From 1916ad3509a3f85e0e6a10b1055ae7c80dae699f Mon Sep 17 00:00:00 2001
From: James Ketrenos <james_eikona@ketrenos.com>
Date: Sat, 25 Jun 2022 15:27:12 -0700
Subject: [PATCH] Updated AI

Signed-off-by: James Ketrenos <james_eikona@ketrenos.com>
---
 client/src/Activities.js          |  13 +-
 server/ai/app.js                  | 876 ++++++++++++++++++++++--------
 server/ai/longest-road.js         | 161 ++++++
 server/routes/games.js            | 497 ++++++++---------
 server/{routes => util}/layout.js |   0
 server/util/validLocations.js     | 120 ++++
 6 files changed, 1165 insertions(+), 502 deletions(-)
 create mode 100644 server/ai/longest-road.js
 rename server/{routes => util}/layout.js (100%)
 create mode 100644 server/util/validLocations.js

diff --git a/client/src/Activities.js b/client/src/Activities.js
index 5843ff4..77aaf26 100644
--- a/client/src/Activities.js
+++ b/client/src/Activities.js
@@ -5,7 +5,7 @@ import { PlayerColor } from './PlayerColor.js';
 import { Dice } from './Dice.js';  
 import { GlobalContext } from "./GlobalContext.js";
 
-const Activity = ({ activity }) => {
+const Activity = ({ keep, activity }) => {
   const [animation, setAnimation] = useState('open');
   const [display, setDisplay] = useState(true)
 
@@ -16,7 +16,7 @@ const Activity = ({ activity }) => {
     setDisplay(false)
   };
 
-  if (display) {
+  if (display && !keep) {
     setTimeout(() => { hide(10000) }, 0);
   }
 
@@ -157,10 +157,11 @@ const Activities = () => {
     discarders.push(<div key={name} className="Requirement">{name} must discard <b>{player.mustDiscard}</b> cards.</div>);
   }
 
-  const list = activities
-    .filter(activity => timestamp - activity.date < 11000)
-    .map(activity => {
-      return <Activity key={activity.date} activity={activity}/>;
+  let list = activities
+    .filter((activity, index) => 
+      activities.length - 1 === index || timestamp - activity.date < 11000);
+  list = list.map((activity, index) => {
+      return <Activity keep={list.length - 1 === index} key={activity.date} activity={activity}/>;
     });
   
   let who;
diff --git a/server/ai/app.js b/server/ai/app.js
index 0979bbc..67d04b1 100644
--- a/server/ai/app.js
+++ b/server/ai/app.js
@@ -1,6 +1,10 @@
 const fetch = require('node-fetch');
 const WebSocket = require('ws');
 const fs = require('fs').promises;
+const calculateLongestRoad = require('./longest-road.js');
+
+const { getValidRoads, getValidCorners } = require('../util/validLocations.js');
+const layout = require('../util/layout.js');
 
 const version = '0.0.1';
 
@@ -18,16 +22,28 @@ For example:
 
 const server = process.argv[2];
 const gameId = process.argv[3];
-let session = undefined;
 const name = process.argv[4];
 
 const game = {};
+const anyValue = undefined;
 
 process.env["NODE_TLS_REJECT_UNAUTHORIZED"] = 0;
 
+
+/* Do not use arrow function as this is rebound to have 
+ * this as the WebSocket */
+let send = function (data) {
+  if (data.type === 'get') {
+    console.log(`ws - send: get`, data.fields);
+  } else {
+    console.log(`ws - send: ${data.type}`);
+  }
+  this.send(JSON.stringify(data));
+};
+
 const error = (e) => {
   console.log(`ws - error`, e);
-}
+};
 
 const connect = async () => {
   let loc = new URL(server), new_uri;
@@ -69,6 +85,8 @@ const connect = async () => {
         'Cookie': `player=${player}`
       }
     });
+  send = send.bind(ws);
+
   return new Promise((resolve, reject) => {
     const headers = (e) => {
       console.log(`ws - headers`);
@@ -92,27 +110,182 @@ const connect = async () => {
     ws.on('headers', headers);
     ws.on('close', close);
     ws.on('error', error);
-    ws.on('message', async (data) => { await message(ws, data); });
+    ws.on('message', async (data) => { await message(data); });
   });
 };
 
-const createPlayer = (ws) => {
-  const send = (data) => {
-    ws.send(JSON.stringify(data));
-  };
+const createPlayer = () => {
+};
 
-  if (game.name === '') {
-    send({ type: 'player-name', name });
-    return;
-  }
+const types = [ 'wheat', 'brick', 'stone', 'sheep', 'wood' ];
 
-  if (game.state !== 'lobby') {
-    return;
+const tryBuild = () => {
+  let waitingFor = undefined;
+
+  if (!waitingFor
+  && game.private.settlements
+  && game.private.wood 
+  && game.private.brick
+  && game.private.sheep
+  && game.private.wheat) {
+    const corners = getValidCorners(game, game.color);
+    if (corners.length) {
+      send({
+        type: 'buy-settlement'
+      });
+      waitingFor = { 
+        turn: {
+          actions: anyValue
+        }
+      };
+    }
   }
   
-  if (game.unselected.indexOf(name) === -1) {
+  if (!waitingFor
+  && game.private.cities
+  && game.private.stone >= 3
+  && game.private.wheat >= 2) {
+    const corners = getValidCorners(game, game.color, 'settlement');
+    if (corners.length) {
+      send({
+        type: 'buy-city'
+      });
+      waitingFor = {
+        turn: {
+          actions: anyValue
+        }
+      };
+    }
+  }  
+
+  if (!waitingFor
+  && game.private.roads
+  && game.private.wood
+  && game.private.brick) {
+    const roads = getValidRoads(game, game.color);
+    if (roads.length) {
+      send({
+        type: 'buy-road'
+      });
+      waitingFor = {
+        turn: {
+          actions: anyValue
+        }
+      };
+    }
+  }
+
+  if (!waitingFor
+    && game.private.wheat
+    && game.private.stone
+    && game.private.sheep) {
+    send({
+      type: 'buy-development'
+    });
+    waitingFor = {
+      private: {
+        development: anyValue
+      }
+    };
+  }
+
+  return waitingFor;
+};
+
+let sleeping = false;
+const sleep = async (delay) => {
+  if (sleeping) {
     return;
   }
+  sleeping = true;
+  return new Promise((resolve) => {
+    setTimeout(() => {
+      sleeping = false;
+      resolve();
+    }, delay);
+  });
+};
+
+const bestRoadPlacement = (game) => {
+  const road = calculateLongestRoad(game);
+  console.log(`${name} - could make road ${road.segments + 1} long on ${road.index}`);
+
+  let attempt = -1;
+  layout.roads[road.index].corners.forEach(cornerIndex => {
+    if (attempt !== -1) {
+      return;
+    }
+    layout.corners[cornerIndex].roads.forEach(roadIndex => {
+      if (attempt !== -1) {
+        return;
+      }
+      const placedRoad = game.placements.roads[roadIndex];
+      if (placedRoad.color) {
+        return;
+      }
+      attempt = roadIndex;
+    });
+  });
+
+  if (game.turn.limits.roads.indexOf(attempt) !== -1) {
+    console.log(`${name} - attempting to place on end of longest road`);
+    return attempt;
+  } else {
+    console.log(`${name} - selecting a random road location`);
+    return game.turn.limits.roads[Math.floor(
+      Math.random() * game.turn.limits.roads.length)];
+  }
+}
+
+const isMatch = (input, received) => {
+  for (let key in input) {
+    /* received update didn't contain this field */
+    if (!(key in received)) {
+      return false;
+    }
+    /* Received object had a value we were waiting to have set */
+    if (input[key] === anyValue && (key in received)) {
+      continue;
+    }
+    /* waitingFor field is an object, so recurse */
+    if (typeof input[key] === 'object') {
+      if (!isMatch(input[key], received[key])) {
+        return false
+      }
+      /* object matched; go to next field */
+      continue;
+    }
+    /* No match in requested key... */
+    if (input[key] !== received[key]) {
+      return false;
+    }
+    /* Value matches */
+  }
+  /* All fields set or matched */
+  return true;
+};
+
+const processLobby = (received) => {
+  if (game.name === '' && !received.name) {
+    send({ type: 'player-name', name });
+    /* Wait for the game.name to be set to 'name' and for unselected */
+    return { name, players: anyValue, unselected: anyValue };
+  }
+
+  if (!received.unselected) {
+    return {
+      unselected: anyValue
+    };
+  }
+
+  /* AI selected a Player. Wait for game-order */
+  if (received.unselected.indexOf(name) === -1) {
+    send({
+      type: 'chat',
+      message: `Woohoo! Robot AI ${version} is alive and playing as ${game.color}!`
+    });
+    return { state: 'game-order' };
+  }
 
   const slots = [];
   for (let color in game.players) {
@@ -120,11 +293,16 @@ const createPlayer = (ws) => {
       slots.push(color);
     }
   }
+
   if (slots.length === 0) {
-    return;
+    send({
+      chat: `There are no slots for me to play :(. Waiting for one to open up.`
+    });
+    return { unselected: anyValue };
   }
+
   const index = Math.floor(Math.random() * slots.length);
-  console.log(`Requesting to play as ${slots[index]}.`);
+  console.log(`${name} - requesting to play as ${slots[index]}.`);
   game.unselected = game.unselected.filter(
     color => color === slots[index]);
   send({
@@ -132,248 +310,502 @@ const createPlayer = (ws) => {
     field: 'color',
     value: slots[index]
   });
-  send({
-    type: 'chat',
-    message: `Woohoo! Robot AI ${version} is alive!`
-  });
+  return { color: slots[index], state: 'game-order' };
 };
 
-const tryBuild = (ws) => {
-  const send = (data) => {
-    console.log(`ws - send`);
-    ws.send(JSON.stringify(data));
+const processGameOrder = async () => {
+  if (!game.color) {
+    console.log(`game-order - player not active`);
+    return { color };
+  }
+  console.log(`game-order - `, {
+    color: game.color,
+    players: game.players
+  });
+  if (!game.players[game.color].orderRoll || game.players[game.color].tied) {
+    console.log(`Time to roll as ${game.color}`);
+    send({ type: 'roll' });
+  }
+
+  return { turn: { color: game.color }};
+};
+
+const processInitialPlacement = async (received) => {
+  if (!game.turn || game.turn.color !== game.color) {
+    return {
+      turn: {
+        color: game.color,
+      }
+    }
   };
-  let trying = false;
-  if (game.private.settlements
-  && game.private.wood 
-  && game.private.brick
-  && game.private.sheep
-  && game.private.wheat) {
-    send({
-      type: 'buy-settlement'
+
+  if (!game.placements) {
+    return {
+      turn: {
+        color: game.color,
+      },
+      placements: anyValue
+    };
+  }
+
+  if (!game.turn.actions) {
+    return {
+      turn: {
+        color: game.color,
+        actions: anyValue
+      },
+      placements: anyValue
+    };
+  }
+
+  let index;
+  const type = game.turn.actions[0];
+  if (type === 'place-road') {
+    index = bestRoadPlacement(game);
+  } else if (type === 'place-settlement') {
+    index = game.turn.limits.corners[Math.floor(
+      Math.random() * game.turn.limits.corners.length)];
+  }
+  console.log(`Selecting ${type} at ${index}`);
+  send({
+    type, index
+  });
+  /* Wait for this player's turn again */
+  return { turn: { color: game.color } };
+}
+
+/* Start watching for a name entry */
+let waitingFor = { name: anyValue }, received = {};
+
+const reducedGame = (game) => {
+  const filters = [ 'chat', 'activities', 'placements', 'players', 'private', 'dice' ];
+  const value = {};
+  for (let key in game) {
+    if (filters.indexOf(key) === -1) {
+      value[key] = game[key];
+    } else {
+      if (Array.isArray(game[key])) {
+        value[key] = `length(${game[key].length})`;
+      } else {
+        value[key] = `...filtered`;
+      }
+    }
+  }
+  return value;
+}
+
+const processWaitingFor = (waitingFor) => {
+  const value = {
+    type: 'get',
+    fields: []
+  };
+  for (let key in waitingFor) {
+    value.fields.push(key);
+  }
+  send(value);
+  received = {};
+}
+
+const processDiscard = async (received) => {
+  if (!game.players) {
+    waitingFor = {
+      players: {}
+    };
+    waitingFor.players[game.color] = undefined;
+    return waitingFor;
+  }
+
+  let mustDiscard = game.players[game.color].mustDiscard;
+
+  if (!mustDiscard) {
+    return;
+  }
+
+  const cards = [],
+    discards = {};
+  types.forEach(type => {
+    for (let i = 0; i < game.private[type]; i++) {
+      cards.push(type);
+    }
+  });
+  while (mustDiscard--) {
+    const type = cards[Math.floor(Math.random() * cards.length)];
+    if (!(type in discards)) {
+      discards[type] = 1;
+    } else {
+      discards[type]++;
+    }
+  }
+  console.log(`discarding - `, discards);
+  send({
+    type: 'discard',
+    discards
+  });
+  waitingFor = {
+    turn: anyValue,
+    players: {}
+  }
+  waitingFor.players[game.color] = anyValue;
+  return waitingFor;
+};
+
+const processTrade = async (received) => {
+  const enough = [];
+  let shouldTrade = true;
+
+  /* Check and see which resources we have enough of */
+  types.forEach(type => {
+    if (game.private[type] >= 4) {
+      enough.push(type);
+    }
+  });
+  shouldTrade = enough.length > 0;
+
+  let least = { type: undefined, count: 0 };
+
+  if (shouldTrade) {
+    /* Find out which resource we have the least amount of */
+    types.forEach(type => {
+      if (game.private[type] <= least.count) {
+        least.type = type;
+        least.count = game.private[type];
+      }
     });
-    trying = true;
+    if (least.count >= 4) {
+      shouldTrade = false;
+    }
+  }
+
+  /* If trade not active, see if it should be... */
+  if (shouldTrade 
+    && (!received.turn.actions 
+      || received.turn.actions.indexOf('trade') === -1)) {
+    /* Request trade mode, and wait for it... */
+    console.log(`${name} - starting trade negotiations`);
+    send({
+      type: 'trade'
+    });
+    return {
+      turn: { actions: anyValue }
+    }
   }
   
-  if (game.private.wood && game.private.brick && game.private.roads) {
+  /* If we do not have enough resources, and trade is active, cancel */
+  if (!shouldTrade
+    && received.turn.actions
+    && received.turn.actions.indexOf('trade') !== -1) {
+    console.log(`${name} - cancelling trade negotiations`);
     send({
-      type: 'buy-road'
+      type: 'trade',
+      action: 'cancel'
     });
-    trying = true;
+    return {
+      turn: anyValue
+    };
   }
 
-  return trying;
-};
+  if (!shouldTrade) {
+    return;
+  }
 
-
-const sleep = async (delay) => {
-  return new Promise((resolve) => {
-    setTimeout(resolve, delay);
-  });
-};
-
-const message = async (ws, data) => {
-  const send = (data) => {
-    console.log(`ws - send: ${data.type}`);
-    ws.send(JSON.stringify(data));
+  const give = {
+    type: enough[Math.floor(Math.random() * enough.length)],
+    count: 4
+  }, get = {
+    type: least.type,
+    count: 1
+  };
+  const offer = {
+    gives: [give],
+    gets: [get]
   };
 
-  data = JSON.parse(data);
-  switch (data.type) {
-  case 'game-update':
-    
-    Object.assign(game, data.update);
-    delete data.update.chat;
-    delete data.update.activities;
-    console.log(`ws - receive - `,
-      data.update
-    );
+  if (received.turn.offer) {
+    send({
+      type: 'trade',
+      action: 'accept',
+      offer: {
+        name: 'The bank',
+        gets: [{ type: get.type, count: 1 }],
+        gives: [{ type: give.type, count: give.count }]
+      }
+    });
+    return {
+      turn: {
+        actions: anyValue
+      }
+    };
+  }
 
-    console.log(`state - ${game.state}`);
+  /* Initiate offer... */
+
+  if (!received.turn.offer) {
+    console.log(`trade - `, offer);
+    send({
+      type: 'trade',
+      action: 'offer',
+      offer
+    });
+
+    return {
+      private: { offerRejected: anyValue }
+    };
+  }
+
+  return {
+    turn: anyValue
+  };
+}
+
+const processNormal = async (received) => {
+  let waitingFor = undefined;
+
+  if (!game.turn || !game.private) {
+    return {
+      turn: anyValue,
+      private: anyValue
+    }
+  };
+  
+  /* Process things that happen on everyone's turn */
+  waitingFor = await processDiscard(received);
+  if (waitingFor) {
+    return waitingFor;
+  }
+
+  /* From here on it is only actions that occur on the player's turn */
+  if (!received.turn || received.turn.color !== game.color) {
+    console.log(`${name} - waiting for turn... ${game.players[game.turn.color].name} is active.`);
+    console.log({
+      wheat: game.private.wheat,
+      sheep: game.private.sheep,
+      stone: game.private.stone,
+      brick: game.private.brick,
+      wood: game.private.wood,
+    });
+    return {
+      turn: { color: game.color },
+      dice: anyValue
+    };
+  }
+
+  console.log(`${name}'s turn. Processing...`);
+
+  if (!game.dice) {
+    console.log(`${name} - rolling...`);
+    send({
+      type: 'roll'
+    });
+    return {
+      turn: { 
+        color: game.color
+      }, 
+      dice: anyValue
+    };
+  }
+
+  if (received.turn.actions && received.turn.actions.indexOf('place-road') !== -1) {
+    index = bestRoadPlacement(game);
+    send({
+      type: 'place-road', index
+    });
+    return {
+      turn: { color: game.color }
+    };
+  }
+
+  if (game.turn.actions && game.turn.actions.indexOf('place-city') !== -1) {
+    index = game.turn.limits.corners[Math.floor(
+      Math.random() * game.turn.limits.corners.length)];
+    send({
+      type: 'place-city', index
+    });
+    return {
+      turn: { color: game.color }
+    };
+  }
+
+  if (game.turn.actions && game.turn.actions.indexOf('place-settlement') !== -1) {
+    console.log({ corners: game.turn.limits.corners });
+    index = game.turn.limits.corners[Math.floor(
+      Math.random() * game.turn.limits.corners.length)];
+    send({
+      type: 'place-settlement', index
+    });
+    return {
+      turn: { color: game.color }
+    };
+  }
+
+  if (game.turn.actions
+    && game.turn.actions.indexOf('place-robber') !== -1) {
+    console.log({ pips: game.turn.limits.pips });
+    const index = game.turn.limits.pips[Math.floor(Math.random() * game.turn.limits.pips.length)];
+    console.log(`placing robber - ${index}`)
+    send({
+      type: 'place-robber',
+      index
+    });
+    return {
+      turn: { color: game.color }
+    };
+  }
+
+  if (game.turn.actions && game.turn.actions.indexOf('steal-resource') !== -1) {
+    if (!game.turn.limits.players) {
+      console.warn(`No players in limits with steal-resource`);
+      return;
+    }
+    const { color } = game.turn.limits.players[Math.floor(Math.random() * game.turn.limits.players.length)];
+    console.log(`stealing resouce from ${game.players[color].name}`);
+    send({
+      type: 'steal-resource',
+      color
+    });
+    return;
+  }
+
+  if (game.turn.robberInAction) {
+    console.log({ turn: game.turn });
+    return;
+  } 
+
+  console.log({
+    wheat: game.private.wheat,
+    sheep: game.private.sheep,
+    stone: game.private.stone,
+    brick: game.private.brick,
+    wood: game.private.wood,
+  });
+
+  waitingFor = await tryBuild(received);
+  if (waitingFor) {
+    return waitingFor;
+  }
+  
+  waitingFor = await processTrade(received);
+  if (waitingFor) {
+    return waitingFor;
+  }
+
+  console.log(`${name} - passing`);
+  send({
+    type: 'pass'
+  });
+
+  return { turn: anyValue };
+};
+
+const message = async (data) => {
+  try {
+    data = JSON.parse(data);
+  } catch (error) {
+    console.error(error);
+    console.log(data);
+    return;
+  }
+
+  switch (data.type) {
+  case 'warning':
+    if (game.turn.color === game.color && game.state !== 'lobby') {
+      console.log(`WARNING: ${data.warning}. Passing.`);
+      send({
+        type: 'pass'
+      });
+      waitingFor = {
+        turn: { color: game.color }
+      };
+      processWaitingFor(waitingFor);
+    }
+    break;
+
+  case 'game-update':
+    /* Keep game updated with the latest information */
+    Object.assign(game, data.update);
+    if (sleeping) {
+      if (waitingFor) {
+        Object.assign(received, data.update);
+      }
+      console.log(`${name} - sleeping`);
+      return;
+    }
+
+    if (waitingFor) {
+      Object.assign(received, data.update);
+      if (!isMatch(waitingFor, received)) {
+        console.log(`${name} - still waiting - waitingFor: `,
+          waitingFor);
+        if (game.robberInAction) {
+          console.log(`${name} - robber in action! Must check discards...`);
+        } else {
+          return;
+        }
+      } else {
+        console.log(`${name} - received match - received: `,
+          reducedGame(received));
+        console.log(`${name} - going to sleep`);
+        await sleep(1000 + Math.random() * 500);
+        console.log(`${name} - waking up`);
+        waitingFor = undefined;
+      }
+    }
 
     switch (game.state) {
     case undefined:
     case 'lobby':
-      createPlayer(ws);
-      break;
+      waitingFor = await processLobby(received);
+      if (waitingFor) {
+        processWaitingFor(waitingFor);
+      }
+      return;
 
     case 'game-order':
-      if (!game.color) {
-        console.log(`game-order - player not active`);
-        return;
+      waitingFor = await processGameOrder(received);
+      if (waitingFor) {
+        processWaitingFor(waitingFor);
       }
-      console.log(`game-order - `, { 
-        color: game.color, 
-        players: game.players
-      });
-      if (!game.players[game.color].orderRoll || game.players[game.color].tied) {
-        console.log(`Time to roll as ${game.color}`);
-        send({ type: 'roll' });
-      }
-      break;
+      return;
 
-    case 'initial-placement': {
-      await sleep(1000 + Math.random() * 500);
-      console.log({ color: game.color, state: game.state, turn: game.turn });
-      if (game.turn.color !== game.color) {
-        break;
+    case 'initial-placement':
+      waitingFor = await processInitialPlacement(received);
+      if (waitingFor) {
+        processWaitingFor(waitingFor);
       }
-
-      let index;
-      const type = game.turn.actions[0];
-      if (type === 'place-road') {
-        console.log({ roads: game.turn.limits.roads });
-        index = game.turn.limits.roads[Math.floor(
-          Math.random() * game.turn.limits.roads.length)];
-      } else if (type === 'place-settlement') {
-        console.log({ corners: game.turn.limits.corners });
-        index = game.turn.limits.corners[Math.floor(
-          Math.random() * game.turn.limits.corners.length)];
-      }
-      console.log(`Selecting ${type} at ${index}`);
-      send({
-        type, index
-      });
-    } break;
-
+      return;
+      
     case 'normal':
-      if (game.players[game.color].mustDiscard) {
-        await sleep(1000 + Math.random() * 500);
-        let mustDiscard = game.players[game.color].mustDiscard;
-        if (!mustDiscard) {
-          return;
-        }
-        const cards = [],
-          discards = {};
-        const types = ['wheat', 'sheep', 'stone', 'brick', 'wood'];
-        types.forEach(type => {
-          for (let i = 0; i < game.private[type]; i++) {
-            cards.push(type);
-          }
-        });
-        while (mustDiscard--) {
-          const type = cards[Math.floor(Math.random() * cards.length)];
-          if (!(type in discards)) {
-            discards[type] = 1;
-          } else {
-            discards[type]++;
-          }
-        }
-        console.log(`discarding - `, discards);
-        send({
-          type: 'discard',
-          discards
-        });
-        return;
+      waitingFor = await processNormal(received);
+      if (waitingFor) {
+        processWaitingFor(waitingFor);
       }
-
-      if (game.turn.color !== game.color) {
-        console.log(`not ${name}'s turn.`)
-        return;
-      }
-
-      await sleep(1000 + Math.random() * 500);
-      if (game.turn.color !== game.color) {
-        return;
-      }
-
-      if (game.turn.actions && game.turn.actions.indexOf('place-road') !== -1) {
-        index = game.turn.limits.roads[Math.floor(
-          Math.random() * game.turn.limits.roads.length)];
-        send({
-          type: 'place-road', index
-        });
-        return;
-      } 
-      
-      if (game.turn.actions && game.turn.actions.indexOf('place-settlement') !== -1)  {
-        console.log({ corners: game.turn.limits.corners });
-        index = game.turn.limits.corners[Math.floor(
-          Math.random() * game.turn.limits.corners.length)];
-        send({
-          type: 'place-settlement', index
-        });
-        return;
-      } 
-      
-      if (!game.dice) {
-        console.log(`Rolling...`);
-        send({
-          type: 'roll'
-        });
-        return;
-      } 
-      
-      if (game.turn.actions 
-      && game.turn.actions.indexOf('place-robber') !== -1) {
-        console.log({ pips: game.turn.limits.pips });
-        const index = game.turn.limits.pips[Math.floor(Math.random() * game.turn.limits.pips.length)];
-        console.log(`placing robber - ${index}`)
-        send({
-          type: 'place-robber', 
-          index
-        });
-        return;
-      } 
-         
-      if (game.turn.actions && game.turn.actions.indexOf('steal-resource') !== -1) {
-        if (!game.turn.limits.players) {
-          console.warn(`No players in limits with steal-resource`);
-          return;
-        }
-        const { color } = game.turn.limits.players[Math.floor(Math.random() * game.turn.limits.players.length)];
-        console.log(`stealing resouce from ${game.players[color].name}`);
-        send({
-          type: 'steal-resource',
-          color
-        });
-        return;
-      }
-      
-      if (game.turn.robberInAction) {
-        console.log({ turn: game.turn });
-      } else {
-        console.log({ 
-          turn: game.turn,
-          wheat: game.private.wheat, 
-          sheep: game.private.sheep,
-          stone: game.private.stone,
-          brick: game.private.brick,
-          wood: game.private.wood,
-        });
-        if (!tryBuild(ws)) {
-          send({
-            type: 'pass'
-          });
-        }
-      }
-      break;
-    default:
-      console.log({ state: game.state, turn: game.turn });
-      break;
-    } 
-    break;
- 
-  case 'ping':
-    if (!game.state) {
-      console.log(`ping received with no game. Sending update request`);
-      ws.send(JSON.stringify({
-        type: 'game-update'
-      }));
+      return;
     }
     break;
 
+  case 'ping':
+    if (!game.state && !received.state) {
+      console.log(`ping received with no game. Sending update request`);
+      send({
+        type: 'game-update'
+      });
+    }
+    return;
+
   default:
     console.log(data);
     break;
   }
 }
 
-const ai = async (ws) => {
+const ai = async () => {
+  send({
+    type: 'get',
+    fields: [ 'dice', 'name', 'color', 'state', 'placements' ]
+  });
 }
 
-connect().then((ws) => {
-  ai(ws)
+connect().then(() => {
+  ai()
   .catch((error) => {
     console.error(error);
     ws.close();
diff --git a/server/ai/longest-road.js b/server/ai/longest-road.js
new file mode 100644
index 0000000..d890987
--- /dev/null
+++ b/server/ai/longest-road.js
@@ -0,0 +1,161 @@
+const layout = require('../util/layout.js');
+
+const processCorner = (game, color, cornerIndex, placedCorner) => {
+  /* If this corner is allocated and isn't assigned to the walking color, skip it */
+  if (placedCorner.color && placedCorner.color !== color) {
+    return 0;
+  }
+  /* If this corner is already being walked, skip it */
+  if (placedCorner.walking) {
+    return 0;
+  }
+
+  placedCorner.walking = true;
+  /* Calculate the longest road branching from both corners */
+  let longest = 0;
+  layout.corners[cornerIndex].roads.forEach(roadIndex => {
+    const placedRoad = game.placements.roads[roadIndex];
+    if (placedRoad.walking) {
+      return;
+    }
+    const tmp = processRoad(game, color, roadIndex, placedRoad);
+    longest = Math.max(tmp, longest);
+    /*if (tmp > longest) {
+      longest = tmp;
+      placedCorner.longestRoad = roadIndex;
+      placedCorner.longest
+    }
+    longest = Math.max(
+      */
+  });
+
+  return longest;
+};
+
+const buildCornerGraph = (game, color, cornerIndex, placedCorner, set) => {
+  /* If this corner is allocated and isn't assigned to the walking color, skip it */
+  if (placedCorner.color && placedCorner.color !== color) {
+    return;
+  }
+  /* If this corner is already being walked, skip it */
+  if (placedCorner.walking) {
+    return;
+  }
+ 
+  placedCorner.walking = true;
+  /* Calculate the longest road branching from both corners */
+  layout.corners[cornerIndex].roads.forEach(roadIndex => {
+    const placedRoad = game.placements.roads[roadIndex];
+    buildRoadGraph(game, color, roadIndex, placedRoad, set);
+  });
+};
+
+const processRoad = (game, color, roadIndex, placedRoad) => {
+  /* If this road isn't assigned to the walking color, skip it */
+  if (placedRoad.color !== color) {
+   return 0;
+  }
+
+  /* If this road is already being walked, skip it */
+  if (placedRoad.walking) {
+    return 0;
+  }
+
+  placedRoad.walking = true;
+  /* Calculate the longest road branching from both corners */
+  let roadLength = 1;
+  layout.roads[roadIndex].corners.forEach(cornerIndex => {
+    const placedCorner = game.placements.corners[cornerIndex];
+    if (placedCorner.walking) {
+      return;
+    }
+    roadLength += processCorner(game, color, cornerIndex, placedCorner);
+  });
+
+  return roadLength;
+};
+
+const buildRoadGraph = (game, color, roadIndex, placedRoad, set) => {
+  /* If this road isn't assigned to the walking color, skip it */
+  if (placedRoad.color !== color) {
+    return;
+  }
+  /* If this road is already being walked, skip it */
+  if (placedRoad.walking) {
+    return;
+  }
+
+  placedRoad.walking = true;
+  set.push(roadIndex);
+  /* Calculate the longest road branching from both corners */
+  layout.roads[roadIndex].corners.forEach(cornerIndex => {
+    const placedCorner = game.placements.corners[cornerIndex];
+    buildCornerGraph(game, color, cornerIndex, placedCorner, set)
+  });
+};
+
+const clearRoadWalking = (game) => {
+  /* Clear out walk markers on roads */
+  layout.roads.forEach((item, itemIndex) => {
+    delete game.placements.roads[itemIndex].walking;
+  });
+
+  /* Clear out walk markers on corners */
+  layout.corners.forEach((item, itemIndex) => {
+    delete game.placements.corners[itemIndex].walking;
+  });
+}
+
+const calculateRoadLengths = (game) => {
+  const color = game.color;
+  clearRoadWalking(game);
+
+  /* Build a set of connected road graphs. Once all graphs are 
+   * constructed, walk through each graph, starting from each
+   * location in the graph. If the length ever equals the
+   * number of items in the graph, short circuit--longest path.
+   * Otherwise, check all paths from each segment. This is
+   * needed to catch loops where starting from an outside end
+   * point may result in not counting the length of the loop
+   */
+  let graphs = [];
+  layout.roads.forEach((_, roadIndex) => {
+    const placedRoad = game.placements.roads[roadIndex];
+    if (placedRoad.color === color) {
+      let set = [];
+      buildRoadGraph(game, color, roadIndex, placedRoad, set);
+      if (set.length) {
+        graphs.push({ color, set });
+      }
+    }
+  });
+
+  let final = {
+    segments: 0,
+    index: -1
+  };
+
+  clearRoadWalking(game);
+  graphs.forEach(graph => {
+    graph.longestRoad = 0;
+    graph.set.forEach(roadIndex => {
+      const placedRoad = game.placements.roads[roadIndex];
+      clearRoadWalking(game);
+      const length = processRoad(game, color, roadIndex, placedRoad);
+      if (length >= graph.longestRoad) {
+        graph.longestStartSegment = roadIndex;
+        graph.longestRoad = length;
+        if (length > final.segments) {
+          final.segments = length;
+          final.index = roadIndex;
+        }
+      }
+    });
+  });
+
+  game.placements.roads.forEach(road => delete road.walking);
+
+  return final;
+};
+
+module.exports = calculateRoadLengths;
\ No newline at end of file
diff --git a/server/routes/games.js b/server/routes/games.js
index 883472c..3280a34 100755
--- a/server/routes/games.js
+++ b/server/routes/games.js
@@ -8,12 +8,17 @@ const express = require("express"),
   accessSync = fs.accessSync,
   randomWords = require("random-words"),
   equal = require("fast-deep-equal");
-const layout = require('./layout.js');
+const layout = require('../util/layout.js');
+
+const { getValidRoads, getValidCorners, isRuleEnabled } = require('../util/validLocations.js');
+
 
 const MAX_SETTLEMENTS = 5;
 const MAX_CITIES = 4;
 const MAX_ROADS = 15;
 
+const types = [ 'wheat', 'stone', 'sheep', 'wood', 'brick' ];
+
 const debug = {
   audio: false,
   get: true,
@@ -419,10 +424,7 @@ const pickRobber = (game) => {
   }
 }
 
-const isRuleEnabled = (game, rule) => {
-  return rule in game.rules && game.rules[rule].enabled;
-};
- 
+
 const processRoll = (game, session, dice) => {
   if (!dice[1]) {
     console.error(`Invalid roll sequence!`);
@@ -1565,115 +1567,6 @@ const calculateRoadLengths = (game, session) => {
   }
 };
 
-const getValidCorners = (game, color, type) => {
-  const limits = [];
-
-  /* For each corner, if the corner already has a color set, skip it if type
-   * isn't set. If type is set, if it is a match, and the color is a match,
-   * add it to the list.
-   * 
-   * If we are limiting based on active player, a corner is only valid
-   * if it connects to a road that is owned by that player.
-   * 
-   * If no color is set, walk each road that leaves that corner and
-   * check to see if there is a settlement placed at the end of that road
-   * 
-   * If so, this location cannot have a settlement. 
-   * 
-   * If still valid, and we are in initial settlement placement, and if
-   * Volcano is enabled, verify the tile is not the Volcano.
-   */
-  layout.corners.forEach((corner, cornerIndex) => {
-    const placement = game.placements.corners[cornerIndex];
-    if (type) {
-      if (placement.color === color && placement.type === type) {
-        limits.push(cornerIndex);
-      }
-      return;
-    }
-
-    if (placement.color) {
-      return;
-    }
-
-    let valid;
-    if (!color) {
-      valid = true; /* Not filtering based on current player */
-    } else {
-      valid = false;
-      for (let r = 0; !valid && r < corner.roads.length; r++) {
-        valid = game.placements.roads[corner.roads[r]].color === color;
-      }
-    }
-
-    for (let r = 0; valid && r < corner.roads.length; r++) {
-      const road = layout.roads[corner.roads[r]];
-      for (let c = 0; valid && c < road.corners.length; c++) {
-        /* This side of the road is pointing to the corner being validated. 
-         * Skip it. */
-        if (road.corners[c] === cornerIndex) {
-          continue;
-        }
-        /* There is a settlement within one segment from this
-         * corner, so it is invalid for settlement placement */
-        if (game.placements.corners[road.corners[c]].color) {
-          valid = false;
-        }
-      }
-    }
-    if (valid) {
-      /* During initial placement, if volcano is enabled, do not allow
-       * placement on a corner connected to the volcano (robber starts
-       * on the volcano) */
-      if (!(game.state === 'initial-placement' 
-        && isRuleEnabled(game, 'volcano')
-        && layout.tiles[game.robber].corners.indexOf(cornerIndex) !== -1
-      )) {
-        limits.push(cornerIndex);
-      }
-    }
-  });
-
-  return limits;
-}
-
-const getValidRoads = (game, color) => {
-  const limits = [];
-
-  /* For each road, if the road is set, skip it.
-   * If no color is set, check the two corners. If the corner
-   * has a matching color, add this to the set. Otherwise skip.
-   */
-  layout.roads.forEach((road, roadIndex) => {
-    if (game.placements.roads[roadIndex].color) {
-      return;
-    }
-    let valid = false;
-    for (let c = 0; !valid && c < road.corners.length; c++) {
-      const corner = layout.corners[road.corners[c]],
-        cornerColor = game.placements.corners[road.corners[c]].color;
-      /* Roads do not pass through other player's settlements */
-      if (cornerColor && cornerColor !== color) {
-        continue;
-      }
-      for (let r = 0; !valid && r < corner.roads.length; r++) {
-        /* This side of the corner is pointing to the road being validated. Skip it. */
-        if (corner.roads[r] === roadIndex) {
-          continue;
-        }
-        if (game.placements.roads[corner.roads[r]].color === color) {
-          valid = true;
-        }
-      }
-    }
-    if (valid) {
-      limits.push(roadIndex);
-    }
-  });
-
-  return limits;
-}
-
 const isCompatibleOffer = (player, offer) => {
   const isBank = offer.name === 'The bank';
   let valid = player.gets.length === offer.gives.length &&
@@ -1699,7 +1592,7 @@ const isCompatibleOffer = (player, offer) => {
       return;
     }
     valid = offer.gives.find(item => 
-      (item.type === get.type || item.type === '*') &&
+      (item.type === get.type || isBank) &&
       item.count === get.count) !== undefined;
   });
 
@@ -1708,7 +1601,7 @@ const isCompatibleOffer = (player, offer) => {
       return;
     }
     valid = offer.gets.find(item => 
-      (item.type === give.type || item.type === 'bank') &&
+      (item.type === give.type || isBank) &&
       item.count === give.count) !== undefined;
   });
   return valid;
@@ -1773,6 +1666,11 @@ const checkPlayerOffer = (game, player, offer) => {
       return;
     }
 
+    if (give.count <= 0) {
+      error = `${give.count} must be more than 0!`
+      return;
+    }
+
     if (player[give.type] < give.count) {
       error = `${name} does do not have ${give.count} ${give.type}!`;
       return;
@@ -1788,6 +1686,10 @@ const checkPlayerOffer = (game, player, offer) => {
     if (error) {
       return;
     }
+    if (get.count <= 0) {
+      error = `${get.count} must be more than 0!`;
+      return;
+    }
     if (offer.gives.find(give => get.type === give.type)) {
       error = `${name} can not give and get the same resource type!`;
     };
@@ -1800,10 +1702,10 @@ const canMeetOffer = (player, offer) => {
   for (let i = 0; i < offer.gets.length; i++) {
     const get = offer.gets[i];
     if (get.type === 'bank') {
-      if (player[player.gives[0].type] < get.count) {
+      if (player[player.gives[0].type] < get.count || get.count <= 0) {
         return false;
       }
-    } else if (player[get.type] < get.count) {
+    } else if (player[get.type] < get.count || get.count <= 0) {
       return false;
     }
   }
@@ -1900,183 +1802,229 @@ router.put("/:id/:action/:value?", async (req, res) => {
   return res.status(400).send(error);
 });
 
-const trade = (game, session, action, offer) => {
-  const name = session.name, player = session.player;
-  let warning;
+const startTrade = (game, session) => {
+  /* Only the active player can begin trading */
+  if (game.turn.name !== session.name) {
+    return `You cannot start trading negotiations when it is not your turn.`
+  }
+  /* Clear any free gives if the player begins trading */
+  if (game.turn.free) {
+    delete game.turn.free;
+  }
+  game.turn.actions = ['trade'];
+  game.turn.limits = {};
+  for (let key in game.players) {
+    game.players[key].gives = [];
+    game.players[key].gets = [];
+    delete game.players[key].offerRejected;
+  }
+  addActivity(game, session, 
+    `${session.name} requested to begin trading negotiations.`);
+};
 
+const cancelTrade = (game, session) => {
+  /* TODO: Perhaps 'cancel' is how a player can remove an offer... */
+  if (game.turn.name !== session.name) {
+    return `Only the active player can cancel trading negotiations.`;
+  }
+  game.turn.actions = [];
+  game.turn.limits = {};
+  addActivity(game, session, `${session.name} has cancelled trading negotiations.`);
+};
+
+const processOffer = (game, session, offer) => {
+  let warning = checkPlayerOffer(game, session.player, offer);
+  if (warning) {
+    return warning;
+  }
+
+  if (isSameOffer(session.player, offer)) {
+    console.log(session.player);
+    return `You already have a pending offer submitted for ${offerToString(offer)}.`;
+  }
+
+  session.player.gives = offer.gives;
+  session.player.gets = offer.gets;
+  session.player.offerRejected = {};
+
+  if (game.turn.color === session.color) {
+    game.turn.offer = offer;
+  }
+
+  /* If this offer matches what another player wants, clear rejection
+    * on of that other player's offer */
+  for (let color in game.players) {
+    if (color === session.color) {
+      continue;
+    }
+    const other = game.players[color];
+    if (other.status !== 'Active') {
+      continue;
+    }
+    /* Comparison reverses give/get order */
+    if (isSameOffer(other, { gives: offer.gets, gets: offer.gives })) {
+      if (other.offerRejected) {
+        delete other.offerRejected[session.color];
+      }
+    }
+  }
+
+  addActivity(game, session, `${session.name} submitted an offer to give ${offerToString(offer)}.`);
+};
+
+const rejectOffer = (game, session, offer) => {
+  /* If the active player rejected an offer, they rejected another player */
+  const other = game.players[offer.color];
+  if (!other.offerRejected) {
+    other.offerRejected = {};
+  }
+  other.offerRejected[session.color] = true;
+  if (!session.player.offerRejected) {
+    session.player.offerRejected = {};
+  }
+  session.player.offerRejected[offer.color] = true;
+  addActivity(game, session, `${session.name} rejected ${other.name}'s offer.`);
+};
+
+const acceptOffer = (game, session, offer) => {
+  const name = session.name;
+
+  if (game.turn.name !== name) {
+    return `Only the active player can accept an offer.`;
+  }
+
+  let target;
+
+  console.log({ description: offerToString(offer) });
+
+  let warning = checkPlayerOffer(game, session.player, offer);
+  if (warning) {
+    return warning;
+  }
+
+  if (!isCompatibleOffer(session.player, { 
+    name: offer.name, 
+    gives: offer.gets, 
+    gets: offer.gives 
+  })) {
+    return `Unfortunately, trades were re-negotiated in transit and 1 ` +
+      `the deal is invalid!`;
+  }
+
+  /* Verify that the offer sent by the active player matches what
+    * the latest offer was that was received by the requesting player */
+  if (!offer.name || offer.name !== 'The bank') {
+    target = game.players[offer.color];
+    if (offer.color in target.offerRejected) {
+      return `${target.name} rejected this offer.`;
+    }
+    if (!isCompatibleOffer(target, offer)) {
+      return `Unfortunately, trades were re-negotiated in transit and ` +
+        `the deal is invalid!`;
+    }
+
+    warning = checkPlayerOffer(game, target, { 
+      gives: offer.gets, 
+      gets: offer.gives 
+    });
+    if (warning) {
+      return warning;
+    }
+
+    if (!isSameOffer(target, { gives: offer.gets, gets: offer.gives })) {
+      console.log({ target, offer });
+      return `These terms were not agreed to by ${target.name}!`;
+    }
+
+    if (!canMeetOffer(target, player)) {
+      return `${target.name} cannot meet the terms.`;
+    }
+  } else {
+    target = offer;
+  }
+
+  debugChat(game, 'Before trade');
+
+  /* Transfer goods */
+  const player = session.player;
+  offer.gets.forEach(item => {
+    if (target.name !== 'The bank') {
+      target[item.type] -= item.count;
+      target.resources -= item.count;
+    }
+    player[item.type] += item.count;
+    player.resources += item.count;
+  });
+  offer.gives.forEach(item => {
+    if (target.name !== 'The bank') {
+      target[item.type] += item.count;
+      target.resources += item.count;
+    }
+    player[item.type] -= item.count;
+    player.resources -= item.count;
+  });
+
+  const from = (offer.name === 'The bank') ? 'the bank' : offer.name;
+  addChatMessage(game, session, `${session.name} traded ` +
+    ` ${offerToString(offer)} ` +
+    `from ${from}.`);
+  addActivity(game, session, `${session.name} accepted a trade from ${from}.`)
+  delete game.turn.offer;
+  if (target) {
+    delete target.gives;
+    delete target.gets;
+  }
+  delete session.player.gives;
+  delete session.player.gets;
+  delete game.turn.offer;
+
+  debugChat(game, 'After trade');
+
+  /* Debug!!! */
+  for (let key in game.players) {
+    if (!game.players[key].state === 'Active') {
+      continue;
+    }
+    types.forEach(type => {
+      if (game.players[key][type] < 0) {
+        throw new Error(`Player resources are below zero! BUG BUG BUG!`);
+      }
+    });
+  }
+  game.turn.actions = [];
+};
+
+const trade = (game, session, action, offer) => {
   if (game.state !== "normal") {
     return `Game not in correct state to begin trading.`;
   }
 
   if (!game.turn.actions || game.turn.actions.indexOf('trade') === -1) {
-    /* Only the active player can begin trading */
-    if (game.turn.name !== name) {
-      return `You cannot start trading negotiations when it is not your turn.`
-    }
-    /* Clear any free gives if the player begins trading */
-    if (game.turn.free) {
-      delete game.turn.free;
-    }
-    game.turn.actions = [ 'trade' ];
-    game.turn.limits = {};
-    for (let key in game.players) {
-      game.players[key].gives = [];
-      game.players[key].gets = [];
-      delete game.players[key].offerRejected;
-    }
-    addActivity(game, session, `${name} requested to begin trading negotiations.`);
-    return;
+    return startTrade(game, session);
   }
 
   /* Only the active player can cancel trading */
   if (action === 'cancel') {
-    /* TODO: Perhaps 'cancel' is how a player can remove an offer... */
-    if (game.turn.name !== name) {
-      return `Only the active player can cancel trading negotiations.`;
-    }
-    game.turn.actions = [];
-    game.turn.limits = {};
-    addActivity(game, session, `${name} has cancelled trading negotiations.`);
-    return;
+    return cancelTrade(game, session);
   }
 
   /* Any player can make an offer */
   if (action === 'offer') {
-    warning = checkPlayerOffer(game, session.player, offer);
-    if (warning) {
-      return warning;
-    }
-    
-    if (isSameOffer(session.player, offer)) {
-      console.log(session.player);
-      return `You already have a pending offer submitted for ${offerToString(offer)}.`;
-    }
-    
-    session.player.gives = offer.gives;
-    session.player.gets = offer.gets;
-    session.player.offerRejected = {};
-
-    if (game.turn.color === session.color) {
-      game.turn.offer = offer;
-    }
-
-    /* If this offer matches what another player wants, clear rejection
-      * on of that other player's offer */
-    for (let color in game.players) {
-      if (color === session.color) {
-        continue;
-      }
-      const other = game.players[color];
-      if (other.status !== 'Active') {
-        continue;
-      }
-      /* Comparison reverses give/get order */
-      if (isSameOffer(other, { gives: offer.gets, gets: offer.gives })) {
-        if (other.offerRejected) {
-          delete other.offerRejected[session.color];
-        }
-      }
-    }
-
-    addActivity(game, session, `${session.name} submitted an offer to give ${offerToString(offer)}.`);
-    return;
+    return processOffer(game, session, offer);
   }
 
   /* Any player can reject an offer */
   if (action === 'reject') {
-    /* If the active player rejected an offer, they rejected another player */
-    const other = game.players[offer.color];
-    if (!other.offerRejected) {
-      other.offerRejected = {};
-    }
-    other.offerRejected[session.color] = true;
-    if (!session.player.offerRejected) {
-      session.player.offerRejected = {};
-    }
-    session.player.offerRejected[offer.color] = true;
-    addActivity(game, session, `${session.name} rejected ${other.name}'s offer.`);
-    return;
+    return rejectOffer(game, session, offer);
   }
 
   /* Only the active player can accept an offer */
   if (action === 'accept') {
-    if (game.turn.name !== name) {
-      return `Only the active player can accept an offer.`;
+    if (offer.name === 'The bank') {
+      session.player.gets = offer.gets;
+      session.player.gives = offer.gives;
     }
-
-    let target;
-
-    console.log({ offer, description: offerToString(offer) });
-
-    warning = checkPlayerOffer(game, session.player, offer);
-    if (warning) {
-      return warning;
-    }
-
-    /* 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') {
-      target = game.players[offer.color];
-      if (offer.color in target.offerRejected) {
-        return `${target.name} rejected this offer.`;
-      }
-      if (!isCompatibleOffer(target, offer)) {
-        return `Unfortunately, trades were re-negotiated in transit and the deal is invalid!`;
-      }
-
-      warning = checkPlayerOffer(game, target, { gives: offer.gets, gets: offer.gives });
-      if (warning) {
-        return warning;
-      }
-
-      if (!isSameOffer(target, { gives: offer.gets, gets: offer.gives })) {
-        console.log( { target, offer });
-        return `These terms were not agreed to by ${target.name}!`;
-      }
-
-      if (!canMeetOffer(target, player)) {
-        return `${target.name} cannot meet the terms.`;
-      }
-    } else {
-      target = offer;
-    }
-
-    debugChat(game, 'Before trade');
-
-    /* Transfer goods */
-    offer.gets.forEach(item => {
-      if (target.name !== 'The bank') {
-        target[item.type] -= item.count;
-        target.resources -= item.count;
-      }
-      player[item.type] += item.count;
-      player.resources += item.count;
-    });
-    offer.gives.forEach(item => {
-      if (target.name !== 'The bank') {
-        target[item.type] += item.count;
-        target.resources += item.count;
-      }
-      player[item.type] -= item.count;
-      player.resources -= item.count;
-    });
-
-    const from = (offer.name === 'The bank') ? 'the bank' : offer.name;
-    addChatMessage(game, session, `${session.name} traded ` +
-      ` ${offerToString(offer)} ` +
-      `from ${from}.`);
-    addActivity(game, session, `${session.name} accepted a trade from ${from}.`)
-    delete game.turn.offer;
-    if (target) {
-      delete target.gives;
-      delete target.gets;
-    }
-    delete session.player.gives;
-    delete session.player.gets;
-
-    debugChat(game, 'After trade');
-
-    game.turn.actions = [];
+    return acceptOffer(game, session, offer);
   }
 }
 
@@ -3044,7 +2992,8 @@ const buyRoad = (game, session) => {
   addActivity(game, session, `${game.turn.name} is considering building a road.`);
   sendUpdateToPlayers(game, {
     turn: game.turn,
-    chat: game.chat
+    chat: game.chat,
+    activities: game.activities
   });
 }
 
@@ -4316,7 +4265,7 @@ router.ws("/ws/:id", async (ws, req) => {
       break;
     case 'trade':
       console.log(`${short}: <- trade:${getName(session)} - ` +
-        (data.action ? data.action : 'start') + ` - `,
+        (data.action ? data.action : 'start') + ` -`,
         data.offer ? data.offer : 'no trade yet');
       warning = trade(game, session, data.action, data.offer);
       if (warning) {
diff --git a/server/routes/layout.js b/server/util/layout.js
similarity index 100%
rename from server/routes/layout.js
rename to server/util/layout.js
diff --git a/server/util/validLocations.js b/server/util/validLocations.js
new file mode 100644
index 0000000..1b65394
--- /dev/null
+++ b/server/util/validLocations.js
@@ -0,0 +1,120 @@
+const layout = require('./layout.js');
+
+const isRuleEnabled = (game, rule) => {
+  return rule in game.rules && game.rules[rule].enabled;
+};
+
+const getValidRoads = (game, color) => {
+  const limits = [];
+
+  /* For each road, if the road is set, skip it.
+   * If no color is set, check the two corners. If the corner
+   * has a matching color, add this to the set. Otherwise skip.
+   */
+  layout.roads.forEach((road, roadIndex) => {
+    if (game.placements.roads[roadIndex].color) {
+      return;
+    }
+    let valid = false;
+    for (let c = 0; !valid && c < road.corners.length; c++) {
+      const corner = layout.corners[road.corners[c]],
+        cornerColor = game.placements.corners[road.corners[c]].color;
+      /* Roads do not pass through other player's settlements */
+      if (cornerColor && cornerColor !== color) {
+        continue;
+      }
+      for (let r = 0; !valid && r < corner.roads.length; r++) {
+        /* This side of the corner is pointing to the road being validated. Skip it. */
+        if (corner.roads[r] === roadIndex) {
+          continue;
+        }
+        if (game.placements.roads[corner.roads[r]].color === color) {
+          valid = true;
+        }
+      }
+    }
+    if (valid) {
+      limits.push(roadIndex);
+    }
+  });
+
+  return limits;
+}
+
+const getValidCorners = (game, color, type) => {
+  const limits = [];
+
+  /* For each corner, if the corner already has a color set, skip it if type
+   * isn't set. If type is set, if it is a match, and the color is a match,
+   * add it to the list.
+   * 
+   * If we are limiting based on active player, a corner is only valid
+   * if it connects to a road that is owned by that player.
+   * 
+   * If no color is set, walk each road that leaves that corner and
+   * check to see if there is a settlement placed at the end of that road
+   * 
+   * If so, this location cannot have a settlement. 
+   * 
+   * If still valid, and we are in initial settlement placement, and if
+   * Volcano is enabled, verify the tile is not the Volcano.
+   */
+  layout.corners.forEach((corner, cornerIndex) => {
+    const placement = game.placements.corners[cornerIndex];
+    if (type) {
+      if (placement.color === color && placement.type === type) {
+        limits.push(cornerIndex);
+      }
+      return;
+    }
+
+    if (placement.color) {
+      return;
+    }
+
+    let valid;
+    if (!color) {
+      valid = true; /* Not filtering based on current player */
+    } else {
+      valid = false;
+      for (let r = 0; !valid && r < corner.roads.length; r++) {
+        valid = game.placements.roads[corner.roads[r]].color === color;
+      }
+    }
+
+    for (let r = 0; valid && r < corner.roads.length; r++) {
+      const road = layout.roads[corner.roads[r]];
+      for (let c = 0; valid && c < road.corners.length; c++) {
+        /* This side of the road is pointing to the corner being validated. 
+         * Skip it. */
+        if (road.corners[c] === cornerIndex) {
+          continue;
+        }
+        /* There is a settlement within one segment from this
+         * corner, so it is invalid for settlement placement */
+        if (game.placements.corners[road.corners[c]].color) {
+          valid = false;
+        }
+      }
+    }
+    if (valid) {
+      /* During initial placement, if volcano is enabled, do not allow
+       * placement on a corner connected to the volcano (robber starts
+       * on the volcano) */
+      if (!(game.state === 'initial-placement'
+        && isRuleEnabled(game, 'volcano')
+        && layout.tiles[game.robber].corners.indexOf(cornerIndex) !== -1
+      )) {
+        limits.push(cornerIndex);
+      }
+    }
+  });
+
+  return limits;
+}
+
+module.exports = {
+  getValidCorners,
+  getValidRoads,
+  isRuleEnabled
+};
\ No newline at end of file