Only enable/disable building buttons if needed

gorge.js

@@ -248,6 +248,8 @@ function displayBuildings() {
 
   for (const [key, value] of Object.entries(belongings)) {
 
+    let available = states.buildings[key].available;
+
     if (!belongings[key].visible) {
       if (resources.food * 10 >= costOfBuilding(key).food) {
         unlockBuilding(key);
@@ -270,12 +272,14 @@ function displayBuildings() {
     name.innerText = value.count + " " + (value.count == 1 ? buildings[key].name : buildings[key].plural);
     cost.innerText = render(buildingCost.food) + " food";
 
-    if (canAfford(buildingCost) && button.classList.contains("building-button-disabled")) {
+    if (canAfford(buildingCost) && available !== true) {
       button.classList.remove("building-button-disabled");
       cost.classList.add("building-button-cost-valid");
-    } else if (!canAfford(buildingCost) && !button.classList.contains("building-button-disabled")) {
+      states.buildings[key].available = true;
+    } else if (!canAfford(buildingCost) && available !== false) {
       button.classList.add("building-button-disabled");
       cost.classList.add("building-button-cost-invalid");
+      states.buildings[key].available = false;
     }
   }
 }
@@ -472,6 +476,17 @@ const states = {};
 // we can just check if they've been handled already
 
 function initializeStates() {
+  const buildingStates = {};
+
+  Object.keys(buildings).forEach(key => {
+    buildingStates[key] = {
+      visible: undefined,
+      available: undefined
+    }
+  });
+
+  states.buildings = buildingStates;
+
   const upgradeStates = {};
 
   Object.keys(upgrades).forEach(key => {