Archived
55 lines
1.5 KiB
TypeScript
55 lines
1.5 KiB
TypeScript
export type PdfRect = [number, number, number, number];
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export interface ParsedPdfAnchor {
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page: number;
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rects: PdfRect[];
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}
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const PDF_ANCHOR_PREFIX = "pdf:v1:";
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export function parsePageHref(href: string): number | null {
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const match = href.match(/^pdf:page:(\d+)$/);
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if (!match) return null;
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const page = Number(match[1]);
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return Number.isFinite(page) && page > 0 ? page : null;
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}
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export function serializePdfAnchor(page: number, rects?: PdfRect[]): string {
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const base = `${PDF_ANCHOR_PREFIX}p=${page}`;
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if (!rects?.length) return base;
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return `${base};rects=${encodeURIComponent(JSON.stringify(rects))}`;
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}
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export function parsePdfAnchor(anchor: string): ParsedPdfAnchor | null {
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if (anchor.startsWith("pdf:page:")) {
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const page = parsePageHref(anchor);
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return page ? { page, rects: [] } : null;
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}
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if (!anchor.startsWith(PDF_ANCHOR_PREFIX)) return null;
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const pageMatch = anchor.match(/p=(\d+)/);
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if (!pageMatch) return null;
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const page = Number(pageMatch[1]);
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if (!Number.isFinite(page) || page < 1) return null;
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const rectsMatch = anchor.match(/rects=([^;]+)/);
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let rects: PdfRect[] = [];
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if (rectsMatch?.[1]) {
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try {
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const parsed = JSON.parse(decodeURIComponent(rectsMatch[1])) as unknown;
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if (Array.isArray(parsed)) {
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rects = parsed.filter(
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(r): r is PdfRect =>
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Array.isArray(r) &&
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r.length === 4 &&
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r.every((n) => typeof n === "number" && Number.isFinite(n)),
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);
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}
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} catch {
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rects = [];
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}
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}
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return { page, rects };
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}
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