V2 Feature overhaul and improvements

lib/analysis/carbon-calculator.js

@@ -0,0 +1,82 @@
+/**
+ * Carbon Calculator
+ * Based on the Sustainable Web Design model.
+ */
+
+// 1 byte = X kWh?
+// The model: 0.81 kWh / GB for data transfer (2021/2022 estimate)
+// Carbon intensity: ~442g/kWh (global average)
+// 
+// Formula:
+// Energy = (Data Transfer (GB) * 0.81) * 0.75 (system boundary)
+// Carbon = Energy * 442g
+
+const SWD_KWH_PER_GB = 0.81;
+const CARBON_INTENSITY_GLOBAL = 442; // g/kWh
+
+/**
+ * Checks if a domain is hosted on green infrastructure.
+ * @param {string} domain 
+ * @returns {Promise<boolean>}
+ */
+async function checkGreenHosting(domain) {
+    try {
+        const res = await fetch(`https://api.thegreenwebfoundation.org/greencheck/${domain}`);
+        const data = await res.json();
+        return data.green || false;
+    } catch (e) {
+        console.warn('Green hosting check failed:', e.message);
+        return false;
+    }
+}
+
+/**
+ * Calculates the carbon footprint of a page load.
+ * @param {number} bytes - Total transfer size in bytes.
+ * @param {boolean} isGreen - Whether the host is green.
+ * @returns {object} - { co2: number (grams), rating: string }
+ */
+function calculateCarbon(bytes, isGreen) {
+    const gb = bytes / (1024 * 1024 * 1024);
+    let energy = gb * SWD_KWH_PER_GB * 0.75; // kWh
+    
+    // Carbon intensity adjustment
+    // If green, we assume a lower intensity or offset (often considered 0 or low, but let's say 50g/kWh for production/network overhead)
+    // The standard generally keeps network intensity the same but reduced datacenter intensity.
+    // For simplicity/standard SWD: Green hosting reduces the data center portion.
+    // Let's use simple factor: if green, reduce total by 10-20%? 
+    // Actually, SWD v3 splits it:
+    // Consumer device: 52%
+    // Network: 14%
+    // Data Center: 15%
+    // Hardware production: 19%
+    // 
+    // Green hosting only affects Data Center (15%).
+    // So if green, we assume 0 emissions for that 15%, reducing total by 15%.
+    
+    const intensity = isGreen ? CARBON_INTENSITY_GLOBAL * 0.85 : CARBON_INTENSITY_GLOBAL;
+    
+    const co2 = energy * intensity;
+    
+    // Rating (Eco-Index style)
+    // < 0.5g -> A+
+    // < 1g -> A
+    // < 2g -> B
+    // < 3g -> C
+    // > 5g -> F
+    let rating = 'F';
+    if(co2 < 0.5) rating = 'A+';
+    else if(co2 < 1.0) rating = 'A';
+    else if(co2 < 2.0) rating = 'B';
+    else if(co2 < 3.0) rating = 'C';
+    else if(co2 < 4.0) rating = 'D';
+    else if(co2 < 5.0) rating = 'E';
+
+    return {
+        co2: parseFloat(co2.toFixed(3)),
+        rating,
+        energy: parseFloat(energy.toFixed(5))
+    };
+}
+
+module.exports = { checkGreenHosting, calculateCarbon };