			return Chunk(offset,int.from_bytes(data)),arr
		def pull_all_chunks(arr):
			while len(arr)>3:
				chunk,arr=extract_chunk(arr)
				yield chunk
		return cls(list(pull_all_chunks(byte_array)))
	def __init__(self,chunks):self.chunks = chunks
	def apply(self,arr):
		for chunk in self.chunks:
			arr[chunk.position:chunk.position+chunk.size]=chunk.data
		return arr

if __name__=="__main__":
	from sys import argv;argv=argv[1:]
	from os.path import isfile
	patches,target=[],None
	for filename in argv:
		if not isfile(filename):continue
		if filename[:filename.rfind(".")].lower()=='ips':
			patches.append(filename)
		else:target=filename
	if target and patches:
		base_data = open(target,'rb').read()#read in the data to modify.
		for patch in map(IPS.create_from_stream,map(lambda fn:open(fn,'rb'),patches)):
			base_data=patch.apply(base_data)
		with open('patched-{}-{}'.format("-".join(map(patch_name,patches)),target),'wb') as output:
			output.write(base_data)