Figma Swap Theme Token.js

// how might this work outside of the local library? It looks like we may need to auth with and use the REST API todo this the most effcient way.
// This possibly means hardcoding the auth key in this plugin. It's private so that might be okay(?). We could ask for it up front but that seems counter productive https://www.figma.com/developers/api#get-file-styles-endpoint

const localStyles = figma.getLocalPaintStyles();
const selectedNodes = figma.currentPage.selection;

if (selectedNodes.length === 0) {
  figma.notify("Nothing was selected...");
  figma.closePlugin();
}

const getSwappedStyle = (style: PaintStyle) => {
  const [_, currentTheme] = style.name.split("/");
  const newTheme = currentTheme === "dark" ? "light" : "dark";
  const newStyleName = style.name.replace(currentTheme, newTheme);
  const newStyle = localStyles.find((style) => style.name === newStyleName);

  return newStyle;
};

const swapTheme = (node: any) => {
  console.log(node.type);

  // Is this node a variant instance component?
  if (node.type === "INSTANCE") {
    // Does it have the `theme` property? If not then its not a themable variant
    if (node.variantProperties && node.variantProperties["theme"]) {
      console.log(node.variantProperties["theme"]);
      const currentTheme = node.variantProperties["theme"].toLowerCase();
      const newTheme = currentTheme === "dark" ? "light" : "dark";

      // The node may not have another theme to switch to (if only dark or light is a property value on the component)
      // This will throw an error currently
      node.setProperties({ theme: newTheme });
    } else {
      forAllChildren(node);
    }
    return;
  } else {
    // Not a variant, so walk the tree instead (slower)
    const fillStyle = localStyles.find(
      (style) => style.id === node.fillStyleId
    );

    const strokeStyle = localStyles.find(
      (style) => style.id === node.strokeStyleId
    );

    if (fillStyle && fillStyle.name.startsWith("themes/")) {
      const newFillStyle = getSwappedStyle(fillStyle);
      if (newFillStyle) node.fillStyleId = newFillStyle.id;
    }

    if (strokeStyle && strokeStyle.name.startsWith("themes/")) {
      const newStrokeStyle = getSwappedStyle(strokeStyle);
      if (newStrokeStyle) node.strokeStyleId = newStrokeStyle.id;
    }
  }

  forAllChildren(node);
};

const forAllChildren = (node: any) => {
  if (node.children) {
    node.children.forEach((child) => {
      swapTheme(child);
    });
  }
};

try {
  selectedNodes.forEach((node: any) => swapTheme(node));
} catch (err) {
  console.log(err);
}

figma.closePlugin();