239 lines
7.8 KiB
TypeScript
239 lines
7.8 KiB
TypeScript
/**
|
||
* Next.js App Router - Complete Chat Example
|
||
*
|
||
* Complete production-ready chat interface for Next.js App Router.
|
||
*
|
||
* Features:
|
||
* - v5 useChat with manual input management
|
||
* - Auto-scroll to bottom
|
||
* - Loading states & error handling
|
||
* - Stop generation button
|
||
* - Responsive design
|
||
* - Keyboard shortcuts (Enter to send, Cmd+K to clear)
|
||
*
|
||
* Directory structure:
|
||
* app/
|
||
* ├── chat/
|
||
* │ └── page.tsx (this file)
|
||
* └── api/
|
||
* └── chat/
|
||
* └── route.ts (see nextjs-api-route.ts)
|
||
*
|
||
* Usage:
|
||
* 1. Copy to app/chat/page.tsx
|
||
* 2. Create API route (see nextjs-api-route.ts)
|
||
* 3. Navigate to /chat
|
||
*/
|
||
|
||
'use client';
|
||
|
||
import { useChat } from 'ai/react';
|
||
import { useState, FormEvent, useRef, useEffect } from 'react';
|
||
|
||
export default function ChatPage() {
|
||
const { messages, sendMessage, isLoading, error, stop, reload } = useChat({
|
||
api: '/api/chat',
|
||
onError: (error) => {
|
||
console.error('Chat error:', error);
|
||
},
|
||
});
|
||
|
||
const [input, setInput] = useState('');
|
||
const messagesEndRef = useRef<HTMLDivElement>(null);
|
||
const inputRef = useRef<HTMLInputElement>(null);
|
||
|
||
// Auto-scroll to bottom when new messages arrive
|
||
useEffect(() => {
|
||
messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
|
||
}, [messages]);
|
||
|
||
// Focus input on mount
|
||
useEffect(() => {
|
||
inputRef.current?.focus();
|
||
}, []);
|
||
|
||
const handleSubmit = (e: FormEvent) => {
|
||
e.preventDefault();
|
||
if (!input.trim() || isLoading) return;
|
||
|
||
sendMessage({ content: input });
|
||
setInput('');
|
||
};
|
||
|
||
// Keyboard shortcuts
|
||
const handleKeyDown = (e: React.KeyboardEvent) => {
|
||
// Cmd+K or Ctrl+K to clear (focus input)
|
||
if ((e.metaKey || e.ctrlKey) && e.key === 'k') {
|
||
e.preventDefault();
|
||
inputRef.current?.focus();
|
||
}
|
||
};
|
||
|
||
return (
|
||
<div className="flex flex-col h-screen max-w-4xl mx-auto" onKeyDown={handleKeyDown}>
|
||
{/* Header */}
|
||
<div className="flex items-center justify-between p-4 border-b bg-white">
|
||
<div>
|
||
<h1 className="text-2xl font-bold">AI Assistant</h1>
|
||
<p className="text-sm text-gray-600">
|
||
{messages.length > 0
|
||
? `${messages.length} message${messages.length === 1 ? '' : 's'}`
|
||
: 'Start a conversation'}
|
||
</p>
|
||
</div>
|
||
{messages.length > 0 && !isLoading && (
|
||
<button
|
||
onClick={() => window.location.reload()}
|
||
className="px-3 py-1 text-sm border rounded hover:bg-gray-50"
|
||
>
|
||
New Chat
|
||
</button>
|
||
)}
|
||
</div>
|
||
|
||
{/* Messages */}
|
||
<div className="flex-1 overflow-y-auto p-4 bg-gray-50">
|
||
{messages.length === 0 ? (
|
||
// Empty state
|
||
<div className="flex items-center justify-center h-full">
|
||
<div className="text-center space-y-4">
|
||
<div className="text-4xl">💬</div>
|
||
<div>
|
||
<h2 className="text-xl font-semibold text-gray-900">
|
||
Start a conversation
|
||
</h2>
|
||
<p className="text-gray-600 mt-2">
|
||
Ask me anything or try one of these:
|
||
</p>
|
||
</div>
|
||
<div className="grid gap-2 max-w-md">
|
||
{[
|
||
'Explain quantum computing',
|
||
'Write a haiku about coding',
|
||
'Plan a trip to Tokyo',
|
||
].map((suggestion, idx) => (
|
||
<button
|
||
key={idx}
|
||
onClick={() => setInput(suggestion)}
|
||
className="p-3 text-left border rounded-lg hover:bg-white hover:shadow-sm transition-all"
|
||
>
|
||
{suggestion}
|
||
</button>
|
||
))}
|
||
</div>
|
||
</div>
|
||
</div>
|
||
) : (
|
||
// Messages list
|
||
<div className="space-y-4 max-w-3xl mx-auto">
|
||
{messages.map((message, idx) => (
|
||
<div
|
||
key={message.id}
|
||
className={`flex ${
|
||
message.role === 'user' ? 'justify-end' : 'justify-start'
|
||
}`}
|
||
>
|
||
<div
|
||
className={`max-w-[75%] rounded-lg p-4 ${
|
||
message.role === 'user'
|
||
? 'bg-blue-500 text-white'
|
||
: 'bg-white border shadow-sm'
|
||
}`}
|
||
>
|
||
{/* Role label (only for assistant on first message) */}
|
||
{message.role === 'assistant' && idx === 1 && (
|
||
<div className="text-xs font-semibold text-gray-500 mb-2">
|
||
AI Assistant
|
||
</div>
|
||
)}
|
||
|
||
{/* Message content */}
|
||
<div className="whitespace-pre-wrap break-words">
|
||
{message.content}
|
||
</div>
|
||
</div>
|
||
</div>
|
||
))}
|
||
|
||
{/* Loading indicator */}
|
||
{isLoading && (
|
||
<div className="flex justify-start">
|
||
<div className="bg-white border rounded-lg p-4 shadow-sm">
|
||
<div className="flex items-center space-x-2">
|
||
<div className="flex space-x-1">
|
||
<div className="w-2 h-2 bg-gray-400 rounded-full animate-bounce" />
|
||
<div className="w-2 h-2 bg-gray-400 rounded-full animate-bounce delay-100" />
|
||
<div className="w-2 h-2 bg-gray-400 rounded-full animate-bounce delay-200" />
|
||
</div>
|
||
<span className="text-sm text-gray-600">Thinking...</span>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
)}
|
||
|
||
<div ref={messagesEndRef} />
|
||
</div>
|
||
)}
|
||
</div>
|
||
|
||
{/* Error banner */}
|
||
{error && (
|
||
<div className="p-4 bg-red-50 border-t border-red-200">
|
||
<div className="flex items-center justify-between max-w-4xl mx-auto">
|
||
<div className="flex items-center space-x-2 text-red-700">
|
||
<span className="text-xl">⚠️</span>
|
||
<div>
|
||
<div className="font-semibold">Error</div>
|
||
<div className="text-sm">{error.message}</div>
|
||
</div>
|
||
</div>
|
||
<button
|
||
onClick={reload}
|
||
className="px-3 py-1 text-sm border border-red-300 rounded hover:bg-red-100"
|
||
>
|
||
Retry
|
||
</button>
|
||
</div>
|
||
</div>
|
||
)}
|
||
|
||
{/* Input */}
|
||
<form onSubmit={handleSubmit} className="p-4 border-t bg-white">
|
||
<div className="max-w-4xl mx-auto">
|
||
<div className="flex space-x-2">
|
||
<input
|
||
ref={inputRef}
|
||
type="text"
|
||
value={input}
|
||
onChange={(e) => setInput(e.target.value)}
|
||
placeholder="Type a message..."
|
||
disabled={isLoading}
|
||
className="flex-1 p-3 border rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 disabled:bg-gray-100"
|
||
/>
|
||
{isLoading ? (
|
||
<button
|
||
type="button"
|
||
onClick={stop}
|
||
className="px-6 py-3 bg-red-500 text-white rounded-lg hover:bg-red-600 font-medium"
|
||
>
|
||
Stop
|
||
</button>
|
||
) : (
|
||
<button
|
||
type="submit"
|
||
disabled={!input.trim()}
|
||
className="px-6 py-3 bg-blue-500 text-white rounded-lg disabled:bg-gray-300 disabled:cursor-not-allowed hover:bg-blue-600 font-medium"
|
||
>
|
||
Send
|
||
</button>
|
||
)}
|
||
</div>
|
||
<div className="mt-2 text-xs text-gray-500 text-center">
|
||
Press Enter to send • Cmd+K to focus input
|
||
</div>
|
||
</div>
|
||
</form>
|
||
</div>
|
||
);
|
||
}
|