Stirling-PDF/shared-operations/src/functions/arrangePages.ts

import { PdfFile } from '../wrappers/PdfFile.js';
import { Sorts } from './common/pageIndexesSorting.js';
import { getPages } from './common/getPagesByIndex.js';
import { parsePageIndexSpecification } from './common/pageIndexesUtils.js';

export type ArrangePagesParamsType = {
    file: PdfFile;
    arrangementConfig: string; // a member of Sorts, or a page index specification
}
export async function arrangePages(params: ArrangePagesParamsType) {
    const { file, arrangementConfig } = params;
    const pdfLibDocument = await file.pdfLibDocument;
    const pageCount = pdfLibDocument.getPageCount();

    let sortIndexes: number[];
    if (arrangementConfig in Sorts) {
        const sortFunction = Sorts[arrangementConfig];
        sortIndexes = sortFunction(pageCount);
    } else {
        sortIndexes = parsePageIndexSpecification(arrangementConfig, pageCount);
    }
    
    const newFile = await getPages(file, sortIndexes);
    newFile.filename += "arrangedPages"
    return newFile;
}