#!/usr/bin/env python

import cocotb
from cocotb.triggers import *
from cocotb.result import *
from cocotb.queue import Queue

class tx_buffer:
	def __init__(self, dut, prefix):
		self.queue = Queue()
		self.queue_start_ev = Event()
		self.queue_done_ev = Event()
		self.dut = dut
		self.prefix = prefix
		pass

	async def main(self):
		while True:
			await self.queue_start_ev.wait()
			self.queue_start_ev.clear()
			while not self.queue.empty():
				data = await self.queue.get()
				getattr(self.dut, self.prefix + "dv").value = True
				for byte in data:
					getattr(self.dut, self.prefix + "d").value = byte
					await Edge(getattr(self.dut, self.prefix + "da"))
				getattr(self.dut, self.prefix + "dv").value = False
				await Edge(getattr(self.dut, self.prefix + "da"))
			self.queue_done_ev.set()

	async def start(self):
		await cocotb.start(self.main())

	async def send(self, data, send_now=True, wait=None):
		if wait is None:
			wait = send_now
		self.queue.put_nowait(data)
		if send_now:
			self.queue_start_ev.set()
		if wait:
			await self.queue_done_ev.wait()
			self.queue_done_ev.clear()

class rx_buffer:
	def __init__(self, dut, prefix):
		self.queue = Queue()
		self.dut = dut
		self.prefix = prefix

	async def main(self):
		while True:
			d = bytearray(b'')
			await RisingEdge(getattr(self.dut, self.prefix + "a"))
			while True:
				await First(Edge(getattr(self.dut, self.prefix + "dt")), Edge(getattr(self.dut, self.prefix + "a")))
				if not getattr(self.dut, self.prefix + "a").value:
					break
				d.append(getattr(self.dut, self.prefix + "d").value)
			self.queue.put_nowait(d)

	async def start(self):
		await cocotb.start(self.main())