# SPDX-License-Identifier: Apache-2.0
import pytest

from vllm.config import CacheConfig, ModelConfig, SchedulerConfig, VllmConfig
from vllm.sampling_params import SamplingParams
from vllm.v1.core.scheduler_output import (CachedRequestData, NewRequestData,
                                           SchedulerOutput)
from vllm.v1.worker.gpu_model_runner import GPUModelRunner


@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",
    )
    vllm_config = VllmConfig(
        model_config=model_config,
        cache_config=cache_config,
        scheduler_config=scheduler_config,
    )

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


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],
                prompt="test",
                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_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
    )


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 test_update_states_new_request(model_runner):
    req_id = "req_0"

    # new req
    scheduler_output = _schedule_new_request(req_id)

    batch_changed = model_runner._update_states(scheduler_output)
    assert batch_changed is True
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(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_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids={req_id},
        free_encoder_input_ids=[],
    )

    batch_changed = model_runner._update_states(scheduler_output)
    assert batch_changed is True
    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_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids={},
        free_encoder_input_ids=[],
    )

    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_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_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
    )

    batch_changed = model_runner._update_states(scheduler_output)
    assert batch_changed is True
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(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_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
    )

    batch_changed = model_runner._update_states(scheduler_output)
    assert batch_changed is False
    assert _is_req_added(model_runner, req_id)
    assert _is_req_scheduled(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_encoder_inputs={},
        num_common_prefix_blocks=0,
        finished_req_ids=set(),
        free_encoder_input_ids=[],
    )

    batch_changed = model_runner._update_states(scheduler_output)
    assert batch_changed is True

    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])
