#
# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
# Copyright 2023 The vLLM team.
#
# 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.
# This file is a part of the vllm-ascend project.
# Adapted from vllm-project/vllm/blob/main/tests/v1/kv_connector/unit/test_remote_decode_lifecycle.py
#
import copy

from vllm.v1.outputs import EMPTY_MODEL_RUNNER_OUTPUT, KVConnectorOutput
from vllm.v1.request import FinishReason, RequestStatus

from tests.ut.kv_offload.utils import (
    assert_scheduler_empty,
    create_model_runner_output,
    create_request,
    create_scheduler,
    create_vllm_config,
)


def test_basic_lifecycle():
    """Test lifecycle of a Remote Decode request."""

    vllm_config = create_vllm_config()
    scheduler = create_scheduler(vllm_config)

    BLOCK_SIZE = vllm_config.cache_config.block_size
    NUM_EXTERNAL_FULL_BLOCKS = 2
    NUM_TOKENS = int(BLOCK_SIZE * (NUM_EXTERNAL_FULL_BLOCKS + 0.5))

    request = create_request(
        request_id=1, max_tokens=1, num_tokens=NUM_TOKENS, do_remote_decode=True, block_size=BLOCK_SIZE
    )

    scheduler.add_request(request)
    request_id = request.request_id

    # STEP (1): Prefill.
    # (1a): schedule()
    scheduler_output = scheduler.schedule()
    assert len(scheduler.requests) == 1
    assert len(scheduler.running) == 1
    assert len(scheduler_output.scheduled_new_reqs) == 1

    # (1b): execute_model()
    model_runner_output = create_model_runner_output(reqs=[request])

    # (1c): update_from_output()
    engine_core_outputs = scheduler.update_from_output(scheduler_output, model_runner_output)

    assert request.is_finished()
    assert request.status == RequestStatus.FINISHED_LENGTH_CAPPED
    output = engine_core_outputs[0].outputs[0]
    assert output.finish_reason == FinishReason.LENGTH
    # MooncakeConnector.request_finished returns (delay_free_blocks, None),
    # so kv_transfer_params is None in the output.
    assert output.kv_transfer_params is None

    # Request freed in Scheduler but blocks should not be freed.
    assert request_id in scheduler.finished_req_ids
    assert len(scheduler.running) == 0
    assert len(scheduler.waiting) == 0
    assert len(scheduler.requests) == 1
    blocks = scheduler.kv_cache_manager.coordinator.single_type_managers[0].req_to_blocks[request_id]
    for block in blocks:
        assert block.ref_cnt == 1

    # STEP (2): Send Finished to PB.
    scheduler_output = scheduler.schedule()
    assert len(scheduler.requests) == 1
    assert len(scheduler.running) == 0
    assert len(scheduler_output.finished_req_ids) == 1
    assert request_id in scheduler_output.finished_req_ids
    assert len(scheduler_output.scheduled_new_reqs) == 0
    assert scheduler_output.scheduled_cached_reqs.num_reqs == 0
    assert len(scheduler.finished_req_ids) == 0

    model_runner_output = EMPTY_MODEL_RUNNER_OUTPUT
    scheduler.update_from_output(scheduler_output, model_runner_output)

    # STEP (3): Finished sending.
    scheduler_output = scheduler.schedule()
    assert len(scheduler.requests) == 1
    assert len(scheduler.running) == 0
    assert len(scheduler_output.finished_req_ids) == 0
    assert len(scheduler_output.scheduled_new_reqs) == 0
    assert scheduler_output.scheduled_cached_reqs.num_reqs == 0
    assert len(scheduler.finished_req_ids) == 0

    model_runner_output = copy.deepcopy(EMPTY_MODEL_RUNNER_OUTPUT)
    model_runner_output.kv_connector_output = KVConnectorOutput(finished_sending={request_id})

    scheduler.update_from_output(scheduler_output, model_runner_output)

    assert_scheduler_empty(scheduler)


def test_prefix_cache_lifecycle():
    """Test that remote decode params still works with a prefix cache hit."""

    vllm_config = create_vllm_config()
    scheduler = create_scheduler(vllm_config)

    # Prime the KVCache.
    BLOCK_SIZE = vllm_config.cache_config.block_size
    NUM_EXTERNAL_FULL_BLOCKS = 3
    NUM_TOKENS = int(BLOCK_SIZE * (NUM_EXTERNAL_FULL_BLOCKS + 0.5))

    request_normal = create_request(request_id=1, num_tokens=NUM_TOKENS, block_size=BLOCK_SIZE)

    scheduler.add_request(request_normal)
    scheduler_output = scheduler.schedule()
    model_runner_output = create_model_runner_output(reqs=[request_normal], use_eos=True)
    scheduler.update_from_output(scheduler_output, model_runner_output)
    scheduler_output = scheduler.schedule()
    scheduler.update_from_output(scheduler_output, EMPTY_MODEL_RUNNER_OUTPUT)

    # Step (1): Send the KV Transfer.
    NUM_EXTERNAL_FULL_BLOCKS -= 1
    NUM_TOKENS = int(BLOCK_SIZE * (NUM_EXTERNAL_FULL_BLOCKS + 0.5))

    request_remote = create_request(request_id=1, num_tokens=NUM_TOKENS, do_remote_decode=True, block_size=BLOCK_SIZE)

    scheduler.add_request(request_remote)
    scheduler_output = scheduler.schedule()
    model_runner_output = create_model_runner_output(reqs=[request_remote])
    scheduler.update_from_output(scheduler_output, model_runner_output)

    # STEP (2): Ensure it is freed.
    scheduler_output = scheduler.schedule()
    model_runner_output = copy.deepcopy(EMPTY_MODEL_RUNNER_OUTPUT)
    model_runner_output.kv_connector_output = KVConnectorOutput(finished_sending={request_remote.request_id})
    scheduler.update_from_output(scheduler_output, model_runner_output)
    assert_scheduler_empty(scheduler)