1 files changed, 93 insertions, 0 deletions
diff --git a/src/context/accessibility-layout.ts b/src/context/accessibility-layout.ts
new file mode 100644
index 0000000..110100f
--- /dev/null
+++ b/src/context/accessibility-layout.ts
@@ -0,0 +1,93 @@
+import { getContext, setContext } from 'svelte';
+
+import type { Shelf } from '@jet-app/app-store/api/models';
+import { isAccessibilityHeaderShelf } from '~/components/jet/shelf/AccessibilityHeaderShelf.svelte';
+import { isAccessibilityFeaturesShelf } from '~/components/jet/shelf/AccessibilityFeaturesShelf.svelte';
+import { isAccessibilityDeveloperLinkShelf } from '~/components/jet/shelf/AccessibilityDeveloperLinkShelf.svelte';
+
+/**
+ * Describes the layout configuration for accessibility shelves
+ */
+interface AccessibilityLayoutConfiguration {
+    withBottomPadding: boolean;
+}
+
+const ACCESSIBILITY_LAYOUT_FALLBACK: AccessibilityLayoutConfiguration =
+    Object.freeze({
+        withBottomPadding: false,
+    });
+
+type AccessibilityLayoutStore = WeakMap<
+    Shelf,
+    AccessibilityLayoutConfiguration
+>;
+type AccessibilityLayoutStoreContext = AccessibilityLayoutStore | undefined;
+
+const ACCESSIBILITY_LAYOUT_CONTEXT_ID = 'accessibility-layout-context';
+
+/**
+ * Check if a shelf is accessibility-related
+ */
+function isAccessibilityRelated(shelf: Shelf): boolean {
+    return (
+        shelf.contentType === 'accessibilityParagraph' ||
+        shelf.contentType === 'accessibilityFeatures'
+    );
+}
+
+/**
+ * Check if a shelf is one of the target accessibility shelves
+ */
+function isTargetAccessibilityShelf(shelf: Shelf): boolean {
+    return (
+        isAccessibilityHeaderShelf(shelf) ||
+        isAccessibilityFeaturesShelf(shelf) ||
+        isAccessibilityDeveloperLinkShelf(shelf)
+    );
+}
+
+/**
+ * Store the {@linkcode AccessibilityLayoutConfiguration} for each accessibility shelf
+ * in "context", so it can be retrieved at the shelf-component level
+ *
+ * This determines bottom padding based on whether the next shelf is accessibility-related
+ */
+export function setAccessibilityLayoutContext(page: { shelves: Shelf[] }) {
+    const store: AccessibilityLayoutStore = new WeakMap();
+
+    for (let i = 0; i < page.shelves.length; i++) {
+        const shelf = page.shelves[i];
+
+        // Only process target accessibility shelves
+        if (!isTargetAccessibilityShelf(shelf)) {
+            continue;
+        }
+
+        // Check if the next shelf is accessibility-related
+        const nextShelf = page.shelves[i + 1];
+        const hasAccessibilityNext =
+            nextShelf && isAccessibilityRelated(nextShelf);
+
+        store.set(shelf, {
+            withBottomPadding: !hasAccessibilityNext,
+        });
+    }
+
+    setContext<AccessibilityLayoutStoreContext>(
+        ACCESSIBILITY_LAYOUT_CONTEXT_ID,
+        store,
+    );
+}
+
+/**
+ * Retrieve the {@linkcode AccessibilityLayoutConfiguration} for a given accessibility shelf
+ */
+export function getAccessibilityLayoutConfiguration(
+    shelf: Shelf,
+): AccessibilityLayoutConfiguration {
+    const accessibilityLayout = getContext<AccessibilityLayoutStoreContext>(
+        ACCESSIBILITY_LAYOUT_CONTEXT_ID,
+    );
+
+    return accessibilityLayout?.get(shelf) ?? ACCESSIBILITY_LAYOUT_FALLBACK;
+}