feat(export): add book-to-Typst source generator

src/export/typst.ts

@@ -0,0 +1,116 @@
+import type { JSONContent } from "@tiptap/core";
+import type { Book, TrimSize } from "../model/book";
+
+const TRIM: Record<TrimSize, { w: string; h: string }> = {
+  "6x9": { w: "6in", h: "9in" },
+  "5.5x8.5": { w: "5.5in", h: "8.5in" },
+  "5x8": { w: "5in", h: "8in" },
+  a5: { w: "148mm", h: "210mm" },
+};
+
+const INLINE_SPECIAL = /[\\#$*_`<>@~[\]]/g;
+
+function esc(text: string): string {
+  return text.replace(INLINE_SPECIAL, (m) => "\\" + m);
+}
+
+function guardLineStart(line: string): string {
+  if (/^[=\-+/]/.test(line)) return "\\" + line;
+  if (/^\d+\./.test(line)) return line.replace(".", "\\.");
+  return line;
+}
+
+function str(value: string): string {
+  return JSON.stringify(value);
+}
+
+function inline(node: JSONContent): string {
+  if (node.type === "text") {
+    let text = esc(node.text ?? "");
+    const marks = (node.marks ?? []).map((m) => m.type);
+    if (marks.includes("italic")) text = `#emph[${text}]`;
+    if (marks.includes("bold")) text = `#strong[${text}]`;
+    return text;
+  }
+  if (node.type === "hardBreak") return "#linebreak()";
+  return "";
+}
+
+function inlines(content: JSONContent[] = []): string {
+  return content.map(inline).join("");
+}
+
+function listItem(item: JSONContent): string {
+  return (item.content ?? [])
+    .filter((c) => c.type === "paragraph")
+    .map((p) => inlines(p.content))
+    .join(" ");
+}
+
+function block(node: JSONContent): string {
+  switch (node.type) {
+    case "paragraph":
+      return guardLineStart(inlines(node.content));
+    case "heading":
+      return `#heading(level: ${node.attrs?.level ?? 2})[${inlines(node.content)}]`;
+    case "blockquote":
+      return `#blockquote[${(node.content ?? []).map(block).join("\n\n")}]`;
+    case "bulletList":
+      return (node.content ?? []).map((li) => `- ${listItem(li)}`).join("\n");
+    case "orderedList":
+      return (node.content ?? []).map((li) => `+ ${listItem(li)}`).join("\n");
+    case "horizontalRule":
+      return "#scenebreak";
+    default:
+      return "";
+  }
+}
+
+function chapterBody(content: JSONContent): string {
+  return (content.content ?? [])
+    .map(block)
+    .filter((s) => s.length > 0)
+    .join("\n\n");
+}
+
+function preamble(book: Book): string {
+  const trim = TRIM[book.settings.trim];
+  const meta = book.metadata;
+  return `#set document(title: ${str(meta.title || "Untitled")}, author: ${str(meta.author)})
+#set page(
+  width: ${trim.w},
+  height: ${trim.h},
+  margin: (inside: 0.875in, outside: 0.625in, top: 0.8in, bottom: 0.8in),
+  binding: left,
+  numbering: "1",
+)
+#set text(font: "Literata", size: 11pt, lang: ${str(meta.language || "en")}, hyphenate: true)
+#set par(justify: true, leading: 0.72em, spacing: 0.72em, first-line-indent: (amount: 1.3em, all: false))
+#show heading: set text(font: "Literata", weight: "medium")
+#show heading: set block(above: 1.4em, below: 0.8em)
+
+#let scenebreak = align(center)[#v(0.5em) #line(length: 13%, stroke: 0.5pt + rgb("#d6cfbd")) #v(0.5em)]
+
+#let blockquote(body) = pad(left: 1.2em, rest: 0pt)[#set text(style: "italic", fill: rgb("#6b6458")); #body]
+
+#let chapteropener(num, title) = {
+  pagebreak(weak: true, to: "odd")
+  v(2.1in)
+  align(center)[
+    #text(font: "Hanken Grotesk", size: 8.5pt, weight: "semibold", tracking: 0.28em)[#upper("Chapter " + num)]
+    #v(0.7em)
+    #text(font: "Literata", size: 22pt, weight: "medium")[#title]
+  ]
+  v(1.5em)
+}`;
+}
+
+export function bookToTypst(book: Book): string {
+  const body = book.chapters
+    .map((chapter, i) => {
+      const opener = `#chapteropener(${str(String(i + 1))}, [${esc(chapter.title || "Untitled")}])`;
+      return `${opener}\n\n${chapterBody(chapter.content)}`;
+    })
+    .join("\n\n");
+  return `${preamble(book)}\n\n${body}\n`;
+}