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

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

export function setupFixDimensionsUI() {
    const targetSizeSelect = document.getElementById('target-size');
    const customSizeWrapper = document.getElementById('custom-size-wrapper');
    if (targetSizeSelect && customSizeWrapper) {
        targetSizeSelect.addEventListener('change', () => {
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            customSizeWrapper.classList.toggle('hidden', targetSizeSelect.value !== 'Custom');
        });
    }
}

export async function fixDimensions() {
    // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
    const targetSizeKey = document.getElementById('target-size').value;
    // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
    const orientation = document.getElementById('orientation').value;
    // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'Element'.
    const scalingMode = document.querySelector('input[name="scaling-mode"]:checked').value;
    // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
    const backgroundColor = hexToRgb(document.getElementById('background-color').value);
    
    showLoader('Standardizing pages...');
    try {
        let targetWidth, targetHeight;

        if (targetSizeKey === 'Custom') {
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            const width = parseFloat(document.getElementById('custom-width').value);
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            const height = parseFloat(document.getElementById('custom-height').value);
            // @ts-expect-error TS(2339) FIXME: Property 'value' does not exist on type 'HTMLEleme... Remove this comment to see the full error message
            const units = document.getElementById('custom-units').value;
            if (units === 'in') {
                targetWidth = width * 72;
                targetHeight = height * 72;
            } else { // mm
                targetWidth = width * (72 / 25.4);
                targetHeight = height * (72 / 25.4);
            }
        } else {
            [targetWidth, targetHeight] = PageSizes[targetSizeKey];
        }

        if (orientation === 'landscape' && targetWidth < targetHeight) {
            [targetWidth, targetHeight] = [targetHeight, targetWidth];
        } else if (orientation === 'portrait' && targetWidth > targetHeight) {
            [targetWidth, targetHeight] = [targetHeight, targetWidth];
        }

        const sourceDoc = state.pdfDoc;
        const newDoc = await PDFLibDocument.create();
        
        for (const sourcePage of sourceDoc.getPages()) {
            const { width: sourceWidth, height: sourceHeight } = sourcePage.getSize();
            const embeddedPage = await newDoc.embedPage(sourcePage);
            
            const newPage = newDoc.addPage([targetWidth, targetHeight]);
            newPage.drawRectangle({ x: 0, y: 0, width: targetWidth, height: targetHeight, color: rgb(backgroundColor.r, backgroundColor.g, backgroundColor.b) });
            
            const scaleX = targetWidth / sourceWidth;
            const scaleY = targetHeight / sourceHeight;
            const scale = scalingMode === 'fit' ? Math.min(scaleX, scaleY) : Math.max(scaleX, scaleY);
            
            const scaledWidth = sourceWidth * scale;
            const scaledHeight = sourceHeight * scale;
            
            const x = (targetWidth - scaledWidth) / 2;
            const y = (targetHeight - scaledHeight) / 2;

            newPage.drawPage(embeddedPage, { x, y, width: scaledWidth, height: scaledHeight });
        }

        const newPdfBytes = await newDoc.save();
        downloadFile(new Blob([newPdfBytes], { type: 'application/pdf' }), 'standardized.pdf');

    } catch (e) {
        console.error(e);
        showAlert('Error', 'An error occurred while standardizing pages.');
    } finally {
        hideLoader();
    }
}