# SPDX-License-Identifier: Apache-2.0

import pytest

from vllm.config import (CacheConfig, ModelConfig, ParallelConfig,
                         SchedulerConfig, VllmConfig)
from vllm.sampling_params import SamplingParams
from vllm.v1.core.sched.output import (CachedRequestData, NewRequestData,
                                       SchedulerOutput)
from vllm.v1.kv_cache_interface import (FullAttentionSpec, KVCacheConfig,
                                        KVCacheGroupSpec, KVCacheTensor)
from vllm.v1.sample.metadata import SamplingMetadata
from vllm.v1.worker.gpu_input_batch import InputBatch
from vllm.v1.worker.gpu_model_runner import GPUModelRunner


def initialize_kv_cache(runner: GPUModelRunner):
    """
    Only perform necessary steps in GPUModelRunner.initialize_kv_cache()
    """
    kv_cache_config = KVCacheConfig(
        num_blocks=10,
        tensors={
            "layer.0": KVCacheTensor(size=1024),
        },
        kv_cache_groups=[
            KVCacheGroupSpec(
                layer_names=["layer.0"],
                kv_cache_spec=FullAttentionSpec(
                    block_size=16,
                    num_kv_heads=runner.model_config.get_num_kv_heads(
                        runner.parallel_config),
                    head_size=runner.model_config.get_head_size(),
                    dtype=runner.kv_cache_dtype,
                    use_mla=False,
                ))
        ])
    runner.kv_cache_config = kv_cache_config
    runner.input_batch = InputBatch(
        max_num_reqs=runner.max_num_reqs,
        max_model_len=runner.max_model_len,
        max_num_batched_tokens=runner.max_num_tokens,
        device=runner.device,
        pin_memory=runner.pin_memory,
        vocab_size=runner.model_config.get_vocab_size(),
        kv_cache_config=kv_cache_config,
    )
    runner.initialize_attn_backend(kv_cache_config)


@pytest.fixture
def model_runner():
    scheduler_config = SchedulerConfig(
        max_num_seqs=10,
        max_num_batched_tokens=512,
        max_model_len=512,
    )
    model_config = ModelConfig(
        model="facebook/opt-125m",
        task="generate",
        tokenizer="facebook/opt-125m",
        tokenizer_mode="auto",
        trust_remote_code=True,
        dtype="float16",
        seed=42,
    )
    cache_config = CacheConfig(
        block_size=16,
        gpu_memory_utilization=0.9,
        swap_space=0,
        cache_dtype="auto",
    )
    parallel_config = ParallelConfig()
    vllm_config = VllmConfig(
        model_config=model_config,
        cache_config=cache_config,
        scheduler_config=scheduler_config,
        parallel_config=parallel_config,
    )

    device = "cuda"
    runner = GPUModelRunner(vllm_config, device)
    initialize_kv_cache(runner)
    return runner


def _schedule_new_request(*req_ids: str) -> SchedulerOutput:
    new_reqs = []
    num_scheduled_tokens = {}
    total_num_scheduled_tokens = 0
    for req_id in req_ids:
        new_reqs.append(
            NewRequestData(
                req_id=req_id,
                prompt_token_ids=[1, 2, 3],
                mm_inputs=[],
                mm_hashes=[],
                mm_positions=[],
                sampling_params=SamplingParams(),
                block_ids=[[0]],
                num_computed_tokens=0,
                lora_request=None,
            ))
        num_scheduled_tokens[req_id] = 3
        total_num_scheduled_tokens += num_scheduled_tokens[req_id]

    return SchedulerOutput(
        scheduled_new_reqs=new_reqs,
        scheduled_cached_reqs=[],
        num_scheduled_tokens=num_scheduled_tokens,
        total_num_scheduled_tokens=total_num_scheduled_tokens,
        scheduled_spec_decode_tokens={},
        scheduled_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
        structured_output_request_ids={},
        grammar_bitmask=None,
    )


def _is_req_scheduled(model_runner, req_id: str) -> bool:
    return req_id in model_runner.input_batch.req_id_to_index


def _is_req_added(model_runner, req_id: str) -> bool:
    return req_id in model_runner.requests


def _is_sampling_metadata_changed(model_runner,
                                  sampling_metadata_before: SamplingMetadata):
    return model_runner.input_batch.sampling_metadata is not (
        sampling_metadata_before)


def _is_req_state_block_table_match(model_runner, req_id: str) -> bool:
    req_index = model_runner.input_batch.req_id_to_index[req_id]
    block_table = model_runner.input_batch.block_table[0]
    req_state = model_runner.requests[req_id]
    if block_table.num_blocks_per_row[req_index] != len(
            req_state.block_ids[0]):
        return False
    num_blocks = block_table.num_blocks_per_row[req_index]
    return (block_table.block_table_np[req_index, :num_blocks] ==
            req_state.block_ids[0]).all()


def test_update_states_new_request(model_runner):
    req_id = "req_0"

    # new req
    scheduler_output = _schedule_new_request(req_id)

    metadata_before = model_runner.input_batch.sampling_metadata
    model_runner._update_states(scheduler_output)
    assert _is_sampling_metadata_changed(model_runner, metadata_before)
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(model_runner, req_id)
    assert _is_req_state_block_table_match(model_runner, req_id)


def test_update_states_request_finished(model_runner):
    req_id = "req_0"

    # new req
    scheduler_output = _schedule_new_request(req_id)

    model_runner._update_states(scheduler_output)
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(model_runner, req_id)

    # finish req
    scheduler_output = SchedulerOutput(
        scheduled_new_reqs=[],
        scheduled_cached_reqs=[],
        num_scheduled_tokens={},
        total_num_scheduled_tokens=0,
        scheduled_spec_decode_tokens={},
        scheduled_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids={req_id},
        free_encoder_input_ids=[],
        structured_output_request_ids={},
        grammar_bitmask=None,
    )

    metadata_before = model_runner.input_batch.sampling_metadata
    model_runner._update_states(scheduler_output)
    assert _is_sampling_metadata_changed(model_runner, metadata_before)
    assert not _is_req_added(model_runner, req_id)
    assert not _is_req_scheduled(model_runner, req_id)


def test_update_states_request_resumed(model_runner):
    req_id = "req_0"

    # new req
    scheduler_output = _schedule_new_request(req_id)

    model_runner._update_states(scheduler_output)
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(model_runner, req_id)

    # unschedule req
    scheduler_output = SchedulerOutput(
        scheduled_new_reqs=[],
        scheduled_cached_reqs=[],
        num_scheduled_tokens={},
        total_num_scheduled_tokens=0,
        scheduled_spec_decode_tokens={},
        scheduled_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
        structured_output_request_ids={},
        grammar_bitmask=None,
    )

    model_runner._update_states(scheduler_output)
    assert _is_req_added(model_runner, req_id)
    assert not _is_req_scheduled(model_runner, req_id)

    # resume req
    cached_req_data = CachedRequestData(
        req_id=req_id,
        resumed_from_preemption=False,
        new_token_ids=[],
        new_block_ids=[[]],
        num_computed_tokens=0,
    )

    scheduler_output = SchedulerOutput(
        scheduled_new_reqs=[],
        scheduled_cached_reqs=[cached_req_data],
        num_scheduled_tokens={req_id: 1},
        total_num_scheduled_tokens=1,
        scheduled_spec_decode_tokens={},
        scheduled_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
        structured_output_request_ids={},
        grammar_bitmask=None,
    )

    metadata_before = model_runner.input_batch.sampling_metadata
    model_runner._update_states(scheduler_output)
    assert _is_sampling_metadata_changed(model_runner, metadata_before)
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(model_runner, req_id)
    assert _is_req_state_block_table_match(model_runner, req_id)


def test_update_states_no_changes(model_runner):
    req_id = "req_0"

    # new req
    scheduler_output = _schedule_new_request(req_id)

    model_runner._update_states(scheduler_output)
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(model_runner, req_id)

    # schedule req
    scheduler_output = SchedulerOutput(
        scheduled_new_reqs=[],
        scheduled_cached_reqs=[],
        num_scheduled_tokens={req_id: 1},
        total_num_scheduled_tokens=1,
        scheduled_spec_decode_tokens={},
        scheduled_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
        structured_output_request_ids={},
        grammar_bitmask=None,
    )

    metadata_before = model_runner.input_batch.sampling_metadata
    model_runner._update_states(scheduler_output)
    assert not _is_sampling_metadata_changed(model_runner, metadata_before)
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(model_runner, req_id)
    assert _is_req_state_block_table_match(model_runner, req_id)


def test_update_states_request_unscheduled(model_runner):
    req_ids = ("req_0", "req_1")

    # new reqs
    scheduler_output = _schedule_new_request(*req_ids)

    model_runner._update_states(scheduler_output)

    assert _is_req_added(model_runner, req_ids[0])
    assert _is_req_scheduled(model_runner, req_ids[0])

    assert _is_req_added(model_runner, req_ids[1])
    assert _is_req_scheduled(model_runner, req_ids[1])

    # unschedule req_1
    scheduler_output = SchedulerOutput(
        scheduled_new_reqs=[],
        scheduled_cached_reqs=[],
        num_scheduled_tokens={req_ids[0]: 1},
        total_num_scheduled_tokens=1,
        scheduled_spec_decode_tokens={},
        scheduled_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
        structured_output_request_ids={},
        grammar_bitmask=None,
    )

    metadata_before = model_runner._update_states(scheduler_output)
    assert _is_sampling_metadata_changed(model_runner, metadata_before)

    assert _is_req_added(model_runner, req_ids[0])
    assert _is_req_scheduled(model_runner, req_ids[0])

    assert _is_req_added(model_runner, req_ids[1])
    assert not _is_req_scheduled(model_runner, req_ids[1])
