import { z } from 'zod';

/**
 * Admin form validation schemas
 * Provides type-safe validation for admin settings and user management forms
 */

/**
 * Email validation schema
 * Ensures valid email format with reasonable length constraints
 */
export const emailSchema = z
  .string()
  .trim()
  .min(1, 'Email is required')
  .max(255, 'Email must be less than 255 characters')
  .email('Invalid email address')
  .toLowerCase();

/**
 * URL validation schema
 * Validates URLs with http/https protocol and reasonable length
 */
export const urlSchema = z
  .string()
  .trim()
  .min(1, 'URL is required')
  .max(2048, 'URL must be less than 2048 characters')
  .url('Invalid URL format')
  .refine(
    (url) => url.startsWith('http://') || url.startsWith('https://'),
    'URL must start with http:// or https://'
  );

/**
 * Username validation schema
 * Alphanumeric with underscores and hyphens, 3-30 characters
 */
export const usernameSchema = z
  .string()
  .trim()
  .min(3, 'Username must be at least 3 characters')
  .max(30, 'Username must be less than 30 characters')
  .regex(
    /^[a-zA-Z0-9_-]+$/,
    'Username can only contain letters, numbers, underscores, and hyphens'
  );

/**
 * Display name validation schema
 * More permissive than username, allows spaces and special characters
 */
export const displayNameSchema = z
  .string()
  .trim()
  .min(1, 'Display name is required')
  .max(100, 'Display name must be less than 100 characters');

/**
 * Admin settings validation schema
 * For system-wide configuration values
 */
export const adminSettingsSchema = z.object({
  email: emailSchema.optional(),
  url: urlSchema.optional(),
  username: usernameSchema.optional(),
  displayName: displayNameSchema.optional(),
});

/**
 * User search validation schema
 * For searching users in admin panel
 */
export const userSearchSchema = z.object({
  query: z
    .string()
    .trim()
    .min(1, 'Search query must be at least 1 character')
    .max(100, 'Search query must be less than 100 characters'),
});

/**
 * Helper function to validate email
 */
export function validateEmail(email: string): { valid: boolean; error?: string } {
  try {
    emailSchema.parse(email);
    return { valid: true };
  } catch (error: unknown) {
    if (error instanceof z.ZodError) {
      return { valid: false, error: error.issues[0]?.message };
    }
    return { valid: false, error: 'Invalid email' };
  }
}

/**
 * Helper function to validate URL
 */
export function validateUrl(url: string): { valid: boolean; error?: string } {
  try {
    urlSchema.parse(url);
    return { valid: true };
  } catch (error: unknown) {
    if (error instanceof z.ZodError) {
      return { valid: false, error: error.issues[0]?.message };
    }
    return { valid: false, error: 'Invalid URL' };
  }
}

/**
 * Helper function to validate username
 */
export function validateUsername(username: string): { valid: boolean; error?: string } {
  try {
    usernameSchema.parse(username);
    return { valid: true };
  } catch (error: unknown) {
    if (error instanceof z.ZodError) {
      return { valid: false, error: error.issues[0]?.message };
    }
    return { valid: false, error: 'Invalid username' };
  }
}