import { onWillUnmount } from "./lifecycle_hooks";
import { BDom, text, VNode } from "./blockdom";
import { Component } from "./component";

const VText: any = text("").constructor;

class VPortal extends VText implements Partial<VNode<VPortal>> {
  //   selector: string;
  realBDom: BDom | null;
  target: HTMLElement | null = null;

  constructor(selector: string, realBDom: BDom) {
    super("");
    this.selector = selector;
    this.realBDom = realBDom;
  }
  mount(parent: HTMLElement, anchor: ChildNode) {
    super.mount(parent, anchor);
    this.target = document.querySelector(this.selector) as any;
    if (!this.target) {
      let el: any = this.el;
      while (el && el.parentElement instanceof HTMLElement) {
        el = el.parentElement;
      }
      this.target = el && el.querySelector(this.selector);
      if (!this.target) {
        throw new Error("invalid portal target");
      }
    }
    this.realBDom!.mount(this.target!, null);
  }

  beforeRemove() {
    this.realBDom!.beforeRemove();
  }
  remove() {
    if (this.realBDom) {
      super.remove();
      this.realBDom!.remove();
      this.realBDom = null;
    }
  }

  patch(other: VPortal) {
    super.patch(other);
    if (this.realBDom) {
      this.realBDom.patch(other.realBDom!, true);
    } else {
      this.realBDom = other.realBDom;
      this.realBDom!.mount(this.target!, null);
    }
  }
}

/**
 * <t t-slot="default"/>
 */
export function portalTemplate(app: any, bdom: any, helpers: any) {
  let { callSlot } = helpers;
  return function template(ctx: any, node: any, key = "") {
    return callSlot(ctx, node, key, "default", false, null);
  };
}

export class Portal extends Component {
  static template = "__portal__";
  static props = {
    target: {
      type: String,
    },
    slots: true,
  };

  setup() {
    const node = this.__owl__;
    const renderFn = node.renderFn;
    node.renderFn = () => new VPortal(this.props.target, renderFn());
    onWillUnmount(() => {
      if (node.bdom) {
        node.bdom.remove();
      }
    });
  }
}