No more cheating during trades!

Signed-off-by: James Ketrenos <james_eikona@ketrenos.com>

server/routes/games.js

@@ -646,6 +646,10 @@ const setPlayerName = (game, session, name) => {
     }
   }
   
+  if (name === 'The bank') {
+    return `You cannot play as the bank!`;
+  }
+
   const old = session.name;
   let message;
 
@@ -1090,6 +1094,79 @@ const getValidRoads = (game, color) => {
   return limits;
 }
 
+const isCompatibleOffer = (player, offer) => {
+  const isBank = offer.name === 'The bank';
+  let valid = player.gets.length === offer.gives.length &&
+    player.gives.length === offer.gets.length;
+
+  if (!valid) {
+    console.log(`Gives and gets lengths do not match!`);
+    return false;
+  }
+  
+  console.log(player.gets, player.gives, offer);
+
+  player.gets.forEach(get => {
+    if (!valid) {
+      return;
+    }
+    valid = offer.gives.find(item => 
+      (item.type === get.type || item.type === '*') &&
+      item.count === get.count) !== undefined;
+  });
+
+  if (valid) player.gives.forEach(give => {
+    if (!valid) {
+      return;
+    }
+    valid = offer.gets.find(item => 
+      item.type === give.type &&
+      item.count === give.count) !== undefined;
+  });
+  return valid;
+};
+
+const checkOffer = (player, offer) => {
+  let error = undefined;
+  offer.gives.forEach(give => {
+    if (!error) {
+      return;
+    }
+
+    if (!(give.type in player)) {
+      error = `${give.type} is not a valid resource!`;
+      return;
+    }
+
+    if (player[give.type] < give.count) {
+      error = `You do not have ${give.count} ${give.type}!`;
+      return;
+    }
+
+    if (offer.gets.find(get => give.type === get.type)) {
+      error = `You can not give and get the same resource type!`;
+      return;
+    }
+  });
+
+  if (!error) offer.gets.forEach(get => {
+    if (error) {
+      return;
+    }
+    if (offer.gives.find(give => get.type === give.type)) {
+      error = `You can not give and get the same resource type!`;
+    };
+  })
+
+  return error;
+};
+
+const offerToString = (offer) => {
+  return offer.gives.map(item => `${item.count} ${item.type}`).join(', ') +
+    ' in exchange for ' +
+    offer.gets.map(item => `${item.count} ${item.type}`).join(', ');
+}
+
 router.put("/:id/:action/:value?", async (req, res) => {
   const { action, id } = req.params,
     value = req.params.value ? req.params.value : "";
@@ -1152,7 +1229,7 @@ router.put("/:id/:action/:value?", async (req, res) => {
       }
       game.turn.actions = [ 'trade' ];
       game.turn.limits = {};
-      addChatMessage(game, session, `${name} has requested to begin trading negotiations.`);
+      addChatMessage(game, session, `${name} requested to begin trading negotiations.`);
       break;
     }
 
@@ -1172,24 +1249,30 @@ router.put("/:id/:action/:value?", async (req, res) => {
     /* Any player can make an offer */
     if (value === 'offer') {
       const offer = req.body;
-      console.log('TODO: Verify player has sufficient resources.');
+     
+      error = checkOffer(session.player, offer);
+      if (error) {
+        break;
+      }
       session.player.gives = offer.gives;
       session.player.gets = offer.gets;
       if (game.turn.name === name) {
         game.turn.offer = offer;
       }
-      addChatMessage(game, session, `${session.name} has submitted a trade offer.`);
+      addChatMessage(game, session, `${session.name} submitted an offer to give ${offerToString(offer)}.`);
       break;
     }
 
     /* Only the active player can accept an offer */
     if (value === 'accept') {
       if (game.turn.name !== name) {
-        error = `Only the active player can accept a trade offer.`;
+        error = `Only the active player can accept an offer.`;
         break;
       }
+
       const offer = req.body;
       let target;
+
       /* Verify that the offer sent by the active player matches what
        * the latest offer was that was received by the requesting player */
       if (!offer.name || offer.name !== 'The bank') {
@@ -1213,31 +1296,29 @@ router.put("/:id/:action/:value?", async (req, res) => {
           error = `Unfortunately, trades were re-negotiated in transit and the deal is invalid!`;
           break;
         }
-      } 
+      } else {
+        target = offer;
+      }
+
+      /* Verify the requesting offer wasn't jacked --\
+       * make sure the target.gives === player.gets and target.gives === player.gets */
+      if (!isCompatibleOffer(player, target)) {
+        error = `The requested offer does not match the negotiated terms!`;
+        break;
+      }
 
-      /* Verify the requesting offer wasn't jacked */
-      console.log('TODO: Verify the player trade matches the offer target');
-      
       /* Transfer goods */
       player.gets.forEach(item => {
-        if (target) {
+        if (target.name !== 'The bank') {
           target[item.type] -= item.count;
-          if (target[item.type] < 0) {
-            console.log(`Cheating!!!`);
-            target[item.type] = 0;
-          }
         }
         player[item.type] += item.count;
       });
       player.gives.forEach(item => {
-        if (target) {
+        if (target.name !== 'The bank') {
           target[item.type] += item.count;
         }
         player[item.type] -= item.count;
-        if (player[item.type] < 0) {
-          console.log(`Cheating!!!`);
-          player[item.type] = 0;
-        }
       });
 
       delete game.turn.offer;
@@ -1403,7 +1484,7 @@ router.put("/:id/:action/:value?", async (req, res) => {
     if (game.turn.developmentPurchased) {
       error = `You have already purchased a development card this turn.`;
     }
-    addChatMessage(game, session, `Purchased a development card.`);
+    addChatMessage(game, session, `${session.name} purchased a development card.`);
     player.stone--;
     player.wheat--;
     player.sheep--;