// ==UserScript==
// @name         EyeWire II - UI Guard
// @namespace    local.eyewire.ui
// @version      1.0.0
// @description  Fixed segment legend and persistent manual-only Selection Details.
// @match        https://eyewire-ii-community-dot-brain-wire-dot-seung-lab.ue.r.appspot.com/*
// @run-at       document-start
// @grant        none
// ==/UserScript==

(() => {
  'use strict';

  const LEGEND = '.nge-seg-legend';

  const PANEL =
    '.neuroglancer-side-panel.neuroglancer-selection-details';

  const CLOSE =
    '.neuroglancer-icon[title="Close panel"]';

  const SETTINGS =
    'button.nge-settings-advanced-btn';

  const STORAGE_KEY = 'ew-ui-guard-selection-closed';

  let legend = null;
  let legendPosition = null;

  // Restore the user's previous choice after refresh.
  // If Selection was manually closed, keep it locked.
  let selectionLocked = false;

  try {
    selectionLocked =
      localStorage.getItem(STORAGE_KEY) === 'true';
  } catch (error) {
    console.warn('[EW Guard] Storage unavailable:', error);
  }

  // Manual Settings opening remains allowed.
  let manualOpenUntil = 0;

  function saveSelectionLock(locked) {
    selectionLocked = locked;

    try {
      localStorage.setItem(
        STORAGE_KEY,
        locked ? 'true' : 'false'
      );
    } catch (error) {
      console.warn('[EW Guard] Could not save preference:', error);
    }
  }

  // =========================================================
  // 1. SEGMENT LEGEND — unchanged from working version
  // =========================================================

  function editingActive() {
    return !!document.querySelector(
      '.nge-split-merge-overlay, ' +
      '.graphene-merge-segments, ' +
      '.graphene-multicut'
    );
  }

  function findLegend() {
    const found = document.querySelector(LEGEND);
    if (!found || found === legend) return;
    legend = found;
    legendPosition = null;
  }

  function captureLegendPosition() {
    if (!legend || legendPosition || editingActive()) return;
    const rect = legend.getBoundingClientRect();
    if (rect.width < 10 || rect.height < 5) return;
    legendPosition = {
      left: rect.left,
      top: rect.top,
      width: rect.width
    };
    console.info('[EW Guard] Legend baseline:', legendPosition);
  }

  function anchorLegend() {
    if (!legend || !legendPosition) return;
    const p = legendPosition;
    legend.style.setProperty('position', 'fixed', 'important');
    legend.style.setProperty('left', `${p.left}px`, 'important');
    legend.style.setProperty('top', `${p.top}px`, 'important');
    legend.style.setProperty('bottom', 'auto', 'important');
    legend.style.setProperty('right', 'auto', 'important');
    legend.style.setProperty('width', `${p.width}px`, 'important');
    legend.style.setProperty('margin', '0', 'important');
    legend.style.setProperty('transform', 'none', 'important');
    legend.style.setProperty('transition', 'none', 'important');
    legend.style.setProperty('z-index', '1000', 'important');
  }

  // =========================================================
  // 2. MANUAL SELECTION OPEN / CLOSE
  // =========================================================

  function settingsButtonFrom(target) {
    if (!(target instanceof Element)) return null;

    const button = target.closest(SETTINGS);
    if (!button) return null;

    return /selection\s*details/i.test(
      button.textContent || ''
    ) ? button : null;
  }

  function closeButtonFrom(target) {
    if (!(target instanceof Element)) return null;
    return target.closest(`${PANEL} ${CLOSE}`);
  }

  function authorizeManualOpen() {
    // Allow the user to open Selection through Settings.
    // Do not erase the saved "keep closed" preference:
    // it should still apply after the next refresh.
    selectionLocked = false;

    manualOpenUntil = performance.now() + 2000;
  }

  function recordManualClose() {
    saveSelectionLock(true);
    manualOpenUntil = 0;
  }

  // Capture events before Neuroglancer's own handlers.
  document.addEventListener('pointerdown', event => {
    if (!event.isTrusted) return;

    if (settingsButtonFrom(event.target)) {
      authorizeManualOpen();
    } else if (closeButtonFrom(event.target)) {
      recordManualClose();
    }
  }, true);

  document.addEventListener('click', event => {
    if (!event.isTrusted) return;

    if (settingsButtonFrom(event.target)) {
      authorizeManualOpen();
    } else if (closeButtonFrom(event.target)) {
      recordManualClose();
    }
  }, true);

  document.addEventListener('keydown', event => {
    if (!event.isTrusted) return;

    if (event.key !== 'Enter' && event.key !== ' ') return;

    if (settingsButtonFrom(event.target)) {
      authorizeManualOpen();
    } else if (closeButtonFrom(event.target)) {
      recordManualClose();
    }
  }, true);

  // =========================================================
  // 3. BLOCK UNWANTED SELECTION PANEL INSERTION
  // =========================================================

  function containsSelectionPanel(node) {
    if (!(node instanceof Element)) return false;

    return (
      node.matches(PANEL) ||
      !!node.querySelector(PANEL)
    );
  }

  function shouldBlock(node, receiver) {
    if (!selectionLocked) return false;

    if (performance.now() < manualOpenUntil) {
      return false;
    }

    if (!containsSelectionPanel(node)) {
      return false;
    }

    const parent =
      receiver instanceof Element
        ? receiver
        : null;

    if (!parent) return false;

    return (
      parent.matches('.neuroglancer-side-panel-column') ||
      !!parent.closest('.neuroglancer-side-panel-column')
    );
  }

  const originalInsertBefore = Node.prototype.insertBefore;

  Node.prototype.insertBefore = function(node, reference) {
    if (shouldBlock(node, this)) {
      return node;
    }

    return originalInsertBefore.call(this, node, reference);
  };

  const originalAppendChild = Node.prototype.appendChild;

  Node.prototype.appendChild = function(node) {
    if (shouldBlock(node, this)) {
      return node;
    }

    return originalAppendChild.call(this, node);
  };

  // =========================================================
  // 4. LEGEND WATCHER
  // =========================================================

  let updatePending = false;

  function update() {
    if (updatePending) return;
    updatePending = true;

    requestAnimationFrame(() => {
      updatePending = false;
      findLegend();
      captureLegendPosition();
      anchorLegend();
    });
  }

  function start() {
    const observer = new MutationObserver(update);

    observer.observe(document.documentElement, {
      childList: true,
      subtree: true
    });

    update();

    setInterval(update, 500);
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', start, {
      once: true
    });
  } else {
    start();
  }
})();