`;
productDetailsContainer.classList.remove('hidden');
};
// --- IV. EVENT LISTENERS ---
tabButtons.forEach((button, index) => button.addEventListener('click', () => showTab(index)));
prevBtn.addEventListener('click', () => showTab(currentTabIndex - 1));
nextBtn.addEventListener('click', () => showTab(currentTabIndex + 1));
updateDataBtn.addEventListener('click', () => {
try {
const newData = JSON.parse(dataInput.value);
if (Array.isArray(newData)) {
currentForecastData = newData;
jsonErrorMsg.classList.add('hidden');
updateDashboard();
alert('Dashboard updated successfully!');
showTab(0);
} else { throw new Error("Data is not an array."); }
} catch (error) {
jsonErrorMsg.classList.remove('hidden');
}
});
productSelect.addEventListener('change', showProductDetails);
downloadPdfBtn.addEventListener('click', async () => {
const dashboardArea = getElement('dashboard-export-area');
if (!dashboardArea) return;
const originalButtonText = downloadPdfBtn.textContent;
downloadPdfBtn.textContent = 'Generating PDF...';
downloadPdfBtn.disabled = true;
try {
const canvas = await html2canvas(dashboardArea, {
scale: 2, useCORS: true, logging: false,
width: dashboardArea.scrollWidth, height: dashboardArea.scrollHeight,
windowWidth: dashboardArea.scrollWidth, windowHeight: dashboardArea.scrollHeight
});
const imgData = canvas.toDataURL('image/png');
const { jsPDF } = window.jspdf;
const pdfWidth = 297, pdfHeight = 210, margin = 15;
const aspectRatio = canvas.width / canvas.height;
let scaledWidth = pdfWidth - (margin * 2);
let scaledHeight = scaledWidth / aspectRatio;
if (scaledHeight > pdfHeight - (margin * 2)) {
scaledHeight = pdfHeight - (margin * 2);
scaledWidth = scaledHeight * aspectRatio;
}
const xOffset = (pdfWidth - scaledWidth) / 2;
const yOffset = (pdfHeight - scaledHeight) / 2;
const pdf = new jsPDF({ orientation: 'landscape', unit: 'mm', format: 'a4' });
pdf.addImage(imgData, 'PNG', xOffset, yOffset, scaledWidth, scaledHeight);
pdf.save('Product_Demand_Forecast_Dashboard.pdf');
} catch (error) {
console.error("PDF generation failed:", error);
alert("Sorry, there was an error generating the PDF. Please try again.");
} finally {
downloadPdfBtn.textContent = originalButtonText;
downloadPdfBtn.disabled = false;
}
});
// --- V. INITIALIZATION CALLS ---
dataInput.value = JSON.stringify(initialForecastData, null, 4);
updateDashboard();
showTab(0);
});
