// ==UserScript==
// @name         Neuroglancer Auto Import Settings
// @namespace    eyewire-elite
// @version      2.2.0
// @description  Safely auto-imports named Neuroglancer presets on newly opened links after the viewer stabilizes, but never on refresh.
// @match        https://spelunker.cave-explorer.org/*
// @run-at       document-idle
// @grant        unsafeWindow
// ==/UserScript==

(function () {
  'use strict';


  const CONFIG = Object.freeze({
    /*
     * API exposed by the matched Import/export settings script.
     */
    importerApiName:
      'NGSettingsPresets',

    /*
     * New three-slot storage.
     */
    settingsStorageKey:
      'ng-settings-3-slots',

    /*
     * Never import immediately.
     */
    minimumWaitMilliseconds:
      3000,

    /*
     * Viewer state must remain unchanged
     * for this long.
     */
    requiredStableMilliseconds:
      2500,

    /*
     * How often readiness is checked.
     */
    checkIntervalMilliseconds:
      250,

    /*
     * Stop waiting for the actual viewer
     * after this amount of time.
     */
    maximumWaitMilliseconds:
      45000,

    /*
     * Once the viewer is stable, give the
     * Import/Export userscript a little extra
     * time to expose its API if necessary.
     */
    importerApiWaitMilliseconds:
      5000
  });


  // ==========================================================================
  // RELOAD PROTECTION
  // ==========================================================================

  /*
   * Never auto-import after:
   *
   * - F5
   * - Ctrl+F5
   * - Ctrl+R
   * - browser Reload button
   *
   * A genuinely newly opened link is allowed.
   */
  if (
    isReloadNavigation()
  ) {
    console.log(
      '[Auto import] Page reload detected. Automatic settings import skipped.'
    );

    return;
  }


  // ==========================================================================
  // SAVED-PRESET CHECK
  // ==========================================================================

  /*
   * Look specifically for the new three-slot store.
   *
   * The Import/Export script itself handles migration
   * from old ng-settings if needed.
   */
  if (
    !hasSavedPresets()
  ) {
    console.log(
      '[Auto import] No saved named presets found. Viewer will remain unchanged.'
    );

    return;
  }


  const startedAt =
    performance.now();

  let lastSnapshot =
    null;

  let stableSince =
    null;

  let importTriggered =
    false;


  const intervalId =
    window.setInterval(
      checkViewer,
      CONFIG
        .checkIntervalMilliseconds
    );


  // ==========================================================================
  // NAVIGATION TYPE
  // ==========================================================================

  function isReloadNavigation() {
    try {
      const entries =
        performance
          .getEntriesByType(
            'navigation'
          );

      if (
        Array.isArray(entries) &&
        entries.length > 0
      ) {
        return (
          entries[0].type ===
          'reload'
        );
      }

    } catch (error) {
      console.warn(
        '[Auto import] Could not read Navigation Timing data:',
        error
      );
    }


    try {
      if (
        performance.navigation &&
        performance.navigation.type === 1
      ) {
        return true;
      }

    } catch (_) {
      // Ignore old-browser fallback failure.
    }


    return false;
  }


  // ==========================================================================
  // SAVED PRESETS
  // ==========================================================================

  function hasSavedPresets() {
    try {
      const text =
        localStorage.getItem(
          CONFIG
            .settingsStorageKey
        );

      if (!text) {
        /*
         * The three-slot script may not yet have had a
         * chance to migrate the old single ng-settings
         * value during this page load.
         *
         * If the legacy key exists, allow Auto Import
         * to continue waiting. The importer will migrate it.
         */
        return Boolean(
          localStorage.getItem(
            'ng-settings'
          )
        );
      }


      const parsed =
        JSON.parse(text);


      return Boolean(
        parsed &&
        Array.isArray(
          parsed.slots
        ) &&
        parsed.slots.some(
          slot =>
            Boolean(
              slot &&
              slot.settings
            )
        )
      );

    } catch (error) {
      console.warn(
        '[Auto import] Could not inspect saved presets:',
        error
      );

      return false;
    }
  }


  // ==========================================================================
  // VIEWER STABILITY
  // ==========================================================================

  function checkViewer() {
    if (
      importTriggered
    ) {
      window.clearInterval(
        intervalId
      );

      return;
    }


    const now =
      performance.now();


    const totalElapsed =
      now -
      startedAt;


    if (
      totalElapsed >=
      CONFIG.maximumWaitMilliseconds
    ) {
      window.clearInterval(
        intervalId
      );


      console.warn(
        '[Auto import] Viewer did not reach a stable state within ' +
        Math.round(
          CONFIG.maximumWaitMilliseconds /
          1000
        ) +
        ' seconds. Automatic import skipped; press / manually.'
      );


      return;
    }


    if (
      totalElapsed <
      CONFIG.minimumWaitMilliseconds
    ) {
      return;
    }


    const pageViewer =
      getPageViewer();


    if (
      !isViewerReady(
        pageViewer
      )
    ) {
      resetStability();

      return;
    }


    if (
      isLoginPromptVisible()
    ) {
      resetStability();

      return;
    }


    let snapshot;


    try {
      snapshot =
        createMeaningfulSnapshot(
          pageViewer
        );

    } catch (_) {
      resetStability();

      return;
    }


    if (
      snapshot !==
      lastSnapshot
    ) {
      lastSnapshot =
        snapshot;

      stableSince =
        now;

      return;
    }


    if (
      stableSince === null
    ) {
      stableSince =
        now;

      return;
    }


    const stableElapsed =
      now -
      stableSince;


    if (
      stableElapsed >=
      CONFIG.requiredStableMilliseconds
    ) {
      /*
       * Stop the stability monitor BEFORE calling
       * the importer so it can never trigger twice.
       */
      importTriggered =
        true;


      window.clearInterval(
        intervalId
      );


      console.log(
        '[Auto import] Viewer stabilized after ' +
        (
          totalElapsed /
          1000
        ).toFixed(2) +
        ' seconds.'
      );


      callImporterWhenReady();
    }
  }


  // ==========================================================================
  // DIRECT IMPORTER API
  // ==========================================================================

  async function callImporterWhenReady() {
    const deadline =
      performance.now() +
      CONFIG
        .importerApiWaitMilliseconds;


    let api =
      getImporterApi();


    while (
      !api &&
      performance.now() <
        deadline
    ) {
      await sleep(100);

      api =
        getImporterApi();
    }


    if (
      !api ||
      typeof api.importSettings !==
        'function'
    ) {
      console.warn(
        '[Auto import] Import/export preset API was not available. Press / manually.'
      );

      return;
    }


    let presets =
      [];


    try {
      if (
        typeof api.getPresets ===
        'function'
      ) {
        presets =
          api.getPresets() ||
          [];
      }

    } catch (error) {
      console.warn(
        '[Auto import] Could not read preset list:',
        error
      );
    }


    if (
      presets.length === 0
    ) {
      console.log(
        '[Auto import] No presets remain to import.'
      );

      return;
    }


    if (
      presets.length === 1
    ) {
      console.log(
        '[Auto import] One preset exists. Automatically importing "' +
        presets[0].name +
        '".'
      );

    } else {
      console.log(
        '[Auto import] ' +
        presets.length +
        ' presets exist. Asking which state to import.'
      );
    }


    /*
     * IMPORTANT:
     *
     * Direct API call.
     *
     * We DO NOT synthesize the "/" key anymore.
     * This means exactly one restore operation is requested.
     */
    try {
      const result =
        api.importSettings({
          source:
            'auto',

          quietWhenEmpty:
            true
        });


      if (
        result &&
        result.ok
      ) {
        console.log(
          '[Auto import] Settings import completed from "' +
          result.name +
          '".'
        );

      } else {
        console.log(
          '[Auto import] No automatic settings import was performed.',
          result
        );
      }

    } catch (error) {
      console.error(
        '[Auto import] Import API call failed:',
        error
      );
    }
  }


  function getImporterApi() {
    /*
     * The Import/Export script uses @grant none,
     * so its API exists in the actual page window.
     */
    try {
      if (
        typeof unsafeWindow !==
          'undefined' &&
        unsafeWindow &&
        unsafeWindow[
          CONFIG.importerApiName
        ]
      ) {
        return unsafeWindow[
          CONFIG.importerApiName
        ];
      }

    } catch (_) {
      // Continue to window fallback.
    }


    try {
      return (
        window[
          CONFIG.importerApiName
        ] ||
        null
      );

    } catch (_) {
      return null;
    }
  }


  // ==========================================================================
  // VIEWER ACCESS
  // ==========================================================================

  function getPageViewer() {
    try {
      if (
        typeof unsafeWindow !==
          'undefined' &&
        unsafeWindow &&
        unsafeWindow.viewer
      ) {
        return unsafeWindow.viewer;
      }

    } catch (_) {
      // Continue.
    }


    try {
      if (
        window.viewer
      ) {
        return window.viewer;
      }

    } catch (_) {
      // Viewer not ready.
    }


    return null;
  }


  function isViewerReady(
    pageViewer
  ) {
    try {
      if (
        !pageViewer ||
        !pageViewer.state ||
        typeof pageViewer
          .state
          .toJSON !==
          'function'
      ) {
        return false;
      }


      const state =
        pageViewer
          .state
          .toJSON();


      if (
        !state ||
        !Array.isArray(
          state.layers
        ) ||
        state.layers.length === 0
      ) {
        return false;
      }


      const hasSegmentation =
        state.layers.some(
          layer =>
            Boolean(
              layer &&
              layer.type ===
                'segmentation' &&
              layer.source
            )
        );


      if (
        !hasSegmentation
      ) {
        return false;
      }


      const topBar =
        document.querySelector(
          '.neuroglancer-viewer-top-row'
        );


      const renderedPanel =
        document.querySelector(
          '.neuroglancer-rendered-data-panel, canvas'
        );


      return Boolean(
        topBar &&
        renderedPanel
      );

    } catch (_) {
      return false;
    }
  }


  // ==========================================================================
  // STABILITY SNAPSHOT
  // ==========================================================================

  function createMeaningfulSnapshot(
    pageViewer
  ) {
    const state =
      pageViewer
        .state
        .toJSON();


    const layers =
      state.layers.map(
        layer => {
          const result = {
            name:
              layer.name ||
              '',

            type:
              layer.type ||
              '',

            source:
              normalizeSource(
                layer.source
              ),

            visible:
              Object.prototype
                .hasOwnProperty.call(
                  layer,
                  'visible'
                )
                ? layer.visible
                : null
          };


          if (
            layer.type ===
            'segmentation'
          ) {
            result.segments =
              Array.isArray(
                layer.segments
              )
                ? layer.segments.map(
                    String
                  )
                : [];


            result.segmentCount =
              result
                .segments
                .length;
          }


          if (
            layer.type ===
            'annotation'
          ) {
            result.annotationCount =
              Array.isArray(
                layer.annotations
              )
                ? layer
                    .annotations
                    .length
                : 0;
          }


          return result;
        }
      );


    const snapshot = {
      url:
        window.location.href,

      dimensions:
        Object.prototype
          .hasOwnProperty.call(
            state,
            'dimensions'
          )
          ? state.dimensions
          : null,

      position:
        Object.prototype
          .hasOwnProperty.call(
            state,
            'position'
          )
          ? state.position
          : null,

      crossSectionScale:
        Object.prototype
          .hasOwnProperty.call(
            state,
            'crossSectionScale'
          )
          ? state.crossSectionScale
          : null,

      projectionScale:
        Object.prototype
          .hasOwnProperty.call(
            state,
            'projectionScale'
          )
          ? state.projectionScale
          : null,

      projectionDepth:
        Object.prototype
          .hasOwnProperty.call(
            state,
            'projectionDepth'
          )
          ? state.projectionDepth
          : null,

      projectionOrientation:
        Object.prototype
          .hasOwnProperty.call(
            state,
            'projectionOrientation'
          )
          ? state.projectionOrientation
          : null,

      layerCount:
        layers.length,

      layers,

      canvasCount:
        document.querySelectorAll(
          'canvas'
        ).length,

      renderedPanelCount:
        document.querySelectorAll(
          '.neuroglancer-rendered-data-panel'
        ).length
    };


    return JSON.stringify(
      snapshot
    );
  }


  function normalizeSource(
    source
  ) {
    if (
      source === undefined ||
      source === null
    ) {
      return null;
    }


    if (
      typeof source ===
      'string'
    ) {
      return source;
    }


    try {
      return JSON.stringify(
        source
      );

    } catch (_) {
      return String(
        source
      );
    }
  }


  // ==========================================================================
  // LOGIN / STABILITY HELPERS
  // ==========================================================================

  function isLoginPromptVisible() {
    const text =
      document.body
        ? document.body
            .innerText
            .toLowerCase()
        : '';


    return (
      text.includes(
        'login required'
      ) ||
      text.includes(
        'request login'
      )
    );
  }


  function resetStability() {
    lastSnapshot =
      null;

    stableSince =
      null;
  }


  function sleep(
    milliseconds
  ) {
    return new Promise(
      resolve => {
        window.setTimeout(
          resolve,
          milliseconds
        );
      }
    );
  }

})();