diff --git a/common/GameCommon.js b/common/GameCommon.js
new file mode 100644
index 0000000..0e886df
--- /dev/null
+++ b/common/GameCommon.js
@@ -0,0 +1,412 @@
+import Geometry from './Geometry.js'
+
+const GAMES = {}
+
+function exists(gameId) {
+  return (!!GAMES[gameId]) || false
+}
+
+function setGame(gameId, game) {
+  GAMES[gameId] = game
+}
+
+function addPlayer(gameId, playerId) {
+  GAMES[gameId].players[playerId] = {
+    id: playerId,
+    x: 0,
+    y: 0,
+    down: false
+  }
+  GAMES[gameId].evtInfos[playerId] = {
+    _last_mouse: null,
+    _last_mouse_down: null,
+  }
+}
+
+function addSocket(gameId, socket) {
+  const sockets = GAMES[gameId].sockets
+
+  if (!sockets.includes(socket)) {
+    sockets.push(socket)
+  }
+}
+
+function get(gameId) {
+  return GAMES[gameId]
+}
+
+function getSockets(gameId) {
+  return GAMES[gameId].sockets
+}
+
+function changePlayer(gameId, playerId, change) {
+  for (let k of Object.keys(change)) {
+    GAMES[gameId].players[playerId][k] = change[k]
+  }
+}
+
+function changeData(gameId, change) {
+  for (let k of Object.keys(change)) {
+    GAMES[gameId].puzzle.data[k] = change[k]
+  }
+}
+
+function changeTile(gameId, tileIdx, change) {
+  for (let k of Object.keys(change)) {
+    GAMES[gameId].puzzle.tiles[tileIdx][k] = change[k]
+  }
+}
+
+const getTile = (gameId, tileIdx) => {
+  return GAMES[gameId].puzzle.tiles[tileIdx]
+}
+
+const getTileGroup = (gameId, tileIdx) => {
+  const tile = getTile(gameId, tileIdx)
+  return tile.group
+}
+
+const getFinalTilePos = (gameId, tileIdx) => {
+  const info = GAMES[gameId].puzzle.info
+  const boardPos = {
+    x: (info.table.width - info.width) / 2,
+    y: (info.table.height - info.height) / 2
+  }
+  const srcPos = srcPosByTileIdx(gameId, tileIdx)
+  return Geometry.pointAdd(boardPos, srcPos)
+}
+
+const getTilePos = (gameId, tileIdx) => {
+  const tile = getTile(gameId, tileIdx)
+  return tile.pos
+}
+
+const getTileZIndex = (gameId, tileIdx) => {
+  const tile = getTile(gameId, tileIdx)
+  return tile.z
+}
+
+const getFirstOwnedTileIdx = (gameId, userId) => {
+  for (let t of GAMES[gameId].puzzle.tiles) {
+    if (t.owner === userId) {
+      return t.idx
+    }
+  }
+  return -1
+}
+
+const getMaxGroup = (gameId) => {
+  return GAMES[gameId].puzzle.data.maxGroup
+}
+
+const getMaxZIndex = (gameId) => {
+  return GAMES[gameId].puzzle.data.maxZ
+}
+
+const getMaxZIndexByTileIdxs = (gameId, tileIdxs) => {
+  let maxZ = 0
+  for (let tileIdx of tileIdxs) {
+    let tileZIndex = getTileZIndex(gameId, tileIdx)
+    if (tileZIndex > maxZ) {
+      maxZ = tileZIndex
+    }
+  }
+  return maxZ
+}
+
+function srcPosByTileIdx(gameId, tileIdx) {
+  const info = GAMES[gameId].puzzle.info
+
+  const c = info.coords[tileIdx]
+  const cx = c.x * info.tileSize
+  const cy = c.y * info.tileSize
+
+  return { x: cx, y: cy }
+}
+
+function getSurroundingTilesByIdx(gameId, tileIdx) {
+  const info = GAMES[gameId].puzzle.info
+
+  const _X = info.coords[tileIdx].x
+  const _Y = info.coords[tileIdx].y
+
+  return [
+    // top
+    (_Y > 0) ?               (tileIdx - info.tilesX) : -1,
+    // right
+    (_X < info.tilesX - 1) ? (tileIdx + 1)           : -1,
+    // bottom
+    (_Y < info.tilesY - 1) ? (tileIdx + info.tilesX) : -1,
+    // left
+    (_X > 0) ?               (tileIdx - 1)           : -1,
+  ]
+}
+
+const setTilesZIndex = (gameId, tileIdxs, zIndex) => {
+  for (let tilesIdx of tileIdxs) {
+    changeTile(gameId, tilesIdx, { z: zIndex })
+  }
+}
+
+const moveTileDiff = (gameId, tileIdx, diff) => {
+  const oldPos = getTilePos(gameId, tileIdx)
+  const pos = Geometry.pointAdd(oldPos, diff)
+  changeTile(gameId, tileIdx, { pos })
+}
+
+const moveTilesDiff = (gameId, tileIdxs, diff) => {
+  for (let tileIdx of tileIdxs) {
+    moveTileDiff(gameId, tileIdx, diff)
+  }
+}
+
+const finishTiles = (gameId, tileIdxs) => {
+  for (let tileIdx of tileIdxs) {
+    changeTile(gameId, tileIdx, { owner: -1, z: 1 })
+  }
+}
+
+const setTilesOwner = (gameId, tileIdxs, owner) => {
+  for (let tileIdx of tileIdxs) {
+    changeTile(gameId, tileIdx, { owner })
+  }
+}
+
+// get all grouped tiles for a tile
+function getGroupedTileIdxs(gameId, tileIdx) {
+  const tiles = GAMES[gameId].puzzle.tiles
+  const tile = tiles[tileIdx]
+
+  const grouped = []
+  if (tile.group) {
+    for (let other of tiles) {
+      if (other.group === tile.group) {
+        grouped.push(other.idx)
+      }
+    }
+  } else {
+    grouped.push(tile.idx)
+  }
+  return grouped
+}
+
+// Returns the index of the puzzle tile with the highest z index
+// that is not finished yet and that matches the position
+const freeTileIdxByPos = (gameId, pos) => {
+  let info = GAMES[gameId].puzzle.info
+  let tiles = GAMES[gameId].puzzle.tiles
+
+  let maxZ = -1
+  let tileIdx = -1
+  for (let idx = 0; idx < tiles.length; idx++) {
+    const tile = tiles[idx]
+    if (tile.owner !== 0) {
+      continue
+    }
+
+    const collisionRect = {
+      x: tile.pos.x,
+      y: tile.pos.y,
+      w: info.tileSize,
+      h: info.tileSize,
+    }
+    if (Geometry.pointInBounds(pos, collisionRect)) {
+      if (maxZ === -1 || tile.z > maxZ) {
+        maxZ = tile.z
+        tileIdx = idx
+      }
+    }
+  }
+  return tileIdx
+}
+
+// determine if two tiles are grouped together
+const areGrouped = (gameId, tileIdx1, tileIdx2) => {
+  const g1 = getTileGroup(gameId, tileIdx1)
+  const g2 = getTileGroup(gameId, tileIdx2)
+  return g1 && g1 === g2
+}
+
+function handleInput(gameId, playerId, input) {
+  let puzzle = GAMES[gameId].puzzle
+  let players = GAMES[gameId].players
+  let evtInfo = GAMES[gameId].evtInfos[playerId]
+
+  let changes = []
+
+  const _dataChange = () => {
+    changes.push(['data', puzzle.data])
+  }
+
+  const _tileChange = (tileIdx) => {
+    changes.push(['tile', getTile(gameId, tileIdx)])
+  }
+
+  const _tileChanges = (tileIdxs) => {
+    for (let tileIdx of tileIdxs) {
+      _tileChange(tileIdx)
+    }
+  }
+
+  const _playerChange = () => {
+    changes.push(['player', players[playerId]])
+  }
+
+  // put both tiles (and their grouped tiles) in the same group
+  const groupTiles = (gameId, tileIdx1, tileIdx2) => {
+    let tiles = GAMES[gameId].puzzle.tiles
+    let group1 = getTileGroup(gameId, tileIdx1)
+    let group2 = getTileGroup(gameId, tileIdx2)
+
+    let group
+    let searchGroups = []
+    if (group1) {
+      searchGroups.push(group1)
+    }
+    if (group2) {
+      searchGroups.push(group2)
+    }
+    if (group1) {
+      group = group1
+    } else if (group2) {
+      group = group2
+    } else {
+      let maxGroup = getMaxGroup(gameId) + 1
+      changeData(gameId, { maxGroup })
+      _dataChange()
+      group = getMaxGroup(gameId)
+    }
+
+    changeTile(gameId, tileIdx1, { group })
+    _tileChange(tileIdx1)
+    changeTile(gameId, tileIdx2, { group })
+    _tileChange(tileIdx2)
+
+    // TODO: strange
+    if (searchGroups.length > 0) {
+      for (let tile of tiles) {
+        if (searchGroups.includes(tile.group)) {
+          changeTile(gameId, tile.idx, { group })
+          _tileChange(tile.idx)
+        }
+      }
+    }
+  }
+
+  let [type, x, y] = input
+  let pos = {x, y}
+  if (type === 'down') {
+    changePlayer(gameId, playerId, { down: true })
+    _playerChange()
+    evtInfo._last_mouse_down = pos
+
+    const tileIdxAtPos = freeTileIdxByPos(gameId, pos)
+    if (tileIdxAtPos >= 0) {
+      console.log('tile: ', tileIdxAtPos)
+      let maxZ = getMaxZIndex(gameId) + 1
+      changeData(gameId, { maxZ })
+      _dataChange()
+      const tileIdxs = getGroupedTileIdxs(gameId, tileIdxAtPos)
+      setTilesZIndex(gameId, tileIdxs, getMaxZIndex(gameId))
+      setTilesOwner(gameId, tileIdxs, playerId)
+      _tileChanges(tileIdxs)
+    }
+
+  } else if (type === 'move') {
+    changePlayer(gameId, playerId, pos)
+    _playerChange()
+
+    if (evtInfo._last_mouse_down !== null) {
+      let tileIdx = getFirstOwnedTileIdx(gameId, playerId)
+      if (tileIdx >= 0) {
+        const diffX = x - evtInfo._last_mouse_down.x
+        const diffY = y - evtInfo._last_mouse_down.y
+        const diff = { x: diffX, y: diffY }
+        const tileIdxs = getGroupedTileIdxs(gameId, tileIdx)
+        moveTilesDiff(gameId, tileIdxs, diff)
+        _tileChanges(tileIdxs)
+      }
+
+      evtInfo._last_mouse_down = pos
+    }
+  } else if (type === 'up') {
+    changePlayer(gameId, playerId, { down: false })
+    _playerChange()
+    evtInfo._last_mouse_down = null
+
+    let tileIdx = getFirstOwnedTileIdx(gameId, playerId)
+    if (tileIdx >= 0) {
+      // drop the tile(s)
+      let tileIdxs = getGroupedTileIdxs(gameId, tileIdx)
+      setTilesOwner(gameId, tileIdxs, 0)
+      _tileChanges(tileIdxs)
+
+      // Check if the tile was dropped near the final location
+      let tilePos = getTilePos(gameId, tileIdx)
+      let finalPos = getFinalTilePos(gameId, tileIdx)
+      if (Geometry.pointDistance(finalPos, tilePos) < puzzle.info.snapDistance) {
+        let diff = Geometry.pointSub(finalPos, tilePos)
+        // Snap the tile to the final destination
+        moveTilesDiff(gameId, tileIdxs, diff)
+        finishTiles(gameId, tileIdxs)
+        _tileChanges(tileIdxs)
+      } else {
+        // Snap to other tiles
+        const check = (gameId, tileIdx, otherTileIdx, off) => {
+          let info = GAMES[gameId].puzzle.info
+          if (otherTileIdx < 0) {
+            return false
+          }
+          if (areGrouped(gameId, tileIdx, otherTileIdx)) {
+            return false
+          }
+          const tilePos = getTilePos(gameId, tileIdx)
+          const dstPos = Geometry.pointAdd(
+            getTilePos(gameId, otherTileIdx),
+            {x: off[0] * info.tileSize, y: off[1] * info.tileSize}
+          )
+          if (Geometry.pointDistance(tilePos, dstPos) < info.snapDistance) {
+            let diff = Geometry.pointSub(dstPos, tilePos)
+            let tileIdxs = getGroupedTileIdxs(gameId, tileIdx)
+            moveTilesDiff(gameId, tileIdxs, diff)
+            groupTiles(gameId, tileIdx, otherTileIdx)
+            tileIdxs = getGroupedTileIdxs(gameId, tileIdx)
+            const zIndex = getMaxZIndexByTileIdxs(gameId, tileIdxs)
+            console.log('z:' , zIndex, tileIdxs)
+            setTilesZIndex(gameId, tileIdxs, zIndex)
+            _tileChanges(tileIdxs)
+            return true
+          }
+          return false
+        }
+
+        for (let tileIdxTmp of getGroupedTileIdxs(gameId, tileIdx)) {
+          let othersIdxs = getSurroundingTilesByIdx(gameId, tileIdxTmp)
+          if (
+            check(gameId, tileIdxTmp, othersIdxs[0], [0, 1]) // top
+            || check(gameId, tileIdxTmp, othersIdxs[1], [-1, 0]) // right
+            || check(gameId, tileIdxTmp, othersIdxs[2], [0, -1]) // bottom
+            || check(gameId, tileIdxTmp, othersIdxs[3], [1, 0]) // left
+          ) {
+            break
+          }
+        }
+      }
+    }
+  }
+  // console.log(mouse)
+  evtInfo._last_mouse = pos
+
+  return changes
+}
+
+
+export default {
+  setGame,
+  exists,
+  addPlayer,
+  addSocket,
+  get,
+  getSockets,
+  handleInput,
+}
diff --git a/game/Communication.js b/game/Communication.js
index 9a91573..0c9ea5c 100644
--- a/game/Communication.js
+++ b/game/Communication.js
@@ -15,10 +15,10 @@ function send(message) {
 
 let clientSeq
 let events
-function connect(gameId, playerId) {
+function connect(gameId, clientId) {
   clientSeq = 0
   events = {}
-  conn = new WsClient(WS_ADDRESS, playerId + '|' + gameId)
+  conn = new WsClient(WS_ADDRESS, clientId + '|' + gameId)
   return new Promise(r => {
     conn.connect()
     send([Protocol.EV_CLIENT_INIT])
@@ -29,6 +29,11 @@ function connect(gameId, playerId) {
         const game = msg[1]
         r(game)
       } else if (msgType === Protocol.EV_SERVER_EVENT) {
+        const msgClientId = msg[1]
+        const msgClientSeq = msg[2]
+        if (msgClientId === clientId && events[msgClientSeq]) {
+          delete events[msgClientSeq]
+        }
         changesCallback(msg)
       }
     })
diff --git a/game/Game.js b/game/Game.js
new file mode 100644
index 0000000..93800b7
--- /dev/null
+++ b/game/Game.js
@@ -0,0 +1,6 @@
+import GameCommon from './../common/GameCommon.js'
+
+export default {
+  createGame: GameCommon.setGame,
+  handleInput: GameCommon.handleInput,
+}
diff --git a/game/index.js b/game/index.js
index 786260b..637c39f 100644
--- a/game/index.js
+++ b/game/index.js
@@ -6,6 +6,7 @@ import Debug from './Debug.js'
 import Communication from './Communication.js'
 import Util from './../common/Util.js'
 import PuzzleGraphics from './PuzzleGraphics.js'
+import Game from './Game.js'
 
 if (typeof GAME_ID === 'undefined') throw '[ GAME_ID not set ]'
 if (typeof WS_ADDRESS === 'undefined') throw '[ WS_ADDRESS not set ]'
@@ -95,12 +96,13 @@ export default class EventAdapter {
 
 async function main() {
   let gameId = GAME_ID
-  let me = initme()
+  let CLIENT_ID = initme()
 
   let cursorGrab = await Graphics.loadImageToBitmap('/grab.png')
   let cursorHand = await Graphics.loadImageToBitmap('/hand.png')
 
-  const game = await Communication.connect(gameId, me)
+  const game = await Communication.connect(gameId, CLIENT_ID)
+  Game.createGame(GAME_ID, game);
 
   const bitmaps = await PuzzleGraphics.loadPuzzleBitmaps(game.puzzle)
   const puzzle = game.puzzle
@@ -110,7 +112,7 @@ async function main() {
 
   const changePlayer = (change) => {
     for (let k of Object.keys(change)) {
-      players[me][k] = change[k]
+      players[CLIENT_ID][k] = change[k]
     }
   }
 
@@ -137,7 +139,7 @@ async function main() {
     for(let [changeType, changeData] of evChanges) {
       switch (changeType) {
         case 'player': {
-          if (changeData.id !== me) {
+          if (changeData.id !== CLIENT_ID) {
             players[changeData.id] = changeData
             rerender = true
           }
@@ -166,14 +168,16 @@ async function main() {
   let _last_mouse_down = null
   const onUpdate = () => {
     for (let evt of evts.consumeAll()) {
+
+      // LOCAL ONLY CHANGES
+      // -------------------------------------------------------------
       const type = evt[0]
       const pos = {x: evt[1], y: evt[2]}
-
       if (type === 'move') {
         rerender = true
         changePlayer(pos)
 
-        if (_last_mouse_down && !getFirstOwnedTile(puzzle, me)) {
+        if (_last_mouse_down && !getFirstOwnedTile(puzzle, CLIENT_ID)) {
             // move the cam
             const mouse = viewport.worldToViewport(pos)
             const diffX = Math.round(mouse.x - _last_mouse_down.x)
@@ -197,6 +201,10 @@ async function main() {
           changePlayer(pos)
         }
       }
+
+      // LOCAL + SERVER CHANGES
+      // -------------------------------------------------------------
+      Game.handleInput(GAME_ID, CLIENT_ID, evt)
       Communication.sendClientEvent(evt)
     }
   }
diff --git a/server/Game.js b/server/Game.js
index a316133..5d722dc 100644
--- a/server/Game.js
+++ b/server/Game.js
@@ -1,419 +1,23 @@
 import { createPuzzle } from './Puzzle.js'
-import Geometry from './../common/Geometry.js'
-
-const GAMES = {}
-
-function exists(gameId) {
-  return (!!GAMES[gameId]) || false
-}
+import GameCommon from './../common/GameCommon.js'
 
 async function createGame(gameId, targetTiles, image) {
-  GAMES[gameId] = {
+  const game = {
     puzzle: await createPuzzle(targetTiles, image),
     players: {},
 
     sockets: [],
     evtInfos: {},
   }
+  GameCommon.setGame(gameId, game)
 }
 
-function addPlayer(gameId, playerId) {
-  GAMES[gameId].players[playerId] = {
-    id: playerId,
-    x: 0,
-    y: 0,
-    down: false
-  }
-  GAMES[gameId].evtInfos[playerId] = {
-    _last_mouse: null,
-    _last_mouse_down: null,
-  }
-}
-
-function addSocket(gameId, socket) {
-  const sockets = GAMES[gameId].sockets
-
-  if (!sockets.includes(socket)) {
-    sockets.push(socket)
-  }
-}
-
-function get(gameId) {
-  return GAMES[gameId]
-}
-
-function getSockets(gameId) {
-  return GAMES[gameId].sockets
-}
-
-function changePlayer(gameId, playerId, change) {
-  for (let k of Object.keys(change)) {
-    GAMES[gameId].players[playerId][k] = change[k]
-  }
-}
-
-function changeData(gameId, change) {
-  for (let k of Object.keys(change)) {
-    GAMES[gameId].puzzle.data[k] = change[k]
-  }
-}
-
-function changeTile(gameId, tileIdx, change) {
-  for (let k of Object.keys(change)) {
-    GAMES[gameId].puzzle.tiles[tileIdx][k] = change[k]
-  }
-}
-
-const getTile = (gameId, tileIdx) => {
-  return GAMES[gameId].puzzle.tiles[tileIdx]
-}
-
-const getTileGroup = (gameId, tileIdx) => {
-  const tile = getTile(gameId, tileIdx)
-  return tile.group
-}
-
-const getFinalTilePos = (gameId, tileIdx) => {
-  const info = GAMES[gameId].puzzle.info
-  const boardPos = {
-    x: (info.table.width - info.width) / 2,
-    y: (info.table.height - info.height) / 2
-  }
-  const srcPos = srcPosByTileIdx(gameId, tileIdx)
-  return Geometry.pointAdd(boardPos, srcPos)
-}
-
-const getTilePos = (gameId, tileIdx) => {
-  const tile = getTile(gameId, tileIdx)
-  return tile.pos
-}
-
-const getTileZIndex = (gameId, tileIdx) => {
-  const tile = getTile(gameId, tileIdx)
-  return tile.z
-}
-
-const getFirstOwnedTileIdx = (gameId, userId) => {
-  for (let t of GAMES[gameId].puzzle.tiles) {
-    if (t.owner === userId) {
-      return t.idx
-    }
-  }
-  return -1
-}
-
-const getMaxGroup = (gameId) => {
-  return GAMES[gameId].puzzle.data.maxGroup
-}
-
-const getMaxZIndex = (gameId) => {
-  return GAMES[gameId].puzzle.data.maxZ
-}
-
-const getMaxZIndexByTileIdxs = (gameId, tileIdxs) => {
-  let maxZ = 0
-  for (let tileIdx of tileIdxs) {
-    let tileZIndex = getTileZIndex(gameId, tileIdx)
-    if (tileZIndex > maxZ) {
-      maxZ = tileZIndex
-    }
-  }
-  return maxZ
-}
-
-function srcPosByTileIdx(gameId, tileIdx) {
-  const info = GAMES[gameId].puzzle.info
-
-  const c = info.coords[tileIdx]
-  const cx = c.x * info.tileSize
-  const cy = c.y * info.tileSize
-
-  return { x: cx, y: cy }
-}
-
-function getSurroundingTilesByIdx(gameId, tileIdx) {
-  const info = GAMES[gameId].puzzle.info
-
-  const _X = info.coords[tileIdx].x
-  const _Y = info.coords[tileIdx].y
-
-  return [
-    // top
-    (_Y > 0) ?               (tileIdx - info.tilesX) : -1,
-    // right
-    (_X < info.tilesX - 1) ? (tileIdx + 1)           : -1,
-    // bottom
-    (_Y < info.tilesY - 1) ? (tileIdx + info.tilesX) : -1,
-    // left
-    (_X > 0) ?               (tileIdx - 1)           : -1,
-  ]
-}
-
-const setTilesZIndex = (gameId, tileIdxs, zIndex) => {
-  for (let tilesIdx of tileIdxs) {
-    changeTile(gameId, tilesIdx, { z: zIndex })
-  }
-}
-
-const moveTileDiff = (gameId, tileIdx, diff) => {
-  const oldPos = getTilePos(gameId, tileIdx)
-  const pos = Geometry.pointAdd(oldPos, diff)
-  changeTile(gameId, tileIdx, { pos })
-}
-
-const moveTilesDiff = (gameId, tileIdxs, diff) => {
-  for (let tileIdx of tileIdxs) {
-    moveTileDiff(gameId, tileIdx, diff)
-  }
-}
-
-const finishTiles = (gameId, tileIdxs) => {
-  for (let tileIdx of tileIdxs) {
-    changeTile(gameId, tileIdx, { owner: -1, z: 1 })
-  }
-}
-
-const setTilesOwner = (gameId, tileIdxs, owner) => {
-  for (let tileIdx of tileIdxs) {
-    changeTile(gameId, tileIdx, { owner })
-  }
-}
-
-// get all grouped tiles for a tile
-function getGroupedTileIdxs(gameId, tileIdx) {
-  const tiles = GAMES[gameId].puzzle.tiles
-  const tile = tiles[tileIdx]
-
-  const grouped = []
-  if (tile.group) {
-    for (let other of tiles) {
-      if (other.group === tile.group) {
-        grouped.push(other.idx)
-      }
-    }
-  } else {
-    grouped.push(tile.idx)
-  }
-  return grouped
-}
-
-// Returns the index of the puzzle tile with the highest z index
-// that is not finished yet and that matches the position
-const freeTileIdxByPos = (gameId, pos) => {
-  let info = GAMES[gameId].puzzle.info
-  let tiles = GAMES[gameId].puzzle.tiles
-
-  let maxZ = -1
-  let tileIdx = -1
-  for (let idx = 0; idx < tiles.length; idx++) {
-    const tile = tiles[idx]
-    if (tile.owner !== 0) {
-      continue
-    }
-
-    const collisionRect = {
-      x: tile.pos.x,
-      y: tile.pos.y,
-      w: info.tileSize,
-      h: info.tileSize,
-    }
-    if (Geometry.pointInBounds(pos, collisionRect)) {
-      if (maxZ === -1 || tile.z > maxZ) {
-        maxZ = tile.z
-        tileIdx = idx
-      }
-    }
-  }
-  return tileIdx
-}
-
-// determine if two tiles are grouped together
-const areGrouped = (gameId, tileIdx1, tileIdx2) => {
-  const g1 = getTileGroup(gameId, tileIdx1)
-  const g2 = getTileGroup(gameId, tileIdx2)
-  return g1 && g1 === g2
-}
-
-function handleInput(gameId, playerId, input) {
-  let puzzle = GAMES[gameId].puzzle
-  let players = GAMES[gameId].players
-  let evtInfo = GAMES[gameId].evtInfos[playerId]
-
-  let changes = []
-
-  const _dataChange = () => {
-    changes.push(['data', puzzle.data])
-  }
-
-  const _tileChange = (tileIdx) => {
-    changes.push(['tile', getTile(gameId, tileIdx)])
-  }
-
-  const _tileChanges = (tileIdxs) => {
-    for (let tileIdx of tileIdxs) {
-      _tileChange(tileIdx)
-    }
-  }
-
-  const _playerChange = () => {
-    changes.push(['player', players[playerId]])
-  }
-
-  // put both tiles (and their grouped tiles) in the same group
-  const groupTiles = (gameId, tileIdx1, tileIdx2) => {
-    let tiles = GAMES[gameId].puzzle.tiles
-    let group1 = getTileGroup(gameId, tileIdx1)
-    let group2 = getTileGroup(gameId, tileIdx2)
-
-    let group
-    let searchGroups = []
-    if (group1) {
-      searchGroups.push(group1)
-    }
-    if (group2) {
-      searchGroups.push(group2)
-    }
-    if (group1) {
-      group = group1
-    } else if (group2) {
-      group = group2
-    } else {
-      let maxGroup = getMaxGroup(gameId) + 1
-      changeData(gameId, { maxGroup })
-      _dataChange()
-      group = getMaxGroup(gameId)
-    }
-
-    changeTile(gameId, tileIdx1, { group })
-    _tileChange(tileIdx1)
-    changeTile(gameId, tileIdx2, { group })
-    _tileChange(tileIdx2)
-
-    // TODO: strange
-    if (searchGroups.length > 0) {
-      for (let tile of tiles) {
-        if (searchGroups.includes(tile.group)) {
-          changeTile(gameId, tile.idx, { group })
-          _tileChange(tile.idx)
-        }
-      }
-    }
-  }
-
-  let [type, x, y] = input
-  let pos = {x, y}
-  if (type === 'down') {
-    changePlayer(gameId, playerId, { down: true })
-    _playerChange()
-    evtInfo._last_mouse_down = pos
-
-    const tileIdxAtPos = freeTileIdxByPos(gameId, pos)
-    if (tileIdxAtPos >= 0) {
-      console.log('tile: ', tileIdxAtPos)
-      let maxZ = getMaxZIndex(gameId) + 1
-      changeData(gameId, { maxZ })
-      _dataChange()
-      const tileIdxs = getGroupedTileIdxs(gameId, tileIdxAtPos)
-      setTilesZIndex(gameId, tileIdxs, getMaxZIndex(gameId))
-      setTilesOwner(gameId, tileIdxs, playerId)
-      _tileChanges(tileIdxs)
-    }
-
-  } else if (type === 'move') {
-    changePlayer(gameId, playerId, pos)
-    _playerChange()
-
-    if (evtInfo._last_mouse_down !== null) {
-      let tileIdx = getFirstOwnedTileIdx(gameId, playerId)
-      if (tileIdx >= 0) {
-        const diffX = x - evtInfo._last_mouse_down.x
-        const diffY = y - evtInfo._last_mouse_down.y
-        const diff = { x: diffX, y: diffY }
-        const tileIdxs = getGroupedTileIdxs(gameId, tileIdx)
-        moveTilesDiff(gameId, tileIdxs, diff)
-        _tileChanges(tileIdxs)
-      }
-
-      evtInfo._last_mouse_down = pos
-    }
-  } else if (type === 'up') {
-    changePlayer(gameId, playerId, { down: false })
-    _playerChange()
-    evtInfo._last_mouse_down = null
-
-    let tileIdx = getFirstOwnedTileIdx(gameId, playerId)
-    if (tileIdx >= 0) {
-      // drop the tile(s)
-      let tileIdxs = getGroupedTileIdxs(gameId, tileIdx)
-      setTilesOwner(gameId, tileIdxs, 0)
-      _tileChanges(tileIdxs)
-
-      // Check if the tile was dropped near the final location
-      let tilePos = getTilePos(gameId, tileIdx)
-      let finalPos = getFinalTilePos(gameId, tileIdx)
-      if (Geometry.pointDistance(finalPos, tilePos) < puzzle.info.snapDistance) {
-        let diff = Geometry.pointSub(finalPos, tilePos)
-        // Snap the tile to the final destination
-        moveTilesDiff(gameId, tileIdxs, diff)
-        finishTiles(gameId, tileIdxs)
-        _tileChanges(tileIdxs)
-      } else {
-        // Snap to other tiles
-        const check = (gameId, tileIdx, otherTileIdx, off) => {
-          let info = GAMES[gameId].puzzle.info
-          if (otherTileIdx < 0) {
-            return false
-          }
-          if (areGrouped(gameId, tileIdx, otherTileIdx)) {
-            return false
-          }
-          const tilePos = getTilePos(gameId, tileIdx)
-          const dstPos = Geometry.pointAdd(
-            getTilePos(gameId, otherTileIdx),
-            {x: off[0] * info.tileSize, y: off[1] * info.tileSize}
-          )
-          if (Geometry.pointDistance(tilePos, dstPos) < info.snapDistance) {
-            let diff = Geometry.pointSub(dstPos, tilePos)
-            let tileIdxs = getGroupedTileIdxs(gameId, tileIdx)
-            moveTilesDiff(gameId, tileIdxs, diff)
-            groupTiles(gameId, tileIdx, otherTileIdx)
-            tileIdxs = getGroupedTileIdxs(gameId, tileIdx)
-            const zIndex = getMaxZIndexByTileIdxs(gameId, tileIdxs)
-            console.log('z:' , zIndex, tileIdxs)
-            setTilesZIndex(gameId, tileIdxs, zIndex)
-            _tileChanges(tileIdxs)
-            return true
-          }
-          return false
-        }
-
-        for (let tileIdxTmp of getGroupedTileIdxs(gameId, tileIdx)) {
-          let othersIdxs = getSurroundingTilesByIdx(gameId, tileIdxTmp)
-          if (
-            check(gameId, tileIdxTmp, othersIdxs[0], [0, 1]) // top
-            || check(gameId, tileIdxTmp, othersIdxs[1], [-1, 0]) // right
-            || check(gameId, tileIdxTmp, othersIdxs[2], [0, -1]) // bottom
-            || check(gameId, tileIdxTmp, othersIdxs[3], [1, 0]) // left
-          ) {
-            break
-          }
-        }
-      }
-    }
-  }
-  // console.log(mouse)
-  evtInfo._last_mouse = pos
-
-  return changes
-}
-
-
 export default {
   createGame,
-  exists,
-  addPlayer,
-  addSocket,
-  get,
-  getSockets,
-  handleInput,
+  exists: GameCommon.exists,
+  addPlayer: GameCommon.addPlayer,
+  addSocket: GameCommon.addSocket,
+  get: GameCommon.get,
+  getSockets: GameCommon.getSockets,
+  handleInput: GameCommon.handleInput,
 }