1 files changed, 90 insertions, 0 deletions
diff --git a/src/client/react/reducers/search.ts b/src/client/react/reducers/search.ts
new file mode 100644
index 0000000..658d3ca
--- /dev/null
+++ b/src/client/react/reducers/search.ts
@@ -0,0 +1,90 @@
+import * as fuzzy from 'fuzzy';
+import users, { User } from '../users';
+import { InputChangeAction, ChangeSelectedResultAction } from '../actions/search';
+
+export interface State {
+  results: string[],
+  selectedResult: string | null,
+  isExactMatch: boolean,
+};
+
+export type Action = InputChangeAction | ChangeSelectedResultAction;
+
+const DEFAULT_STATE: State = {
+  results: [
+    's/18562',
+  ],
+  selectedResult: null,
+  isExactMatch: false,
+};
+
+function getSearchResults(allUsers: User[], query: string) {
+  if (query.trim() === '') {
+    return [];
+  }
+
+  const allResults = fuzzy.filter(query, allUsers, {
+    extract: (user: User) => user.value,
+  });
+
+  const firstResults = allResults.splice(0, 4);
+  const userIds = firstResults.map((result: { original: User }) => result.original.id);
+
+  return userIds;
+}
+
+const search = (state = DEFAULT_STATE, action: Action): State => {
+  switch (action.type) {
+    case 'SEARCH/INPUT_CHANGE': {
+      const results = getSearchResults(users.allUsers, action.typedValue);
+      let selectedResult = null;
+      let isExactMatch = false;
+
+      // Is the typed value exactly the same as the first result? Then show the
+      // appropiate icon instead of the generic search icon.
+      if ((results.length === 1) && (action.typedValue === users.byId[results[0]].value)) {
+        [selectedResult] = results;
+        isExactMatch = true;
+      }
+
+      return {
+        ...state,
+        results,
+        selectedResult,
+        isExactMatch,
+      };
+    }
+
+    case 'SEARCH/CHANGE_SELECTED_RESULT': {
+      const { results, isExactMatch } = state;
+
+      if (isExactMatch) return state;
+
+      const prevSelectedResult = state.selectedResult;
+      const prevSelectedResultIndex = results.indexOf(prevSelectedResult);
+      let nextSelectedResultIndex =
+        prevSelectedResultIndex + action.relativeChange;
+
+      if (nextSelectedResultIndex < -1) {
+        nextSelectedResultIndex = results.length - 1;
+      } else if (nextSelectedResultIndex > results.length - 1) {
+        nextSelectedResultIndex = -1;
+      }
+
+      const nextSelectedResult =
+        nextSelectedResultIndex === -1
+          ? null
+          : results[nextSelectedResultIndex];
+
+      return {
+        ...state,
+        selectedResult: nextSelectedResult,
+      };
+    }
+
+    default:
+      return state;
+  }
+};
+
+export default search;