bentopdf/src/js/logic/add-header-footer.ts

import { showLoader, hideLoader, showAlert } from '../ui.js';
import { downloadFile, hexToRgb, parsePageRanges } from '../utils/helpers.js';
import { state } from '../state.js';

import { PDFDocument as PDFLibDocument, rgb, StandardFonts } from 'pdf-lib';


export function setupHeaderFooterUI() {
    const totalPagesSpan = document.getElementById('total-pages');
    if (totalPagesSpan && state.pdfDoc) {
        totalPagesSpan.textContent = state.pdfDoc.getPageCount();
    }
}

export async function addHeaderFooter() {
    showLoader('Adding header & footer...');
    try {
        const helveticaFont = await state.pdfDoc.embedFont(StandardFonts.Helvetica);
        const allPages = state.pdfDoc.getPages();
        const totalPages = allPages.length;
        const margin = 40;

        // --- 1. Get new formatting options from the UI ---
        // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
        const fontSize = parseInt(document.getElementById('font-size').value) || 10;
        // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
        const colorHex = document.getElementById('font-color').value;
        const fontColor = hexToRgb(colorHex);
        // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
        const pageRangeInput = document.getElementById('page-range').value;

        // --- 2. Get text values ---
        const texts = {
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            headerLeft: document.getElementById('header-left').value,
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            headerCenter: document.getElementById('header-center').value,
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            headerRight: document.getElementById('header-right').value,
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            footerLeft: document.getElementById('footer-left').value,
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            footerCenter: document.getElementById('footer-center').value,
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            footerRight: document.getElementById('footer-right').value,
        };

        // --- 3. Parse page range to determine which pages to modify ---
        const indicesToProcess = parsePageRanges(pageRangeInput, totalPages);
        if (indicesToProcess.length === 0) {
            throw new Error("Invalid page range specified. Please check your input (e.g., '1-3, 5').");
        }

        // --- 4. Define drawing options with new values ---
        const drawOptions = {
            font: helveticaFont,
            size: fontSize,
            color: rgb(fontColor.r, fontColor.g, fontColor.b)
        };
        
        // --- 5. Loop over only the selected pages ---
        for (const pageIndex of indicesToProcess) {
            // @ts-expect-error TS(2538) FIXME: Type 'unknown' cannot be used as an index type.
            const page = allPages[pageIndex];
            const { width, height } = page.getSize();
            // @ts-expect-error TS(2365) FIXME: Operator '+' cannot be applied to types 'unknown' ... Remove this comment to see the full error message
            const pageNumber = pageIndex + 1; // For dynamic text

            // Helper to replace placeholders like {page} and {total}
            const processText = (text: any) => text
                .replace(/{page}/g, pageNumber)
                .replace(/{total}/g, totalPages);

            // Get processed text for the current page
            const processedTexts = {
                headerLeft: processText(texts.headerLeft),
                headerCenter: processText(texts.headerCenter),
                headerRight: processText(texts.headerRight),
                footerLeft: processText(texts.footerLeft),
                footerCenter: processText(texts.footerCenter),
                footerRight: processText(texts.footerRight),
            };

            if (processedTexts.headerLeft) page.drawText(processedTexts.headerLeft, { ...drawOptions, x: margin, y: height - margin });
            if (processedTexts.headerCenter) page.drawText(processedTexts.headerCenter, { ...drawOptions, x: (width / 2) - helveticaFont.widthOfTextAtSize(processedTexts.headerCenter, fontSize) / 2, y: height - margin });
            if (processedTexts.headerRight) page.drawText(processedTexts.headerRight, { ...drawOptions, x: width - margin - helveticaFont.widthOfTextAtSize(processedTexts.headerRight, fontSize), y: height - margin });
            if (processedTexts.footerLeft) page.drawText(processedTexts.footerLeft, { ...drawOptions, x: margin, y: margin });
            if (processedTexts.footerCenter) page.drawText(processedTexts.footerCenter, { ...drawOptions, x: (width / 2) - helveticaFont.widthOfTextAtSize(processedTexts.footerCenter, fontSize) / 2, y: margin });
            if (processedTexts.footerRight) page.drawText(processedTexts.footerRight, { ...drawOptions, x: width - margin - helveticaFont.widthOfTextAtSize(processedTexts.footerRight, fontSize), y: margin });
        }

        const newPdfBytes = await state.pdfDoc.save();
        downloadFile(new Blob([newPdfBytes], { type: 'application/pdf' }), 'header-footer-added.pdf');

    } catch (e) {
        console.error(e);
        showAlert('Error', e.message || 'Could not add header or footer.');
    } finally {
        hideLoader();
    }
}