# pylint: disable=cell-var-from-loop
# a python uops emulator
# works to test the tensor cores, and all the uops in general
# this is the (living) definition of uops
import sys
from typing import Optional, Any, TYPE_CHECKING
import pickle, base64, itertools, time, struct
from tinygrad.dtype import DType, dtypes, ImageDType, PtrDType, truncate
from tinygrad.helpers import all_same, getenv, flatten, get_single_element
from tinygrad.device import Compiled, Compiler, Allocator
from tinygrad.ops import exec_alu, Ops, UOp, GroupOp
from tinygrad.renderer import Renderer
from tinygrad.renderer.cstyle import CUDARenderer, MetalRenderer, AMDRenderer, IntelRenderer, ClangRenderer

def _load(m, i):
  if i is None: return 0.0
  if i < 0 or i >= len(m): raise IndexError(f"load out of bounds, size is {len(m)} and access is {i}")
  return m[i]

def load(inp, j=0):
  if len(inp) == 3: return [_load(m, x+j if x is not None else None) if gate else default for (m,x),default,gate in zip(*inp)]
  return [_load(m, x+j if x is not None else None) for m,x in inp[0]]

def _store(m, i, v):
  if i < 0 or i >= len(m): raise IndexError(f"store out of bounds, size is {len(m)}, access is {i}, value is {v}")
  m[i] = v

class PythonProgram:
  def __init__(self, name:str, lib:bytes):
    self.uops: list[tuple[Ops, Optional[DType], list[int], Any]] = pickle.loads(lib)
  def __call__(self, *bufs, global_size:tuple[int,int,int]=(1,1,1), local_size:tuple[int,int,int]=(1,1,1), vals:tuple[int, ...]=(), wait=False):
    st = time.perf_counter()
    warp = list(itertools.product(*[range(x) for x in local_size[::-1]]))
    warp_size = len(warp)
    for idxs in itertools.product(*[range(x) for x in global_size[::-1]]):
      ul: dict[int, Any] = {}
      dl: dict[int, DType] = {}
      pbufs: list[memoryview] = list(bufs)
      pvals: list[int] = list(vals)
      i = 0
      loop_ends: dict[int, int] = {}
      while i < len(self.uops):
        uop, dtype, idp, arg = self.uops[i]
        void_ops = {Ops.STORE, Ops.ENDRANGE, Ops.BARRIER, Ops.IF, Ops.ENDIF}
        if uop is Ops.DEFINE_ACC: idp = [idp[0]]
        inp = [ul[v] for v in idp if self.uops[v][0] not in void_ops]
        dtp = [dl[v] for v in idp if self.uops[v][0] not in void_ops]
        if getenv("TRACE"): print(i, uop, dtype, arg, inp, dtp)
        if uop is Ops.STORE:
          if len(inp) == 2: inp.append([True] * len(inp[0]))  # set the gate to True
          if dtp[1].count > 1:
            for j,val in enumerate(inp[1]):
              for (m,o),v,g in zip(inp[0], val, inp[2]):
                if g: _store(m, o+j, v)
          else:
            for (m,o),v,g in zip(*inp):
              if g: _store(m, o, v)
          i += 1
          continue
        if uop is Ops.ENDRANGE:
          loop_ends[idp[0]] = i
          i = idp[0]
          continue
        if uop in (Ops.BARRIER, Ops.IF, Ops.ENDIF):
          # in the python emulator, the warp is always in sync
          i += 1
          continue
        assert dtype is not None, f"{uop} is missing a dtype"
        dl[i] = dtype
        if uop in {Ops.DEFINE_GLOBAL, Ops.DEFINE_LOCAL}:
          assert dtype.fmt is not None
          if TYPE_CHECKING or sys.version_info < (3, 12): assert dtype.fmt != "e"
          buf = memoryview(bytearray(arg[1]*dtype.itemsize)) if uop is Ops.DEFINE_LOCAL else pbufs.pop(0)
          ul[i] = [buf.cast(dtype.fmt)] * warp_size
        elif uop is Ops.DEFINE_VAR:
          ul[i] = [pvals.pop(0)] * warp_size
        elif uop is Ops.SPECIAL:
          if arg[0][0] == 'g': ul[i] = [idxs[2-int(arg[0][-1])]] * warp_size
          elif arg[0][0] == 'l': ul[i] = [x[2-int(arg[0][-1])] for x in warp]
        elif uop is Ops.CONST: ul[i] = [arg] * warp_size
        elif uop is Ops.DEFINE_ACC:
          ul[i] = [[inp[0][0][0]] * warp_size for _ in range(dtype.count)] if dtype.count > 1 else [inp[0][0]] * warp_size
        elif uop is Ops.INDEX:
          ret = []
          if isinstance(dtp[0], ImageDType):
            for m,ox,oy in zip(inp[0], inp[1][0], inp[1][1]):
              if ox < 0 or ox >= dtp[0].shape[1] or oy < 0 or oy >= dtp[0].shape[0]: ret.append((m, None))
              else: ret.append((m, ox*4 + oy*dtp[0].shape[1]*4))
          else:
            for m,o in zip(inp[0], inp[1]): ret.append((m,o))
          ul[i] = ret
        elif uop is Ops.CAST and isinstance(dtype, PtrDType):
          ul[i] = inp[0]
        elif uop is Ops.RANGE:
          if i not in ul: ul[i] = [inp[0][0]] * warp_size
          else:
            for j in range(len(ul[i])):
              ul[i][j] += 1
            if ul[i][0] == inp[1][0]:
              del ul[i]
              i = loop_ends[i] + 1
              continue
        elif uop is Ops.VECTORIZE: ul[i] = inp
        elif uop in {Ops.CAST, Ops.BITCAST}:
          assert dtp[0].fmt and dtype.fmt
          pack_format, unpack_format = str(warp_size) + dtp[0].fmt, str(warp_size) + dtype.fmt
          if uop is Ops.BITCAST: ul[i] = list(struct.unpack(unpack_format, struct.pack(pack_format, *inp[0])))
          else: ul[i] = [truncate.get(dtype, lambda dt: dt)(dtypes.as_const(x, dtype)) for x in inp[0]]
        elif uop is Ops.LOAD:
          if dtype.count > 1:
            ul[i] = [load([inp[i][j] if i != 0 and dtp[i].count > 1 else inp[i] for i in range(len(inp))], j) for j in range(dtype.count)]
          else:
            ul[i] = load(inp)
        elif uop is Ops.ASSIGN:
          for j in range(len(inp[0])): inp[0][j] = inp[1][j]
          ul[i] = inp[0]
        elif uop is Ops.GEP: ul[i] = inp[0][get_single_element(arg)]
        elif uop is Ops.WMMA:
          # here are the models for the WMMA instruction on the different hardware
          def wmma_helper(WARP_THREADS, K, NUM_A, NUM_B, NUM_C, a_elem, b_elem, c_map):
            for cc, tinp, num in zip(("A", "B", "C"), inp, (NUM_A, NUM_B, NUM_C)):
              assert len(tinp) == num, f"{cc} must have {num} elements per thread, it has {len(tinp)}"
              assert len(flatten(tinp)) == num * warp_size, f"WMMA must have {num * warp_size} total elements for {cc} in WMMA"
            assert warp_size > 0 and warp_size % WARP_THREADS == 0, f"must have multiples of {WARP_THREADS} warp threads"
            out = [inp[2][elem_idx][:] for elem_idx in range(NUM_C)]
            for goff in range(0, warp_size, WARP_THREADS):
              for lane_id in range(WARP_THREADS):
                for elem_idx in range(NUM_C): # calculate new muls and add to acc
                  (c_i, c_j) = c_map(lane_id, elem_idx)
                  out[elem_idx][goff+lane_id] += sum(a_elem(inp[0], _k, c_j, goff) * b_elem(inp[1], c_i, _k, goff) for _k in range(K))
            return out

          # TODO: refactor these to a shared TensorCoreLayout in kernel.py
          if arg[4] == "METAL":
            # A (2 elements on 32 threads): row major
            def a_b_elem(x, i, j, goff): return x[(i%2)][goff+(i//2)%2+(j%4)*2+(i//4)*8+(j//4)*16]
            # (i, j), C, D (2 elements on 32 threads): row major same as A/B
            def c_map(lane, elem): return (elem + ((lane%2)*2) + ((lane//8)%2)*4, ((lane//2)%4) + (lane//16)*4)
            ul[i] = wmma_helper(32, 8, 2, 2, 2, a_b_elem, a_b_elem, c_map)
          elif arg[4] == "AMD":
            # A (16 elements on 32 threads): col major, lane 16-32 == lane 0-15
            def a_elem(x, i, j, goff):
              assert x[i][goff+j] == x[i][goff+j+16], "warp elements not duplicated properly across lanes"
              return x[i][goff+j]
            # B (16 elements on 32 threads): row major, lane 16-32 == lane 0-15
            def b_elem(x, i, j, goff): return a_elem(x, j, i, goff)  # pylint: disable=arguments-out-of-order
            def c_map(lane, elem): return (lane%16, lane//16+elem*2) # (i, j), C, D (8 elements on 32 threads): row major
            ul[i] = wmma_helper(32, 16, 16, 16, 8, a_elem, b_elem, c_map)
          elif arg[4] == "CUDA":
            # A (8 elements on 32 threads)
            def a_elem(x, i, j, goff): return x[(i%2)+(j//8)*2+(i//8)*4][goff+((i//2)%4)+(j%8)*4]
            # B (4 elements on 32 threads)
            def b_elem(x, i, j, goff): return x[(j%2)+(j//8)*2][goff+(j//2)%4+(i)*4]
            # (i, j), C, D (4 elements on 32 threads)
            def c_map(lane, elem): return ((elem%2)+(lane%4)*2, (lane//4)+(elem//2)*8)
            ul[i] = wmma_helper(32, 16, 8, 4, 4, a_elem, b_elem, c_map)
          elif arg[4] == "INTEL":
            # A (16 elements on 8 threads)
            def a_elem(x, i, j, goff): return x[i%2+j*2][goff+i//2]
            # B (16 elements on 8 threads)
            def b_elem(x, i, j, goff): return x[j][goff+i]
            # C, D (8 elements on 8 threads)
            def c_map(lane, elem): return (lane, elem)
            ul[i] = wmma_helper(8, 16, 16, 16, 8, a_elem, b_elem, c_map)
          elif arg[4] == "CLANG":
            def elem(x, i, j, _): return x[i+j][0]
            def c_map(_, elem): return (elem%16, elem//16)
            ul[i] = wmma_helper(1, 1, 16, 16, 256, elem, elem, c_map)
          else: raise NotImplementedError(f"unimplemented tensor core {arg}")
        elif uop in GroupOp.ALU:
          assert all_same([len(x) for x in inp]), f"{[len(x) for x in inp]} doesn't match on {uop}"
          assert all_same([dtype] + dtp) or uop in {Ops.CMPNE, Ops.CMPLT, Ops.WHERE}, f"dtype mismatch on {uop}"
          ul[i] = [exec_alu(uop, dtype, p) for p in zip(*inp)]
        assert i in ul, (uop, dtype, idp, arg)
        i += 1
    return time.perf_counter() - st

class PythonRenderer(Renderer):
  device = "PYTHON"
  def __init__(self):
    if getenv("EMULATE_METAL"): self.device, self.tensor_cores = "METAL", MetalRenderer.tensor_cores
    if getenv("EMULATE_AMD"): self.device, self.tensor_cores = "AMD", AMDRenderer.tensor_cores
    if getenv("EMULATE_CUDA"): self.device, self.tensor_cores = "CUDA", CUDARenderer.tensor_cores
    if getenv("EMULATE_INTEL"): self.device, self.suffix, self.tensor_cores = "INTEL", "INTEL", IntelRenderer.tensor_cores
    if getenv("EMULATE_AMX"): self.device, self.tensor_cores = "CLANG", ClangRenderer.tensor_cores

  def render(self, name:str, uops:list[UOp]) -> str:
    lops = [(u.op, u.dtype, [uops.index(v) for v in u.src], u.arg) for u in uops]
    return base64.b64encode(pickle.dumps(lops)).decode()

class PythonCompiler(Compiler):
  def compile(self, src:str) -> bytes: return base64.b64decode(src)

class PythonAllocator(Allocator):
  def _alloc(self, size, options): return memoryview(bytearray(size))
  def _copyin(self, dest, src:memoryview): dest[:] = src
  def _copyout(self, dest:memoryview, src): dest[:] = src

class PythonDevice(Compiled):
  def __init__(self, device:str): super().__init__(device, PythonAllocator(), PythonRenderer(), PythonCompiler(), PythonProgram)