feat(chat): Copy buttons for code blocks

feat(chat): New models
feat(chat): Gemini with less thinking
fix(chat): Better scroll to bottom

chat.html

@@ -6,26 +6,21 @@
         <title>Cet ci pi ti</title>
         <style>
             :root {
-                /* Light theme variables */
+                color-scheme: light dark;
-                --bg-primary: #ffffff;
+                --bg-primary: Canvas;
-                --bg-secondary: hsl(220, 20%, 90%);
+                --bg-secondary: #ccc;
-                --bg-user-message: hsl(220, 58%, 80%);
+                --bg-input: #f0f0f0;
-                --bg-code: #f8f8f8;
+                --bg-user-message: Highlight;
-                --text-primary: #2c3e50;
+                --bg-code: Field;
-                --text-user: hsl(220, 78%, 22%);
+                --text-primary: CanvasText;
-                --border-color: #e1e1e1;
+                --text-user: HighlightText;
+                --border-color: #aaa;
             }
 
             @media (prefers-color-scheme: dark) {
                 :root {
-                    /* Dark theme variables */
+                    --bg-secondary: #555;
-                    --bg-primary: #1a1a1a;
+                    --bg-input: #444;
-                    --bg-secondary: hsl(220, 20%, 15%);
-                    --bg-user-message: hsl(220, 30%, 25%);
-                    --bg-code: #2d2d2d;
-                    --text-primary: #e1e1e1;
-                    --text-user: hsl(220, 58%, 80%);
-                    --border-color: #404040;
                 }
             }
 
@@ -38,12 +33,11 @@
 
             body {
                 margin: 0;
-                font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
+                /* font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; */
                 font-family: "JetBrains Mono", Consolas, Menlo, monospace;
                 line-height: 1.6;
                 font-size: 14px;
-                background-color: var(--bg-primary);
+                /* color: var(--text-primary); */
-                color: var(--text-primary);
             }
 
             a {
@@ -78,6 +72,13 @@
             textarea,
             button {
                 font-size: inherit;
+                font-family: inherit;
+                appearance: none;
+            }
+
+            .button {
+                text-transform: uppercase;
+                letter-spacing: 0.05em;
             }
 
             .message + .message {
@@ -97,14 +98,36 @@
             }
 
             .system-message pre,
-            .system-message code {
+            .system-message code,
+            .system-message pre {
                 font-family: menlo, consolas, monospace;
                 background: var(--bg-code);
-                padding: 0.5rem;
                 border-radius: 0.4rem;
+            }
+            .system-message pre {
+                position: relative;
+                padding: 0.5rem 2.5rem 0.5rem 0.5rem;
                 white-space: pre;
                 overflow-x: auto;
             }
+            .copy-btn {
+                position: absolute;
+                top: 0.4rem;
+                right: 0.6rem;
+                background: var(--bg-secondary);
+                color: var(--text-primary);
+                border: none;
+                border-radius: 0.3rem;
+                padding: 0.2rem 0.6rem;
+                font-size: 0.9em;
+                cursor: pointer;
+                opacity: 0.6;
+                transition: opacity 0.2s;
+                z-index: 2;
+            }
+            .copy-btn:hover {
+                opacity: 1;
+            }
 
             .system-message code {
                 padding: 2px 4px;
@@ -114,20 +137,20 @@
                 grid-area: prompt;
                 min-height: 40px;
                 padding: 0.8rem;
-                border: 1px solid var(--border-color);
+                border: none;
                 border-radius: 0.4rem;
-                background: var(--bg-primary);
+                /* background: var(--bg-input); */
-                color: var(--text-primary);
+                /* color: var(--text-primary); */
                 resize: vertical;
             }
 
             .submit {
                 grid-area: submit;
                 cursor: pointer;
-                padding: 0.8rem 1.6rem;
+                padding: 0.8rem 2rem;
                 background: var(--bg-secondary);
-                color: var(--text-primary);
+                /* color: var(--text-primary); */
-                border: 1px solid var(--border-color);
+                border: none;
                 border-radius: 0.4rem;
                 transition: background-color 0.2s ease;
             }
@@ -161,12 +184,32 @@
                 anchor-name: --submit;
             }
 
+            @keyframes pulse {
+                20% {
+                    opacity: 0.8;
+                }
+            }
+
+            .submit.busy {
+                animation: both pulse 1s;
+            }
+
             #model-selector {
                 position: absolute;
                 position-anchor: --submit;
                 bottom: anchor(top);
                 right: anchor(right);
+                opacity: 0.3;
+                padding: 0.5rem;
             }
+            #model-selector:is(:hover, [open]) {
+                opacity: 1;
+            }
+
+            #model-selector summary {
+                font-weight: bold;
+            }
+
             .model-opt__label {
                 display: block;
             }
@@ -210,9 +253,9 @@
         <div id="app">
             <div class="chat-container">
                 <div id="messages" class="messages"></div>
-                <textarea rows="5" id="prompt" class="prompt" placeholder="Type your message..."></textarea>
+                <textarea rows="6" id="prompt" class="prompt" placeholder="Type your message..."></textarea>
-                <button id="submit" class="submit">Send</button>
+                <button id="submit" class="submit button">Send</button>
-                <details id="model-selector" popover>
+                <details id="model-selector">
                     <summary>Model</summary>
                 </details>
             </div>
@@ -224,10 +267,10 @@
             const models = [
                 { name: "gpt-4.1", chat: chatWithOpenAI },
                 { name: "gpt-4.1-mini", chat: chatWithOpenAI },
-                { name: "gemini-2.5-flash", chat: chatWithGemini },
+                { name: "gemini-3-flash-preview", chat: chatWithGemini },
-                { name: "claude-3-7-sonnet-20250219", chat: chatWithClaude },
+                { name: "claude-haiku-4-5-20251001", chat: chatWithClaude },
             ];
-            window.env.MODEL ||= "gemini-2.5-flash";
+            window.env.MODEL ||= "gemini-3-flash-preview";
 
             const systemPrompt = `You are a helpful AI assistant.
                                     Do not preach about implications,
@@ -248,6 +291,18 @@
             const $submit = document.querySelector("#submit");
             const $modelSelector = document.querySelector("#model-selector");
 
+            // grow the prompt textarea as needed
+            const minRows = +$prompt.rows;
+            const maxRows = 10;
+            $prompt.addEventListener(
+                "input",
+                debounce((e) => {
+                    const lines = e.target.value.split("\n").length;
+                    e.target.rows = Math.min(maxRows, Math.max(minRows, lines));
+                }, 100)
+            );
+
+            // populate model selector
             $modelSelector.append(
                 ...models.map((model) => {
                     return Object.assign(document.createElement("label"), {
@@ -256,7 +311,7 @@
                     });
                 })
             );
-            $modelSelector.addEventListener("mouseover", (e) => {
+            $modelSelector.addEventListener("mouseenter", (e) => {
                 const open = $modelSelector.hasAttribute("open");
                 if (!open) {
                     $modelSelector.setAttribute("open", "");
@@ -301,14 +356,14 @@
                 $modelSelector.removeAttribute("open");
 
                 // Add user message
-                const userMessage = createMessageElement(prompt, true);
+                const $userMessage = createMessageElement(prompt, true);
-                $messages.appendChild(userMessage);
+                $messages.appendChild($userMessage);
                 messages.push({ role: "user", content: prompt });
 
                 // Prepare for system response
-                const systemMessage = createMessageElement("", false);
+                const $systemMessage = createMessageElement("", false);
-                const md = new StreamingMarkdown(systemMessage);
+                $messages.appendChild($systemMessage);
-                $messages.appendChild(systemMessage);
+                const md = new StreamingMarkdown($systemMessage);
                 let fullResponse = "";
 
                 $prompt.value = "";
@@ -326,14 +381,18 @@
                 }
 
                 $submit.textContent = "Cancel";
+                $submit.classList.add("busy");
                 try {
                     await chat({
                         model: pickedModel,
                         onContent: (content) => {
                             fullResponse += content;
-                            smd.parser_write(parser, content);
+                            md.append(content);
                             scrollToBottom($messages);
                         },
+                        onError(e) {
+                            md.append("ERROR:```\n" + e.message + "\n```");
+                        },
                         messages,
                         signal: abortController.signal,
                     });
@@ -349,6 +408,7 @@
                 } finally {
                     md.finish();
                     $submit.textContent = "Send";
+                    $submit.classList.remove("busy");
                     abortController = null;
                 }
             }
@@ -371,14 +431,12 @@
                 return $el.scrollHeight - $el.clientHeight - $el.scrollTop <= threshold;
             }
 
-            // Function to scroll to bottom (only called when new content arrives)
+            const scrollToBottom = throttle(($el) => {
-            function scrollToBottom($el) {
                 if (!userHasScrolledUp) {
                     $el.scrollTop = $el.scrollHeight;
                 }
-            }
+            }, 500);
 
-            // Listen for user scroll events to detect if they scrolled up
             $messages.addEventListener("scroll", () => {
                 userHasScrolledUp = !isAtBottom($messages);
             });
@@ -390,12 +448,23 @@
              *  extraHeaders: Record<string, string>,
              *  signal: AbortSignal,
              *  apiKey: string,
-             *  model: string
+             *  model: string,
+             *  [key: string]: any
              * }} ChatArgs
              */
 
             /** @param {ChatArgs} args - The arguments for the chatWithClaude function. */
-            async function chatWithOpenAI({ baseUrl = "https://api.openai.com/v1", onContent, messages, signal, apiKey = window.env.OPENAI_API_KEY, model, extraHeaders = {} }) {
+            async function chatWithOpenAI({
+                baseUrl = "https://api.openai.com/v1",
+                onContent,
+                onError,
+                messages,
+                signal,
+                apiKey = window.env.OPENAI_API_KEY,
+                model,
+                extraHeaders = {},
+                ...rest
+            }) {
                 const response = await fetch(`${baseUrl}/chat/completions`, {
                     method: "POST",
                     headers: {
@@ -407,10 +476,17 @@
                         model,
                         messages,
                         stream: true,
+                        ...rest,
                     }),
                     signal,
                 });
 
+                if (!response.ok) {
+                    const text = await response.text();
+                    await onError?.(new Error(`HTTP ${response.status}:\n${text.trim()}`));
+                    return;
+                }
+
                 const reader = response.body.getReader();
                 const decoder = new TextDecoder();
 
@@ -422,7 +498,7 @@
                     const lines = text
                         .split("\n\n")
                         .filter((line) => !!line.trim())
-                        .map((line) => line.replace("data: ", ""));
+                        .map((line) => line.trim().replace("data: ", ""));
 
                     for (const line of lines) {
                         if (line === "[DONE]") return;
@@ -440,6 +516,7 @@
             /*** @param {ChatArgs} args - The arguments for the chatWithClaude function. */
             async function chatWithClaude(args) {
                 return chatWithOpenAI({
+                    ...args,
                     baseUrl: "https://api.anthropic.com/v1",
                     extraHeaders: {
                         "x-api-key": args.apiKey,
@@ -447,34 +524,181 @@
                         "anthropic-dangerous-direct-browser-access": "true",
                     },
                     apiKey: window.env.ANTHROPIC_API_KEY,
-                    ...args,
                 });
             }
 
             /*** @param {ChatArgs} args - The arguments for the chatWithGemini function. */
-            async function chatWithGemini(args) {
+            /**
-                return chatWithOpenAI({
+             * Native Gemini Implementation
-                    baseUrl: "https://generativelanguage.googleapis.com/v1beta/openai",
+             * @param {ChatArgs} args
-                    apiKey: window.env.GEMINI_API_KEY,
+             */
-                    ...args,
+            async function chatWithGemini({ onContent, onError, messages, signal, apiKey = window.env.GEMINI_API_KEY, model = "gemini-3-flash-preview", ...rest }) {
+                // Convert OpenAI message format to Gemini format
+                const contents = messages.map((msg) => ({
+                    role: msg.role === "assistant" ? "model" : "user",
+                    parts: [{ text: msg.content }],
+                }));
+
+                try {
+                    const response = await fetch(`https://generativelanguage.googleapis.com/v1beta/models/${model}:streamGenerateContent?key=${apiKey}`, {
+                        method: "POST",
+                        headers: {
+                            "Content-Type": "application/json",
+                        },
+                        body: JSON.stringify({
+                            contents,
+                            generationConfig: {
+                                thinkingConfig: {
+                                    thinkingLevel: "low",
+                                },
+                                ...rest,
+                            },
+                        }),
+                        signal,
                     });
+
+                    if (!response.ok) {
+                        const text = await response.text();
+                        await onError?.(new Error(`Gemini API Error ${response.status}: ${text}`));
+                        return;
+                    }
+
+                    const reader = response.body.getReader();
+                    const decoder = new TextDecoder();
+                    let buffer = "";
+
+                    while (true) {
+                        const { done, value } = await reader.read();
+                        if (done) break;
+
+                        buffer += decoder.decode(value, { stream: true });
+
+                        // Gemini's native stream returns a JSON array of objects.
+                        // In a streaming context, it looks like: [ { ... }, { ... } ]
+                        // We need to strip the brackets and commas or parse the chunks.
+
+                        // Note: This is a simplified parser for the typical Gemini stream format
+                        // which arrives as an array of JSON objects.
+                        let startIdx;
+                        while ((startIdx = buffer.indexOf("{")) !== -1) {
+                            let endIdx = -1;
+                            let depth = 0;
+
+                            // Find the matching closing bracket
+                            for (let i = startIdx; i < buffer.length; i++) {
+                                if (buffer[i] === "{") depth++;
+                                else if (buffer[i] === "}") depth--;
+
+                                if (depth === 0) {
+                                    endIdx = i;
+                                    break;
+                                }
+                            }
+
+                            if (endIdx === -1) break; // Incomplete JSON object
+
+                            const jsonStr = buffer.substring(startIdx, endIdx + 1);
+                            buffer = buffer.substring(endIdx + 1);
+
+                            try {
+                                const parsed = JSON.parse(jsonStr);
+                                const content = parsed.candidates?.[0]?.content?.parts?.[0]?.text;
+                                if (content) {
+                                    await onContent(content);
+                                }
+                            } catch (e) {
+                                console.error("Error parsing Gemini chunk", e);
+                            }
+                        }
+                    }
+                } catch (err) {
+                    if (err.name !== "AbortError") {
+                        await onError?.(err);
+                    }
+                }
             }
 
             class StreamingMarkdown {
                 constructor($el) {
                     this.$el = $el;
-                    this.renderer = smd.default_renderer(systemMessage);
+                    this.renderer = smd.default_renderer($el);
-                    this.parser = smd.parser(renderer);
+                    this.parser = smd.parser(this.renderer);
                 }
 
                 append(markdown) {
                     smd.parser_write(this.parser, markdown);
+                    // Add copy buttons after rendering new markdown
+                    addCopyButtonsToCodeBlocks(this.$el);
                 }
 
                 finish() {
                     smd.parser_end(this.parser);
+                    addCopyButtonsToCodeBlocks(this.$el);
                 }
             }
+
+            /**
+             * Creates a debounced function that delays execution
+             * @param {Function} func - Function to debounce
+             * @param {number} delay - Delay in milliseconds
+             * @returns {Function} Debounced function
+             */
+            function debounce(func, delay) {
+                let timeoutId;
+                return function debounced(...args) {
+                    clearTimeout(timeoutId);
+                    timeoutId = setTimeout(() => func.apply(this, args), delay);
+                };
+            }
+
+            /**
+             * Creates a throttled function that limits execution frequency
+             * @param {Function} func - Function to throttle
+             * @param {number} limit - Minimum time between calls in milliseconds
+             * @returns {Function} Throttled function
+             */
+            function throttle(func, limit) {
+                let inThrottle;
+                return function throttled(...args) {
+                    if (!inThrottle) {
+                        func.apply(this, args);
+                        inThrottle = true;
+                        setTimeout(() => (inThrottle = false), limit);
+                    }
+                };
+            }
+
+            // Add copy-to-clipboard buttons to code blocks in system messages
+            function addCopyButtonsToCodeBlocks($container) {
+                // Only add to <pre><code>...</code></pre> blocks
+                $container.querySelectorAll("pre").forEach(($pre) => {
+                    // Avoid duplicate buttons
+                    if ($pre.querySelector(".copy-btn")) return;
+                    const $code = $pre.querySelector("code");
+                    if (!$code) return;
+                    const $btn = document.createElement("button");
+                    $btn.className = "copy-btn";
+                    $btn.type = "button";
+                    $btn.textContent = "Copy";
+                    $btn.addEventListener("click", (e) => {
+                        try {
+                            const textArea = document.createElement("textarea");
+                            textArea.value = $code.innerText;
+                            document.body.appendChild(textArea);
+                            textArea.select();
+                            document.execCommand("copy");
+                            document.body.removeChild(textArea);
+
+                            $btn.textContent = "Copied!";
+                            setTimeout(() => ($btn.textContent = "Copy"), 1200);
+                        } catch {
+                            $btn.textContent = "Failed";
+                            setTimeout(() => ($btn.textContent = "Copy"), 1200);
+                        }
+                    });
+                    $pre.appendChild($btn);
+                });
+            }
         </script>
     </body>
 </html>