import { AdapterState } from "./adapter"

class HistoryNode {
  id: string;
  type: string;
  prev: HistoryNode | null = null;
  next: HistoryNode | null = null;
  
  constructor(id: string, type: string) {
    this.id = id;
    this.type = type;
  }
}

export class NavigatorElement extends HTMLElement {
  static observedAttributes = [ "data-author", "data-message" ];
  
  private _adapter: string = "";
  private _history: HistoryNode | null = null;
  private _replyWith: string | null = null;
  private _gateway: string = "";
  constructor() {
    super();
    this.innerHTML = `<nav><button class="nav_prev">&larr;</button><button class="nav_next">&rarr;</button><button class="nav_clear">&times;</button></nav><div class="nav_container"></div>`
  }
  
  connectedCallback() {
    this._adapter = this.getAttribute("data-adapter") ?? "";
    this._replyWith = this.getAttribute("data-replywith");
    this._gateway = this.getAttribute("data-gateway") ?? "";
  
    const prevBtn = this.querySelector(".nav_prev");
    const nextBtn = this.querySelector(".nav_next");
    const clearBtn = this.querySelector(".nav_clear");
    
    if (prevBtn) {
      prevBtn.addEventListener("click", this.goPrev);
    }
    if (nextBtn) {
      nextBtn.addEventListener("click", this.goNext);
    }
    if (clearBtn) {
      clearBtn.addEventListener("click", this.clear);
    }
  }
  
  attributeChangedCallback(attr: string, prev: string, next: string) {
    switch (attr) {
      case "data-author":
      case "data-message":
        if (next == prev) {
          return;
        }
        if (this._history && this._history.prev && this._history.prev.id == next) {
          this._history = this._history.prev;
        } else {
          const h = this._history;
          this._history = new HistoryNode(next, attr.slice(attr.indexOf("-") + 1));
          this._history.prev = h;
        }
        const panel = this.querySelector(".nav_container");
        const datastore = AdapterState._instance.data.get(this._adapter);
        if (datastore && panel) {
          switch (attr) {
            case "data-author":
              const author = datastore.profileCache.get(next);
              panel.innerHTML = `<underbbs-profile data-gateway="${this._gateway}" data-adapter="${this._adapter}" data-target="${next}"></underbbs-profile><underbbs-timeline data-gateway="${this._gateway}" data-target="${next}" data-adapter="${this._adapter}" data-interactable data-mode="fetch" data-inspectwith="${this.getAttribute("id")??""}" data-replywith="${this._replyWith}"></underbbs-timeline>`
              
              const profile = this.querySelector("underbbs-profile");
              const tl = this.querySelector("underbbs-timeline");
              if (profile && tl) {
                if (!author) {
                  profile.setAttribute("data-target", next);
                } else {
                  profile.setAttribute("data-latest", next);
                }
                tl.setAttribute("data-target", next);
              }
              break;
            case "data-message":
              const msg = datastore.messages.get(next);
              panel.innerHTML = `<underbbs-message  data-gateway="${this._gateway}" data-adapter="${this._adapter}" data-target="${next}" data-interactable data-inspectwith="${this.getAttribute("id")??""}" data-replywith="${this._replyWith}"></underbbs-message>`
              const e = this.querySelector("underbbs-message");
              if (e) {
                if (!msg) {
                  e.setAttribute("data-target", next);
                } else {
                  e.setAttribute("data-latest", next);
                }
              }
              break;
        
          }
          
        }
        
    }
  }
  
  private goNext() {
  }
  
  private goPrev() {
  }
  
  private clear() {
  }
}