Add state persistance function

src/components/main/lib/state.ts

@@ -0,0 +1,36 @@
+import { modifyPath, mergeDeepRight } from "ramda";
+
+const STORAGE_KEY = "ecoplanet";
+
+const defaultState = {
+  dateCache: undefined,
+  options: {
+    lineWidth: undefined,
+    defaultDate: undefined,
+  },
+};
+
+const stringifyState = function (state) {
+  return JSON.stringify(state);
+};
+
+const parseState = function (jsonString) {
+  const state = JSON.parse(jsonString);
+  return modifyPath(["options", "defaultDate"], Date.parse, state);
+};
+
+export const persistStorage = function (state) {
+  localStorage.setItem(STORAGE_KEY, stringifyState(state));
+};
+
+export const loadStorage = function () {
+  const storageStateString = localStorage.getItem(STORAGE_KEY);
+
+  if (storageStateString) {
+    return parseState(storageStateString);
+  }
+};
+
+export const loadStorageOrDefault = function (state) {
+  return mergeDeepRight(loadStorage(), defaultState);
+};