// Doc Analyzer - PDF Rendering and Theme Toggle

// Theme toggle functionality
function initTheme() {
    const savedTheme = localStorage.getItem('theme') || 'dark';
    document.documentElement.setAttribute('data-theme', savedTheme);
    
    const themeToggle = document.querySelector('.theme-toggle');
    if (themeToggle) {
        themeToggle.addEventListener('click', () => {
            const currentTheme = document.documentElement.getAttribute('data-theme');
            const newTheme = currentTheme === 'dark' ? 'light' : 'dark';
            document.documentElement.setAttribute('data-theme', newTheme);
            localStorage.setItem('theme', newTheme);
        });
    }
}

// PDF rendering functionality
async function renderPDF(pdfUrl, canvasId) {
    const canvas = document.getElementById(canvasId);
    if (!canvas) return;
    
    const ctx = canvas.getContext('2d');
    
    try {
        // Load PDF.js from CDN
        const pdfjsLib = await import('https://cdnjs.cloudflare.com/ajax/libs/pdf.js/3.11.174/pdf.min.mjs');
        pdfjsLib.GlobalWorkerOptions.workerSrc = 'https://cdnjs.cloudflare.com/ajax/libs/pdf.js/3.11.174/pdf.worker.min.mjs';
        
        // Load the PDF document
        const loadingTask = pdfjsLib.getDocument(pdfUrl);
        const pdf = await loadingTask.promise;
        
        // Get first page
        const page = await pdf.getPage(1);
        
        // Calculate scale to fit canvas width
        const viewport = page.getViewport({ scale: 1 });
        const scale = canvas.width / viewport.width;
        const scaledViewport = page.getViewport({ scale: scale });
        
        // Set canvas dimensions
        canvas.height = scaledViewport.height;
        canvas.width = scaledViewport.width;
        
        // Render page
        const renderContext = {
            canvasContext: ctx,
            viewport: scaledViewport
        };
        
        await page.render(renderContext).promise;
    } catch (error) {
        console.error('Error rendering PDF:', error);
        ctx.fillStyle = '#ef4444';
        ctx.font = '16px Arial';
        ctx.fillText('Error loading PDF', 10, 30);
    }
}

// Initialize on page load
document.addEventListener('DOMContentLoaded', () => {
    initTheme();
    
    // Check for PDF to render
    const pdfUrl = document.getElementById('pdf-url');
    const canvasId = document.getElementById('canvas-id');
    
    if (pdfUrl && canvasId) {
        renderPDF(pdfUrl.value, canvasId.value);
    }
});