// 1. Centralized Pricing Configuration (Filename : Price in KES Cents)
const topicPrices = {
    "Thermochemistry.html": 15000,         // KES 150
    "Solubility.html": 15000,               // KES 150
    "Reaction Rate.html": 20000,            // KES 200
    "The Cell.html": 10000,                 // KES 100
    "Gaseous exchange.html": 12000,         // KES 120
    "InorganicQAsampleTest1.html": 20000,    // KES 200
    "InorganicQAsampleTest2.html": 20000     // KES 200
};
const DEFAULT_PRICE_CENTS = 10000;          // Fallback Price: KES 100

// Helper function to extract targeted practical name from URL query parameters
function getTargetFile() {
    const urlParams = new URLSearchParams(window.location.search);
    return urlParams.get('returnTo') || "InorganicQAsampleTest1.html";
}

// 2. Page Initialization: Display Topic Info Immediately upon loading page
document.addEventListener("DOMContentLoaded", function() {
    const targetFile = getTargetFile();
    
    let cleanName = targetFile.replace(".html", "").replace(/[-_]/g, " ");
    const priceCents = topicPrices[targetFile] || DEFAULT_PRICE_CENTS;
    const priceKES = priceCents / 100;

    document.getElementById("displayName").innerText = cleanName;
    document.getElementById("displayPrice").innerText = priceKES.toFixed(2);
});

// 3. Execution Layer: Trigger Payment API Interface
function payWithPaystack() {
    const phone = document.getElementById('phoneNumber').value.trim();

    if (!phone || phone.length < 10) {
        alert("Please enter a valid M-Pesa phone number.");
        return;
    }

    const targetFile = getTargetFile();
    const finalAmountCents = topicPrices[targetFile] || DEFAULT_PRICE_CENTS;

    const cleanPhone = phone.replace(/[^0-9]/g, ""); 
    const generatedEmail = `mpesa_${cleanPhone}@vsl-simulations.com`;

    const popup = new PaystackPop();
    popup.newTransaction({
        key: 'pk_test_f9804874de89577124d605a1ec7a9a3a2458aadb', // ⚠️ REMEMBER TO PASTE YOUR ACTUAL PAYSTACK PUBLIC KEY HERE
        email: generatedEmail,
        amount: finalAmountCents,
        currency: 'KES',
        
        onSuccess: function(transaction) {
            // 1. Calculate expiration parameters matching target access profile (e.g. 24 Hours)
            let expiryDate = new Date();
            expiryDate.setTime(expiryDate.getTime() + (24 * 60 * 60 * 1000)); 

            // 2. Save individual strict authorization state token parameters targeting specific file
            document.cookie = `access_${targetFile}=true; expires=${expiryDate.toUTCString()}; path=/; secure; samesite=strict`;

            alert("Payment Verified! Loading your simulation now...");

            // 3. Transform current tab directly into the premium simulation file!
            window.location.href = "/" + targetFile;
        },
        onCancel: function() {
            alert("Transaction cancelled. Your account has not been charged.");
        }
    });
}