refactor(pool): share batch selection helpers

frontend/src/composables/useBatchSelection.ts

@@ -0,0 +1,89 @@
+import { computed, ref, type Ref } from 'vue'
+
+export function useBatchSelection<TItem>(options: {
+  pageItems: Ref<TItem[]>
+  filteredTotal: Ref<number>
+  getItemId: (item: TItem) => string
+}) {
+  const selectedIds = ref<string[]>([])
+  const selectAllFiltered = ref(false)
+  const knownItemsById = ref<Record<string, TItem>>({})
+
+  const selectedIdSet = computed(() => new Set(selectedIds.value))
+  const selectedCount = computed(() => (
+    selectAllFiltered.value ? options.filteredTotal.value : selectedIds.value.length
+  ))
+  const isAllFilteredSelected = computed(() => (
+    selectAllFiltered.value && options.filteredTotal.value > 0
+  ))
+  const isPartiallyFilteredSelected = computed(() => (
+    !selectAllFiltered.value && selectedIds.value.length > 0
+  ))
+  const isCurrentPageFullySelected = computed(() => {
+    const pageIds = options.pageItems.value.map(options.getItemId)
+    return pageIds.length > 0 && pageIds.every((id) => selectedIdSet.value.has(id))
+  })
+  const canClearSelection = computed(() => selectAllFiltered.value || selectedIds.value.length > 0)
+
+  function rememberItems(items: TItem[]): void {
+    if (items.length === 0) return
+    const next = { ...knownItemsById.value }
+    for (const item of items) {
+      next[options.getItemId(item)] = item
+    }
+    knownItemsById.value = next
+  }
+
+  function resetSelection(clearKnown = false): void {
+    selectAllFiltered.value = false
+    selectedIds.value = []
+    if (clearKnown) knownItemsById.value = {}
+  }
+
+  function toggleOne(id: string, checked: boolean): void {
+    if (selectAllFiltered.value) return
+    const set = new Set(selectedIds.value)
+    if (checked) set.add(id)
+    else set.delete(id)
+    selectedIds.value = [...set]
+  }
+
+  function toggleSelectFiltered(checked: boolean | 'indeterminate'): void {
+    selectAllFiltered.value = checked === true
+    if (selectAllFiltered.value) selectedIds.value = []
+  }
+
+  function toggleSelectCurrentPage(): void {
+    if (selectAllFiltered.value || options.pageItems.value.length === 0) return
+    const set = new Set(selectedIds.value)
+    const pageIds = options.pageItems.value.map(options.getItemId)
+    const shouldUnselect = pageIds.every((id) => set.has(id))
+    for (const id of pageIds) {
+      if (shouldUnselect) set.delete(id)
+      else set.add(id)
+    }
+    selectedIds.value = [...set]
+  }
+
+  function clearSelection(): void {
+    resetSelection()
+  }
+
+  return {
+    selectedIds,
+    selectAllFiltered,
+    knownItemsById,
+    selectedIdSet,
+    selectedCount,
+    isAllFilteredSelected,
+    isPartiallyFilteredSelected,
+    isCurrentPageFullySelected,
+    canClearSelection,
+    rememberItems,
+    resetSelection,
+    toggleOne,
+    toggleSelectFiltered,
+    toggleSelectCurrentPage,
+    clearSelection,
+  }
+}