import addon from "../utils/addon";
import { QWidget } from "../QtWidgets/QWidget";
import { QLayout, QLayoutSignals } from "../QtWidgets/QLayout";
import { FlexNode } from "./YogaWidget";

export type FlexLayoutSignals = QLayoutSignals;

/**

> Custom layout to help layout child widgets using flex layout.

* **This class is a JS wrapper around custom Qt layout implemented using [Yoga](https://github.com/facebook/yoga)**

A `FlexLayout` can be used to layout all child Vixen widgets using flex.

### Example

```javascript
import { FlexLayout, QWidget, QLabel } from "@vixen-js/core";

const view = new QWidget();
const layout = new FlexLayout();
view.setLayout(layout);

const label = new QLabel();
label.setText("label1");
const label2 = new QLabel();
label2.setText("label2");

layout.addWidget(label);
layout.addWidget(label2);
```
 */
export class FlexLayout extends QLayout<FlexLayoutSignals> {
  protected flexNode?: FlexNode;

  constructor(parent?: QWidget) {
    let native;
    if (parent) {
      native = new addon.FlexLayout(parent.native);
    } else {
      native = new addon.FlexLayout();
    }
    super(native);
    if (parent) {
      this.setFlexNode(parent.getFlexNode());
    }
  }

  addWidget(childWidget: QWidget, childFlexNode?: FlexNode): void {
    const childYogaNode = childFlexNode || childWidget.getFlexNode();
    if (this.children().includes(childWidget)) {
      this.removeWidget(childWidget, childYogaNode);
    }
    this.native?.addWidget(childWidget.native, childYogaNode);
  }

  insertChildBefore(
    childWidget: QWidget,
    beforeChildWidget: QWidget,
    childFlexNode?: FlexNode,
    beforeChildFlexNode?: FlexNode
  ): void {
    const childYogaNode = childFlexNode || childWidget.getFlexNode();
    if (this.children().includes(childWidget)) {
      this.removeWidget(childWidget, childYogaNode);
    }
    const beforeChildYogaNode =
      beforeChildFlexNode || beforeChildWidget.getFlexNode();
    this.native?.insertChildBefore(
      childWidget.native,
      beforeChildYogaNode,
      childYogaNode
    );
  }

  removeWidget(childWidget: QWidget, childFlexNode?: FlexNode): void {
    const childYogaNode = childFlexNode || childWidget.getFlexNode();
    this.native?.removeWidget(childWidget.native, childYogaNode);
  }

  setFlexNode(flexNode: FlexNode): void {
    this.flexNode = flexNode;
    this.native?.setFlexNode(flexNode);
  }

  getChildIndex(childWidget: QWidget): number {
    return this.children().indexOf(childWidget);
  }

  getNextSibling(childWidget: QWidget): QWidget | null {
    const childIndex = this.getChildIndex(childWidget);
    const widgetArr = this.children();
    if (childIndex !== -1) {
      return (widgetArr[childIndex + 1] as QWidget) || null;
    }
    return null;
  }
}