// The root interpreter class that holds state about the mapping between DOM and VirtualDom
// This always lives in the JS side of things, and is extended by the native and web interpreters

import { setAttributeInner } from "./set_attribute";

export type NodeId = number;

export class BaseInterpreter {
  // non bubbling events listen at the element the listener was created at
  global: {
    [key: string]: { active: number, callback: EventListener }
  };
  // bubbling events can listen at the root element
  local: {
    [key: string]: {
      [key: string]: EventListener
    }
  };

  root: HTMLElement;
  handler: EventListener;
  nodes: Node[];
  stack: Node[];
  templates: {
    [key: string]: Node[]
  };

  // sledgehammer is generating this...
  m: any;

  constructor(root: HTMLElement, handler: EventListener) {
    this.handler = handler;
    this.initialize(root);
  }

  initialize(root: HTMLElement, handler: EventListener | null = null) {
    this.global = {};
    this.local = {};
    this.root = root;

    this.nodes = [root];
    this.stack = [root];
    this.templates = {};

    if (handler) {
      this.handler = handler;
    }
  }

  createListener(event_name: string, element: HTMLElement, bubbles: boolean) {
    if (bubbles) {
      if (this.global[event_name] === undefined) {
        this.global[event_name] = { active: 1, callback: this.handler };
        this.root.addEventListener(event_name, this.handler);
      } else {
        this.global[event_name].active++;
      }
    } else {
      const id = element.getAttribute("data-dioxus-id");
      if (!this.local[id]) {
        this.local[id] = {};
      }
      element.addEventListener(event_name, this.handler);
    }
  }

  removeListener(element: HTMLElement, event_name: string, bubbles: boolean) {
    if (bubbles) {
      this.removeBubblingListener(event_name);
    } else {
      this.removeNonBubblingListener(element, event_name);
    }
  }

  removeBubblingListener(event_name: string) {
    this.global[event_name].active--;
    if (this.global[event_name].active === 0) {
      this.root.removeEventListener(event_name, this.global[event_name].callback);
      delete this.global[event_name];
    }
  }

  removeNonBubblingListener(element: HTMLElement, event_name: string) {
    const id = element.getAttribute("data-dioxus-id");
    delete this.local[id][event_name];
    if (Object.keys(this.local[id]).length === 0) {
      delete this.local[id];
    }
    element.removeEventListener(event_name, this.handler);
  }

  removeAllNonBubblingListeners(element: HTMLElement) {
    const id = element.getAttribute("data-dioxus-id");
    delete this.local[id];
  }

  getNode(id: NodeId): Node {
    return this.nodes[id];
  }

  appendChildren(id: NodeId, many: number) {
    const root = this.nodes[id];
    const els = this.stack.splice(this.stack.length - many);
    for (let k = 0; k < many; k++) {
      root.appendChild(els[k]);
    }
  }

  loadChild(ptr: number, len: number): Node {
    // iterate through each number and get that child
    let node = this.stack[this.stack.length - 1] as Node;
    let ptr_end = ptr + len;

    for (; ptr < ptr_end; ptr++) {
      let end = this.m.getUint8(ptr);
      for (node = node.firstChild; end > 0; end--) {
        node = node.nextSibling;
      }
    }

    return node;
  }

  saveTemplate(nodes: HTMLElement[], tmpl_id: string) {
    this.templates[tmpl_id] = nodes;
  }

  hydrateRoot(ids: { [key: number]: number }) {
    const hydrateNodes = document.querySelectorAll('[data-node-hydration]');

    for (let i = 0; i < hydrateNodes.length; i++) {
      const hydrateNode = hydrateNodes[i] as HTMLElement;
      const hydration = hydrateNode.getAttribute('data-node-hydration');
      const split = hydration!.split(',');
      const id = ids[parseInt(split[0])];

      this.nodes[id] = hydrateNode;

      if (split.length > 1) {
        // @ts-ignore
        hydrateNode.listening = split.length - 1;
        hydrateNode.setAttribute('data-dioxus-id', id.toString());
        for (let j = 1; j < split.length; j++) {
          const listener = split[j];
          const split2 = listener.split(':');
          const event_name = split2[0];
          const bubbles = split2[1] === '1';
          this.createListener(event_name, hydrateNode, bubbles);
        }
      }
    }

    const treeWalker = document.createTreeWalker(
      document.body,
      NodeFilter.SHOW_COMMENT,
    );

    let currentNode = treeWalker.nextNode();

    while (currentNode) {
      const id = currentNode.textContent!;
      const split = id.split('node-id');

      if (split.length > 1) {
        this.nodes[ids[parseInt(split[1])]] = currentNode.nextSibling;
      }

      currentNode = treeWalker.nextNode();
    }
  }

  setAttributeInner(node: HTMLElement, field: string, value: string, ns: string) {
    setAttributeInner(node, field, value, ns);
  }
}