Invoice print

// Copyright (c) 2026 Bruno Delorence. MIT License.'use client';import {  useEffect,  useEffectEvent,  useId,  useLayoutEffect,  useRef,  useState,  type CSSProperties,} from 'react';import { GhostPointer, runDemo } from './ghost-pointer';import { CheckIcon, DownloadIcon, TrayIcon } from './icons';import { INVOICES, money, plainText, totalOf, type Invoice } from './invoices';import { FEED, IN, OUT, OUTLINE, PEEK, RETRACT, SHEET, TAIL, TEAR, feedEasing } from './motion';import { Sheet } from './sheet';import { useAutoplay } from './use-autoplay';import styles from './invoice-print.module.css';/* * Invoice print: the moment an invoice is ready, told as a receipt printer. A dialog card says * the invoice is ready and prints it out of a slot: the paper feeds out downwards a line at a

/* Invoice print (invoice-print.tsx, sheet.tsx). Sizes are in em: the stage sets the font-size from   its own width (a container query), up to 16px, so that the card and its 19em sheet always fit,   and everything follows. The paper's geometry (--sheet-w, --sheet-h, --tail, --peek) and the   feed's easing (--feed, --feed-ms) come from motion.ts, through the component's inline style.   A light stage with a white card, or at night a near-black stage with a dark grey card; the   sheet is paper in both. */.root {  /* Its colours, light and dark: each light-dark() pair resolves by the color-scheme the root     inherits from the page, or the one the colorScheme prop sets (below). */  /* The stage, the card a step up, and New invoice on the card, then under the pointer. */  --surface: #e6e6e9;  --surface-2: #fff;  --surface-3: #f1f1f3;  --surface-3-hover: #e9e9ec;  /* Text on the card: titles and buttons, then the lines under them. */  --ink: #1d1d1f;  --ink-muted: #6e6e73;  /* The stage's edge and dots, the card's edge, New invoice's edge. */  --line: rgb(0 0 0 / 0.06);  --dots: rgb(0 0 0 / 0.05);  --card-line: rgb(0 0 0 / 0.04);  --button-line: rgb(0 0 0 / 0.05);  /* Download: its fill, under the pointer, and its text; the focus ring. */

import { Monogram } from './icons';import { amount, money, totalOf, type Invoice } from './invoices';import styles from './invoice-print.module.css';/* * The printed invoice, as text a screen reader can read and a reader can select: the studio's * mark, the number and date, who it is from and who pays it, the items, the total due, how to pay * and a last line of thanks. Every line keeps to one line (the sheet's size never changes), and * the items take whatever room is left, so one item or two fit the same sheet. */export function Sheet({ invoice }: { invoice: Invoice }) {  return (    <div className={styles.receipt}>      <div className={styles.masthead} data-part="masthead">        <Monogram className={styles.mark} />        <p className={styles.wordmark}>{invoice.from.name}</p>        <p className={styles.reference}>          <span className={styles.kind}>Invoice</span>          <span>{invoice.number}</span>          <span>{invoice.issued}</span>        </p>      </div>      <div className={styles.parties} data-part="parties">

/* * The paper: its size, how it moves, and its outline. Sizes are in em of the card's text, so * the stylesheet and the animations agree whatever the card's size. * * - The feed. A receipt printer pushes the paper out a line at a time. The whole print is one *   animation of the sheet's transform, and its easing is a CSS linear() curve drawn as a *   staircase: a short push, eased out, then a pause, again and again, with a little give at the *   end as the paper settles. The stylesheet plays it for the first print, so it runs before *   JavaScript does; the component plays the same curve with the Web Animations API afterwards. * - The tear. The sheet is tugged down, rips along the slot and drops into the tray, fading. * - The outline. The paper is an SVG path, filled and edged with a hairline. Its bottom edge is *   serrated where the last sheet was torn off; once torn, its top edge gets the same teeth, so *   the two edges fit. The path is drawn in em, the units of the box it fills. *//** The sheet, in em. */export const SHEET = { width: 19, height: 21 };/** How much paper stays in the printer, above the slot, in em: the settle never shows its end. */export const TAIL = 1.2;/** How far the paper's serrated edge peeks out of the slot between two sheets, in em. */export const PEEK = 0.32;/** A length in em, rounded, for the keyframes. */const em = (value: number) => `${+value.toFixed(3)}em`;

/* * The invoices: their shape, the sample ones the demo prints (a made-up studio billing made-up * clients), and the two ways out of the component, a total in dollars and a plain-text copy. * Amounts are in cents, so they always add up. */export type Party = {  /** A person or a company. */  name: string;  /** The lines under the name: a company, a street, a town. Two read best. */  lines: string[];};export type LineItem = {  description: string;  quantity: number;  /** The price of one, in cents. */  price: number;};export type Invoice = {  /** As printed: "INV-0042". */  number: string;  /** The dates, as printed. */

/* * The icons, drawn on a 24 × 24 grid with round strokes in the current colour. All of them are * decorative: the text next to them says what they mean. */type IconProps = { className?: string };/** An arrow going down into a tray: the invoice is ready to download. */export function TrayIcon({ className }: IconProps) {  return (    <svg className={className} viewBox="0 0 24 24" aria-hidden="true">      <path d="M4.5 13.5v3.25a2.75 2.75 0 0 0 2.75 2.75h9.5a2.75 2.75 0 0 0 2.75-2.75V13.5" />      <g data-arrow="">        <path d="M12 4.25v10" />        <path d="m8.25 10.75 3.75 3.75 3.75-3.75" />      </g>    </svg>  );}/** The download button's arrow, onto a line. */export function DownloadIcon({ className }: IconProps) {  return (    <svg className={className} viewBox="0 0 24 24" aria-hidden="true">

'use client';import type { CSSProperties, Ref } from 'react';/* * The demo's ghost pointer, and the timeline that moves it. A demo is a script of awaited steps: * wait, glide the pointer onto a control, press it and call the component's own handler, as a * click would. Stopping the demo (the reader takes over, or it scrolls away) ends the step in * progress at once: its promise rejects, which ends the script right there, and the pointer * fades out. */export type Demo = {  /** Resolves after `ms`. */  wait: (ms: number) => Promise<void>;  /** Glides the pointer onto `target`: its middle, or a point given as shares of its size. */  moveTo: (target: Element | null | undefined, at?: { x: number; y: number }) => Promise<void>;  /** Presses and lets go; `action` runs as the pointer goes down. */  press: (action: () => void) => Promise<void>;};/** What a stopped demo's pending step rejects with. */class Stopped extends Error {}

'use client';import { useCallback, useEffect, useRef, useState } from 'react';/* * When a demo may play on its own: while part of it is on screen and the tab is visible, never * under reduced motion, and not while the reader is using it. `take()` hands it to the reader; it * takes back over `idle` ms after their last input. */export function useAutoplay<T extends HTMLElement>(idle = 6000) {  const ref = useRef<T>(null);  const [visible, setVisible] = useState(false);  const [reduced, setReduced] = useState(true);  const [taken, setTaken] = useState(false);  const timer = useRef(0);  useEffect(() => {    const element = ref.current;    if (!element) return;    let onScreen = false;    const update = () => setVisible(onScreen && !document.hidden);    const observer = new IntersectionObserver(      ([entry]) => {        onScreen = entry.isIntersecting;