from __future__ import annotations

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.dependencies import get_admin_user, get_db
from app.enums.llm_billing import LLM_BILLING_SCENE_LABELS
from app.models.llm_billing.policy import LlmBillingPolicyModel
from app.models.user import User
from app.schemas.llm_billing import LlmBillingPolicyCreate, LlmBillingPolicyUpdate
from app.services.llm_billing.query_service import list_executions_with_calls
from app.services.operation_log_service import log_operation_event
from app.utils.id_gen import generate_id

router = APIRouter(prefix="/admin/llm-billing", tags=["admin-llm-billing"])


@router.get("/policies")
async def list_policies(
    admin: User = Depends(get_admin_user),
    db: AsyncSession = Depends(get_db),
):
    result = await db.execute(select(LlmBillingPolicyModel).order_by(LlmBillingPolicyModel.scene_code))
    return list(result.scalars().all())


@router.post("/policies")
async def create_policy(
    data: LlmBillingPolicyCreate,
    admin: User = Depends(get_admin_user),
    db: AsyncSession = Depends(get_db),
):
    if data.scene_code not in LLM_BILLING_SCENE_LABELS:
        raise HTTPException(status_code=400, detail="不支持的LLM业务场景")
    existing = await db.execute(select(LlmBillingPolicyModel.id).where(LlmBillingPolicyModel.scene_code == data.scene_code).limit(1))
    if existing.scalar_one_or_none():
        raise HTTPException(status_code=409, detail="该LLM业务场景已存在")
    policy = LlmBillingPolicyModel(
        id=generate_id(),
        scene_code=data.scene_code,
        scene_name=LLM_BILLING_SCENE_LABELS[data.scene_code],
        pre_deduct_credits=data.pre_deduct_credits,
        is_active=data.is_active,
        version=1,
        created_by=admin.id,
        updated_by=admin.id,
    )
    db.add(policy)
    await db.flush()
    log_operation_event(domain="llm_billing", module="admin", event_type="LLM_BILLING_POLICY_CREATED", user_id=admin.id, detail={"scene_code": policy.scene_code, "credits": float(policy.pre_deduct_credits)})
    return policy


@router.put("/policies/{policy_id}")
async def update_policy(
    policy_id: str,
    data: LlmBillingPolicyUpdate,
    admin: User = Depends(get_admin_user),
    db: AsyncSession = Depends(get_db),
):
    result = await db.execute(select(LlmBillingPolicyModel).where(LlmBillingPolicyModel.id == policy_id).limit(1).with_for_update())
    policy = result.scalar_one_or_none()
    if not policy:
        raise HTTPException(status_code=404, detail="LLM计费场景不存在")
    payload = data.model_dump(exclude_unset=True)
    payload.pop("scene_name", None)
    for key, value in payload.items():
        setattr(policy, key, value)
    policy.scene_name = LLM_BILLING_SCENE_LABELS.get(policy.scene_code, policy.scene_name)
    policy.version += 1
    policy.updated_by = admin.id
    await db.flush()
    log_operation_event(domain="llm_billing", module="admin", event_type="LLM_BILLING_POLICY_UPDATED", user_id=admin.id, detail={"scene_code": policy.scene_code, "version": policy.version})
    return policy


@router.get("/executions")
async def list_executions(
    page: int = Query(1, ge=1),
    page_size: int = Query(20, ge=1, le=100),
    scene_code: str | None = Query(default=None),
    status: str | None = Query(default=None),
    user_id: str | None = Query(default=None),
    admin: User = Depends(get_admin_user),
    db: AsyncSession = Depends(get_db),
):
    items, total = await list_executions_with_calls(db, page=page, page_size=page_size, scene_code=scene_code, status=status, user_id=user_id)
    return {"items": items, "total": total}