SvelteKit to NextJS: Migrate

TODO: collapasable, copyable, download, etc

Please port this SvelteKit code to the equivalent NextJs code. I am using the app router style. Please tell me file names when you print out the migrated code. Here is all of my relevant SvelteKit source code:

src/routes/settings/+page.svelte

	import { page } from '$app/stores';
	import { Heading, Radio } from 'flowbite-svelte';

	type UserSettingKey =
		| 'inferenceEndpointVersion'
		| 'showAnomalies'
		| 'markInteresting'
		| 'showIntent';

	let inferenceEndpointVersionState = $page.data.inferenceEndpointVersion;
	let showAnomaliesState = $page.data.showAnomalies;
	let markInterestingState = $page.data.markInteresting;
	let showIntentState = $page.data.showIntent;

	const handleChange = async (event: Event, settingsKey: UserSettingKey) => {
		// This is a gotcha. The handler doesn't see the updated version
		// of these values.
		const currentSettings = {
			inferenceEndpointVersion: inferenceEndpointVersionState,
			showAnomalies: showAnomaliesState,
			markInteresting: markInterestingState,
			showIntent: showIntentState
		};
		currentSettings[settingsKey] = event?.target?.value;

		const newSettings = {
			...currentSettings
		};

		const res = await fetch('/api/settings', {
			method: 'POST',
			headers: {
				'Content-Type': 'application/json'
			},
			body: JSON.stringify(newSettings)
		});

		if (!res.ok) {
			console.error(res);
		}
	};
</script>

<div class="flex justify-center mt-12">
	<div class="max-w-md">
		<Heading tag="h1" class="mb-4" customSize="text-4xl font-extrabold">Settings</Heading>

		<p class="mb-4 font-semibold text-gray-900 dark:text-white">Inference service endpoint</p>
		<ul
			class="items-center w-full rounded-lg border border-gray-200 sm:flex dark:bg-gray-800 dark:border-gray-600 divide-x rtl:divide-x-reverse divide-gray-200 dark:divide-gray-600"
		>
			<li class="w-full">
				<Radio
					bind:group={inferenceEndpointVersionState}
					value="v1"
					on:change={(event) => handleChange(event, 'inferenceEndpointVersion')}
					class="p-3">v1</Radio
				>
			</li>
			<li class="w-full">
				<Radio
					bind:group={inferenceEndpointVersionState}
					value="v2"
					on:change={(event) => handleChange(event, 'inferenceEndpointVersion')}
					class="p-3">v2</Radio
				>
			</li>
		</ul>
		<p class="mb-4 font-semibold text-gray-900 dark:text-white">Show Anomalous Intervals</p>
		<ul
			class="items-center w-full rounded-lg border border-gray-200 sm:flex dark:bg-gray-800 dark:border-gray-600 divide-x rtl:divide-x-reverse divide-gray-200 dark:divide-gray-600"
		>
			<li class="w-full">
				<Radio
					bind:group={showAnomaliesState}
					value="true"
					on:change={(event) => handleChange(event, 'showAnomalies')}
					class="p-3">true</Radio
				>
			</li>
			<li class="w-full">
				<Radio
					bind:group={showAnomaliesState}
					value="false"
					on:change={(event) => handleChange(event, 'showAnomalies')}
					class="p-3">false</Radio
				>
			</li>
		</ul>
		<p class="mb-4 font-semibold text-gray-900 dark:text-white">Enable Pin Chart</p>
		<ul
			class="items-center w-full rounded-lg border border-gray-200 sm:flex dark:bg-gray-800 dark:border-gray-600 divide-x rtl:divide-x-reverse divide-gray-200 dark:divide-gray-600"
		>
			<li class="w-full">
				<Radio
					bind:group={markInterestingState}
					value="true"
					on:change={(event) => handleChange(event, 'markInteresting')}
					class="p-3">true</Radio
				>
			</li>
			<li class="w-full">
				<Radio
					bind:group={markInterestingState}
					value="false"
					on:change={(event) => handleChange(event, 'markInteresting')}
					class="p-3">false</Radio
				>
			</li>
		</ul>
		<p class="mb-4 font-semibold text-gray-900 dark:text-white">Show Intent Selector</p>
		<ul
			class="items-center w-full rounded-lg border border-gray-200 sm:flex dark:bg-gray-800 dark:border-gray-600 divide-x rtl:divide-x-reverse divide-gray-200 dark:divide-gray-600"
		>
			<li class="w-full">
				<Radio
					bind:group={showIntentState}
					value="true"
					on:change={(event) => handleChange(event, 'showIntent')}
					class="p-3">true</Radio
				>
			</li>
			<li class="w-full">
				<Radio
					bind:group={showIntentState}
					value="false"
					on:change={(event) => handleChange(event, 'showIntent')}
					class="p-3">false</Radio
				>
			</li>
		</ul>
		<code class="mt-48 block"
			><pre>
request.url {$page.data.url}
origin: {new URL($page.data.url).origin}
		</pre></code
		>
	</div>
</div>

src/routes/settings/+page.server.js

/** @type {import('./$types').PageServerLoad} */
export async function load({ request, cookies }) {
	let inferenceEndpointVersion = cookies.get('inferenceEndpointVersion') || 'v2';
	let showAnomalies = cookies.get('showAnomalies') || 'false';
	let markInteresting = cookies.get('markInteresting') || 'false';
	let showIntent = cookies.get('showIntent') || 'false';
	return {
		url: request.url,
		inferenceEndpointVersion,
		showAnomalies,
		markInteresting,
		showIntent
	};
}

src/routes/api/settings/+server.js

export async function POST({ request, cookies }) {
	const { inferenceEndpointVersion, showAnomalies, markInteresting, showIntent } =
		await request.json();

	console.log('Setting inferenceEndpointVersion=', inferenceEndpointVersion);

	const setCookie = (/** @type {string} */ key, /** @type {string} */ value) => {
		cookies.set(key, value, {
			path: '/',
			maxAge: 60 * 60 * 24 * 400
		});
	};

	setCookie('inferenceEndpointVersion', inferenceEndpointVersion);
	setCookie('showAnomalies', showAnomalies);
	setCookie('markInteresting', markInteresting);
	setCookie('showIntent', showIntent);

	return json({
		ok: true
	});
}
```To port the provided SvelteKit code to Next.js while adhering to the app router style, the migration process involves creating equivalent React components and API routes. The key difference lies in how state management, server-side logic, and API handling are implemented in Next.js compared to SvelteKit.

### 1. Page Component (`settings/index.jsx` or `settings/index.tsx`)

For the SvelteKit page component, you'll use a React component in Next.js. Here's the equivalent Next.js code, assuming you're using TypeScript based on your SvelteKit script. The filename for this component would be `pages/settings/index.tsx`:

```tsx
// pages/settings/index.tsx

import { useState, useEffect } from 'react';
import { useRouter } from 'next/router';

const SettingsPage = () => {
  const [settings, setSettings] = useState({
    inferenceEndpointVersion: 'v2',
    showAnomalies: 'false',
    markInteresting: 'false',
    showIntent: 'false',
  });

  // Fetch settings from API or use Next.js server-side props for initial values

  const handleChange = async (event: React.ChangeEvent<HTMLInputElement>, settingsKey: keyof typeof settings) => {
    const newSettings = {
      ...settings,
      [settingsKey]: event.target.value,
    };
    setSettings(newSettings);

    const res = await fetch('/api/settings', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(newSettings),
    });

    if (!res.ok) {
      console.error(await res.text());
    }
  };

  // JSX goes here, replace <Radio> with equivalent React component
  return (
    <div className="flex justify-center mt-12">
      <div className="max-w-md">
        {/* Heading and Radio components go here */}
      </div>
    </div>
  );
};

export default SettingsPage;

In Next.js, you often use getServerSideProps or getStaticProps for fetching initial data, but since your SvelteKit example seems to rely on client-side behavior for fetching settings, I've omitted that part. You'll need to replace the Svelte-specific <Radio> component with a React equivalent.

2. API Route (/api/settings.js or /api/settings.ts)

Next.js handles API routes with a similar file-based routing mechanism. Here's how you can port your SvelteKit API route to Next.js. The filename for this API route would be pages/api/settings.ts:

// pages/api/settings.ts

import type { NextApiRequest, NextApiResponse } from 'next';

export default async function handler(req: NextApiRequest, res: NextApiResponse) {
  if (req.method === 'POST') {
    const { inferenceEndpointVersion, showAnomalies, markInteresting, showIntent } = req.body;

    console.log('Setting inferenceEndpointVersion=', inferenceEndpointVersion);

    // Set cookies here, using `res.setHeader('Set-Cookie', ...)` in Next.js

    res.status(200).json({ ok: true });
  } else {
    res.setHeader('Allow', ['POST']);
    res.status(405).end(`Method ${req.method} Not Allowed`);
  }
}

In Next.js, you manage cookies on the server-side by manipulating the response headers directly using res.setHeader(). The syntax for setting cookies is slightly different from SvelteKit's, and you'll need to format the Set-Cookie header according to the HTTP specification.

3. Note on State Management and Cookies

For the full migration, remember to handle cookies properly in the API route and consider how you'll manage and fetch the initial state for your settings page (possibly using getServerSideProps). The cookie management in Next.js within API routes requires manual handling of the Set-Cookie header, as shown in the API route example above.

This migration outline covers the structural changes needed. Given the specifics of React's and Next.js's libraries for UI components (like replacing flowbite-svelte components with their React equivalents), you'll need to adjust the JSX accordingly.

SvelteKit to NextJS: Migrate created at Tue Jan 20 1970 18:57:17 GMT+0000 (Coordinated Universal Time)