import csv

class MappedReg:
	def __init__(self, readfn, writefn, name, addr, length, busword, mode):
		self.readfn = readfn
		self.writefn = writefn
		self.addr = addr
		self.length = length
		self.busword = busword
		self.mode = mode

	def read(self, repeats=None):
		if self.mode not in ["rw", "ro"]:
			raise KeyError(name + "register not readable")

		def to_int(v):
			return 1 if v is None else v
		read_datas = self.readfn(self.addr, burst_length=self.length, repeats=repeats)
		datas = []
		for i in range(to_int(repeats)):
			data = 0
			for j in range(self.length):
				data = data << self.busword
				data |= read_datas[i*self.length+j]
			datas.append(data)
		if repeats is None:
			return datas[0]
		else:
			return datas

	def write(self, value):
		if self.mode not in ["rw", "wo"]:
			raise KeyError(name + "register not writable")
		datas = []
		for i in range(self.length):
			datas.append((value >> ((self.length-1-i)*self.busword)) & (2**self.busword-1))
		self.writefn(self.addr, datas)

class MappedRegs:
	def __init__(self, d):
		self.d = d

	def __getattr__(self, attr):
		try:
			return self.__dict__['d'][attr]
		except KeyError:
			pass
		raise KeyError("No such register " + attr)

def	build_map(addrmap, busword, readfn, writefn):
	csv_reader = csv.reader(open(addrmap), delimiter=',', quotechar='#')
	d = {}
	for item in csv_reader:
		name, addr, length, mode = item
		addr = int(addr.replace("0x", ""), 16)
		length = int(length)
		d[name] = MappedReg(readfn, writefn, name, addr, length, busword, mode)
	return MappedRegs(d)