feat : composable de matrice mensuelle avec n° de semaine ISO (#MUI-33)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/components/malio/date/composables/useMonthMatrix.ts

@@ -0,0 +1,60 @@
+import {computed, type ComputedRef, type Ref} from 'vue'
+
+export type DayCell = {
+  isoDate: string
+  day: number
+  isCurrentMonth: boolean
+  isToday: boolean
+}
+export type WeekRow = {
+  weekNumber: number
+  days: DayCell[]
+}
+
+const toIso = (d: Date): string => {
+  const y = d.getFullYear()
+  const m = String(d.getMonth() + 1).padStart(2, '0')
+  const day = String(d.getDate()).padStart(2, '0')
+  return `${y}-${m}-${day}`
+}
+
+const isoWeek = (d: Date): number => {
+  const target = new Date(Date.UTC(d.getFullYear(), d.getMonth(), d.getDate()))
+  const dayNum = target.getUTCDay() || 7 // dimanche = 7
+  target.setUTCDate(target.getUTCDate() + 4 - dayNum) // jeudi de la semaine
+  const yearStart = new Date(Date.UTC(target.getUTCFullYear(), 0, 1))
+  return Math.ceil((((target.getTime() - yearStart.getTime()) / 86400000) + 1) / 7)
+}
+
+export function useMonthMatrix(
+  month: Ref<number>,
+  year: Ref<number>,
+): {weeks: ComputedRef<WeekRow[]>} {
+  const weeks = computed<WeekRow[]>(() => {
+    const todayIso = toIso(new Date())
+    const first = new Date(year.value, month.value, 1)
+    // recule jusqu'au lundi (getDay : 0 = dimanche)
+    const offset = (first.getDay() + 6) % 7
+    const start = new Date(year.value, month.value, 1 - offset)
+
+    const rows: WeekRow[] = []
+    const cursor = new Date(start)
+    for (let w = 0; w < 6; w++) {
+      const days: DayCell[] = []
+      for (let i = 0; i < 7; i++) {
+        const iso = toIso(cursor)
+        days.push({
+          isoDate: iso,
+          day: cursor.getDate(),
+          isCurrentMonth: cursor.getMonth() === month.value,
+          isToday: iso === todayIso,
+        })
+        cursor.setDate(cursor.getDate() + 1)
+      }
+      rows.push({weekNumber: isoWeek(new Date(`${days[0].isoDate}T00:00:00`)), days})
+    }
+    return rows
+  })
+
+  return {weeks}
+}