import binascii
import random
import struct
import threading
import time
from unittest.mock import patch

from opendbc.car.structs import CarParams
from panda.tests.hitl.base import PandaTestCase
from panda import Panda
from panda.python.spi import PandaSpiNackResponse, PandaSpiMissingAck, REQ_HEADER, CRC, SLAVE_READY, ACK, NACK, POLL


class TestSpi(PandaTestCase):
  def _ping(self, panda):
    # should work with no retries
    with patch.object(panda._handle, '_transfer_spidev', wraps=panda._handle._transfer_spidev) as spy:
      panda.health()
      assert spy.call_count == 1

  def test_info(self):
    p = self.p
    for bootstub in (False, True):
      p.reset(enter_bootstub=bootstub)
      v = p._handle.get_info()

      uid = binascii.hexlify(v[:12]).decode()
      assert uid == p.get_uid()

      hwtype = v[12]
      assert hwtype == ord(p.get_type())

      bstub = v[13]
      assert bstub == (0xEE if bootstub else 0xCC)

  def test_all_comm_types(self):
    p = self.p
    spy = self.enterContext(patch.object(p._handle, '_transfer_spidev', wraps=p._handle._transfer_spidev))

    # controlRead + controlWrite
    p.health()
    p.can_clear(0)
    assert spy.call_count == 2

    # bulkRead + bulkWrite
    p.can_recv()
    p.can_send(0x123, b"somedata", 0)
    assert spy.call_count == 4

  def test_bad_crc(self):
    # dropped, and the panda is ready for the next request
    p = self.p
    cnt = p.health()['spi_error_count']
    with p._handle.dev.acquire() as spi:
      pkt = REQ_HEADER.pack(0, 1, 8, 72) + b"\xd2" + b"\x00"*7
      pkt += CRC.pack(binascii.crc32(pkt) ^ 1)
      while spi.xfer(pkt)[0] != SLAVE_READY:
        pass
      while (dat := spi.xfer(bytes([POLL, ]) * 72))[0] not in (ACK, NACK, SLAVE_READY):
        pass
      assert dat[0] == SLAVE_READY
    self._ping(p)
    assert (p.health()['spi_error_count'] - cnt) == 1

  def test_garbage(self):
    # random bytes, of random lengths, at any point in the protocol
    p = self.p
    for _ in range(100):
      with p._handle.dev.acquire() as spi:
        for _ in range(random.randint(1, 5)):
          spi.xfer(random.randbytes(random.randint(1, 4096)))
      self._ping(p)

  def test_abandoned_transfers(self):
    # host gives up at every stage of a transfer
    p = self.p
    with p._handle.dev.acquire() as spi:
      pkt = REQ_HEADER.pack(0, 1, 8, 72) + b"\xd2" + b"\x00"*7
      pkt += CRC.pack(binascii.crc32(pkt))
      while spi.xfer(pkt)[0] != SLAVE_READY:
        pass
    self._ping(p)

    # read only part of the response
    with p._handle.dev.acquire() as spi:
      while spi.xfer(pkt)[0] != SLAVE_READY:
        pass
      for _ in range(100):
        if spi.xfer(bytes([POLL, ]) * 8)[0] == ACK:
          break
      else:
        raise AssertionError("no response")
    self._ping(p)

  def test_timeout(self):
    p = self.p
    # never equal to a byte, unlike 0xFF which MISO reads while the panda queues the next transfer
    with patch('panda.python.spi.SLAVE_READY', 0x100), self.assertRaises(PandaSpiMissingAck):
      p._handle.controlRead(Panda.REQUEST_IN, 0xd2, 0, 0, p.HEALTH_STRUCT.size, timeout=50)
    self._ping(p)

  def test_non_existent_endpoint(self):
    p = self.p
    for _ in range(10):
      ep = random.randint(4, 20)
      with self.assertRaises(PandaSpiNackResponse):
        p._handle.bulkRead(ep, random.randint(1, 1000), timeout=50)

      self._ping(p)

      with self.assertRaises(PandaSpiNackResponse):
        p._handle.bulkWrite(ep, b"abc", timeout=50)

      self._ping(p)

  def test_multiple_clients(self):
    # every client's request runs, even when it's identical to another client's
    self.p.set_safety_mode(CarParams.SafetyModel.allOutput)
    self.p.set_can_loopback(True)
    with Panda(self.p._serial) as p1, Panda(self.p._serial) as p2:
      for _ in range(100):
        p1.can_send(0x123, b"\x01" * 8, 0)
        p2.can_send(0x123, b"\x01" * 8, 0)
    time.sleep(0.1)
    assert len([m for m in self.p.can_recv() if m[2] == 0]) == 200

  def test_can_exactly_once(self):
    # more than a full transfer each way, so writes and reads are split into chunks
    self.p.set_safety_mode(CarParams.SafetyModel.allOutput)
    self.p.set_can_loopback(True)
    sent = [struct.pack(">Q", i) for i in range(600)]
    self.p.can_send_many([(0x123, dat, 0) for dat in sent], timeout=0)
    time.sleep(0.5)
    got = []
    while len(r := self.p.can_recv()):
      got += [m[1] for m in r if m[2] == 0]
    assert sorted(got) == sent

  def test_thread_safe(self):
    # one handle shared by threads, like pandad
    errors = []
    def hammer():
      try:
        for _ in range(200):
          self.p.health()
      except Exception as e:
        errors.append(e)
    threads = [threading.Thread(target=hammer) for _ in range(4)]
    for t in threads:
      t.start()
    for t in threads:
      t.join()
    assert errors == []

  def test_max_sizes(self):
    # around the first read size and the max transfer size
    for n in (1, 1013, 1014, 4032):
      assert len(self.p._handle.bulkRead(0xAB, n)) == n