1 files changed, 35 insertions, 0 deletions
diff --git a/modern/src/reducers/index.js b/modern/src/reducers/index.js
new file mode 100644
index 00000000..752a4c3f
--- /dev/null
+++ b/modern/src/reducers/index.js
@@ -0,0 +1,35 @@
+const initialState = {
+  devices: new Map(),
+  positions: new Map()
+};
+
+function updateMap(map, array, key) {
+  for (let value of array) {
+    map.set(value[key], value);
+  }
+  return map;
+}
+
+function rootReducer(state = initialState, action) {
+  switch (action.type) {
+    case 'UPDATE_DEVICES':
+      return Object.assign({}, {
+        ...state,
+        devices: updateMap(state.devices, action.devices, 'id')
+      });
+    case 'UPDATE_POSITIONS':
+      return Object.assign({}, {
+        ...state,
+        positions: updateMap(state.positions, action.positions, 'deviceId')
+      });
+    case 'SELECT_DEVICE':
+      return Object.assign({}, {
+        ...state,
+        selectedDevice: action.device.id
+      });
+    default:
+      return state;
+  }
+}
+
+export default rootReducer