import unittest
import numpy as np
from tinygrad.helpers import CI, DTYPES_DICT, getenv, DType, DEBUG, ImageDType, PtrDType, OSX, temp
from tinygrad import Device
from tinygrad.tensor import Tensor, dtypes
from typing import Any, List
from hypothesis import given, strategies as st

def is_dtype_supported(dtype: DType):
  # for GPU, cl_khr_fp16 isn't supported (except now we don't need it!)
  # for LLVM, it segfaults because it can't link to the casting function
  if dtype == dtypes.half: return not (CI and Device.DEFAULT in ["GPU", "LLVM"]) and Device.DEFAULT != "WEBGPU" and getenv("CUDACPU") != 1
  if dtype == dtypes.bfloat16: return False # numpy doesn't support bf16, tested separately in TestBFloat16DType
  if dtype == dtypes.float64: return Device.DEFAULT not in ["WEBGPU", "METAL"] and (not OSX and Device.DEFAULT == "GPU")
  if dtype in [dtypes.int8, dtypes.uint8]: return Device.DEFAULT not in ["WEBGPU"]
  if dtype in [dtypes.int16, dtypes.uint16]: return Device.DEFAULT not in ["WEBGPU", "TORCH"]
  if dtype == dtypes.uint32: return Device.DEFAULT not in ["TORCH"]
  if dtype in [dtypes.int64, dtypes.uint64]: return Device.DEFAULT not in ["WEBGPU", "TORCH"]
  if dtype == dtypes.bool:
   # host-shareablity is a requirement for storage buffers, but 'bool' type is not host-shareable
    if Device.DEFAULT == "WEBGPU": return False
  return True

def get_available_cast_dtypes(dtype: DType) -> List[DType]: return [v for k, v in DTYPES_DICT.items() if v != dtype and is_dtype_supported(v) and not k.startswith("_")] # dont cast internal dtypes

def _test_to_np(a:Tensor, np_dtype, target):
  if DEBUG >= 2: print(a)
  na = a.numpy()
  if DEBUG >= 2: print(na, na.dtype, a.lazydata.realized)
  try:
    assert na.dtype == np_dtype
    np.testing.assert_allclose(na, target)
  except AssertionError as e:
    raise AssertionError(f"\ntensor {a.numpy()} does not match target {target} with np_dtype {np_dtype}") from e

def _assert_eq(tensor:Tensor, target_dtype:DType, target):
  if DEBUG >= 2: print(tensor.numpy())
  try:
    assert tensor.dtype == target_dtype
    np.testing.assert_allclose(tensor.numpy(), target)
  except AssertionError as e:
    raise AssertionError(f"\ntensor {tensor.numpy()} dtype {tensor.dtype} does not match target {target} with dtype {target_dtype}") from e

def _test_op(fxn, target_dtype:DType, target): _assert_eq(fxn(), target_dtype, target)
def _test_cast(a:Tensor, target_dtype:DType): _test_op(lambda: a.cast(target_dtype), target_dtype, a.numpy().astype(target_dtype.np).tolist())
def _test_bitcast(a:Tensor, target_dtype:DType, target=None): _test_op(lambda: a.bitcast(target_dtype), target_dtype, target or a.numpy().view(target_dtype.np).tolist())

class TestDType(unittest.TestCase):
  DTYPE: Any = None
  DATA: Any = None
  @classmethod
  def setUpClass(cls):
    if not cls.DTYPE or not is_dtype_supported(cls.DTYPE): raise unittest.SkipTest("dtype not supported")
    cls.DATA = np.random.randint(0, 100, size=10, dtype=cls.DTYPE.np).tolist() if dtypes.is_int(cls.DTYPE) else np.random.choice([True, False], size=10).tolist() if cls.DTYPE == dtypes.bool else np.random.uniform(0, 1, size=10).tolist()
  def setUp(self):
    if self.DTYPE is None: raise unittest.SkipTest("base class")

  def test_to_np(self): _test_to_np(Tensor(self.DATA, dtype=self.DTYPE), self.DTYPE.np, np.array(self.DATA, dtype=self.DTYPE.np))

  def test_casts_to(self): list(map(
    lambda dtype: _test_cast(Tensor(self.DATA, dtype=dtype), self.DTYPE),
    get_available_cast_dtypes(self.DTYPE)
  ))
  def test_casts_from(self): list(map(
    lambda dtype: _test_cast(Tensor(self.DATA, dtype=self.DTYPE), dtype),
    get_available_cast_dtypes(self.DTYPE)
  ))

  def test_same_size_ops(self):
    def get_target_dtype(dtype):
      if any([dtypes.is_float(dtype), dtypes.is_float(self.DTYPE)]): return max([dtype, self.DTYPE], key=lambda x: x.priority)
      return dtype if dtypes.is_unsigned(dtype) else self.DTYPE
    list(map(
      lambda dtype: _test_ops(a_dtype=self.DTYPE, b_dtype=dtype, target_dtype=get_target_dtype(dtype)) if dtype.itemsize == self.DTYPE.itemsize else None,
      get_available_cast_dtypes(self.DTYPE)
    ))
  def test_upcast_ops(self): list(map(
    lambda dtype: _test_ops(a_dtype=self.DTYPE, b_dtype=dtype) if dtype.itemsize > self.DTYPE.itemsize else None,
    get_available_cast_dtypes(self.DTYPE)
  ))
  def test_upcast_to_ops(self):
    list(map(
    lambda dtype: _test_ops(a_dtype=dtype, b_dtype=self.DTYPE) if dtype.itemsize < self.DTYPE.itemsize else None,
    get_available_cast_dtypes(self.DTYPE)
  ))
  def test_bitcast(self):
    if self.DTYPE == dtypes.bool: raise unittest.SkipTest("no bools in bitcast")
    list(map(
      lambda dtype: _test_bitcast(Tensor(self.DATA, dtype=self.DTYPE), dtype) if dtype.itemsize == self.DTYPE.itemsize and dtype != dtypes.bool else None,
     get_available_cast_dtypes(self.DTYPE)
    ))

def _test_ops(a_dtype:DType, b_dtype:DType, target_dtype=None):
  if not is_dtype_supported(a_dtype) or not is_dtype_supported(b_dtype): return
  if a_dtype == dtypes.bool or b_dtype == dtypes.bool: return
  target_dtype = target_dtype or (max([a_dtype, b_dtype], key=lambda x: x.priority) if a_dtype.priority != b_dtype.priority else max([a_dtype, b_dtype], key=lambda x: x.itemsize))
  _assert_eq(Tensor([1,2,3,4], dtype=a_dtype)+Tensor([1,2,3,4], dtype=b_dtype), target_dtype, [2,4,6,8])
  _assert_eq(Tensor([1,2,3,4], dtype=a_dtype)*Tensor([1,2,3,4], dtype=b_dtype), target_dtype, [1,4,9,16])
  _assert_eq(Tensor([[1,2],[3,4]], dtype=a_dtype)@Tensor.eye(2, dtype=b_dtype), target_dtype, [[1,2],[3,4]])
  _assert_eq(Tensor([1,1,1,1], dtype=a_dtype)+Tensor.ones((4,4), dtype=b_dtype), target_dtype, 2*Tensor.ones(4,4).numpy())

class TestBFloat16DType(unittest.TestCase):
  def setUp(self):
    if not is_dtype_supported(dtypes.bfloat16): raise unittest.SkipTest("bfloat16 not supported")
  def test_bf16_to_float(self):
    with self.assertRaises(AssertionError):
      _test_cast(Tensor([100000], dtype=dtypes.bfloat16), dtypes.float32, [100000])

  def test_float_to_bf16(self):
    with self.assertRaises(AssertionError):
      _test_cast(Tensor([100000], dtype=dtypes.float32), dtypes.bfloat16, [100000])

  # torch.tensor([10000, -1, -1000, -10000, 20]).type(torch.bfloat16)

  def test_bf16(self):
    t = Tensor([10000, -1, -1000, -10000, 20]).cast(dtypes.bfloat16)
    t.realize()
    back = t.cast(dtypes.float32)
    assert tuple(back.numpy().tolist()) == (9984., -1, -1000, -9984, 20)

  def test_bf16_disk_write_read(self):
    t = Tensor([10000, -1, -1000, -10000, 20]).cast(dtypes.float32)
    t.to(f"disk:{temp('f32')}").realize()

    # hack to "cast" f32 -> bf16
    dat = open(temp('f32'), "rb").read()
    adat = b''.join([dat[i+2:i+4] for i in range(0, len(dat), 4)])
    with open(temp('bf16'), "wb") as f: f.write(adat)

    t = Tensor.empty(5, dtype=dtypes.bfloat16, device=f"disk:{temp('bf16')}").llvm().realize()
    back = t.cast(dtypes.float32)
    assert tuple(back.numpy().tolist()) == (9984., -1, -1000, -9984, 20)

class TestHalfDtype(TestDType): DTYPE = dtypes.half

class TestFloatDType(TestDType): DTYPE = dtypes.float

class TestDoubleDtype(TestDType): DTYPE = dtypes.double

class TestInt8Dtype(TestDType):
  DTYPE = dtypes.int8
  @unittest.skipIf(getenv("CUDA",0)==1 or getenv("PTX", 0)==1, "cuda saturation works differently")
  def test_int8_to_uint8_negative(self): _test_op(lambda: Tensor([-1, -2, -3, -4], dtype=dtypes.int8).cast(dtypes.uint8), dtypes.uint8, [255, 254, 253, 252])

class TestUint8Dtype(TestDType):
  DTYPE = dtypes.uint8
  @unittest.skipIf(getenv("CUDA",0)==1 or getenv("PTX", 0)==1, "cuda saturation works differently")
  def test_uint8_to_int8_overflow(self): _test_op(lambda: Tensor([255, 254, 253, 252], dtype=dtypes.uint8).cast(dtypes.int8), dtypes.int8, [-1, -2, -3, -4])

class TestBitCast(unittest.TestCase):
  def test_shape_change_bitcast(self):
    with self.assertRaises(AssertionError):
      _test_bitcast(Tensor([100000], dtype=dtypes.float32), dtypes.uint8, [100000])

class TestInt16Dtype(TestDType): DTYPE = dtypes.int16
class TestUint16Dtype(TestDType): DTYPE = dtypes.uint16

class TestInt32Dtype(TestDType): DTYPE = dtypes.int32
class TestUint32Dtype(TestDType): DTYPE = dtypes.uint32

class TestInt64Dtype(TestDType): DTYPE = dtypes.int64
class TestUint64Dtype(TestDType): DTYPE = dtypes.uint64

class TestBoolDtype(TestDType): DTYPE = dtypes.bool

class TestImageDType(unittest.TestCase):
  def test_image_scalar(self):
    assert dtypes.imagef((10,10)).scalar() == dtypes.float32
    assert dtypes.imageh((10,10)).scalar() == dtypes.float32
  def test_image_vec(self):
    assert dtypes.imagef((10,10)).vec(4) == dtypes.float32.vec(4)
    assert dtypes.imageh((10,10)).vec(4) == dtypes.float32.vec(4)

class TestEqStrDType(unittest.TestCase):
  def test_image_ne(self):
    if ImageDType is None: raise unittest.SkipTest("no ImageDType support")
    assert dtypes.float == dtypes.float32, "float doesn't match?"
    assert dtypes.imagef((1,2,4)) != dtypes.imageh((1,2,4)), "different image dtype doesn't match"
    assert dtypes.imageh((1,2,4)) != dtypes.imageh((1,4,2)), "different shape doesn't match"
    assert dtypes.imageh((1,2,4)) == dtypes.imageh((1,2,4)), "same shape matches"
    assert isinstance(dtypes.imageh((1,2,4)), ImageDType)
  def test_ptr_ne(self):
    if PtrDType is None: raise unittest.SkipTest("no PtrDType support")
    # TODO: is this the wrong behavior?
    assert PtrDType(dtypes.float32) == dtypes.float32
    #assert PtrDType(dtypes.float32) == PtrDType(dtypes.float32)
    #assert PtrDType(dtypes.float32) != dtypes.float32
  def test_strs(self):
    if PtrDType is None: raise unittest.SkipTest("no PtrDType support")
    self.assertEqual(str(dtypes.imagef((1,2,4))), "dtypes.imagef((1, 2, 4))")
    self.assertEqual(str(PtrDType(dtypes.float32)), "ptr.dtypes.float")

class TestHelpers(unittest.TestCase):
  signed_ints = (dtypes.int8, dtypes.int16, dtypes.int32, dtypes.int64)
  uints = (dtypes.uint8, dtypes.uint16, dtypes.uint32, dtypes.uint64)
  floats = (dtypes.float16, dtypes.float32, dtypes.float64)

  @given(st.sampled_from(signed_ints+uints), st.integers(min_value=1, max_value=8))
  def test_is_int(self, dtype, amt):
    assert dtypes.is_int(dtype.vec(amt) if amt > 1 else dtype)
    assert not dtypes.is_float(dtype.vec(amt) if amt > 1 else dtype)

  @given(st.sampled_from(uints), st.integers(min_value=1, max_value=8))
  def test_is_unsigned_uints(self, dtype, amt):
    assert dtypes.is_unsigned(dtype.vec(amt) if amt > 1 else dtype)

  @given(st.sampled_from(signed_ints), st.integers(min_value=1, max_value=8))
  def test_is_unsigned_signed_ints(self, dtype, amt):
    assert not dtypes.is_unsigned(dtype.vec(amt) if amt > 1 else dtype)

  @given(st.sampled_from(floats), st.integers(min_value=1, max_value=8))
  def test_is_float(self, dtype, amt):
    assert dtypes.is_float(dtype.vec(amt) if amt > 1 else dtype)
    assert not dtypes.is_int(dtype.vec(amt) if amt > 1 else dtype)
    assert not dtypes.is_unsigned(dtype.vec(amt) if amt > 1 else dtype)

  @given(st.sampled_from([d for d in DTYPES_DICT.values() if dtypes.is_float(d) or dtypes.is_int(d)]), st.integers(min_value=2, max_value=8))
  def test_scalar(self, dtype, amt):
    assert dtype.vec(amt).scalar() == dtype

if __name__ == '__main__':
  unittest.main()