#!/usr/bin/env python
# SPDX-License-Identifier: CERN-OHL-S-2.0
"""

Copyright (c) 2021-2025 FPGA Ninja, LLC

Authors:
- Alex Forencich

"""

import itertools
import logging
import os
import random

import cocotb_test.simulator
import pytest

import cocotb
from cocotb.clock import Clock
from cocotb.triggers import RisingEdge
from cocotb.regression import TestFactory

from cocotbext.axi import AxiStreamBus, AxiStreamFrame, AxiStreamSource, AxiStreamSink


class TB(object):
    def __init__(self, dut):
        self.dut = dut

        self.log = logging.getLogger("cocotb.tb")
        self.log.setLevel(logging.DEBUG)

        cocotb.start_soon(Clock(dut.clk, 10, units="ns").start())

        self.source = AxiStreamSource(AxiStreamBus.from_entity(dut.s_axis), dut.clk, dut.rst)
        self.sink = AxiStreamSink(AxiStreamBus.from_entity(dut.m_axis), dut.clk, dut.rst)

        dut.pause_req.setimmediatevalue(0)

    def set_idle_generator(self, generator=None):
        if generator:
            self.source.set_pause_generator(generator())

    def set_backpressure_generator(self, generator=None):
        if generator:
            self.sink.set_pause_generator(generator())

    async def reset(self):
        self.dut.rst.setimmediatevalue(0)
        await RisingEdge(self.dut.clk)
        await RisingEdge(self.dut.clk)
        self.dut.rst.value = 1
        await RisingEdge(self.dut.clk)
        await RisingEdge(self.dut.clk)
        self.dut.rst.value = 0
        await RisingEdge(self.dut.clk)
        await RisingEdge(self.dut.clk)


async def run_test(dut, payload_lengths=None, payload_data=None, idle_inserter=None, backpressure_inserter=None):

    tb = TB(dut)

    id_count = 2**len(tb.source.bus.tid)

    cur_id = 1

    await tb.reset()

    tb.set_idle_generator(idle_inserter)
    tb.set_backpressure_generator(backpressure_inserter)

    test_frames = []

    for test_data in [payload_data(x) for x in payload_lengths()]:
        test_frame = AxiStreamFrame(test_data)
        test_frame.tid = cur_id
        test_frame.tdest = cur_id

        test_frames.append(test_frame)
        await tb.source.send(test_frame)

        cur_id = (cur_id + 1) % id_count

    for test_frame in test_frames:
        rx_frame = await tb.sink.recv()

        assert rx_frame.tdata == test_frame.tdata
        assert rx_frame.tid == test_frame.tid
        assert rx_frame.tdest == test_frame.tdest
        assert not rx_frame.tuser

    assert tb.sink.empty()

    await RisingEdge(dut.clk)
    await RisingEdge(dut.clk)


async def run_test_tuser_assert(dut):

    tb = TB(dut)

    await tb.reset()

    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), 32))
    test_frame = AxiStreamFrame(test_data, tuser=1)
    await tb.source.send(test_frame)

    if dut.DROP_BAD_FRAME.value:
        for k in range(64):
            await RisingEdge(dut.clk)

    else:
        rx_frame = await tb.sink.recv()

        assert rx_frame.tdata == test_data
        assert rx_frame.tuser

    assert tb.sink.empty()

    await RisingEdge(dut.clk)
    await RisingEdge(dut.clk)


async def run_test_init_sink_pause(dut):

    tb = TB(dut)

    await tb.reset()

    tb.sink.pause = True

    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), 32))
    test_frame = AxiStreamFrame(test_data)
    await tb.source.send(test_frame)

    for k in range(64):
        await RisingEdge(dut.clk)

    tb.sink.pause = False

    rx_frame = await tb.sink.recv()

    assert rx_frame.tdata == test_data
    assert not rx_frame.tuser

    assert tb.sink.empty()

    await RisingEdge(dut.clk)
    await RisingEdge(dut.clk)


async def run_test_init_sink_pause_reset(dut):

    tb = TB(dut)

    await tb.reset()

    tb.sink.pause = True

    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), 32))
    test_frame = AxiStreamFrame(test_data)
    await tb.source.send(test_frame)

    for k in range(64):
        await RisingEdge(dut.clk)

    await tb.reset()

    tb.sink.pause = False

    for k in range(64):
        await RisingEdge(dut.clk)

    assert tb.sink.empty()

    await RisingEdge(dut.clk)
    await RisingEdge(dut.clk)


async def run_test_pause(dut):

    tb = TB(dut)

    byte_lanes = tb.source.byte_lanes

    await tb.reset()

    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), 16*byte_lanes))
    test_frame = AxiStreamFrame(test_data)

    for k in range(16):
        await tb.source.send(test_frame)

    for k in range(60):
        await RisingEdge(dut.clk)

    dut.pause_req.value = 1

    for k in range(64):
        await RisingEdge(dut.clk)

    assert tb.sink.idle()

    dut.pause_req.value = 0

    for k in range(16):
        rx_frame = await tb.sink.recv()

        assert rx_frame.tdata == test_data
        assert not rx_frame.tuser

    assert tb.sink.empty()

    await RisingEdge(dut.clk)
    await RisingEdge(dut.clk)


async def run_test_overflow(dut):

    tb = TB(dut)

    depth = int(dut.DEPTH.value)
    byte_lanes = tb.source.byte_lanes

    await tb.reset()

    tb.sink.pause = True

    size = (16*byte_lanes)
    count = depth*2 // size

    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), size))
    test_frame = AxiStreamFrame(test_data)
    for k in range(count):
        await tb.source.send(test_frame)

    for k in range((depth//byte_lanes)*3):
        await RisingEdge(dut.clk)

    if dut.DROP_WHEN_FULL.value or dut.MARK_WHEN_FULL.value:
        assert tb.source.idle()
    else:
        assert not tb.source.idle()

    tb.sink.pause = False

    if dut.DROP_WHEN_FULL.value or dut.MARK_WHEN_FULL.value:
        for k in range((depth//byte_lanes)*3):
            await RisingEdge(dut.clk)

        rx_count = 0

        while not tb.sink.empty():
            rx_frame = await tb.sink.recv()

            if dut.MARK_WHEN_FULL.value and rx_frame.tuser:
                continue

            assert rx_frame.tdata == test_data
            assert not rx_frame.tuser

            rx_count += 1

        assert rx_count < count

    else:
        for k in range(count):
            rx_frame = await tb.sink.recv()

            assert rx_frame.tdata == test_data
            assert not rx_frame.tuser

    assert tb.sink.empty()

    await RisingEdge(dut.clk)
    await RisingEdge(dut.clk)


async def run_test_oversize(dut):

    tb = TB(dut)

    depth = int(dut.DEPTH.value)
    byte_lanes = tb.source.byte_lanes

    await tb.reset()

    tb.sink.pause = True

    test_data = bytearray(itertools.islice(itertools.cycle(range(256)), depth*2))
    test_frame = AxiStreamFrame(test_data)
    await tb.source.send(test_frame)

    for k in range((depth//byte_lanes)*2):
        await RisingEdge(dut.clk)

    tb.sink.pause = False

    if dut.DROP_OVERSIZE_FRAME.value:
        for k in range((depth//byte_lanes)*2):
            await RisingEdge(dut.clk)

    else:
        rx_frame = await tb.sink.recv()

        if dut.MARK_WHEN_FULL.value:
            assert rx_frame.tuser
        else:
            assert rx_frame.tdata == test_data
            assert not rx_frame.tuser

    assert tb.sink.empty()

    await RisingEdge(dut.clk)
    await RisingEdge(dut.clk)


async def run_stress_test(dut, idle_inserter=None, backpressure_inserter=None):

    tb = TB(dut)

    byte_lanes = tb.source.byte_lanes
    id_count = 2**len(tb.source.bus.tid)

    cur_id = 1

    await tb.reset()

    tb.set_idle_generator(idle_inserter)
    tb.set_backpressure_generator(backpressure_inserter)

    test_frames = []

    for k in range(512):
        length = random.randint(1, byte_lanes*16)
        test_data = bytearray(itertools.islice(itertools.cycle(range(256)), length))
        test_frame = AxiStreamFrame(test_data)
        test_frame.tid = cur_id
        test_frame.tdest = cur_id

        test_frames.append(test_frame)
        await tb.source.send(test_frame)

        cur_id = (cur_id + 1) % id_count

    if dut.DROP_WHEN_FULL.value or dut.MARK_WHEN_FULL.value:
        cycles = 0
        while cycles < 100:
            cycles += 1
            if not tb.source.idle() or int(dut.s_axis.tvalid.value) or int(dut.m_axis.tvalid.value) or int(dut.status_depth.value):
                cycles = 0
            await RisingEdge(dut.clk)

        while not tb.sink.empty():
            rx_frame = await tb.sink.recv()

            if dut.MARK_WHEN_FULL.value and rx_frame.tuser:
                continue

            assert not rx_frame.tuser

            assert len(test_frames) > 0

            while True:
                test_frame = test_frames.pop(0)
                if rx_frame.tid == test_frame.tid and rx_frame.tdest == test_frame.tdest and rx_frame.tdata == test_frame.tdata:
                    break

        assert len(test_frames) < 512

    else:
        for test_frame in test_frames:
            rx_frame = await tb.sink.recv()

            assert rx_frame.tdata == test_frame.tdata
            assert rx_frame.tid == test_frame.tid
            assert rx_frame.tdest == test_frame.tdest
            assert not rx_frame.tuser

    assert tb.sink.empty()

    await RisingEdge(dut.clk)
    await RisingEdge(dut.clk)


def cycle_pause():
    return itertools.cycle([1, 1, 1, 0])


def size_list():
    data_width = len(cocotb.top.m_axis.tdata)
    byte_width = data_width // 8
    return list(range(1, byte_width*4+1))+[512]+[1]*64


def incrementing_payload(length):
    return bytearray(itertools.islice(itertools.cycle(range(256)), length))


if getattr(cocotb, 'top', None) is not None:

    factory = TestFactory(run_test)
    factory.add_option("payload_lengths", [size_list])
    factory.add_option("payload_data", [incrementing_payload])
    factory.add_option("idle_inserter", [None, cycle_pause])
    factory.add_option("backpressure_inserter", [None, cycle_pause])
    factory.generate_tests()

    for test in [
                run_test_tuser_assert,
                run_test_init_sink_pause,
                run_test_init_sink_pause_reset,
                run_test_pause,
                run_test_overflow,
                run_test_oversize
            ]:

        factory = TestFactory(test)
        factory.generate_tests()

    factory = TestFactory(run_stress_test)
    factory.add_option("idle_inserter", [None, cycle_pause])
    factory.add_option("backpressure_inserter", [None, cycle_pause])
    factory.generate_tests()


# cocotb-test

tests_dir = os.path.dirname(__file__)
rtl_dir = os.path.abspath(os.path.join(tests_dir, '..', '..', 'rtl'))
lib_dir = os.path.abspath(os.path.join(tests_dir, '..', '..', 'lib'))
taxi_src_dir = os.path.abspath(os.path.join(lib_dir, 'taxi', 'src'))


def process_f_files(files):
    lst = {}
    for f in files:
        if f[-2:].lower() == '.f':
            with open(f, 'r') as fp:
                l = fp.read().split()
            for f in process_f_files([os.path.join(os.path.dirname(f), x) for x in l]):
                lst[os.path.basename(f)] = f
        else:
            lst[os.path.basename(f)] = f
    return list(lst.values())


@pytest.mark.parametrize(("frame_fifo", "drop_oversize_frame", "drop_bad_frame",
    "drop_when_full", "mark_when_full"),
    [(0, 0, 0, 0, 0), (1, 0, 0, 0, 0), (1, 1, 0, 0, 0), (1, 1, 1, 0, 0),
        (1, 1, 1, 1, 0), (0, 0, 0, 0, 1)])
@pytest.mark.parametrize(("ram_pipeline", "output_fifo"),
    [(0, 0), (1, 0), (4, 0), (0, 1), (1, 1), (4, 1)])
@pytest.mark.parametrize("data_w", [8, 16, 32, 64])
def test_taxi_axis_fifo(request, data_w, ram_pipeline, output_fifo,
        frame_fifo, drop_oversize_frame, drop_bad_frame,
        drop_when_full, mark_when_full):

    dut = "taxi_axis_fifo"
    module = os.path.splitext(os.path.basename(__file__))[0]
    toplevel = module

    verilog_sources = [
        os.path.join(tests_dir, f"{toplevel}.sv"),
        os.path.join(rtl_dir, f"{dut}.sv"),
        os.path.join(rtl_dir, "taxi_axis_if.sv"),
    ]

    verilog_sources = process_f_files(verilog_sources)

    parameters = {}

    parameters['DATA_W'] = data_w
    parameters['KEEP_EN'] = int(parameters['DATA_W'] > 8)
    parameters['KEEP_W'] = (parameters['DATA_W'] + 7) // 8
    parameters['STRB_EN'] = 0
    parameters['DEPTH'] = 1024 * parameters['KEEP_W']
    parameters['LAST_EN'] = 1
    parameters['ID_EN'] = 1
    parameters['ID_W'] = 8
    parameters['DEST_EN'] = 1
    parameters['DEST_W'] = 8
    parameters['USER_EN'] = 1
    parameters['USER_W'] = 1
    parameters['RAM_PIPELINE'] = ram_pipeline
    parameters['OUTPUT_FIFO_EN'] = output_fifo
    parameters['FRAME_FIFO'] = frame_fifo
    parameters['USER_BAD_FRAME_VALUE'] = 1
    parameters['USER_BAD_FRAME_MASK'] = 1
    parameters['DROP_OVERSIZE_FRAME'] = drop_oversize_frame
    parameters['DROP_BAD_FRAME'] = drop_bad_frame
    parameters['DROP_WHEN_FULL'] = drop_when_full
    parameters['MARK_WHEN_FULL'] = mark_when_full
    parameters['PAUSE_EN'] = 1
    parameters['FRAME_PAUSE'] = 1

    extra_env = {f'PARAM_{k}': str(v) for k, v in parameters.items()}

    sim_build = os.path.join(tests_dir, "sim_build",
        request.node.name.replace('[', '-').replace(']', ''))

    cocotb_test.simulator.run(
        simulator="verilator",
        python_search=[tests_dir],
        verilog_sources=verilog_sources,
        toplevel=toplevel,
        module=module,
        parameters=parameters,
        sim_build=sim_build,
        extra_env=extra_env,
    )
