"""FastAPI 应用入口。

提供健康检查和项目 CRUD 端点。
"""
from fastapi import FastAPI, HTTPException
from typing import Dict
from app.models import Item, ItemCreate

app = FastAPI(
    title="FastAPI Example",
    description="最小化 CRUD API 示例",
    version="1.0.0"
)

# 内存存储
_items: Dict[int, Item] = {}
_item_id_counter = 0


@app.get("/health", tags=["系统"])
async def health_check():
    """健康检查端点，返回服务状态。"""
    return {"status": "ok"}


@app.post("/items", response_model=Item, tags=["项目"])
async def create_item(item: ItemCreate):
    """创建新项目。"""
    global _item_id_counter
    _item_id_counter += 1
    new_item = Item(id=_item_id_counter, **item.model_dump())
    _items[_item_id_counter] = new_item
    return new_item


@app.get("/items", response_model=list[Item], tags=["项目"])
async def list_items():
    """列出所有项目。"""
    return list(_items.values())


@app.get("/items/{item_id}", response_model=Item, tags=["项目"])
async def get_item(item_id: int):
    """获取单个项目。

    Args:
        item_id: 项目 ID

    Raises:
        HTTPException: 项目不存在时返回 404
    """
    if item_id not in _items:
        raise HTTPException(status_code=404, detail="Item not found")
    return _items[item_id]