# Copyright 2024 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import gc
import importlib
import tempfile
import unittest
from unittest import skip

from packaging import version

from transformers import AqlmConfig, AutoConfig, AutoModelForCausalLM, AutoTokenizer, OPTForCausalLM, StaticCache
from transformers.testing_utils import (
    backend_empty_cache,
    require_accelerate,
    require_aqlm,
    require_torch_gpu,
    require_torch_multi_gpu,
    slow,
    torch_device,
)
from transformers.utils import is_accelerate_available, is_aqlm_available, is_torch_available


if is_torch_available():
    import torch

if is_accelerate_available():
    from accelerate import init_empty_weights


@require_torch_gpu
class AqlmConfigTest(unittest.TestCase):
    def test_to_dict(self):
        """
        Simple test that checks if one uses a config and converts it to a dict, the dict is the same as the config object
        """
        quantization_config = AqlmConfig()
        config_to_dict = quantization_config.to_dict()

        for key in config_to_dict:
            self.assertEqual(getattr(quantization_config, key), config_to_dict[key])

    def test_from_dict(self):
        """
        Simple test that checks if one uses a dict and converts it to a config object, the config object is the same as the dict
        """
        dict = {
            "in_group_size": 32,
            "num_codebooks": 8,
            "nbits_per_codebook": 8,
            "linear_weights_not_to_quantize": ["lm_head.weight"],
        }
        quantization_config = AqlmConfig.from_dict(dict)

        self.assertEqual(dict["in_group_size"], quantization_config.in_group_size)
        self.assertEqual(dict["num_codebooks"], quantization_config.num_codebooks)
        self.assertEqual(dict["nbits_per_codebook"], quantization_config.nbits_per_codebook)
        self.assertEqual(dict["linear_weights_not_to_quantize"], quantization_config.linear_weights_not_to_quantize)


@slow
@require_torch_gpu
@require_aqlm
@require_accelerate
class AqlmTest(unittest.TestCase):
    model_name = "BlackSamorez/Llama-2-7b-AQLM-2Bit-1x16-hf"

    input_text = "Hello my name is"
    max_new_tokens = 32

    EXPECTED_OUTPUT = "Hello my name is Katie. I am a 20 year old college student. I am a very outgoing person. I love to have fun and be active. I"

    # called only once for all test in this class
    @classmethod
    def setUpClass(cls):
        """
        Setup quantized model
        """
        cls.tokenizer = AutoTokenizer.from_pretrained(cls.model_name)
        cls.quantized_model = AutoModelForCausalLM.from_pretrained(
            cls.model_name,
            device_map=torch_device,
        )

    def tearDown(self):
        gc.collect()
        backend_empty_cache(torch_device)
        gc.collect()

    def test_quantized_model_conversion(self):
        """
        Simple test that checks if the quantized model has been converted properly
        """
        from aqlm import QuantizedLinear

        from transformers.integrations import replace_with_aqlm_linear

        model_id = "facebook/opt-350m"
        config = AutoConfig.from_pretrained(model_id, revision="cb32f77e905cccbca1d970436fb0f5e6b58ee3c5")
        quantization_config = AqlmConfig()

        with init_empty_weights():
            model = OPTForCausalLM(config)

        nb_linears = 0
        for module in model.modules():
            if isinstance(module, torch.nn.Linear):
                nb_linears += 1

        model, _ = replace_with_aqlm_linear(model, quantization_config=quantization_config)
        nb_aqlm_linear = 0
        for module in model.modules():
            if isinstance(module, QuantizedLinear):
                nb_aqlm_linear += 1

        self.assertEqual(nb_linears, nb_aqlm_linear)

        # Try with `linear_weights_not_to_quantize`
        with init_empty_weights():
            model = OPTForCausalLM(config)

        model, _ = replace_with_aqlm_linear(
            model, quantization_config=quantization_config, linear_weights_not_to_quantize=["lm_head.weight"]
        )
        nb_aqlm_linear = 0
        for module in model.modules():
            if isinstance(module, QuantizedLinear):
                nb_aqlm_linear += 1

        self.assertEqual(nb_linears - 1, nb_aqlm_linear)

    @skip(
        "inference doesn't work with quantized aqlm models using torch.Any type with recent torch versions. Waiting for the fix from AQLM side"
    )
    def test_quantized_model(self):
        """
        Simple test that checks if the quantized model is working properly
        """
        input_ids = self.tokenizer(self.input_text, return_tensors="pt").to(torch_device)

        output = self.quantized_model.generate(**input_ids, max_new_tokens=self.max_new_tokens)
        self.assertEqual(self.tokenizer.decode(output[0], skip_special_tokens=True), self.EXPECTED_OUTPUT)

    def test_raise_if_non_quantized(self):
        model_id = "facebook/opt-125m"
        quantization_config = AqlmConfig(bits=4)

        with self.assertRaises(ValueError):
            _ = AutoModelForCausalLM.from_pretrained(model_id, quantization_config=quantization_config)

    @skip(
        "inference doesn't work with quantized aqlm models using torch.Any type with recent torch versions. Waiting for the fix from AQLM side"
    )
    def test_save_pretrained(self):
        """
        Simple test that checks if the quantized model is working properly after being saved and loaded
        """
        with tempfile.TemporaryDirectory() as tmpdirname:
            self.quantized_model.save_pretrained(tmpdirname)
            model = AutoModelForCausalLM.from_pretrained(tmpdirname, device_map=torch_device)

            input_ids = self.tokenizer(self.input_text, return_tensors="pt").to(torch_device)

            output = model.generate(**input_ids, max_new_tokens=self.max_new_tokens)
            self.assertEqual(self.tokenizer.decode(output[0], skip_special_tokens=True), self.EXPECTED_OUTPUT)

    @skip(
        "inference doesn't work with quantized aqlm models using torch.Any type with recent torch versions. Waiting for the fix from AQLM side"
    )
    @require_torch_multi_gpu
    def test_quantized_model_multi_gpu(self):
        """
        Simple test that checks if the quantized model is working properly with multiple GPUs
        """
        input_ids = self.tokenizer(self.input_text, return_tensors="pt").to(torch_device)

        quantized_model = AutoModelForCausalLM.from_pretrained(self.model_name, device_map="auto")

        self.assertTrue(set(quantized_model.hf_device_map.values()) == {0, 1})

        output = quantized_model.generate(**input_ids, max_new_tokens=self.max_new_tokens)

        self.assertEqual(self.tokenizer.decode(output[0], skip_special_tokens=True), self.EXPECTED_OUTPUT)

    @unittest.skipUnless(
        is_aqlm_available() and version.parse(importlib.metadata.version("aqlm")) >= version.parse("1.0.3"),
        "test requires `aqlm>=1.0.3`",
    )
    def test_quantized_model_compile(self):
        """
        Simple test that checks if the quantized model is working properly
        """

        # Sample tokens greedily
        def decode_one_tokens(model, cur_token, input_pos, cache_position, past_key_values):
            logits = model(
                cur_token,
                position_ids=input_pos,
                cache_position=cache_position,
                past_key_values=past_key_values,
                return_dict=False,
                use_cache=True,
            )[0]
            new_token = torch.argmax(logits[:, [-1]], dim=-1).to(torch.int)

            return new_token

        # Tokenize the test input
        input_ids = self.tokenizer(self.input_text, return_tensors="pt").to(torch_device)["input_ids"]
        seq_length = input_ids.shape[1]

        # Setup static KV cache for generation
        past_key_values = StaticCache(
            config=self.quantized_model.config,
            max_batch_size=1,
            max_cache_len=seq_length + self.max_new_tokens + 1,
            device=torch_device,
            dtype=self.quantized_model.config._pre_quantization_dtype,
        )

        # Allocate token ids to be generated and copy prefix ids
        cache_position = torch.arange(seq_length, device=torch_device)
        generated_ids = torch.zeros(1, seq_length + self.max_new_tokens, dtype=torch.int, device=torch_device)
        generated_ids[:, cache_position] = input_ids.to(torch_device).to(torch.int)

        # Do a forward pass to fill the prefix cache and compile the kernels if necessary
        logits = self.quantized_model(
            input_ids,
            cache_position=cache_position,
            past_key_values=past_key_values,
            return_dict=False,
            use_cache=True,
        )[0]
        next_token = torch.argmax(logits[:, [-1]], dim=-1).to(torch.int)
        generated_ids[:, [seq_length]] = next_token

        with torch.no_grad():
            # Compile the CUDA graph
            decode_one_tokens = torch.compile(decode_one_tokens, mode="reduce-overhead", fullgraph=True)

            # Generate tokens one by one
            cache_position = torch.tensor([seq_length + 1], device=torch_device)
            for _ in range(1, self.max_new_tokens):
                with torch.backends.cuda.sdp_kernel(enable_flash=False, enable_mem_efficient=False, enable_math=True):
                    next_token = decode_one_tokens(
                        self.quantized_model, next_token.clone(), None, cache_position, past_key_values
                    )
                    generated_ids.index_copy_(1, cache_position, next_token)
                cache_position += 1

        # Check generated text
        self.assertEqual(self.tokenizer.decode(generated_ids[0], skip_special_tokens=True), self.EXPECTED_OUTPUT)