// frontend/src/api/utils/validation.ts
/**
 * Request Validation Utilities
 */

export class RequestValidator {
  static validateEmail(email: string): boolean {
    const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
    return emailRegex.test(email);
  }

  static validatePassword(password: string): {
    valid: boolean;
    errors: string[];
  } {
    const errors: string[] = [];
    
    if (password.length < 8) {
      errors.push('Password must be at least 8 characters long');
    }
    
    if (!/(?=.*[a-z])/.test(password)) {
      errors.push('Password must contain at least one lowercase letter');
    }
    
    if (!/(?=.*[A-Z])/.test(password)) {
      errors.push('Password must contain at least one uppercase letter');
    }
    
    if (!/(?=.*\d)/.test(password)) {
      errors.push('Password must contain at least one number');
    }
    
    return {
      valid: errors.length === 0,
      errors,
    };
  }

  static validateFile(file: File, allowedTypes: string[], maxSize: number): {
    valid: boolean;
    errors: string[];
  } {
    const errors: string[] = [];
    
    if (!allowedTypes.includes(file.type)) {
      errors.push(`File type ${file.type} is not allowed`);
    }
    
    if (file.size > maxSize) {
      errors.push(`File size exceeds maximum of ${maxSize} bytes`);
    }
    
    return {
      valid: errors.length === 0,
      errors,
    };
  }

  static validatePhoneNumber(phone: string): boolean {
    // Basic international phone number validation
    const phoneRegex = /^\+?[1-9]\d{1,14}$/;
    return phoneRegex.test(phone.replace(/\s/g, ''));
  }

  static validateRequired(value: any, fieldName: string): string | null {
    if (value === null || value === undefined || value === '') {
      return `${fieldName} is required`;
    }
    return null;
  }
}