has issues

frontend/src/lib/url-state.ts

@@ -1,7 +1,8 @@
 import type { FeatureMeta, FeatureFilters, ViewState } from '../types';
 import {
-  TRANSPORT_MODES,
-  type TransportMode,
+  MAX_TRAVEL_MINUTES,
+  parseServerMode,
+  resolveTransitVariant,
   type TravelTimeEntry,
   type TravelTimeInitial,
 } from '../hooks/useTravelTime';
@@ -48,6 +49,7 @@ import {
   type PoiFilterName,
 } from './poi-distance-filter';
 import { dedupeTravelTimeEntries } from './travel-params';
+import { isOverlayId, type OverlayId } from './overlays';
 
 const POI_NONE_PARAM = '__none';
 
@@ -55,6 +57,7 @@ export interface UrlState {
   viewState: ViewState;
   filters: FeatureFilters;
   poiCategories: Set<string>;
+  overlays: Set<OverlayId>;
   tab: 'properties' | 'area';
   travelTime?: TravelTimeInitial;
   postcode?: string;
@@ -209,6 +212,7 @@ export function parseUrlState(): UrlState {
     viewState: INITIAL_VIEW_STATE,
     filters: parseFilters(params),
     poiCategories: new Set(),
+    overlays: new Set(),
     tab: 'area',
   };
 
@@ -244,6 +248,11 @@ export function parseUrlState(): UrlState {
     }
   }
 
+  const overlayParams = params.getAll('overlay');
+  if (overlayParams.length > 0) {
+    result.overlays = new Set(overlayParams.filter(isOverlayId));
+  }
+
   // Tab: full name
   const tab = params.get('tab');
   if (tab === 'properties' || tab === 'area') {
@@ -257,15 +266,19 @@ export function parseUrlState(): UrlState {
   }
 
   // Travel time: repeated `tt` params
-  // Format: mode:slug:label or mode:slug:label:b or mode:slug:label:min:max or mode:slug:label:b:min:max
+  // Format: serverMode:slug:label[:b][:min:max]
+  // serverMode is one of: car | bicycle | walking | transit | transit-no-bus
+  // | transit-no-change | transit-no-change-no-bus. transit-one-change[-no-bus]
+  // variants are server-side only and will cause the entry to be dropped here
+  // (parseServerMode returns null) so we don't silently broaden the user's filter.
   const ttParams = params.getAll('tt');
   if (ttParams.length > 0) {
     const entries: TravelTimeEntry[] = [];
     for (const tt of ttParams) {
       const parts = tt.split(':');
       if (parts.length < 3) continue;
-      const mode = parts[0] as TransportMode;
-      if (!TRANSPORT_MODES.includes(mode)) continue;
+      const parsedMode = parseServerMode(parts[0]);
+      if (!parsedMode) continue;
       const slug = parts[1];
       const label = decodeURIComponent(parts[2]);
       const useBest = parts.length >= 4 && parts[3] === 'b';
@@ -275,10 +288,21 @@ export function parseUrlState(): UrlState {
         const min = Number(parts[3 + rangeOffset]);
         const max = Number(parts[4 + rangeOffset]);
         if (!isNaN(min) && !isNaN(max)) {
-          timeRange = [min, max];
+          // Clamp loaded max-time to the data ceiling. Older shared URLs
+          // may have max=120 from the previous slider range; no data exists
+          // above MAX_TRAVEL_MINUTES so the result is identical.
+          timeRange = [min, Math.min(max, MAX_TRAVEL_MINUTES)];
         }
       }
-      entries.push({ mode, slug, label, timeRange, useBest });
+      entries.push({
+        mode: parsedMode.mode,
+        slug,
+        label,
+        timeRange,
+        useBest,
+        noChange: parsedMode.noChange,
+        noBuses: parsedMode.noBuses,
+      });
     }
     if (entries.length > 0) {
       result.travelTime = { entries: dedupeTravelTimeEntries(entries) };
@@ -295,7 +319,8 @@ export function stateToParams(
   selectedPOICategories: Set<string>,
   rightPaneTab: 'properties' | 'area',
   travelTimeEntries?: TravelTimeEntry[],
-  share?: string
+  share?: string,
+  selectedOverlays?: Set<OverlayId>
 ): URLSearchParams {
   const params = new URLSearchParams();
 
@@ -378,11 +403,18 @@ export function stateToParams(
     params.set('tab', 'properties');
   }
 
+  if (selectedOverlays) {
+    for (const overlay of selectedOverlays) {
+      params.append('overlay', overlay);
+    }
+  }
+
   // Travel time: repeated `tt` params
   if (travelTimeEntries) {
     for (const entry of dedupeTravelTimeEntries(travelTimeEntries)) {
       if (!entry.slug) continue;
-      let val = `${entry.mode}:${entry.slug}:${encodeURIComponent(entry.label)}`;
+      const serverMode = resolveTransitVariant(entry);
+      let val = `${serverMode}:${entry.slug}:${encodeURIComponent(entry.label)}`;
       if (entry.useBest) val += ':b';
       if (entry.timeRange) {
         val += `:${entry.timeRange[0]}:${entry.timeRange[1]}`;