feat(targeted): add targeted practice functionality

feat(analytics); add analytics page

src/stores/useExamConfigStore.ts

@@ -0,0 +1,79 @@
+// stores/useExamConfigStore.ts
+import { create } from "zustand";
+import { persist } from "zustand/middleware";
+import type { StartExamPayload, ExamMode } from "../types/test";
+
+interface ExamConfigState {
+  payload: StartExamPayload | null;
+
+  setSheetId: (id: string) => void;
+  storeTopics: (ids: string[]) => void;
+  setDifficulty: (difficulty: StartExamPayload["difficulty"]) => void;
+
+  setQuestionCount: (count: number) => void;
+  storeDuration: (minutes: number) => void;
+  setMode: (mode: ExamMode) => void;
+
+  clearPayload: () => void;
+}
+
+export const useExamConfigStore = create<ExamConfigState>()(
+  persist(
+    (set, get) => ({
+      payload: null,
+
+      setSheetId: (sheet_id) =>
+        set({
+          payload: {
+            ...(get().payload ?? {}),
+            sheet_id,
+          } as StartExamPayload,
+        }),
+
+      storeTopics: (topic_ids) =>
+        set({
+          payload: {
+            ...(get().payload ?? {}),
+            topic_ids,
+          } as StartExamPayload,
+        }),
+
+      setDifficulty: (difficulty) =>
+        set({
+          payload: {
+            ...(get().payload ?? {}),
+            difficulty,
+          } as StartExamPayload,
+        }),
+
+      setQuestionCount: (question_count) =>
+        set({
+          payload: {
+            ...(get().payload ?? {}),
+            question_count,
+          } as StartExamPayload,
+        }),
+
+      storeDuration: (time_limit_minutes) =>
+        set({
+          payload: {
+            ...(get().payload ?? {}),
+            time_limit_minutes,
+          } as StartExamPayload,
+        }),
+
+      setMode: (mode) =>
+        set({
+          payload: {
+            ...(get().payload ?? {}),
+            mode,
+          } as StartExamPayload,
+        }),
+
+      clearPayload: () => set({ payload: null }),
+    }),
+    {
+      name: "exam-config-storage",
+    },
+  ),
+);