feat: add markdown rendering and thinking state UI to chat

src/frontend/src/lib/components/ChatInterface.svelte

@@ -1,11 +1,13 @@
 <script lang="ts">
 	import type { Bot } from '$lib/api';
 	import type { ChatMessage } from '$lib/stores/chatStore';
+	import { parseMarkdown } from '$lib/utils/markdown';
 
 	interface Props {
 		bot: Bot | null;
 		messages: ChatMessage[];
-		isSending?: boolean;
+		isThinking?: boolean;
+		thinkingContent?: string;
 		onSendMessage: (message: string) => void;
 		onSelectBot?: (botId: string) => void;
 		availableBots?: Bot[];
@@ -15,7 +17,8 @@
 	let {
 		bot,
 		messages,
-		isSending = false,
+		isThinking = false,
+		thinkingContent = '',
 		onSendMessage,
 		onSelectBot,
 		availableBots = [],
@@ -24,11 +27,13 @@
 
 	let messageInput = $state('');
 	let chatContainer: HTMLDivElement;
+	let showThinking = $state(false);
 
 	function handleSend() {
 		if (!messageInput.trim()) return;
 		onSendMessage(messageInput);
 		messageInput = '';
+		showThinking = false;
 	}
 
 	function handleKeydown(e: KeyboardEvent) {
@@ -45,6 +50,10 @@
 		}
 	}
 
+	function toggleThinking() {
+		showThinking = !showThinking;
+	}
+
 	$effect(() => {
 		if (messages.length && chatContainer) {
 			setTimeout(() => {
@@ -52,6 +61,17 @@
 			}, 50);
 		}
 	});
+
+	// Watch for thinking state changes
+	$effect(() => {
+		if (isThinking && thinkingContent) {
+			showThinking = true;
+		}
+	});
+
+	function renderContent(content: string) {
+		return parseMarkdown(content);
+	}
 </script>
 
 <div class="chat-interface">
@@ -69,7 +89,7 @@
 	{/if}
 
 	<div class="chat-messages" bind:this={chatContainer}>
-		{#if messages.length === 0}
+		{#if messages.length === 0 && !isThinking}
 			<div class="welcome-message">
 				<p>Welcome to {bot?.name || 'your bot'}! Describe your trading strategy in plain English.</p>
 				<p class="hint">Example: "Buy PEPE when the price drops by 5% within 1 hour"</p>
@@ -79,7 +99,27 @@
 		{#each messages as message}
 			<div class="message {message.role}">
 				<div class="message-content">
-					{message.content}
+					{#each renderContent(message.content) as segment}
+						{#if segment.type === 'bold'}
+							<strong>{segment.content}</strong>
+						{:else if segment.type === 'italic'}
+							<em>{segment.content}</em>
+						{:else if segment.type === 'code'}
+							<code class="inline-code">{segment.content}</code>
+						{:else if segment.type === 'codeBlock'}
+							<pre class="code-block"><code>{segment.content}</code></pre>
+						{:else if segment.type === 'link'}
+							<a href={segment.content} target="_blank" rel="noopener noreferrer">{segment.content}</a>
+						{:else if segment.type === 'list' && segment.items}
+							<ul>
+								{#each segment.items as item}
+									<li>{item}</li>
+								{/each}
+							</ul>
+						{:else}
+							{segment.content}
+						{/if}
+					{/each}
 				</div>
 				<div class="message-time">
 					{message.timestamp.toLocaleTimeString()}
@@ -87,13 +127,47 @@
 			</div>
 		{/each}
 
-		{#if isSending}
-			<div class="message assistant">
-				<div class="message-content typing">
+		{#if isThinking}
+			<div class="message assistant thinking">
+				<div class="message-content">
+					{#if thinkingContent}
+						<div class="thinking-header">
+							<button class="thinking-toggle" onclick={toggleThinking}>
+								<span class="thinking-icon">{showThinking ? '▼' : '▶'}</span>
+								<span class="thinking-label">Thinking</span>
+							</button>
+						</div>
+						{#if showThinking}
+							<div class="thinking-content">
+								{#each renderContent(thinkingContent) as segment}
+									{#if segment.type === 'bold'}
+										<strong>{segment.content}</strong>
+									{:else if segment.type === 'italic'}
+										<em>{segment.content}</em>
+									{:else if segment.type === 'code'}
+										<code class="inline-code">{segment.content}</code>
+									{:else if segment.type === 'codeBlock'}
+										<pre class="code-block"><code>{segment.content}</code></pre>
+									{:else if segment.type === 'list' && segment.items}
+										<ul>
+											{#each segment.items as item}
+												<li>{item}</li>
+											{/each}
+										</ul>
+									{:else}
+										{segment.content}
+									{/if}
+								{/each}
+							</div>
+						{/if}
+					{:else}
+						<div class="typing">
 							<span class="dot"></span>
 							<span class="dot"></span>
 							<span class="dot"></span>
 						</div>
+					{/if}
+				</div>
 			</div>
 		{/if}
 	</div>
@@ -105,9 +179,9 @@
 				onkeydown={handleKeydown}
 				placeholder="Describe your trading strategy..."
 				rows="1"
-				disabled={isSending}
+				disabled={isThinking}
 			></textarea>
-			<button onclick={handleSend} disabled={isSending || !messageInput.trim()}>
+			<button onclick={handleSend} disabled={isThinking || !messageInput.trim()}>
 				Send
 			</button>
 		</div>
@@ -213,6 +287,11 @@
 		border: 1px solid rgba(251, 191, 36, 0.3);
 	}
 
+	.message.thinking .message-content {
+		background: rgba(255, 255, 255, 0.05);
+		border: 1px dashed rgba(255, 255, 255, 0.2);
+	}
+
 	.message-time {
 		font-size: 0.7rem;
 		color: #666;
@@ -220,10 +299,92 @@
 		padding: 0 0.5rem;
 	}
 
+	.thinking-header {
+		display: flex;
+		align-items: center;
+		margin-bottom: 0.5rem;
+	}
+
+	.thinking-toggle {
+		display: flex;
+		align-items: center;
+		gap: 0.5rem;
+		background: none;
+		border: none;
+		color: #888;
+		cursor: pointer;
+		padding: 0.25rem 0.5rem;
+		border-radius: 4px;
+		font-size: 0.8rem;
+		transition: background 0.2s;
+	}
+
+	.thinking-toggle:hover {
+		background: rgba(255, 255, 255, 0.1);
+	}
+
+	.thinking-icon {
+		font-size: 0.6rem;
+	}
+
+	.thinking-label {
+		font-weight: 500;
+		text-transform: uppercase;
+		letter-spacing: 0.5px;
+	}
+
+	.thinking-content {
+		color: #999;
+		font-size: 0.9rem;
+		padding-top: 0.5rem;
+		border-top: 1px solid rgba(255, 255, 255, 0.1);
+		margin-top: 0.5rem;
+	}
+
+	.inline-code {
+		background: rgba(0, 0, 0, 0.3);
+		padding: 0.15rem 0.4rem;
+		border-radius: 4px;
+		font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
+		font-size: 0.85em;
+	}
+
+	.code-block {
+		background: rgba(0, 0, 0, 0.4);
+		padding: 0.75rem;
+		border-radius: 6px;
+		overflow-x: auto;
+		font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace;
+		font-size: 0.85rem;
+		margin: 0.5rem 0;
+	}
+
+	.code-block code {
+		white-space: pre;
+	}
+
+	ul {
+		margin: 0.5rem 0;
+		padding-left: 1.5rem;
+	}
+
+	li {
+		margin: 0.25rem 0;
+	}
+
+	a {
+		color: #667eea;
+		text-decoration: none;
+	}
+
+	a:hover {
+		text-decoration: underline;
+	}
+
 	.typing {
 		display: flex;
 		gap: 4px;
-		padding: 1rem 1.25rem;
+		padding: 0.5rem;
 	}
 
 	.dot {

src/frontend/src/lib/utils/markdown.ts

@@ -0,0 +1,92 @@
+/**
+ * Simple markdown parser for rendering AI responses
+ * Supports: bold, italic, code blocks, inline code, links, lists, headings
+ */
+
+interface ParsedSegment {
+	type: 'text' | 'bold' | 'italic' | 'code' | 'codeBlock' | 'link' | 'list';
+	content: string;
+	items?: string[];
+}
+
+export function parseMarkdown(text: string): ParsedSegment[] {
+	const segments: ParsedSegment[] = [];
+	
+	// Split by code blocks first (they can contain other markdown)
+	const codeBlockRegex = /```[\s\S]*?```/g;
+	const parts = text.split(codeBlockRegex);
+	const codeBlocks = text.match(codeBlockRegex) || [];
+	
+	let partIndex = 0;
+	
+	while (partIndex < parts.length) {
+		const part = parts[partIndex];
+		
+		if (part) {
+			// Process inline formatting
+			segments.push(...parseInlineMarkdown(part));
+		}
+		
+		// Add code block if there's one after this part
+		if (partIndex < codeBlocks.length) {
+			const codeContent = codeBlocks[partIndex].replace(/^```\w*\n?/, '').replace(/```$/, '');
+			segments.push({ type: 'codeBlock', content: codeContent });
+		}
+		
+		partIndex++;
+	}
+	
+	return segments;
+}
+
+function parseInlineMarkdown(text: string): ParsedSegment[] {
+	const segments: ParsedSegment[] = [];
+	
+	// Combined regex for bold, italic, inline code, links
+	const inlineRegex = /(\*\*[^*]+\*\*|\*[^*]+\*|`[^`]+`|\\\[.*?\]\(.*?\))/g;
+	const parts = text.split(inlineRegex);
+	
+	for (const part of parts) {
+		if (!part) continue;
+		
+		if (part.startsWith('**') && part.endsWith('**')) {
+			segments.push({ type: 'bold', content: part.slice(2, -2) });
+		} else if (part.startsWith('*') && part.endsWith('*')) {
+			segments.push({ type: 'italic', content: part.slice(1, -1) });
+		} else if (part.startsWith('`') && part.endsWith('`')) {
+			segments.push({ type: 'code', content: part.slice(1, -1) });
+		} else if (part.startsWith('[') && part.includes('](')) {
+			const linkMatch = part.match(/\[(.*?)\]\((.*?)\)/);
+			if (linkMatch) {
+				segments.push({ type: 'link', content: linkMatch[1] });
+			}
+		} else if (part.includes('\n')) {
+			// Handle newlines and lists
+			const lines = part.split('\n');
+			for (let i = 0; i < lines.length; i++) {
+				const line = lines[i];
+				if (line.match(/^[\-\*]\s/)) {
+					// List item
+					if (segments.length > 0 && segments[segments.length - 1].type === 'list') {
+						segments[segments.length - 1].items?.push(line.slice(2));
+					} else {
+						segments.push({ type: 'list', content: '', items: [line.slice(2)] });
+					}
+				} else if (line.match(/^#{1,6}\s/)) {
+					// Heading
+					segments.push({ type: 'text', content: line });
+				} else if (line) {
+					if (i > 0) {
+						segments.push({ type: 'text', content: '\n' + line });
+					} else {
+						segments.push({ type: 'text', content: line });
+					}
+				}
+			}
+		} else {
+			segments.push({ type: 'text', content: part });
+		}
+	}
+	
+	return segments;
+}

src/frontend/src/routes/bot/[id]/+page.svelte

@@ -108,7 +108,7 @@
 		<ChatInterface
 			bot={$currentBotStore}
 			messages={$chatStore}
-			{isSending}
+			isThinking={isSending}
 		onSendMessage={handleSendMessage}
 		/>
 	</div>