"""GPU 算力分配管理路由。"""
from __future__ import annotations

from typing import Any

from fastapi import APIRouter, Body, Depends, Request

from app.api.v1.endpoints.platform import ok, fail
from app.core.auth import get_current_user, is_admin
from app.db.platform_store import get_platform_store

router = APIRouter(prefix="/compute", tags=["gpu-assignment"])


def _actor_id(request: Request) -> str | None:
    auth = request.headers.get("Authorization", "")
    token = auth.replace("Bearer ", "").strip()
    if token.startswith("platform-token-"):
        return token[len("platform-token-"):]
    return None


@router.get("/gpu-assignments")
def list_assignments(current_user: dict = Depends(get_current_user)) -> dict[str, Any]:
    """查看全部分配关系（仅 admin）。"""
    if not is_admin(current_user):
        raise fail(403, "admin permission required")
    return ok(get_platform_store().gpu_assignments())


@router.post("/gpu-assignments")
def assign_gpus(
    payload: dict[str, Any] = Body(...),
    request: Request = None,
    current_user: dict = Depends(get_current_user),
) -> dict[str, Any]:
    """批量分配 GPU（仅 admin）。body: { assignments: [{ node_id, gpu_index, user_id }] }"""
    if not is_admin(current_user):
        raise fail(403, "admin permission required")
    assignments = payload.get("assignments") or []
    if not assignments:
        raise fail(400, "assignments 不能为空")
    actor = _actor_id(request) if request else None
    result = get_platform_store().assign_gpus(assignments, assigned_by=actor)
    get_platform_store().record_audit(
        action="gpu.assign",
        actor_id=actor,
        target_type="gpu",
        detail=f"count={len(assignments)}",
    )
    return ok(result)


@router.delete("/gpu-assignments/{assignment_id}")
def unassign_gpu(
    assignment_id: str,
    request: Request = None,
    current_user: dict = Depends(get_current_user),
) -> dict[str, Any]:
    """撤销 GPU 分配（仅 admin）。"""
    if not is_admin(current_user):
        raise fail(403, "admin permission required")
    get_platform_store().unassign_gpu(assignment_id)
    actor = _actor_id(request) if request else None
    get_platform_store().record_audit(
        action="gpu.unassign",
        actor_id=actor,
        target_type="gpu",
        target_id=assignment_id,
    )
    return ok({"deleted": assignment_id})


@router.get("/my-gpus")
def my_gpus(current_user: dict = Depends(get_current_user)) -> dict[str, Any]:
    """查看当前用户可用的 GPU 列表。"""
    return ok(get_platform_store().gpu_assignments_for_user(current_user["id"]))