fix : wip

frontend/utils/date.ts

@@ -6,6 +6,74 @@ export const toYmd = (year: number, month: number, day: number) => {
 
 export const normalizeDate = (value: string) => value.slice(0, 10)
 
+export const parseYmd = (value: string) => {
+  const [year, month, day] = value.split('-').map(Number)
+  if (!year || !month || !day) return null
+  return new Date(year, month - 1, day)
+}
+
+export const formatDateLongFr = (date: Date) => {
+  const label = new Intl.DateTimeFormat('fr-FR', {
+    weekday: 'long',
+    day: 'numeric',
+    month: 'long',
+    year: 'numeric'
+  }).format(date)
+
+  return label.charAt(0).toUpperCase() + label.slice(1)
+}
+
+export const formatWeekDayHeaderFr = (dateYmd: string) => {
+  const parsed = parseYmd(dateYmd)
+  if (!parsed) return dateYmd
+  return new Intl.DateTimeFormat('fr-FR', {
+    weekday: 'short',
+    day: '2-digit',
+    month: '2-digit'
+  }).format(parsed)
+}
+
+export const getWeekStartDate = (date: Date) => {
+  const copy = new Date(date)
+  const day = copy.getDay()
+  const diff = day === 0 ? -6 : 1 - day
+  copy.setDate(copy.getDate() + diff)
+  copy.setHours(0, 0, 0, 0)
+  return copy
+}
+
+export const getTodayYmd = () => {
+  const date = new Date()
+  return toYmd(date.getFullYear(), date.getMonth(), date.getDate())
+}
+
+export const getOffsetFromTodayYmd = (offset: number) => {
+  const date = new Date()
+  date.setDate(date.getDate() + offset)
+  return toYmd(date.getFullYear(), date.getMonth(), date.getDate())
+}
+
+export const shiftYmd = (value: string, days: number) => {
+  const parsed = parseYmd(value)
+  if (!parsed) return null
+  parsed.setDate(parsed.getDate() + days)
+  return toYmd(parsed.getFullYear(), parsed.getMonth(), parsed.getDate())
+}
+
+export const formatWeekRangeFr = (date: Date) => {
+  const start = getWeekStartDate(date)
+  const end = new Date(start)
+  end.setDate(start.getDate() + 6)
+
+  const formatter = new Intl.DateTimeFormat('fr-FR', {
+    day: '2-digit',
+    month: '2-digit',
+    year: 'numeric'
+  })
+
+  return `Semaine du ${formatter.format(start)} au ${formatter.format(end)}`
+}
+
 export const getDaysInMonth = (year: number, month: number) => {
   const total = new Date(year, month + 1, 0).getDate()
   const weekdays = ['Dim', 'Lun', 'Mar', 'Mer', 'Jeu', 'Ven', 'Sam']