frontend/src/utils/apiUtils.ts

import axios, { AxiosError } from 'axios';

export interface ApiError {
  message: string;
  details?: string;
  code?: string;
}

interface ApiErrorResponse {
  message?: string;
  error?: string;
  details?: string;
}

export const handleApiError = (error: unknown): ApiError => {
  if (axios.isAxiosError(error)) {
    const axiosError = error as AxiosError<ApiErrorResponse>;
    const responseData = axiosError.response?.data;
    return {
      message: axiosError.message,
      details: responseData?.message || responseData?.error || 'Unknown error occurred',
      code: axiosError.code,
    };
  }
  
  if (error instanceof Error) {
    return {
      message: error.message,
      details: error.stack,
    };
  }
  
  return {
    message: 'An unexpected error occurred',
    details: String(error),
  };
};

export const withRetry = async <T>(
  operation: () => Promise<T>,
  maxRetries: number = 3,
  delay: number = 1000
): Promise<T> => {
  let lastError: unknown;
  
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await operation();
    } catch (error) {
      lastError = error;
      if (i < maxRetries - 1) {
        await new Promise(resolve => setTimeout(resolve, delay * Math.pow(2, i)));
      }
    }
  }
  
  throw lastError;
};

export const validateInput = (input: string, maxLength: number = 100): boolean => {
  if (!input || typeof input !== 'string') return false;
  if (input.trim().length === 0) return false;
  if (input.length > maxLength) return false;
  return true;
};

export const sanitizeInput = (input: string): string => {
  return input
    .trim()
    .replace(/[<>]/g, '') // Remove potential HTML tags
    .replace(/javascript:/gi, '') // Remove potential JavaScript protocol
    .slice(0, 100); // Limit length
};

// Rate limiting utility
export class RateLimiter {
  private timestamps: number[] = [];
  private readonly windowMs: number;
  private readonly maxRequests: number;

  constructor(windowMs: number = 60000, maxRequests: number = 100) {
    this.windowMs = windowMs;
    this.maxRequests = maxRequests;
  }

  canMakeRequest(): boolean {
    const now = Date.now();
    this.timestamps = this.timestamps.filter(time => now - time < this.windowMs);
    
    if (this.timestamps.length >= this.maxRequests) {
      return false;
    }
    
    this.timestamps.push(now);
    return true;
  }
}

// Create a rate limiter instance
export const rateLimiter = new RateLimiter();

// Wrapper for API calls with rate limiting
export const rateLimitedApiCall = async <T>(
  apiCall: () => Promise<T>,
  retryCount: number = 3
): Promise<T> => {
  if (!rateLimiter.canMakeRequest()) {
    throw new Error('Rate limit exceeded. Please try again later.');
  }
  
  return withRetry(apiCall, retryCount);
};