"""在大屏 JSON 副本上新增组件，用于后端校验动作能否执行"""

from app.actions.base import BaseActionHandler
from app.schemas.actions import AddAction
from app.schemas.screen import Screen, ScreenNode


class AddHandler(BaseActionHandler[AddAction]):
    def apply(self, screen: Screen, action: AddAction) -> Screen:
        # 重新校验节点，避免模型创建后被修改成无效内容
        node = ScreenNode.model_validate(action.node.model_dump())

        # 如果新节点 ID 与已有组件重复，拒绝新增，避免后续按 ID 查找时产生歧义
        if any(existing.id == node.id for existing in screen.nodes):
            raise ValueError(f"新增组件 ID 已存在: {node.id}")

        # 深拷贝整个大屏，新增操作只影响返回的副本
        result = screen.model_copy(deep=True)
        # 追加到末尾，不共享动作中的嵌套配置
        result.nodes.append(node.model_copy(deep=True))

        # 返回新增后的完整大屏，供后续动作继续模拟执行
        return result


if __name__ == "__main__":
    screen = Screen.model_validate(
        {"canvas": {"width": 1920, "height": 1080}, "nodes": []}
    )
    action = AddAction.model_validate(
        {
            "type": "add",
            "node": {
                "id": "screen-title",
                "type": "text",
                "layout": {"x": 100, "y": 50, "width": 400, "height": 60},
                "props": {},
            },
        }
    )
    handler = AddHandler()
    final_screen = handler.apply(screen, action)
    print(final_screen.model_dump_json(indent=2))
    print("原始组件数:", len(screen.nodes))
    try:
        handler.apply(final_screen, action)
    except ValueError as error:
        print("重复新增:", error)