1 files changed, 139 insertions, 0 deletions
diff --git a/web/src/js/ducks/utils/view.js b/web/src/js/ducks/utils/view.js
new file mode 100755
index 00000000..adf7fc6a
--- /dev/null
+++ b/web/src/js/ducks/utils/view.js
@@ -0,0 +1,139 @@
+import _ from 'lodash'
+
+export const UPDATE_FILTER = 'VIEW_UPDATE_FILTER'
+export const UPDATE_SORTER = 'VIEW_UPDATE_SORTER'
+export const ADD = 'VIEW_ADD'
+export const UPDATE = 'VIEW_UPDATE'
+export const REMOVE = 'VIEW_REMOVE'
+export const RECEIVE = 'VIEW_RECEIVE'
+
+const defaultState = {
+    data: [],
+    indexOf: {},
+}
+
+export default function reduce(state = defaultState, action) {
+    switch (action.type) {
+
+        case UPDATE_FILTER:
+            const data = action.list.data.filter(action.filter).sort(action.sorter)
+            return {
+                ...state,
+                data,
+                indexOf: _.fromPairs(data.map((item, index) => [item.id, index])),
+            }
+
+        case UPDATE_SORTER:
+            const data = state.data.slice().sort(action.sorter)
+            return {
+                ...state,
+                data,
+                indexOf: _.fromPairs(data.map((item, index) => [item.id, index]))
+            }
+
+        case ADD:
+            if (!action.filter(action.item)) {
+                return state
+            }
+            return {
+                ...state,
+                ...sortedInsert(state, action.item, action.sorter),
+            }
+
+        case REMOVE:
+            return {
+                ...state,
+                ...sortedRemove(state, action.id),
+            }
+
+        case UPDATE:
+            const nextState = {
+                ...state,
+                ...sortedRemove(state, action.id),
+            }
+            if (!action.filter(action.item)) {
+                return nextState
+            }
+            return {
+                ...nextState,
+                ...sortedInsert(nextState, action.item, action.sorter)
+            }
+
+        case RECEIVE:
+            const data = action.list.data.filter(action.filter).sort(action.sorter)
+            return {
+                ...state,
+                data,
+                indexOf: _.fromPairs(data.map((item, index) => [item.id, index])),
+            }
+
+        default:
+            return state
+    }
+}
+
+export function updateFilter(list, filter, sorter) {
+    return { type: UPDATE_FILTER, list, filter, sorter }
+}
+
+export function updateSorter(sorter) {
+    return { type: UPDATE_SORTER, sorter }
+}
+
+export function add(item, filter, sorter) {
+    return { type: ADD, item, filter, sorter }
+}
+
+export function update(id, item, filter, sorter) {
+    return { type: UPDATE, id, item, filter, sorter }
+}
+
+export function remove(id) {
+    return { type: REMOVE, id }
+}
+
+export function receive(list, filter, sorter) {
+    return { type: RECEIVE, list, filter, sorter }
+}
+
+function sortedInsert(state, item, sorter) {
+    const index = sortedIndex(state.data, item, sorter)
+    const data = [...state.data]
+    const indexOf = { ...state.indexOf }
+
+    data.splice(index, 0, item)
+    for (let i = data.length - 1; i >= index; i--) {
+        indexOf[data[i].id] = i
+    }
+
+    return { data, indexOf }
+}
+
+function sortedRemove(state, id) {
+    const index = state.indexOf[id]
+    const data = [...state.data]
+    const indexOf = { ...state.indexOf, [id]: null }
+
+    data.splice(index, 1)
+    for (let i = data.length - 1; i >= index; i--) {
+        indexOf[data[i].id] = i
+    }
+
+    return { data, indexOf }
+}
+
+function sortedIndex(list, item, sorter) {
+    let low = 0
+    let high = list.length
+
+    while (low < high) {
+        const middle = (low + high) >>> 1
+        if (sorter(item, list[middle]) > 0) {
+            low = middle + 1
+        } else {
+            high = middle
+        }
+    }
+
+    return low
+}