import { useEffect, useRef, useState } from "react";
import { codeToTokens } from "shiki";
import { Card } from "@/components/ui/card";
import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
import { CopyableCode } from "@/components/copyable-code";
/**
* A self-cycling gallery of real chat-rs snippets across a mix of providers.
*
* Transitions are a full typewriter: the entire current snippet types out, then
* the entire next one types in. Each snippet is highlighted once with Shiki; the
* typewriter just reveals a prefix of the pre-tokenized output.
*
* Auto-advance shows a progress fill inside the active tab. Selecting a tab
* manually stops the auto-advance entirely: it transitions to that snippet
* and then sits still.
*/
type Snippet = { id: string; label: string; code: string };
type Char = { ch: string; style: Record<string, string> };
/** What's currently on screen: the first `visible` chars of `id`. */
type RenderState = { id: string; visible: number };
const OUT_STEP = 9; // chars deleted per tick
const IN_STEP = 4; // chars typed per tick
const TICK_MS = 16;
const DWELL_MS = 3500; // pause on a settled snippet before auto-advancing
const SNIPPETS: Snippet[] = [
{
id: "streaming",
label: "Streaming",
code: `use chat_rs::{ChatBuilder, StreamEvent, ollama::OllamaBuilder, parts, types::messages};
use futures::StreamExt;
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
// A local model, pulled and run on your machine. No API keys.
let client = OllamaBuilder::new().with_model("llama3.2").pull().await?.build();
let mut chat = ChatBuilder::new().with_model(client).build();
let mut messages = messages::from_user(parts!["Explain ownership in one line."]);
// Interaction is a typed event stream. Consume it as it arrives.
let mut stream = chat.stream(&mut messages).await.map_err(|e| e.err)?;
while let Some(event) = stream.next().await {
if let Ok(StreamEvent::TextChunk(text)) = event {
print!("{text}");
}
}
Ok(())
}`,
},
{
id: "multimodal",
label: "Multimodal",
code: `use chat_rs::{
ChatBuilder, ChatOutcome, gemini::GeminiBuilder, parts,
types::messages::{self, file::File},
};
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
let client = GeminiBuilder::new().with_model("gemini-2.5-flash").build();
let mut chat = ChatBuilder::new().with_model(client).build();
// Text, images, audio, video, and documents are all just Parts.
// One message, mixed modalities, no per-type plumbing.
let mut messages = messages::from_user(parts![
"What's in this picture?",
File::from_path("diagram.png")?,
]);
if let ChatOutcome::Complete(res) = chat.complete(&mut messages).await.map_err(|e| e.err)? {
if let Some(text) = res.content.parts.text_response() {
println!("{text}");
}
}
Ok(())
}`,
},
{
id: "tools",
label: "Tools",
code: `use chat_rs::{ChatBuilder, ChatOutcome, claude::ClaudeBuilder, parts, types::messages};
use tools_rs::{collect_tools, tool};
#[tool]
/// Look up the current weather for a city.
async fn get_weather(city: String) -> String {
format!("It's 22°C and sunny in {city}.")
}
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let client = ClaudeBuilder::new().with_model("claude-sonnet-4").build();
let mut chat = ChatBuilder::new()
.with_tools(collect_tools())
.with_model(client)
.with_max_steps(5)
.build();
let mut messages = messages::from_user(parts!["What's the weather in Lisbon?"]);
// The loop calls your function, feeds the result back, and continues.
if let ChatOutcome::Complete(res) = chat.complete(&mut messages).await.map_err(|e| e.err)? {
if let Some(text) = res.content.parts.text_response() {
println!("{text}");
}
}
Ok(())
}`,
},
{
id: "structured",
label: "Structured",
code: `use chat_rs::{ChatBuilder, ChatOutcome, openai::OpenAIBuilder, parts, types::messages};
use schemars::JsonSchema;
use serde::Deserialize;
#[derive(JsonSchema, Deserialize, Debug)]
struct Recipe {
title: String,
ingredients: Vec<String>,
}
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let client = OpenAIBuilder::new().with_model("gpt-4o").build();
// The model is constrained to your type. You get Recipe back, typed.
let mut chat = ChatBuilder::new()
.with_structured_output::<Recipe>()
.with_model(client)
.build();
let mut messages = messages::from_user(parts!["A simple recipe for pancakes."]);
if let ChatOutcome::Complete(res) = chat.complete(&mut messages).await.map_err(|e| e.err)? {
println!("{}: {} ingredients", res.content.title, res.content.ingredients.len());
}
Ok(())
}`,
},
];
const codeOf = (id: string) => SNIPPETS.find((s) => s.id === id)!.code;
export function CodeGallery() {
const [chars, setChars] = useState<Record<string, Char[]>>({});
const ready = Object.keys(chars).length === SNIPPETS.length;
const [index, setIndex] = useState(0); // target snippet
const [auto, setAuto] = useState(true);
const [dwelling, setDwelling] = useState(false);
const [render, setRender] = useState<RenderState>({
id: SNIPPETS[0].id,
visible: SNIPPETS[0].code.length,
});
const renderRef = useRef(render);
renderRef.current = render;
const autoRef = useRef(auto);
autoRef.current = auto;
// Pre-tokenize every snippet once, dual-theme so it tracks light/dark.
useEffect(() => {
let alive = true;
(async () => {
const entries = await Promise.all(
SNIPPETS.map(async (s) => {
const { tokens } = await codeToTokens(s.code, {
lang: "rust",
themes: { light: "github-light", dark: "github-dark" },
defaultColor: false,
});
const flat: Char[] = [];
tokens.forEach((line, li) => {
for (const tok of line) {
const style = (tok.htmlStyle ?? {}) as Record<string, string>;
for (const ch of tok.content) flat.push({ ch, style });
}
if (li < tokens.length - 1) flat.push({ ch: "\n", style: {} });
});
return [s.id, flat] as const;
}),
);
if (alive) setChars(Object.fromEntries(entries));
})();
return () => {
alive = false;
};
}, []);
// Driver: type the current snippet out in full, then type the next in full.
useEffect(() => {
if (!ready) return;
const fromId = renderRef.current.id;
const toId = SNIPPETS[index].id;
if (fromId === toId) {
setRender({ id: toId, visible: codeOf(toId).length });
if (autoRef.current) setDwelling(true);
return;
}
setDwelling(false);
const target = codeOf(toId).length;
let phase: "out" | "in" = "out";
let visible = codeOf(fromId).length;
let srcId = fromId;
const timer = setInterval(() => {
if (phase === "out") {
visible -= OUT_STEP;
if (visible <= 0) {
visible = 0;
phase = "in";
srcId = toId;
}
} else {
visible += IN_STEP;
if (visible >= target) visible = target;
}
setRender({ id: srcId, visible });
if (phase === "in" && visible >= target) {
clearInterval(timer);
if (autoRef.current) setDwelling(true);
}
}, TICK_MS);
return () => clearInterval(timer);
}, [index, ready]);
const select = (i: number) => {
setAuto(false);
setDwelling(false);
setIndex(i);
};
// Compose the visible characters: the first `visible` chars of the snippet.
const flat = chars[render.id];
const runs: { text: string; style: Record<string, string> }[] = [];
if (flat) {
for (const c of flat.slice(0, render.visible)) {
const last = runs[runs.length - 1];
if (last && last.style === c.style) last.text += c.ch;
else runs.push({ text: c.ch, style: { ...c.style } });
}
}
const activeId = SNIPPETS[index].id;
return (
<Card className="gap-0 border border-border p-0 ring-0">
<CopyableCode code={SNIPPETS[index].code}>
<pre className="shiki not-prose min-h-[27rem] overflow-x-auto px-4 py-5 text-sm leading-relaxed sm:px-6">
<code>
{flat
? runs.map((r, i) => (
<span key={i} style={r.style as React.CSSProperties}>
{r.text}
</span>
))
: codeOf(render.id)}
<span className="gallery-cursor" aria-hidden>
▍
</span>
</code>
</pre>
</CopyableCode>
{/* Bottom tabs (shadcn / Base UI). The progress fill loads inside the
selected tab only; selecting a tab stops the auto-advance. */}
<Tabs
value={activeId}
onValueChange={(value) =>
select(SNIPPETS.findIndex((s) => s.id === value))
}
className="gap-0 border-t border-border"
>
<TabsList
variant="line"
className="flex h-auto w-full flex-wrap bg-transparent p-0"
>
{SNIPPETS.map((s) => (
<TabsTrigger
key={s.id}
value={s.id}
className="font-label relative h-auto flex-1 overflow-hidden px-4 py-3 text-xs uppercase tracking-[0.2em] data-active:text-primary"
>
{auto && dwelling && s.id === activeId && (
<span
className="pointer-events-none absolute inset-y-0 left-0 bg-primary/15"
style={{
animation: `gallery-sweep ${DWELL_MS}ms linear forwards`,
}}
onAnimationEnd={() => {
setDwelling(false);
if (autoRef.current)
setIndex((idx) => (idx + 1) % SNIPPETS.length);
}}
/>
)}
<span className="relative">{s.label}</span>
</TabsTrigger>
))}
</TabsList>
</Tabs>
</Card>
);
}