# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from typing import Optional, Union

import torch

from vllm.config import (CacheConfig, KVTransferConfig, ModelConfig,
                         SchedulerConfig, SpeculativeConfig, VllmConfig)
from vllm.multimodal.inputs import (MultiModalBatchedField,
                                    MultiModalFieldElem, MultiModalKwargsItem,
                                    PlaceholderRange)
from vllm.sampling_params import SamplingParams
from vllm.v1.core.kv_cache_utils import (get_request_block_hasher,
                                         init_none_hash)
from vllm.v1.core.sched.async_scheduler import AsyncScheduler
from vllm.v1.core.sched.scheduler import Scheduler
from vllm.v1.kv_cache_interface import (FullAttentionSpec, KVCacheConfig,
                                        KVCacheGroupSpec)
from vllm.v1.request import Request
from vllm.v1.structured_output import StructuredOutputManager

EOS_TOKEN_ID = 50256


def create_scheduler(
    model: str = "facebook/opt-125m",
    max_num_seqs: int = 16,
    max_num_batched_tokens: int = 8192,
    enable_prefix_caching: Optional[bool] = None,
    long_prefill_token_threshold: int = 0,
    disable_chunked_mm_input: bool = False,
    use_kv_connector: bool = False,
    num_blocks: int = 10000,
    block_size: int = 16,
    max_model_len: Optional[int] = None,
    num_speculative_tokens: Optional[int] = None,
    skip_tokenizer_init: bool = False,
    async_scheduling: bool = False,
) -> Union[Scheduler, AsyncScheduler]:
    '''Create scheduler under test.

    Args:
      model: model under test
      max_num_seqs: max sequences to schedule
      max_num_batch_tokens: max num tokens to batch
      enable_prefix_caching: optionally force APC config
                             (True/False) or use default
                             (None)

    Returns:
      {class}`Scheduler` instance
    '''
    if max_model_len is None:
        max_model_len = max_num_batched_tokens
    scheduler_config = SchedulerConfig(
        max_num_seqs=max_num_seqs,
        max_num_batched_tokens=max_num_batched_tokens,
        max_model_len=max_model_len,
        long_prefill_token_threshold=long_prefill_token_threshold,
        disable_chunked_mm_input=disable_chunked_mm_input,
        enable_chunked_prefill=True,
        async_scheduling=async_scheduling,
    )
    model_config = ModelConfig(
        model=model,
        trust_remote_code=True,
        dtype="float16",
        seed=42,
        skip_tokenizer_init=skip_tokenizer_init,
    )
    # Cache config, optionally force APC
    kwargs_cache = ({} if enable_prefix_caching is None else {
        'enable_prefix_caching': enable_prefix_caching
    })
    cache_config = CacheConfig(
        block_size=block_size,
        gpu_memory_utilization=0.9,
        swap_space=0,
        cache_dtype="auto",
        **kwargs_cache,
    )
    kv_transfer_config = KVTransferConfig(
        kv_connector="SharedStorageConnector",
        kv_role="kv_both",
        kv_connector_extra_config={"shared_storage_path": "local_storage"},
    ) if use_kv_connector else None

    speculative_config: Optional[SpeculativeConfig] = None
    if num_speculative_tokens is not None:
        speculative_config = SpeculativeConfig(
            model="ngram", num_speculative_tokens=num_speculative_tokens)

    vllm_config = VllmConfig(
        scheduler_config=scheduler_config,
        model_config=model_config,
        cache_config=cache_config,
        kv_transfer_config=kv_transfer_config,
        speculative_config=speculative_config,
    )
    kv_cache_config = KVCacheConfig(
        num_blocks=num_blocks,  # A large number of blocks to hold all requests
        kv_cache_tensors=[],
        kv_cache_groups=[
            KVCacheGroupSpec(['layer'],
                             FullAttentionSpec(block_size, 1, 1, torch.float32,
                                               False))
        ],
    )
    cache_config.num_gpu_blocks = num_blocks
    scheduler_cls = AsyncScheduler if async_scheduling else Scheduler
    return scheduler_cls(
        vllm_config=vllm_config,
        kv_cache_config=kv_cache_config,
        log_stats=True,
        structured_output_manager=StructuredOutputManager(vllm_config),
    )


_none_hash_initialized = False


def create_requests(
    num_requests: int,
    num_tokens: int = 10,
    mm_positions: Optional[list[list[PlaceholderRange]]] = None,
    max_tokens: int = 16,
    stop_token_ids: Optional[list[int]] = None,
    prompt_logprobs: Optional[int] = None,
    same_prompt: bool = False,
    block_size: int = 16,
) -> list[Request]:
    global _none_hash_initialized
    if not _none_hash_initialized:
        init_none_hash(hash)
        _none_hash_initialized = True

    block_hasher = get_request_block_hasher(block_size, hash)
    sampling_params = SamplingParams(ignore_eos=False,
                                     max_tokens=max_tokens,
                                     stop_token_ids=stop_token_ids,
                                     prompt_logprobs=prompt_logprobs)
    requests = []
    for i in range(num_requests):
        if mm_positions is not None:
            mm_position = mm_positions[i]
            mm_elem = MultiModalFieldElem(
                modality="dummy_m",
                key="dummy_k",
                data=None,
                field=MultiModalBatchedField(),
            )
            mm_item = MultiModalKwargsItem.from_elems([mm_elem])
            mm_kwargs = [mm_item] * len(mm_position)
            mm_hashes = ["hash"] * len(mm_position)
        else:
            mm_position = None
            mm_kwargs = None
            mm_hashes = None
        prompt_token_ids = ([0] * num_tokens if same_prompt else [i] *
                            num_tokens)
        request = Request(
            request_id=f"{i}",
            prompt_token_ids=prompt_token_ids,
            sampling_params=sampling_params,
            pooling_params=None,
            multi_modal_kwargs=mm_kwargs,
            multi_modal_placeholders=mm_position,
            multi_modal_hashes=mm_hashes,
            eos_token_id=EOS_TOKEN_ID,
            block_hasher=block_hasher,
        )
        requests.append(request)
    return requests