import { LitElement, html, css, unsafeCSS } from 'lit-element';
import { wrapCss } from './misc';

import { unsafeHTML } from 'lit-html/directives/unsafe-html';
import marked from 'marked';

import { getTS, getReplayLink } from './pageutils';

import Split from 'split.js'



// ===========================================================================
class Story extends LitElement
{
  constructor() {
    super();

    this.collInfo = null;

    this.curatedPageMap = {};

    this.currList = 0;

    this.active = false;

    this.lastST = 0;
    this.clickTime = 0;

    this.isSidebar = false;
    this.splitDirection = false;
  }

  static get properties() {
    return {
      collInfo: { type: Object },

      active: { type: Boolean },

      curatedPageMap: { type: Object },

      currList: { type: Number },

      isSidebar: { type: Boolean },
      splitDirection: { type: Boolean }
    }
  }

  recalcSplitter(width) {
    this.splitDirection = this.isSidebar || width < 769 ? "vertical" : "horizontal";
  }

  firstUpdated() {
    this.recalcSplitter(document.documentElement.clientWidth);

    this.obs = new ResizeObserver((entries, observer) => {
      this.recalcSplitter(entries[0].contentRect.width);
    });

    this.obs.observe(this)
  }

  updated(changedProperties) {
    if (changedProperties.has("collInfo")) {
      this.doLoadCurated();
    }

    if (changedProperties.has("collInfo") || changedProperties.has("isSidebar")) {
      this.recalcSplitter(document.documentElement.clientWidth);
    }

    if (changedProperties.has("splitDirection")) {
      this.configureSplitter();
    }

    if (changedProperties.has("currList") && this.active) {
      this.sendChangeEvent({
        currList: this.currList,
      });
    }
  }

  configureSplitter() {
    const sidebar = this.renderRoot.querySelector(".sidebar");
    const content = this.renderRoot.querySelector(".main-content");

    if (this.splitter) {
      try {
        this.splitter.destroy();
      } catch (e) {}
      this.splitter = null;
    }

    if (sidebar && content && !this.splitter) {
      const opts = {
        sizes: [20, 80],

        gutterSize: 4,

        direction: this.splitDirection
      }

      this.splitter = Split([sidebar, content], opts);
    } 
  }

  async doLoadCurated() {
    this.curatedPageMap = {};

    const pageMap = {};

    for (const page of this.collInfo.pages) {
      pageMap[page.id] = page;
    }

    for (const curated of this.collInfo.curatedPages) {
      if (!this.curatedPageMap[curated.list]) {
        this.curatedPageMap[curated.list] = [];
      }
      const page = pageMap[curated.page];
      if (!page) {
        console.log("No Page with id: " + page);
        continue;
      }

      const url = page.url;
      const ts = page.ts;
      const title = page.title || page.url;
      const desc = curated.desc;

      this.curatedPageMap[curated.list].push({url, ts, title, desc});
    }

    this.scrollToList();
  }

  static get styles() {
    return wrapCss(css`
    :host {
      width: 100%;
      height: 100%;
      display: flex;
      flex-direction: column;
      min-width: 0px;

      justify-content: flex-start;
      align-items: center;
    }

    :host(.sidebar) .columns {
      display: flex !important;
      flex-direction: column;
    }

    :host(.sidebar) .column.sidebar.is-one-fifth {
      width: 100% !important;
    }

    ${Story.sidebarStyles(unsafeCSS(`:host(.sidebar)`))}

    .desc p {
      margin-bottom: 1.0em;
    }

    .columns {
      width: 100%;
      height: 100%;
      justify-self: stretch;
      margin: 1.0em 0 0 0 !important;
      min-height: 0;
    }

    .column.main-content {
      min-height: 0;
      display: flex;
      flex-direction: column;
      padding: 0px;
      margin-left: 0.75em;
    }

    .column.main-content.main-scroll {
      padding-right: 0.75em;
      word-break: break-all;
    }

    ul.menu-list a.is-active {
      background-color: #55be6f;
    }
    ol {
      margin-left: 30px;
    }

    @media screen and (min-width: 769px) {
      .columns {
        margin-top: 0.75em;
      }

      .column.sidebar {
        max-height: 100%;
        overflow-y: auto;
      }
    }

    @media screen and (max-width: 768px) {
      ${Story.sidebarStyles()}
    }

    .gutter.gutter-vertical:hover {
      cursor: row-resize;
    }

    .gutter.gutter-horizontal:hover {
      cursor: col-resize;
    }

    `);
  }

  static sidebarStyles(prefix = css``) {
    return css`
    ${prefix} .columns {
      position: relative;
    }

    ${prefix} .column.sidebar {
      overflow-y: auto;
      margin-top: 0.75em;
    }

    ${prefix} .column.main-content {
      position: relative;
      overflow-y: auto;

      border-top: 1px solid black;

      height: 100%;
    }

    ${prefix} .menu {
      font-size: 0.80rem;
    }`;
  }

  render() {
    const currListNum = this.currList;

    return html`
    <div class="is-sr-only" role="heading" aria-level="${this.isSidebar ? "2": "1"}">
      Story for ${this.collInfo.title}
    </div>
    <div class="columns">
      <div class="column sidebar is-one-fifth">
        <aside class="menu">
          <ul class="menu-list">
            <li>
              <a href="#list-0" data-list="0" class="${currListNum === 0 ? 'is-active' : ''} menu-label is-size-4"
                @click=${this.onClickScroll}>${this.collInfo.title}</a>
              <ul class="menu-list">${this.collInfo.lists.map(list => html`
                <li>
                  <a @click=${this.onClickScroll} href="#list-${list.id}"
                  data-list="${list.id}" 
                  class="${currListNum === list.id ? 'is-active' : ''}">${list.title}</a>
                </li>`)}
              </ul>
            </li>
          </ul>
        </aside>
      </div>
      <div @scroll=${this.onScroll} class="column main-content main-scroll">
        <section id="list-0" class="desc">
          <h2 class="has-text-centered title is-3">${this.collInfo.title}</h2>
          ${this.collInfo.desc ? unsafeHTML(marked(this.collInfo.desc)) : ''}
        </section>
        ${this.renderLists()}
      </div>
    </div>
  `;
  }

  renderLists() {
    return html`
    ${this.collInfo.lists.map((list, i) => html`
    <article id="list-${list.id}">
      <div class="content">
        <hr/>
        <h3>${list.title}</h3>
        <p>${list.desc}</p>
        <ol>
          ${this.curatedPageMap[list.id] ? this.curatedPageMap[list.id].map((p) => this.renderCPage(p)) : html``}
        </ol>
      </div>
    </article>
    `)}`;
  }

  renderCPage(p) {
    const date = new Date(p.ts);

    const ts = getTS(date.toISOString());

    return html`
    <li>
      <div class="content">
        <a @click="${this.onReplay}" data-url="${p.url}" data-ts="${ts}"
          href="${getReplayLink("story", p.url, ts)}">
          <p class="is-size-6 has-text-weight-bold has-text-link">${p.title}</p>
          <p class="has-text-dark">${p.url}</p>
        </a>
        <p>${date.toLocaleString()}</p>
        <p>${p.desc}</p>
      </div>
      <hr/>
    </li>`;
  }

  onReplay(event) {
    event.preventDefault();
    const data = {
      url: event.currentTarget.getAttribute("data-url"),
      ts: event.currentTarget.getAttribute("data-ts"),
    };
    this.sendChangeEvent(data);
    return false;
  }

  sendChangeEvent(data) {
    this.dispatchEvent(new CustomEvent("coll-tab-nav", {detail: {data}}));
  }

  onClickScroll(event) {
    event.preventDefault();
    //this.pageView = false;
    this.currList = Number(event.currentTarget.getAttribute("data-list"));
    this.scrollToList();
    return false;
  }

  scrollToList() {
    // lists are 1 based, 0 is header, 1 is first list
    if (this.currList > this.collInfo.lists.length) {
      this.currList = 0;
    }

    const opts = {behavior: "smooth", block: "nearest", inline: "nearest"};
    this.clickTime = new Date().getTime();
    const curr = this.renderRoot.getElementById("list-" + this.currList);
    if (curr) {
      curr.scrollIntoView(opts);
    }
  }

  onScroll(event) {
    const scrollable = event.currentTarget;
    const curr = this.renderRoot.getElementById("list-" + this.currList);

    if (!curr) {
      return;
    }

    let next = curr;
    const target = scrollable.offsetTop;
    const currST = scrollable.scrollTop;

    if (currST > this.lastST) {
      while (next.nextElementSibling && next.nextElementSibling.getBoundingClientRect().top < target) {
        next = next.nextElementSibling;
      }
    } else {
      while (next.previousElementSibling && next.previousElementSibling.getBoundingClientRect().bottom >= target) {
        next = next.previousElementSibling;
      }
    }
    this.lastST = currST;
    if (next && next != curr) {
      if (next.id.startsWith("list-")) {
        this.currList = Number(next.id.slice(5));
      }
    }

    if ((new Date().getTime() - this.clickTime) < 1000) {
      return;
    }

    const sel = this.renderRoot.querySelector(`a[data-list="${this.currList}"]`);
    if (sel) {
      const opts = {behavior: "smooth", block: "nearest", inline: "nearest"};
      sel.scrollIntoView(opts);
    }
  }
}

customElements.define("wr-coll-story", Story);

export { Story };