# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""Shared utilities for omni schedulers."""

import numpy as np
from vllm.v1.core.kv_cache_manager import KVCacheManager
from vllm.v1.outputs import RoutedExpertsLists
from vllm.v1.request import Request


def omni_routed_experts_for_request(routed_experts: RoutedExpertsLists, request) -> np.ndarray | None:
    """Extract per-request routed experts from RoutedExpertsLists using slot_mapping.

    Matches upstream RoutedExpertsManager.get() pattern — filters routing_data
    rows whose slot_mapping entries belong to this request's block_table.
    """
    if routed_experts is None:
        return None
    slots = getattr(request, "block_table", None)
    if slots is None:
        return None
    slot_set = set(slots)
    mask = np.isin(routed_experts.slot_mapping, list(slot_set))
    data = routed_experts.routing_data[mask]
    return data if data.size > 0 else None


def free_kv_blocks_in_physical_order(manager: KVCacheManager, request: Request) -> None:
    """Return non-cached request blocks in increasing physical order.

    vLLM's block pool deliberately honors the eviction-priority order passed
    to ``free_blocks``.  For a non-caching P/D pool there is no LRU priority to
    preserve, so physical order lets native connectors coalesce adjacent
    source/destination pages on the next allocation.
    """

    if manager.enable_caching:
        manager.free(request)
        return
    blocks = manager.pop_blocks_for_free(request)
    manager.block_pool.free_blocks(sorted(blocks, key=lambda block: block.block_id))