"""在大屏副本上更新画布属性，检查修改后的 Canvas 是否有效"""

from copy import deepcopy

from app.actions.base import BaseActionHandler
from app.schemas.actions import UpdateCanvasAction
from app.schemas.screen import Canvas, Screen


class UpdateCanvasHandler(BaseActionHandler[UpdateCanvasAction]):
    def apply(self, screen: Screen, action: UpdateCanvasAction) -> Screen:
        # 将现有画布转成字典，保留动作没有指定的字段；没写过的主题、背景色不补成 null
        properties = screen.canvas.model_dump(exclude_unset=True)
        # 顶层字段整体替换，嵌套对象不做深度合并
        properties.update(deepcopy(action.properties))
        # 校验合并后的画布属性，尺寸等字段不合法时直接抛出异常
        canvas = Canvas.model_validate(properties)
        # 深拷贝大屏后替换画布，避免修改原始快照
        result = screen.model_copy(deep=True)
        result.canvas = canvas

        # 返回包含新画布属性的完整大屏副本
        return result


if __name__ == "__main__":
    screen = Screen.model_validate(
        {"canvas": {"width": 1920, "height": 1080}, "nodes": []}
    )
    action = UpdateCanvasAction(
        properties={"backgroundColor": "#000000", "width": 1600}
    )
    result = UpdateCanvasHandler().apply(screen, action)
    print(result.model_dump_json(indent=2))
    print("原始画布:", screen.canvas.model_dump())