Bistrokarte: Preise auf einem Tabulator

// ═══ Postext Cookbook · Nº 052 · Bistro menu: prices on a tab stop ═══════════════════
// https://postext.dev/en/cookbook/bistro-menu
// Code: MIT · Text: original, in French (CC BY 4.0) · Drawings: generated in code (CC BY 4.0)
// Fonts: Limelight, Noticia Text, Josefin Sans (SIL OFL 1.1) · Needs postext ≥ 1.25.0
// The autumn menu of an imaginary Paris bistro: two sides of one card, each dish a paragraph
// whose price a tab sends to the right margin, the wine list a table with no rules.
import {
  buildDocumentWithFonts, prepareFonts, renderPageToCanvas, registerResourceImage, parseTSV,
  mergeCells,
} from 'https://esm.sh/postext';

const LANG = 'en'; // @lang: the language of the sample document ('en' | 'es')
const RECIPE = 'bistro-menu';

// ─── 1 · Design ─────────────────────────────────────────────────────────────
const palette = { ink: '#1f2a24', paper: '#f6efdf', // green-black text on cream card
  wine: '#6d1f2c', brass: '#a9823a', // the name, heads and labels; rules and the drawings' metal
  straw: '#e8d4a8', bottle: '#2f4235', sage: '#8a9a78', // awning stripes and labels; glass
  muted: '#6b6457' }; // the colophon
const col = (id) => ({ hex: palette[id], model: 'hex', paletteId: id });
// The engine's defaults link to 'main-color' (#295aa3, a blue); this palette makes it the wine red.
const colorPalette = Object.entries({ ...palette, 'main-color': palette.wine })
  .map(([id, hex]) => ({ id, name: id, value: { hex, model: 'hex' } }));
const [TEXT, DISPLAY, LABEL] = ['Noticia Text', 'Limelight', 'Josefin Sans'];
const [BODY, LEAD] = [10.5, 14.5]; // pt: the text, and the leading every table row keeps

// #region answer: dish on the left, price flush right: a tab stop at the end of the measure
// Each course is a :::paragraphs group in the dish style. Its one tab stop stands at the end of
// the measure and ends there the text after the tab, so `:tab **7**` sets the price flush right
// however long the dish is. A backslash at the end of the line breaks it: the dish and its
// translation are one paragraph, and the price shares the dish's first line.
const dish = { id: 'dish', name: 'Dish', textAlign: 'left', // the card is centred; a dish is not
  tabStops: [{ position: 'end', align: 'end' }],
  spaceBetween: pt(LEAD / 2), // half a line between two dishes: each dish 2½ lines of LEAD
  marginTop: pt(LEAD), // a line of air under the course head
  indent: pt(LEAD / 4), endIndent: pt(LEAD / 4) }; // in line with the wine list's cell text
// The wine list stays a table: its prices stand in two columns under the heads 12 cl and 75 cl.
// The document's tableStyle turns off every rule and fill (#region wines).
const tableStyle = { rules: 'none', cellPadding: pt(LEAD / 4), // a row: 1½ lines of LEAD
  bodyFontFamily: TEXT, bodyFontSize: pt(BODY), bodyColor: col('ink'),
  headerFontFamily: LABEL, headerFontSize: pt(8.5), headerColor: col('wine'),
  headerBackgroundEnabled: false }; // header cells: the wine list's labels
// #endregion

// #region type: one resource type for the whole card: set where it stands, never numbered
// No caption prefix and no caption, so no 'Table 1' line prints under the wine list. Placement
// 'here' sets each piece at its ::resource line; a list that outgrows the page is cut
// between rows and goes on at the head of the next one.
const resourceTypes = [{ id: 'menu', name: 'Menu', shortLabel: 'Menu', captionPrefix: '',
  numberingTemplate: '{n}', resetOn: 'never', counterFormat: 'decimal',
  defaultPlacement: { position: 'here' } }];
const piece = (id, kind, body) => ({ id, typeId: 'menu', kind, createdAt: 0, updatedAt: 0,
  ...body });
// #endregion

// #region wines: region rows merged across the three columns, prices under their labels
function wineList(tsv) {
  let m = { ...parseTSV(tsv, { headerRows: 1 }), columnWidths: [5, 1, 1] }; // the head row
  m.rows = m.rows.map((row, r) => row.map((cell, c) => (c === 0 ? cell : { ...cell, align: 'right',
    content: r > 0 && cell.content ? `**${cell.content}**` : cell.content }))); // as the dishes'
  m.rows.forEach(([first, ...rest], r) => { // a line with one field names a region
    if (r === 0 || !first.content || rest.some((cell) => cell.content)) return;
    // One cell across the table, centred on the card like the course heads; a label centred
    // in the first column alone would sit 22.6 mm left of them. The label face is the header's.
    m.rows[r][0] = { ...first, isHeader: true, align: 'center' };
    // mergeCells marks the two cells it covers hiddenBy (gotcha: merged-cells-hiddenby).
    m = mergeCells(m, { start: { row: r, col: 0 }, end: { row: r, col: 2 } });
  });
  return piece('wines', 'table', { table: { model: m } });
}
// #endregion

// #region heads: a course head: its title centred, a brass rule anchored to each side of it
// The title has no width, so it shrink-wraps its text, and 'top' centres it on the column. Each
// rule hangs off one edge of the title ('left-of', 'right-of'), 4 mm away, and 'fill' runs it
// to the column's edge: 66.7 mm beside PLATS, 56.2 mm beside the longer LE COMPTOIR.
const rule = (edge, x) => ({ kind: 'rule', id: `rule-${edge}`, color: col('brass'),
  thickness: pt(0.75), // heavier than the default 0.5 pt hairline
  placement: { anchor: { to: '#title', edge },
    size: { width: 'fill' }, // to the column's edge
    offset: { x: mm(x), y: pt(6) } } }); // 6 pt down: the middle of Limelight's capitals
const courseHead = { enabled: true, slot: { elements: [
  { kind: 'text', id: 'title', content: '{titleText}', fontFamily: DISPLAY, fontSize: pt(15),
    lineHeight: 0.96, // 14.4 pt: the title stays inside one 14.5 pt grid line
    textTransform: 'uppercase', color: col('wine'),
    placement: { anchor: { to: 'container', edge: 'top' } } },
  rule('left-of', -4), rule('right-of', 4),
] } };
// #endregion

// #region badges: dietary badges as chips, explained in small type under the desserts
// A chip is a box around inline text: the V disc is filled, the SG pill only outlined. A chip
// takes the weight of the text around it, so without bold the V is set in 400, a weight not loaded.
const badge = { fontFamily: LABEL, fontSize: pt(7.5), bold: true, // Josefin Sans 700
  borderRadius: pt(8), paddingY: em(0.1), gap: em(0.6) }; // radius clamped to a half-height
const chipStyles = [
  // V: paddingX makes the box as wide as it is tall, a disc. borderWidth 0 removes the default
  // outline, 0.5 pt of main-color, which would ring the green in wine red.
  { id: 'veg', name: 'Vegetarian', ...badge, paddingX: em(0.3), borderWidth: pt(0),
    background: col('bottle'), color: col('paper') },
  { id: 'gf', name: 'Gluten-free', ...badge, paddingX: em(0.45), backgroundEnabled: false,
    borderColor: col('bottle'), borderWidth: pt(0.6), color: col('bottle') },
];
// The notes under the desserts and the colophon on the back: smaller, on the card's axis, a
// line of air above each.
const paragraphStyles = [dish,
  { id: 'notes', name: 'Notes', fontSize: pt(9), marginTop: pt(LEAD) },
  { id: 'colophon', name: 'Colophon', fontSize: pt(7.5), color: col('muted'),
    marginTop: pt(LEAD) },
];
// #endregion

// #region centred: one axis for the card: the name, the course heads and the notes centred
// bodyText (in config) centres the lines under the name and the notes; only the dishes and the
// wine list keep a left edge. Ragged text is hyphenated only with bodyText.hyphenation.ragged,
// so no word on this card is divided, the French dish names included. The config's locale
// names each edition's language, English or Spanish, for the bundle the Sandbox opens.
const headings = { fontFamily: DISPLAY, fontWeight: 400, color: col('wine'), textAlign: 'center',
  levels: [ // Limelight ships one weight, 400, and no italic
    // The H1 break is off: by default an H1 opens a recto, which would part the name from the
    // awning and La Cave from its bottles.
    { level: 1, fontSize: pt(48), lineHeight: pt(3 * LEAD), breakBefore: { enabled: false },
      marginTop: pt(LEAD), marginBottom: pt(0) }, // three grid lines, one of air above
    { level: 2, lineHeight: pt(LEAD), advancedDesign: courseHead, // one line; #region heads
      marginTop: pt(LEAD), marginBottom: pt(0) }, // the dishes below add a line of their own
  ] };
// #endregion

// #region art: a striped awning over the name, a shelf of bottles over the wine list
function awning() { // 158 × 20 mm; the canopy narrows 6 % toward the wall
  const [W, N, ROD, DROP, HEM, INSET] = [1660, 19, 12, 104, 46, 50];
  const s = W / N, top = (i) => INSET + i * (W - 2 * INSET) / N, bottom = (i) => i * s;
  const shade = { [palette.wine]: mix(palette.wine, palette.ink, 0.25), // the valance: each
    [palette.straw]: mix(palette.straw, palette.brass, 0.4) }; // stripe a shade darker
  let shapes = '';
  for (let i = 0; i < N; i++) {
    const fill = i % 2 ? palette.straw : palette.wine, y = ROD + DROP;
    shapes += `<path d="M${top(i)} ${ROD}H${top(i + 1)}L${bottom(i + 1)} ${y}H${bottom(i)}Z" `
      + `fill="${fill}"/><path d="M${bottom(i)} ${y}h${s}v${HEM}a${s / 2} ${s / 2} 0 0 1 `
      + `${-s} 0Z" fill="${shade[fill]}"/>`;
  }
  shapes += `<rect x="${INSET - 16}" y="0" width="${W - 2 * INSET + 32}" height="${ROD}" rx="6" `
    + `fill="${palette.brass}"/><rect x="0" y="${ROD + DROP - 3}" width="${W}" height="6" `
    + `fill="${palette.brass}"/>`; // the rod on the wall, a brass bead along the front edge
  return `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${W} 212" width="${W}" `
    + `height="212">${shapes}</svg>`;
}
function mix(a, b, t) { // a blend of two palette colours, t of the way from a to b
  const rgb = (hex) => [1, 3, 5].map((i) => parseInt(hex.slice(i, i + 2), 16));
  const [x, y] = [rgb(a), rgb(b)];
  return `#${x.map((v, i) => Math.round(v + (y[i] - v) * t).toString(16).padStart(2, '0'))
    .join('')}`;
}
function bottles() { // 158 × 29 mm: glasses, bottles and a carafe on a brass shelf
  const [W, H, BASE] = [1660, 300, 286];
  const glass = (x) => // a tulip glass, a third full
    `<path d="M${x - 34} ${BASE - 170}C${x - 36} ${BASE - 110} ${x - 20} ${BASE - 88} ${x} `
      + `${BASE - 86}C${x + 20} ${BASE - 88} ${x + 36} ${BASE - 110} ${x + 34} ${BASE - 170}Z" `
      + `fill="none" stroke="${palette.bottle}" stroke-width="4"/>`
      + `<path d="M${x - 33} ${BASE - 132}C${x - 30} ${BASE - 104} ${x - 16} ${BASE - 91} ${x} `
      + `${BASE - 90}C${x + 16} ${BASE - 91} ${x + 30} ${BASE - 104} ${x + 33} ${BASE - 132}Z" `
      + `fill="${palette.wine}"/>`
      + `<rect x="${x - 2.5}" y="${BASE - 88}" width="5" height="82" fill="${palette.bottle}"/>`
      + `<ellipse cx="${x}" cy="${BASE - 5}" rx="30" ry="5" fill="${palette.bottle}"/>`;
  const bottle = (x, h, w, shoulder, body, foil) => { // straight or sloping shoulders
    const neck = 13, top = BASE - h, sh = BASE - h * 0.62;
    return `<path d="M${x - w} ${BASE}V${sh}C${x - w} ${sh - shoulder} `
      + `${x - neck} ${sh - shoulder} ${x - neck} ${sh - shoulder * 1.6}`
      + `V${top + 6}Q${x - neck} ${top} ${x - neck + 6} ${top}`
      + `H${x + neck - 6}Q${x + neck} ${top} ${x + neck} ${top + 6}V${sh - shoulder * 1.6}`
      + `C${x + neck} ${sh - shoulder} ${x + w} ${sh - shoulder} ${x + w} ${sh}V${BASE}Z" `
      + `fill="${body}"/>`
      + `<rect x="${x - neck - 1}" y="${top}" width="${2 * neck + 2}" height="${h * 0.16}" `
      + `rx="4" fill="${foil}"/>`
      + `<rect x="${x - w + 8}" y="${BASE - h * 0.44}" width="${2 * w - 16}" height="${h * 0.26}" `
      + `fill="${palette.straw}"/>`
      + `<rect x="${x - w + 8}" y="${BASE - h * 0.3}" width="${2 * w - 16}" height="6" `
      + `fill="${foil}"/>`;
  };
  const carafe = (x) => `<path d="M${x - 16} ${BASE - 200}H${x + 16}V${BASE - 150}`
    + `C${x + 70} ${BASE - 120} ${x + 76} ${BASE - 20} ${x + 44} ${BASE}H${x - 44}`
    + `C${x - 76} ${BASE - 20} ${x - 70} ${BASE - 120} ${x - 16} ${BASE - 150}Z" fill="none" `
    + `stroke="${palette.bottle}" stroke-width="4"/>`
    + `<path d="M${x - 64} ${BASE - 74}C${x - 70} ${BASE - 30} ${x - 58} ${BASE - 8} ${x - 42} `
    + `${BASE - 4}H${x + 42}C${x + 58} ${BASE - 8} ${x + 70} ${BASE - 30} ${x + 64} ${BASE - 74}Z" `
    + `fill="${palette.wine}"/>`;
  const C = W / 2;
  const art = glass(C - 330) + bottle(C - 225, 250, 38, 12, palette.bottle, palette.wine)
    + bottle(C - 125, 262, 42, 34, palette.sage, palette.brass) + carafe(C)
    + bottle(C + 125, 256, 44, 36, palette.bottle, palette.brass)
    + bottle(C + 225, 250, 38, 12, palette.bottle, palette.wine) + glass(C + 330)
    + `<rect x="${C - 420}" y="${BASE}" width="840" height="6" fill="${palette.brass}"/>`;
  return `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${W} ${H}" width="${W}" `
    + `height="${H}">${art}</svg>`;
}
// #endregion

const config = () => ({
  colorPalette, tableStyle, resourceTypes,
  locale: t({ en: 'en-us', es: 'es' }), // the language of each edition, and of its bundle
  page: { sizePreset: 'custom', width: mm(230), height: mm(310), dpi: 150,
    backgroundColor: col('paper'), // one card, printed both sides: margins are not mirrored
    margins: { top: mm(22), bottom: mm(20), left: mm(36), right: mm(36) } },
  layout: { layoutType: 'single' },
  bodyText: { fontFamily: TEXT, fontSize: pt(BODY), lineHeight: pt(LEAD), color: col('ink'),
    boldColor: col('ink'), italicColor: col('ink'), // both default to main-color, the wine red
    textAlign: 'center', firstLineIndent: mm(0) }, // the lines under the name and the notes
  headings, // the card's axis (#region centred)
  chipStyles, paragraphStyles, // the badges and the small print (#region badges)
  header: { elements: [] }, footer: { elements: [] }, // a menu has no running heads or folios
});

// ─── 2 · Content ────────────────────────────────────────────────────────────
const markdown = String.raw`---
Markdown-Beispiel · 94 Zeilen · content.en.md
title: "Les Tanneurs"
---

::resource{id="awning"}

# Les Tanneurs

*Bistrot parisien depuis 1931*

Carte d’automne 2026 · *autumn menu*

## Entrées

:::paragraphs{style="dish"}
**Œuf mayonnaise**, cornichons de la maison :chip[V]{style="veg"} :chip[SG]{style="gf"} :tab **7**\
*Egg mayonnaise, house pickles*

**Velouté de potimarron**, crème crue, noisettes torréfiées :chip[V]{style="veg"} :chip[SG]{style="gf"} :tab **9**\
*Red kuri squash soup, raw cream, toasted hazelnuts*

**Terrine de campagne** au poivre vert, pain grillé :tab **11**\
*Country terrine with green peppercorns, toast*

**Poireaux vinaigrette**, œuf mimosa :chip[V]{style="veg"} :chip[SG]{style="gf"} :tab **10**\
*Leeks in vinaigrette, egg mimosa*
:::

## Plats

:::paragraphs{style="dish"}
**Blanquette de veau** à l’ancienne, riz pilaf :tab **24**\
*Veal blanquette the old way, pilaf rice*

**Paleron de bœuf** braisé au vin rouge, carottes fondantes :tab **26**\
*Beef chuck braised in red wine, slow-cooked carrots*

**Filet de lieu jaune**, beurre blanc, poireaux fondus :chip[SG]{style="gf"} :tab **27**\
*Pollack fillet, beurre blanc, softened leeks*

**Risotto aux cèpes**, mascarpone et sauge :chip[V]{style="veg"} :chip[SG]{style="gf"} :tab **22**\
*Cep risotto, mascarpone and sage*
:::

## Desserts

:::paragraphs{style="dish"}
**Tarte fine aux pommes**, crème fraîche :tab **10**\
*Thin apple tart, crème fraîche*

**Mousse au chocolat noir** :tab **9**\
*Dark chocolate mousse*

**Île flottante**, pralines roses :tab **9**\
*Floating island, pink pralines*

**Trois fromages affinés**, confiture de cerises noires :tab **12**\
*Three matured cheeses, black cherry jam*
:::

:::paragraphs{style="notes"}
:chip[V]{style="veg"} Plat végétarien · *vegetarian* · :chip[SG]{style="gf"} Sans gluten · *gluten-free*

Bœuf d’origine France · *French beef* · Prix nets, service compris · *service included*
:::

:::pagebreak

::resource{id="bottles"}

# La Cave

Vins au verre et à la bouteille · *wine by the glass and by the bottle*

::resource{id="wines"}

## Le Comptoir

:::paragraphs{style="dish"}
**Kir** au vin blanc et cassis :tab **6**\
*White wine with blackcurrant liqueur*

**Pastis**, carafe d’eau fraîche :tab **5**\
*Pastis with a jug of cold water*

**Bière à la pression**, 25 cl :tab **5**\
*Draught beer, 25 cl*

**Café**, noisette ou allongé :tab **3**\
*Espresso, macchiato or lungo*
:::

:::paragraphs{style="colophon"}
Set in Limelight, Noticia Text and Josefin Sans (SIL OFL) · Les Tanneurs is an imaginary bistro · Text and drawings CC BY 4.0
:::
`; // the two sides of the card, in French
const wines = String.raw`Appellation · cépage	12 cl	75 cl
Markdown-Beispiel · 16 Zeilen · content.cave.en.md
BULLES
**Crémant de Loire** brut · *chenin blanc*	9	44

BLANCS
**Muscadet Sèvre-et-Maine** sur lie 2023 · *melon de Bourgogne*	7	32
**Mâcon-Villages** 2022 · *chardonnay*	9	40
**Sancerre** 2023 · *sauvignon blanc*	11	52
**Chablis** 2022 · *chardonnay*	12	58

ROUGES
**Côtes-du-Rhône** 2022 · *grenache, syrah*	7	32
**Saumur-Champigny** 2022 · *cabernet franc*	9	42
**Morgon** 2022 · *gamay*	10	46
**Bordeaux supérieur** 2020 · *merlot, cabernet sauvignon*	8	38
**Saint-Joseph** 2021 · *syrah*	12	56
**Saint-Émilion grand cru** 2018 · *merlot, cabernet franc*	—	78
`; // TSV: head row, regions, wines; one file for both editions
const resources = [
  piece('awning', 'svg', { svg: { fileId: 'awning.svg', width: 1660, height: 212 },
    altText: 'A striped wine-red and straw awning on a brass rod.' }),
  piece('bottles', 'svg', { svg: { fileId: 'bottles.svg', width: 1660, height: 300 },
    altText: 'Two glasses of red wine, four bottles and a carafe on a brass shelf.' }),
  wineList(wines),
];

// ─── 3 · Fonts ──────────────────────────────────────────────────────────────
// Every face the pages paint, loaded before the first build.
const FONTS = { 'Noticia Text': ['400', '400i', '700'], Limelight: ['400'],
  'Josefin Sans': ['700'] };

// ─── 4 · Build & show ───────────────────────────────────────────────────────
const allText = markdown + wines;
await prepareFonts(allText, config(), kitFonts(FONTS));
await loadSvg('awning.svg', awning());
await loadSvg('bottles.svg', bottles());
const doc = await buildDocumentWithFonts({ markdown, resources }, config(),
  { ...kitFonts(FONTS), text: allText });
showPages(doc, { title: t({ en: 'Les Tanneurs: autumn menu',
  es: 'Les Tanneurs: carta de otoño' }) });

Kit · core, fonts, viewer, images: in jedem Rezept gleich · 270 Zeilen
// ─── Kit ── helpers shared by every Cookbook recipe · postext.dev/cookbook ─────

// ─── Kit · core v1 ── the same in every recipe · postext.dev/cookbook
function mm(value) { return { value, unit: 'mm' }; }
function pt(value) { return { value, unit: 'pt' }; }
function em(value) { return { value, unit: 'em' }; }
/** The sample language's string: t({ en: 'Figure', es: 'Figura' }). */
function t(strings) { return strings[LANG] ?? Object.values(strings)[0]; }
/** A file in this recipe's assets folder, served from the Postext repo by jsDelivr. */
function asset(file) { return `https://cdn.jsdelivr.net/gh/drnachio/postext@main/cookbook/${RECIPE}/assets/${file}`; }

// ─── Kit · fonts v3 ── the same in every recipe · postext.dev/cookbook
// Postext loads the faces a config asks for before layout (prepareFonts,
// buildDocumentWithFonts) and asks the kit for the files: Fontsource's, the
// files the PDF embeds too.

/** The options of buildDocumentWithFonts / prepareFonts / withLoadedFonts:
 *  the Fontsource resolver, and the faces of FONTS loaded with the ones the
 *  config names. FONTS = { 'Family Name': ['400', '400i', '700'] }. */
function kitFonts(FONTS = {}) {
  const faces = Object.entries(FONTS).flatMap(([family, specs]) => specs.map((spec) =>
    ({ family, weight: parseInt(spec, 10), style: spec.endsWith('i') ? 'italic' : 'normal' })));
  return { resolve: fontsourceResolver, faces };
}

/** A face's Fontsource files, in a fixed order: latin, then latin-ext and greek
 *  when `text` needs them and the family ships them (kitSubsetsFor), each with
 *  its unicode-range. Null for a weight or slant Fontsource does not ship. */
async function fontsourceResolver(family, weight, style, { text = '' } = {}) {
  const id = fontsourceId(family);
  const meta = await fontsourceMeta(family);
  if (meta && !(meta.weights.includes(weight) && meta.styles.includes(style))) return null;
  kitStatus('Loading fonts…');
  const at = await fontsourceAt(id);
  return ['latin', ...kitSubsetsFor(text, meta)].map((subset) => ({
    source: `${at}files/${id}-${subset}-${weight}-${style}.woff2`,
    unicodeRange: kitRanges()[subset],
  }));
}

/** The unicode-range of each Fontsource file the kit loads (a function: the
 *  kit is inlined after the pen's code, which runs before a const would be set). */
function kitRanges() {
  return {
    latin: 'U+0000-00FF,U+0131,U+0152-0153,U+02BB-02BC,U+02C6,U+02DA,U+02DC,U+0304,U+0308,U+0329,'
      + 'U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD',
    'latin-ext': 'U+0100-02BA,U+02BD-02C5,U+02C7-02CC,U+02CE-02D7,U+02DD-02FF,U+0304,U+0308,U+0329,'
      + 'U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF',
    greek: 'U+0370-03FF',
  };
}

/** For the cjk, arabic and comics blocks, which add their own files: the
 *  faces of `faces` = { 'Family Name': ['400', '400i', '700'] }. `text` is the sample:
 *  č ł † α χ also load latin-ext and greek files (kitSubsetsFor). With
 *  `optional`, a face Fontsource does not ship is skipped instead of failing.
 *  The files are added once all have loaded, in the order asked (latin, then
 *  latin-ext, then greek), whatever order they arrive in: the last one added
 *  wins a character two files hold. Resolves to the number of faces added. */
async function loadFonts(faces, text = '', { optional = false } = {}) {
  kitStatus('Loading fonts…');
  const ranges = kitRanges();
  const jobs = [];
  for (const [family, specs] of Object.entries(faces)) {
    const id = fontsourceId(family);
    const todo = [...new Set(specs)].map((spec) => [parseInt(spec, 10), spec.endsWith('i') ? 'italic' : 'normal'])
      .filter(([weight, style]) => !hasFace(family, weight, style)); // before any await
    const at = fontsourceAt(id);
    const meta = optional || /[^\0-ÿ]/u.test(text) ? await fontsourceMeta(family) : null;
    const subsets = ['latin', ...kitSubsetsFor(text, meta)];
    for (const [weight, style] of todo) {
      if (optional && !(meta?.weights.includes(weight) && meta.styles.includes(style))) continue;
      for (const subset of subsets) {
        const url = `${await at}files/${id}-${subset}-${weight}-${style}.woff2`;
        const face = new FontFace(family, `url(${url}) format('woff2')`,
          { weight: String(weight), style, unicodeRange: ranges[subset] });
        jobs.push(face.load().catch(() => {
          if (subset === 'latin' && !optional) throw new Error(`Fontsource has no ${family} ${weight} ${style}`);
        }));
      }
    }
  }
  const ready = await Promise.all(jobs).catch((error) => { kitFail(error); throw error; });
  return ready.filter((face) => face && document.fonts.add(face)).length;
}

/** A loaded FontFace covers this family, weight and style (fonts.check() would
 *  also say yes for families nobody declared). */
function hasFace(family, weight, style) {
  for (const face of document.fonts) {
    if (face.status !== 'loaded' || face.style !== style) continue;
    if (face.family.replace(/^["']|["']$/g, '') !== family) continue;
    const [low, high = low] = face.weight.split(' ').map(Number);
    if (weight >= low && weight <= high) return true;
  }
  return false;
}

/** The files beyond latin `text` needs that `meta`'s family ships. */
function kitSubsetsFor(text, meta) {
  return [[/[Ā-˿ᴀ-ᶿḀ-ỿ†ℓⱠ-Ɀ꜠-ꟿ]/u, 'latin-ext'], [/[Ͱ-Ͽ]/u, 'greek']]
    .filter(([re, x]) => re.test(text) && meta?.subsets?.includes(x)).map(([, x]) => x);
}

/** Fontsource's id for a family: 'Source Serif 4' → 'source-serif-4'. */
function fontsourceId(family) { return family.toLowerCase().replace(/\s+/g, '-'); }

/** A package's folder at the one version @5 names now (#766). */
function fontsourceAt(id, u = `https://cdn.jsdelivr.net/npm/@fontsource/${id}@`) {
  return (fontsourceAt.c ??= {})[id] ??= fetch(u + '5/package.json').then((r) => r.json())
    .then((p) => p.version || 5, () => 5).then((v) => `${u}${v}/`);
}

/** The family's Fontsource metadata (weights, styles, subsets), or null. */
function fontsourceMeta(family) {
  fontsourceMeta.cache ??= new Map();
  const id = fontsourceId(family);
  if (!fontsourceMeta.cache.has(id)) {
    fontsourceMeta.cache.set(id, fetch(`https://api.fontsource.org/v1/fonts/${id}`)
      .then((res) => (res.ok ? res.json() : null), () => null));
  }
  return fontsourceMeta.cache.get(id);
}

// ─── Kit · viewer v2 ── the same in every recipe · postext.dev/cookbook
/** The pages as spreads on a dark desk, page 1 alone, then verso | recto,
 *  each painted when it scrolls near. Other options go to renderPageToCanvas. */
function showPages(docs, { title, width = 460, ...render } = {}) {
  const root = viewer(title);
  const pages = [docs].flat().flatMap((doc) =>
    doc.pages.map((page) => ({ doc, page, n: (doc.pageIndexOffset ?? 0) + page.index })));
  const spreads = [];
  let verso = null;
  for (const p of pages) {
    if (p.n % 2 === 1) { if (verso) spreads.push([verso, null]); verso = p; }
    else { spreads.push([verso, p]); verso = null; }
  }
  if (verso) spreads.push([verso, null]);
  const density = Math.min(window.devicePixelRatio || 1, 2);
  showPages.painter?.disconnect();
  const painter = new IntersectionObserver((entries) => {
    for (const { isIntersecting, target } of entries) {
      if (!isIntersecting) continue;
      painter.unobserve(target);
      const { doc, page } = target.postext;
      renderPageToCanvas(page, doc, target, { ...render, scale: (width * density) / page.width });
    }
  }, { rootMargin: '800px' });
  showPages.painter = painter;
  root.replaceChildren(...spreads.map((pair) => {
    const spread = document.createElement('div');
    spread.className = 'pt-spread';
    for (const p of pair) {
      const figure = document.createElement('figure');
      if (p) {
        const label = p.page.pageLabel || String(p.n + 1);
        const canvas = document.createElement('canvas');
        canvas.postext = p;
        canvas.style.aspectRatio = `${p.page.width} / ${p.page.height}`;
        canvas.setAttribute('role', 'img');
        canvas.setAttribute('aria-label', `Page ${label}`);
        const folio = document.createElement('figcaption');
        folio.textContent = label;
        figure.append(canvas, folio);
        painter.observe(canvas);
      } else figure.className = 'pt-blank';
      spread.append(figure);
    }
    return spread;
  }));
  kitStatus(`${pages.length} ${pages.length === 1 ? 'page' : 'pages'}`);
  document.documentElement.dataset.postext = 'ready';
  return pages.length;
}

/** The desk, the bar and the error reporting, created once. */
function viewer(title) {
  if (!document.getElementById('pt-kit')) {
    document.head.insertAdjacentHTML('beforeend', `<style id="pt-kit">
      :root { color-scheme: dark; }
      body { margin: 0; background: #0e1014; color: #b9bcc4; font: 13px/1.45 system-ui, sans-serif; }
      #pt-bar { position: sticky; top: 0; z-index: 1; display: flex; flex-wrap: wrap; align-items: center;
        gap: 6px 16px; padding: 10px 16px; background: rgb(14 16 20 / .92); backdrop-filter: blur(6px);
        border-bottom: 1px solid #23262d; }
      #pt-bar strong { color: #f4f1ea; font-weight: 600; }
      #pt-actions { display: flex; gap: 12px; margin-left: auto; }
      #pt-actions a, #pt-actions button { color: #d8a21a; font: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
      #pages { display: grid; justify-items: center; gap: 48px; padding: 32px 16px 72px; }
      .pt-spread { display: flex; }
      .pt-spread figure { margin: 0; width: min(460px, 44vw); }
      .pt-spread canvas { display: block; width: 100%; background: #fff;
        box-shadow: 0 1px 2px rgb(0 0 0 / .5), 0 22px 44px -16px rgb(0 0 0 / .8); }
      .pt-spread figure:first-child canvas { box-shadow: inset -14px 0 14px -14px rgb(0 0 0 / .18), 0 1px 2px rgb(0 0 0 / .5), 0 22px 44px -16px rgb(0 0 0 / .8); }
      .pt-spread figcaption { margin-top: 10px; text-align: center; font: 600 10px/1 system-ui, sans-serif;
        letter-spacing: .18em; text-transform: uppercase; color: #6c7079; }
      .pt-blank { visibility: hidden; }
      @media (max-width: 760px) {
        .pt-spread { flex-direction: column; gap: 32px; }
        .pt-spread figure { width: min(460px, 92vw); }
        .pt-blank { display: none; }
      }
    </style>`);
    document.body.insertAdjacentHTML('afterbegin',
      '<header id="pt-bar"><strong id="pt-title"></strong><span id="pt-status" role="status"></span><span id="pt-actions"></span></header>');
    document.getElementById('pt-title').textContent = document.title || 'Postext';
    addEventListener('error', (event) => kitFail(event.error ?? event.message));
    addEventListener('unhandledrejection', (event) => kitFail(event.reason));
  }
  if (title) document.getElementById('pt-title').textContent = title;
  return document.getElementById('pages')
    ?? document.body.appendChild(Object.assign(document.createElement('main'), { id: 'pages' }));
}

function kitStatus(text) {
  viewer();
  document.getElementById('pt-status').textContent = text;
}

function kitFail(error) {
  document.documentElement.dataset.postext = 'error';
  kitStatus(`Error: ${error?.message ?? error}`);
}

// ─── Kit · images v3 ── recipes with pictures · postext.dev/cookbook
/** Registers a photo or PNG for the canvas and keeps its bytes for the PDF.
 *  fetch → ImageBitmap never taints the canvas (a plain cross-origin <img> would). */
async function loadImage(fileId, url) {
  const res = await fetch(url);
  if (!res.ok) throw new Error(`Image not found (${res.status}): ${url}`);
  const bytes = new Uint8Array(await res.arrayBuffer());
  registerResourceImage(fileId, await createImageBitmap(new Blob([bytes])));
  (loadImage.bytes ??= new Map()).set(fileId, bytes);
}

/** Registers SVG markup as a vector image, its fonts inside (inlineSvgFonts, ≥ 1.25).
 *  `options` go to registerResourceImage: { singleInk: true } tints it on the canvas. */
async function loadSvg(fileId, svg, options) {
  if (typeof inlineSvgFonts === 'function') svg = await inlineSvgFonts(svg, svgFaces);
  const img = new Image();
  img.src = `data:image/svg+xml;charset=utf-8,${encodeURIComponent(svg)}`;
  await img.decode();
  registerResourceImage(fileId, img, options);
  (loadImage.bytes ??= new Map()).set(fileId, new TextEncoder().encode(svg));
}

/** A face's Fontsource files: nearest weight; latin + what the SVG sets. */
async function svgFaces(family, weight, style, { codePoints = [] } = {}) {
  const [id, m] = [fontsourceId(family), await fontsourceMeta(family)];
  const w = m?.weights.reduce((a, b) => (Math.abs(b - weight) < Math.abs(a - weight) ? b : a)) ?? weight;
  const s = m?.styles.includes(style) === false ? 'normal' : style;
  return Promise.all(['latin', ...kitSubsetsFor(String.fromCodePoint(...codePoints), m)].map(async (x) => new Uint8Array(
    await (await fetch(`${await fontsourceAt(id)}files/${id}-${x}-${w}-${s}.woff2`)).arrayBuffer())));
}

/** renderToPdf({ resourceBytes: imageBytes }) */
function imageBytes(fileId) { return loadImage.bytes?.get(fileId); }

/** renderToHtml({ resourceImageUrl: imageUrl }) */
function imageUrl(fileId) {
  const bytes = imageBytes(fileId);
  if (!bytes) return undefined;
  imageUrl.urls ??= new Map();
  if (!imageUrl.urls.has(fileId)) {
    const type = /\.svg$/i.test(fileId) ? 'image/svg+xml' : /\.png$/i.test(fileId) ? 'image/png' : 'image/jpeg';
    imageUrl.urls.set(fileId, URL.createObjectURL(new Blob([bytes], { type })));
  }
  return imageUrl.urls.get(fileId);
}

// ─── /Kit ───────────────────────────────────────────────────────────────────────