from tinygrad.tensor import Tensor
import pickle
import numpy as np
from tinygrad.helpers import prod

def fetch(url):
  if url.startswith("/"):
    with open(url, "rb") as f:
      dat = f.read()
    return dat
  import requests, os, hashlib, tempfile
  fp = os.path.join(tempfile.gettempdir(), hashlib.md5(url.encode('utf-8')).hexdigest())
  if os.path.isfile(fp) and os.stat(fp).st_size > 0 and os.getenv("NOCACHE", None) is None:
    with open(fp, "rb") as f:
      dat = f.read()
  else:
    print("fetching %s" % url)
    r = requests.get(url)
    assert r.status_code == 200
    dat = r.content
    with open(fp+".tmp", "wb") as f:
      f.write(dat)
    os.rename(fp+".tmp", fp)
  return dat

from tinygrad.nn.optim import get_parameters

def my_unpickle(fb0):
  key_prelookup = {}
  class HackTensor:
    def __new__(cls, *args):
      #print(args)
      ident, storage_type, obj_key, location, obj_size = args[0][0:5]
      assert ident == 'storage'

      assert prod(args[2]) == obj_size
      ret = np.zeros(args[2], dtype=storage_type)
      key_prelookup[obj_key] = (storage_type, obj_size, ret, args[2], args[3])
      return ret

  class HackParameter:
    def __new__(cls, *args):
      #print(args)
      pass

  class Dummy:
    pass

  class MyPickle(pickle.Unpickler):
    def find_class(self, module, name):
      #print(module, name)
      if name == 'FloatStorage':
        return np.float32
      if name == 'LongStorage':
        return np.int64
      if name == 'HalfStorage':
        return np.float16
      if module == "torch._utils":
        if name == "_rebuild_tensor_v2":
          return HackTensor
        elif name == "_rebuild_parameter":
          return HackParameter
      else:
        try:
          return pickle.Unpickler.find_class(self, module, name)
        except Exception:
          return Dummy

    def persistent_load(self, pid):
      return pid

  return MyPickle(fb0).load(), key_prelookup

def fake_torch_load_zipped(fb0, load_weights=True):
  import zipfile
  with zipfile.ZipFile(fb0, 'r') as myzip:
    with myzip.open('archive/data.pkl') as myfile:
      ret = my_unpickle(myfile)
    if load_weights:
      for k,v in ret[1].items():
        with myzip.open(f'archive/data/{k}') as myfile:
          if v[2].dtype == "object":
            print(f"issue assigning object on {k}")
            continue
          np.copyto(v[2], np.frombuffer(myfile.read(), v[2].dtype).reshape(v[3]))
  return ret[0]

def fake_torch_load(b0):
  import io
  import struct

  # convert it to a file
  fb0 = io.BytesIO(b0)

  if b0[0:2] == b"\x50\x4b":
    return fake_torch_load_zipped(fb0)

  # skip three junk pickles
  pickle.load(fb0)
  pickle.load(fb0)
  pickle.load(fb0)

  ret, key_prelookup = my_unpickle(fb0)

  # create key_lookup
  key_lookup = pickle.load(fb0)
  key_real = [None] * len(key_lookup)
  for k,v in key_prelookup.items():
    key_real[key_lookup.index(k)] = v

  # read in the actual data
  for storage_type, obj_size, np_array, np_shape, np_strides in key_real:
    ll = struct.unpack("Q", fb0.read(8))[0]
    assert ll == obj_size
    bytes_size = {np.float32: 4, np.int64: 8}[storage_type]
    mydat = fb0.read(ll * bytes_size)
    np.copyto(np_array, np.frombuffer(mydat, storage_type).reshape(np_shape))

    # numpy stores its strides in bytes
    real_strides = tuple([x*bytes_size for x in np_strides])
    np_array.strides = real_strides

  return ret

def get_child(parent, key):
  obj = parent
  for k in key.split('.'):
    if k.isnumeric():
      obj = obj[int(k)]
    elif isinstance(obj, dict):
      obj = obj[k]
    else:
      obj = getattr(obj, k)
  return obj