/*
 * notion-enhancer core: api
 * (c) 2021 dragonwocky <thedragonring.bod@gmail.com> (https://dragonwocky.me/)
 * (c) 2021 CloudHill <rl.cloudhill@gmail.com> (https://github.com/CloudHill)
 * (https://notion-enhancer.github.io/) under the MIT license
 */

'use strict';

/**
 * shared notion-style elements
 * @module notion-enhancer/api/components/side-panel
 */

import { fmt, web, components, registry } from '../_.mjs';
const db = await registry.db('36a2ffc9-27ff-480e-84a7-c7700a7d232d');

web.loadStylesheet('api/components/panel.css');

const _views = [],
  svgExpand = web.raw`<svg viewBox="-1 -1 9 11">
  <path d="M 3.5 0L 3.98809 -0.569442L 3.5 -0.987808L 3.01191 -0.569442L 3.5 0ZM 3.5 9L 3.01191
    9.56944L 3.5 9.98781L 3.98809 9.56944L 3.5 9ZM 0.488094 3.56944L 3.98809 0.569442L 3.01191
    -0.569442L -0.488094 2.43056L 0.488094 3.56944ZM 3.01191 0.569442L 6.51191 3.56944L 7.48809
    2.43056L 3.98809 -0.569442L 3.01191 0.569442ZM -0.488094 6.56944L 3.01191 9.56944L 3.98809
    8.43056L 0.488094 5.43056L -0.488094 6.56944ZM 3.98809 9.56944L 7.48809 6.56944L 6.51191
    5.43056L 3.01191 8.43056L 3.98809 9.56944Z"></path>
</svg>`;

// open + close
let $notionFrame,
  $notionRightSidebar,
  // resize
  dragStartX,
  dragStartWidth,
  dragEventsFired,
  panelWidth,
  // render content
  $notionApp;

// open + close
const $panel = web.html`<div id="enhancer--panel"></div>`,
  $pinnedToggle = web.html`<div id="enhancer--panel-header-toggle" tabindex="0"><div>
    ${await components.feather('chevrons-right')}
  </div></div>`,
  $hoverTrigger = web.html`<div id="enhancer--panel-hover-trigger"></div>`,
  panelPinnedAttr = 'data-enhancer-panel-pinned',
  isPinned = () => $panel.hasAttribute(panelPinnedAttr),
  togglePanel = () => {
    const $elems = [$notionFrame, $notionRightSidebar, $hoverTrigger, $panel].filter(
      ($el) => $el
    );
    if (isPinned()) {
      closeSwitcher();
      for (const $elem of $elems) $elem.removeAttribute(panelPinnedAttr);
    } else {
      for (const $elem of $elems) $elem.setAttribute(panelPinnedAttr, 'true');
    }
    db.set(['panel.pinned'], isPinned());
  },
  // resize
  $resizeHandle = web.html`<div id="enhancer--panel-resize"><div></div></div>`,
  updateWidth = async () => {
    document.documentElement.style.setProperty('--component--panel-width', panelWidth + 'px');
    db.set(['panel.width'], panelWidth);
  },
  resizeDrag = (event) => {
    event.preventDefault();
    dragEventsFired = true;
    panelWidth = dragStartWidth + (dragStartX - event.clientX);
    if (panelWidth < 190) panelWidth = 190;
    if (panelWidth > 480) panelWidth = 480;
    $panel.style.width = panelWidth + 'px';
    $hoverTrigger.style.width = panelWidth + 'px';
    $notionFrame.style.paddingRight = panelWidth + 'px';
    $notionRightSidebar.style.right = panelWidth + 'px';
  },
  resizeEnd = (event) => {
    $panel.style.width = '';
    $hoverTrigger.style.width = '';
    $notionFrame.style.paddingRight = '';
    $notionRightSidebar.style.right = '';
    updateWidth();
    $resizeHandle.style.cursor = '';
    document.body.removeEventListener('mousemove', resizeDrag);
    document.body.removeEventListener('mouseup', resizeEnd);
  },
  resizeStart = (event) => {
    dragStartX = event.clientX;
    dragStartWidth = panelWidth;
    $resizeHandle.style.cursor = 'auto';
    document.body.addEventListener('mousemove', resizeDrag);
    document.body.addEventListener('mouseup', resizeEnd);
  },
  // render content
  $panelTitle = web.html`<div id="enhancer--panel-header-title"></div>`,
  $header = web.render(web.html`<div id="enhancer--panel-header"></div>`, $panelTitle),
  $panelContent = web.html`<div id="enhancer--panel-content"></div>`,
  $switcher = web.html`<div id="enhancer--panel-switcher"></div>`,
  $switcherTrigger = web.html`<div id="enhancer--panel-header-switcher" tabindex="0">
    ${svgExpand}
  </div>`,
  $switcherOverlayContainer = web.html`<div id="enhancer--panel-switcher-overlay-container"></div>`,
  isSwitcherOpen = () => document.body.contains($switcher),
  openSwitcher = () => {
    if (!isPinned()) return togglePanel();
    web.render($notionApp, $switcherOverlayContainer);
    web.empty($switcher);
    for (const view of _views) {
      const open = $panelTitle.contains(view.$title),
        $item = web.render(
          web.html`<div class="enhancer--panel-switcher-item" tabindex="0" ${
            open ? 'data-open' : ''
          }></div>`,
          web.render(
            web.html`<span class="enhancer--panel-view-title"></span>`,
            view.$icon.cloneNode(true),
            view.$title.cloneNode(true)
          )
        );
      $item.addEventListener('click', () => {
        renderView(view);
        db.set(['panel.open'], view.id);
      });
      web.render($switcher, $item);
    }
    const rect = $header.getBoundingClientRect();
    web.render(
      web.empty($switcherOverlayContainer),
      web.render(
        web.html`<div style="position: fixed; top: ${rect.top}px; left: ${rect.left}px;
              width: ${rect.width}px; height: ${rect.height}px;"></div>`,
        web.render(
          web.html`<div style="position: relative; top: 100%; pointer-events: auto;"></div>`,
          $switcher
        )
      )
    );
    $switcher.querySelector('[data-open]').focus();
    $switcher.animate([{ opacity: 0 }, { opacity: 1 }], { duration: 200 });
    document.addEventListener('keydown', switcherKeyListeners);
  },
  closeSwitcher = () => {
    document.removeEventListener('keydown', switcherKeyListeners);
    $switcher.animate([{ opacity: 1 }, { opacity: 0 }], { duration: 200 }).onfinish = () =>
      $switcherOverlayContainer.remove();
  },
  switcherKeyListeners = (event) => {
    if (isSwitcherOpen()) {
      switch (event.key) {
        case 'Escape':
          closeSwitcher();
          event.stopPropagation();
          break;
        case 'Enter':
          document.activeElement.click();
          event.stopPropagation();
          break;
        case 'ArrowUp':
          const $prev = event.target.previousElementSibling;
          ($prev || event.target.parentElement.lastElementChild).focus();
          event.stopPropagation();
          break;
        case 'ArrowDown':
          const $next = event.target.nextElementSibling;
          ($next || event.target.parentElement.firstElementChild).focus();
          event.stopPropagation();
          break;
      }
    }
  },
  renderView = (view) => {
    const prevView = _views.find(({ $content }) => document.contains($content));
    web.render(
      web.empty($panelTitle),
      web.render(
        web.html`<span class="enhancer--panel-view-title"></span>`,
        view.$icon,
        view.$title
      )
    );
    view.onFocus();
    web.render(web.empty($panelContent), view.$content);
    if (prevView) prevView.onBlur();
  };

async function createPanel() {
  await web.whenReady(['.notion-frame']);
  $notionFrame = document.querySelector('.notion-frame');

  const notionRightSidebarSelector = '.notion-cursor-listener > div[style*="flex-end"]',
    detectRightSidebar = () => {
      if (!document.contains($notionRightSidebar)) {
        $notionRightSidebar = document.querySelector(notionRightSidebarSelector);
        if (isPinned() && $notionRightSidebar) {
          $notionRightSidebar.setAttribute(panelPinnedAttr, 'true');
        }
      }
    };
  $notionRightSidebar = document.querySelector(notionRightSidebarSelector);
  web.addDocumentObserver(detectRightSidebar, [notionRightSidebarSelector]);

  if (await db.get(['panel.pinned'])) togglePanel();
  web.addHotkeyListener(await db.get(['panel.hotkey']), togglePanel);
  $pinnedToggle.addEventListener('click', (event) => {
    event.stopPropagation();
    togglePanel();
  });
  web.render(
    $panel,
    web.render($header, $panelTitle, $switcherTrigger, $pinnedToggle),
    $panelContent,
    $resizeHandle
  );

  await enablePanelResize();
  await createViews();

  const cursorListenerSelector =
    '.notion-cursor-listener > :last-child[style^="position: absolute"]';
  await web.whenReady([cursorListenerSelector]);
  document.querySelector(cursorListenerSelector).before($hoverTrigger, $panel);
}

async function enablePanelResize() {
  panelWidth = await db.get(['panel.width'], 240);
  updateWidth();
  $resizeHandle.addEventListener('mousedown', resizeStart);
  $resizeHandle.addEventListener('click', () => {
    if (dragEventsFired) {
      dragEventsFired = false;
    } else togglePanel();
  });
}

async function createViews() {
  $notionApp = document.querySelector('.notion-app-inner');
  $header.addEventListener('click', openSwitcher);
  $switcherTrigger.addEventListener('click', openSwitcher);
  $switcherOverlayContainer.addEventListener('click', closeSwitcher);
}

/**
 * adds a view to the enhancer's side panel
 * @param {object} panel - information used to construct and render the panel
 * @param {string} panel.id - a uuid, used to restore the last open view on reload
 * @param {string} panel.icon - an svg string
 * @param {string} panel.title - the name of the view
 * @param {Element} panel.$content - an element containing the content of the view
 * @param {function} panel.onBlur - runs when the view is selected/focused
 * @param {function} panel.onFocus - runs when the view is unfocused/closed
 */
export const addPanelView = async ({
  id,
  icon,
  title,
  $content,
  onFocus = () => {},
  onBlur = () => {},
}) => {
  const view = {
    id,
    $icon: web.render(
      web.html`<span class="enhancer--panel-view-title-icon"></span>`,
      icon instanceof Element ? icon : web.html`${icon}`
    ),
    $title: web.render(
      web.html`<span class="enhancer--panel-view-title-text"></span>`,
      title,
      web.html`<span class="enhancer--panel-view-title-fade-edge"></span>`
    ),
    $content,
    onFocus,
    onBlur,
  };
  _views.push(view);
  if (_views.length === 1) await createPanel();
  if (_views.length === 1 || (await db.get(['panel.open'])) === id) renderView(view);
};