client/src/utils/storage.js

   1 import { extractTime } from "@/utils/timeControl";
   2
   3 // TODO: show game structure
   4 //const newItem = [
   5 //  { gameId: "", players: [], timeControl: "", clocks: [] }
   6 //];
   7
   8 function dbOperation(callback)
   9 {
  10   let db = null;
  11   let DBOpenRequest = window.indexedDB.open("vchess", 4);
  12
  13   DBOpenRequest.onerror = function(event) {
  14     alert("Database error: " + event.target.errorCode);
  15   };
  16
  17   DBOpenRequest.onsuccess = function(event) {
  18     db = DBOpenRequest.result;
  19     callback(db);
  20     db.close();
  21   };
  22
  23   DBOpenRequest.onupgradeneeded = function(event) {
  24     let db = event.target.result;
  25     db.onerror = function(event) {
  26       alert("Error while loading database: " + event.target.errorCode);
  27     };
  28     // Create objectStore for vchess->games
  29     db.createObjectStore("games", { keyPath: "gameId" });
  30   }
  31 }
  32
  33 // Optional callback to get error status
  34 function addGame(game, callback)
  35 {
  36   dbOperation((db) => {
  37     let transaction = db.transaction(["games"], "readwrite");
  38     if (callback)
  39     {
  40       transaction.oncomplete = function() {
  41         callback({}); //everything's fine
  42       }
  43       transaction.onerror = function() {
  44         callback({errmsg: "addGame failed: " + transaction.error});
  45       };
  46     }
  47     let objectStore = transaction.objectStore("games");
  48     objectStore.add(game);
  49   });
  50 }
  51
  52 // Clear current live game from localStorage
  53 function clear() {
  54   localStorage.deleteItem("gameInfo");
  55   localStorage.deleteItem("gameState");
  56 }
  57
  58 // Current live game:
  59 function getCurrent()
  60 {
  61   return Object.assign({},
  62     JSON.parse(localStorage.getItem("gameInfo")),
  63     JSON.parse(localStorage.getItem("gameState")));
  64 }
  65
  66 // Only called internally after a score update
  67 function transferToDb()
  68 {
  69   addGame(getCurrent(), (err) => {
  70     if (!!err.errmsg)
  71       return err;
  72     clear();
  73   });
  74 }
  75
  76 export const GameStorage =
  77 {
  78   // localStorage:
  79   init: function(o)
  80   {
  81     // Extract times (in [milli]seconds), set clocks, store in localStorage
  82     const tc = extractTime(o.timeControl);
  83
  84     // game infos: constant
  85     const gameInfo =
  86     {
  87       gameId: o.gameId,
  88       vname: o.vname,
  89       fenStart: o.fenStart,
  90       players: o.players,
  91       timeControl: o.timeControl,
  92       increment: tc.increment,
  93       mode: "live", //function for live games only
  94     };
  95
  96     // game state: will be updated
  97     const gameState =
  98     {
  99       fen: o.fenStart,
 100       moves: [],
 101       clocks: [...Array(o.players.length)].fill(tc.mainTime),
 102       started: [...Array(o.players.length)].fill(false),
 103       score: "*",
 104     };
 105
 106     localStorage.setItem("gameInfo", JSON.stringify(gameInfo));
 107     localStorage.setItem("gameState", JSON.stringify(gameState));
 108   },
 109
 110   getInitime: function()
 111   {
 112     const gameState = JSON.parse(localStorage.getItem("gameState"));
 113     return gameState.initime;
 114   },
 115
 116   // localStorage:
 117   // TODO: also option to takeback a move ?
 118   // NOTE: for live games only (all on server for corr)
 119   update: function(o) //colorIdx, move, fen, elapsed, increment, initime, score
 120   {
 121     let gameState = JSON.parse(localStorage.getItem("gameState"));
 122     if (!!o.move)
 123     {
 124       gameState.moves.push(o.move);
 125       gameState.fen = o.fen;
 126       gameState.clocks[o.colorIdx] += (o.increment - o.elapsed);
 127     }
 128     if (!!o.initime) //just a flag (true)
 129       gameState.initime = Date.now();
 130     if (!!o.score)
 131       gameState.score = o.score;
 132     localStorage.setItem("gameState", JSON.stringify(gameState));
 133     if (!!o.score && o.score != "*")
 134       transferToDb(); //game is over
 135   },
 136
 137   // indexedDB:
 138   // Since DB requests are asynchronous, require a callback using the result
 139   // TODO: option for remote retrieval (third arg, or just "gameRef")
 140   getLocal: function(gameId, callback)
 141   {
 142     let games = [];
 143     dbOperation((db) => {
 144       // TODO: if gameId is provided, limit search to gameId (just .get(gameId). ...)
 145       let objectStore = db.transaction('games').objectStore('games');
 146       objectStore.openCursor().onsuccess = function(event) {
 147         var cursor = event.target.result;
 148         // if there is still another cursor to go, keep running this code
 149         if (cursor)
 150         {
 151           games.push(cursor.value);
 152           cursor.continue();
 153         }
 154         else
 155           callback(games);
 156       }
 157     });
 158   },
 159
 160   // Delete a game in indexedDB
 161   remove: function(gameId, callback)
 162   {
 163     dbOperation((db) => {
 164       let transaction = db.transaction(["games"], "readwrite");
 165       if (callback)
 166       {
 167         transaction.oncomplete = function() {
 168           callback({}); //everything's fine
 169         }
 170         transaction.onerror = function() {
 171           callback({errmsg: "deleteGame failed: " + transaction.error});
 172         };
 173       }
 174       transaction.objectStore("games").delete(gameId);
 175     });
 176   },
 177
 178   // Retrieve any live game from its identifiers (remote or not, running or not)
 179   // NOTE: need callback because result might be obtained asynchronously
 180   get: function(gameRef, callback)
 181   {
 182     const gid = gameRef.id;
 183     const rid = gameRef.rid; //may be blank
 184     if (!!rid)
 185     {
 186       // TODO: send request to server which forward to user sid == rid,
 187       // need to listen to "remote game" event in main hall ?
 188       return callback({}); //means "the game will arrive later" (TODO...)
 189     }
 190
 191     const gameInfoStr = localStorage.getItem("gameInfo");
 192     if (gameInfoStr)
 193     {
 194       const gameInfo = JSON.parse(gameInfoStr);
 195       if (gameInfo.gameId == gid)
 196       {
 197         const gameState = JSON.parse(localStorage.getItem("gameState"));
 198         return callback(Object.assign({}, gameInfo, gameState));
 199       }
 200     }
 201
 202     // Game is local and not running
 203     GameStorage.getLocal(gid, callback);
 204   },
 205 };