import logging
import random
import cocotb
from Uart import UartDriver
from Vai import VaiReceiver
from cocotb.clock import Clock
from cocotb.triggers import RisingEdge, Timer


# Reset coroutine
async def reset_dut(reset_n, duration_ns):
    reset_n.value = 0
    await Timer(duration_ns, units="ns")
    reset_n.value = 1


@cocotb.test()
async def test_uartrx(dut):
    """ First simple test """

    clkedge = RisingEdge(dut.clk_i)

    # Connect reset
    reset_n = dut.reset_n_i

    # Instantiate UART driver
    uart_driver = UartDriver(dut.rx_i, dut.clk_i, 10, 8, True);
    # Instantiate VAI receiver
    vai_receiver = VaiReceiver(dut.clk_i, dut.data_o, dut.valid_o, dut.accept_i)

    # Drive input defaults (setimmediatevalue to avoid x asserts)
    dut.rx_i.setimmediatevalue(1)
    dut.accept_i.setimmediatevalue(0)

    clock = Clock(dut.clk_i, 10, units="ns")  # Create a 10 ns period clock
    cocotb.start_soon(clock.start())  # Start the clock

    # Execution will block until reset_dut has completed
    await reset_dut(reset_n, 100)
    dut._log.info("Released reset")

    # Test 10 UART transmissions
    for i in range(10):
        await Timer(100, units="ns")
        val = random.randint(0, 255)
        await uart_driver.send(val)
        rec = await vai_receiver.receive();
        assert rec == val, "UART received data was incorrect on the {}th cycle".format(i)