Refactor code structure and remove redundant changes

lib/api/errorHandler.ts

@@ -0,0 +1,93 @@
+import { AxiosError } from 'axios';
+
+export interface ApiError {
+  message: string;
+  code?: string;
+  status: number;
+  details?: Record<string, string[]>;
+}
+
+export function handleApiError(error: unknown): ApiError {
+  if (error instanceof AxiosError) {
+    const status = error.response?.status || 500;
+    const data = error.response?.data;
+
+    // Django validation errors
+    if (status === 400 && data) {
+      return {
+        message: 'Validation failed',
+        code: 'VALIDATION_ERROR',
+        status,
+        details: data,
+      };
+    }
+
+    // Authentication errors
+    if (status === 401) {
+      return {
+        message: 'Authentication required',
+        code: 'UNAUTHORIZED',
+        status,
+      };
+    }
+
+    // Permission errors
+    if (status === 403) {
+      return {
+        message: 'Permission denied',
+        code: 'FORBIDDEN',
+        status,
+      };
+    }
+
+    // Not found
+    if (status === 404) {
+      return {
+        message: 'Resource not found',
+        code: 'NOT_FOUND',
+        status,
+      };
+    }
+
+    // Rate limiting
+    if (status === 429) {
+      return {
+        message: 'Too many requests',
+        code: 'RATE_LIMITED',
+        status,
+      };
+    }
+
+    // Server errors
+    if (status >= 500) {
+      return {
+        message: 'Server error occurred',
+        code: 'SERVER_ERROR',
+        status,
+      };
+    }
+
+    return {
+      message: data?.message || error.message || 'An error occurred',
+      code: 'API_ERROR',
+      status,
+    };
+  }
+
+  // Network errors
+  return {
+    message: 'Network error occurred',
+    code: 'NETWORK_ERROR',
+    status: 0,
+  };
+}
+
+export function formatErrorForUser(error: ApiError): string {
+  if (error.details) {
+    const messages = Object.entries(error.details)
+      .map(([field, errors]) => `${field}: ${errors.join(', ')}`)
+      .join('\n');
+    return messages;
+  }
+  return error.message;
+}