Feature 15: Recipe Detail and Kitchen Reading Mode (#162)

Co-authored-by: orchestrator-agent <20+orchestrator-agent@code.cubecraftcreations.com>

web/src/dinners/textSize.ts

@@ -0,0 +1,63 @@
+import { useState } from 'react'
+
+// TEXT_SIZE_KEY is the localStorage key remembering, on this device, the text
+// size chosen in Kitchen reading mode.
+export const TEXT_SIZE_KEY = 'mealquest.readingTextSize'
+
+export const TEXT_SIZES = ['small', 'medium', 'large'] as const
+
+export type TextSize = (typeof TEXT_SIZES)[number]
+
+// DEFAULT_TEXT_SIZE is the size of a device that has never chosen one: the
+// handoff's 18 px ingredients and steps.
+export const DEFAULT_TEXT_SIZE: TextSize = 'medium'
+
+// TextSizeState is the text size, and the storage failure, if any, that
+// stopped us reading or saving it.
+type TextSizeState = {
+  size: TextSize
+  failure: { action: 'read' | 'write'; message: string } | null
+}
+
+function isTextSize(value: string): value is TextSize {
+  return (TEXT_SIZES as readonly string[]).includes(value)
+}
+
+// Storage can be unavailable (blocked by the browser or privacy settings), in
+// which case using it throws, and can hold a value MealQuest did not save.
+// Either is reported, never treated as a remembered size.
+function readTextSize(): TextSizeState {
+  try {
+    const saved = window.localStorage.getItem(TEXT_SIZE_KEY)
+    if (saved === null) return { size: DEFAULT_TEXT_SIZE, failure: null }
+    if (!isTextSize(saved)) throw new Error(`"${saved}" is not a text size MealQuest saved`)
+    return { size: saved, failure: null }
+  } catch (err) {
+    return { size: DEFAULT_TEXT_SIZE, failure: { action: 'read', message: String(err) } }
+  }
+}
+
+function writeTextSize(size: TextSize): TextSizeState {
+  try {
+    window.localStorage.setItem(TEXT_SIZE_KEY, size)
+    return { size, failure: null }
+  } catch (err) {
+    return { size, failure: { action: 'write', message: String(err) } }
+  }
+}
+
+export const textSizeFailureText = {
+  read: 'Could not read the text size chosen on this device',
+  write: 'Could not remember the text size on this device',
+}
+
+// useTextSize is Kitchen reading mode's text size on this device: the size,
+// the storage failure if any, choose, which saves a size, and retry, which
+// reads or saves again whatever failed. A size that could not be saved is
+// still used until the screen is left.
+export function useTextSize() {
+  const [state, setState] = useState<TextSizeState>(readTextSize)
+  const choose = (size: TextSize) => setState(writeTextSize(size))
+  const retry = () => setState(state.failure?.action === 'write' ? writeTextSize(state.size) : readTextSize())
+  return { ...state, choose, retry }
+}