feat: AI experiment

app/admin/(private)/ai-assistant/ai-assistant-chat.tsx

@@ -0,0 +1,295 @@
+"use client";
+
+import { createGoogleGenerativeAI } from "@ai-sdk/google";
+import {
+	createIdFromString,
+	type KyselyNotNull,
+	sqliteTrue,
+} from "@evolu/common";
+import { generateText, type ModelMessage, stepCountIs, tool } from "ai";
+import { useAtomValue } from "jotai";
+import { LoaderCircleIcon, SendIcon } from "lucide-react";
+import Link from "next/link";
+import { useMemo, useState } from "react";
+import { toast } from "sonner";
+import { accountAtom } from "@/atoms/account";
+import { Button } from "@/components/ui/button";
+import { ScrollArea } from "@/components/ui/scroll-area";
+import { Textarea } from "@/components/ui/textarea";
+import { useEvolu } from "@/hooks/use-evolu";
+import { useEvoluQuery } from "@/hooks/use-evolu-query";
+import {
+	createItemAssistantSystemPrompt,
+	createItemToolInputSchema,
+	createItemToolName,
+} from "@/lib/ai/item-assistant";
+import { createQuery } from "@/lib/evolu";
+import { createItem } from "@/lib/item/service";
+import { NonEmptyString, NonEmptyString255 } from "@/lib/shared/types";
+import { decimalStringToMinorUnits } from "@/lib/shared/zod/money-codec";
+
+type ChatMessage = {
+	id: string;
+	role: "user" | "assistant";
+	content: string;
+};
+
+const createMessageId = () =>
+	globalThis.crypto?.randomUUID?.() ?? Math.random().toString(36).slice(2);
+
+const toModelMessages = (messages: readonly ChatMessage[]): ModelMessage[] =>
+	messages.map((message) => ({
+		role: message.role,
+		content: message.content,
+	}));
+
+export function AiAssistantChat() {
+	const evolu = useEvolu();
+	const account = useAtomValue(accountAtom);
+	const [messages, setMessages] = useState<ChatMessage[]>([]);
+	const [prompt, setPrompt] = useState("");
+	const [isGenerating, setIsGenerating] = useState(false);
+	const [error, setError] = useState<string | null>(null);
+
+	const settingsId = createIdFromString("");
+
+	const aiSettingsQuery = useMemo(
+		() =>
+			createQuery((db) =>
+				db
+					.selectFrom("aiAssistantSettings")
+					.select(["googleApiKey"] as const)
+					.where("isDeleted", "is not", sqliteTrue)
+					.where("id", "=", settingsId)
+					.where("googleApiKey", "is not", null)
+					.$narrowType<{
+						googleApiKey: KyselyNotNull;
+					}>(),
+			),
+		[settingsId],
+	);
+	const { data: aiSettingsRows } = useEvoluQuery(aiSettingsQuery);
+
+	const billingSettingsQuery = useMemo(
+		() =>
+			createQuery((db) =>
+				db
+					.selectFrom("billingSettings")
+					.select(["defaultCurrency"] as const)
+					.where("isDeleted", "is not", sqliteTrue)
+					.where("id", "=", settingsId)
+					.where("defaultCurrency", "is not", null)
+					.$narrowType<{
+						defaultCurrency: KyselyNotNull;
+					}>(),
+			),
+		[settingsId],
+	);
+	const { data: billingSettingsRows } = useEvoluQuery(billingSettingsQuery);
+
+	const googleApiKey = aiSettingsRows[0]?.googleApiKey ?? null;
+	const defaultCurrency = billingSettingsRows[0]?.defaultCurrency ?? null;
+
+	const submitPrompt = async () => {
+		const nextPrompt = prompt.trim();
+		if (nextPrompt === "" || isGenerating) {
+			return;
+		}
+
+		if (googleApiKey === null) {
+			toast.error("Nejprve nastavte Google API key v nastavení asistenta.");
+			return;
+		}
+
+		const userMessage: ChatMessage = {
+			id: createMessageId(),
+			role: "user",
+			content: nextPrompt,
+		};
+
+		const nextMessages = [...messages, userMessage];
+		setMessages(nextMessages);
+		setPrompt("");
+		setIsGenerating(true);
+		setError(null);
+
+		try {
+			const google = createGoogleGenerativeAI({
+				apiKey: googleApiKey,
+			});
+
+			const result = await generateText({
+				model: google("gemini-2.5-flash-lite"),
+				system: createItemAssistantSystemPrompt({
+					defaultCurrency,
+				}),
+				messages: toModelMessages(nextMessages),
+				tools: {
+					create_item: tool({
+						description: "Create a new sales item in the local inventory.",
+						inputSchema: createItemToolInputSchema,
+						execute: async (input) => {
+							const currency = input.currency ?? defaultCurrency ?? null;
+
+							if (currency === null) {
+								return {
+									success: false,
+									message:
+										"Nemohu vytvořit položku bez měny. Doplň prosím měnu.",
+								};
+							}
+
+							const normalizedPrice = input.price.replace(",", ".").trim();
+							const price = decimalStringToMinorUnits({
+								value: normalizedPrice,
+								currency,
+							});
+
+							if (price === null) {
+								return {
+									success: false,
+									message:
+										"Cena má neplatný formát. Použij prosím číslo, například 49.90.",
+								};
+							}
+
+							const item = createItem({
+								evolu,
+							})({
+								item: {
+									deviceId: account.device.id,
+									label: NonEmptyString255(input.label.trim()),
+									price,
+									currency,
+									unitOfMeasure:
+										input.unitOfMeasure && input.unitOfMeasure.trim() !== ""
+											? NonEmptyString(input.unitOfMeasure.trim())
+											: null,
+									internalCode: null,
+									productCodeType: null,
+									productCodeValue: null,
+									categoryId: null,
+								},
+							});
+
+							toast.success(`Položka "${item.label}" byla vytvořena.`);
+
+							return {
+								success: true,
+								message: `Položka "${item.label}" byla vytvořena.`,
+								itemId: item.id,
+							};
+						},
+					}),
+				},
+				stopWhen: stepCountIs(5),
+			});
+
+			const assistantText = result.text.trim();
+			const firstToolResult = result.toolResults.find(
+				(part) =>
+					part.type === "tool-result" && part.toolName === createItemToolName,
+			);
+			const toolMessage =
+				firstToolResult && "output" in firstToolResult
+					? (firstToolResult.output as { message?: unknown })
+					: null;
+			const fallbackMessage =
+				toolMessage && typeof toolMessage.message === "string"
+					? toolMessage.message
+					: "Hotovo.";
+
+			setMessages((prev) => [
+				...prev,
+				{
+					id: createMessageId(),
+					role: "assistant",
+					content: assistantText === "" ? fallbackMessage : assistantText,
+				},
+			]);
+		} catch (error) {
+			const message =
+				error instanceof Error
+					? error.message
+					: "Nepodařilo se odpovědět. Zkuste to prosím znovu.";
+			setError(message);
+			toast.error("Asistent selhal. Zkuste to prosím znovu.");
+		} finally {
+			setIsGenerating(false);
+		}
+	};
+
+	if (googleApiKey === null) {
+		return (
+			<div className="rounded-md border border-border p-4 text-sm">
+				<div className="mb-3">
+					Pro použití asistenta nejprve uložte Google API klíč v nastavení.
+				</div>
+				<Button
+					render={<Link href="/admin/settings/ai-assistant" />}
+					variant="outline"
+				>
+					Otevřít nastavení asistenta
+				</Button>
+			</div>
+		);
+	}
+
+	return (
+		<div className="space-y-4">
+			<ScrollArea className="h-80 rounded-md border border-border p-3">
+				<div className="flex flex-col gap-2 pr-3">
+					{messages.length === 0 && (
+						<div className="text-sm text-muted-foreground">
+							Napište například: „vytvoř novou prodejní položku Espresso za 59
+							CZK“.
+						</div>
+					)}
+
+					{messages.map((message) => (
+						<div
+							key={message.id}
+							className={
+								"max-w-[85%] rounded-md px-3 py-2 text-sm whitespace-pre-wrap " +
+								(message.role === "user"
+									? "ml-auto bg-primary text-primary-foreground"
+									: "bg-muted text-foreground")
+							}
+						>
+							{message.content}
+						</div>
+					))}
+				</div>
+			</ScrollArea>
+
+			<div className="space-y-2">
+				<Textarea
+					value={prompt}
+					placeholder="Napište požadavek…"
+					onChange={(event) => setPrompt(event.target.value)}
+					onKeyDown={(event) => {
+						if (event.key === "Enter" && !event.shiftKey) {
+							event.preventDefault();
+							void submitPrompt();
+						}
+					}}
+				/>
+				<div className="flex items-center justify-between gap-2">
+					<div className="text-xs text-muted-foreground">{error}</div>
+					<Button
+						type="button"
+						onClick={() => void submitPrompt()}
+						disabled={isGenerating || prompt.trim() === ""}
+					>
+						{isGenerating ? (
+							<LoaderCircleIcon className="animate-spin" />
+						) : (
+							<SendIcon />
+						)}
+						Odeslat
+					</Button>
+				</div>
+			</div>
+		</div>
+	);
+}

app/admin/(private)/ai-assistant/layout.tsx

@@ -0,0 +1,15 @@
+"use client";
+
+import { DefautLayout } from "@/app/admin/defaut-layout";
+
+export default function Layout(
+	props: Readonly<{
+		children: React.ReactNode;
+	}>,
+) {
+	return (
+		<DefautLayout titleKey={"admin:layout.title.aiAssistant"}>
+			{props.children}
+		</DefautLayout>
+	);
+}

app/admin/(private)/ai-assistant/page.tsx

@@ -0,0 +1,31 @@
+"use client";
+
+import { useTranslation } from "react-i18next";
+import { AiAssistantChat } from "@/app/admin/(private)/ai-assistant/ai-assistant-chat";
+import { ResponsiveCard } from "@/components/responsive-card";
+import {
+	CardContent,
+	CardDescription,
+	CardHeader,
+	CardTitle,
+} from "@/components/ui/card";
+
+export default function Home() {
+	const { t } = useTranslation();
+
+	return (
+		<div className="w-full max-w-4xl">
+			<ResponsiveCard>
+				<CardHeader>
+					<CardTitle>{t("settings:page.aiAssistant")}</CardTitle>
+					<CardDescription>
+						{t("settings:page.aiAssistantDescription")}
+					</CardDescription>
+				</CardHeader>
+				<CardContent>
+					<AiAssistantChat />
+				</CardContent>
+			</ResponsiveCard>
+		</div>
+	);
+}