WIP

src/game/Game.ts

@@ -1,4 +1,5 @@
 import { Chess, ChessInstance, Move } from "chess.js";
+import { cleanPGN } from "./PGNHelpers";
 
 class Game {
   private game: ChessInstance;
@@ -12,33 +13,8 @@ class Game {
     this.moves = [];
   }
 
-  private cleanPGN(pgn: string) {
-    const game = new Chess();
-    game.load_pgn(pgn);
-    game.delete_comments();
-    const [_, moves] = game.pgn().split("\n\n");
-
-    const header = Object.entries(game.header())
-      .filter(([key]) =>
-        [
-          "event",
-          "site",
-          "white",
-          "black",
-          "date",
-          "result",
-          "opening",
-        ].includes(key.toLowerCase())
-      )
-      .map(([key, val]) => `[${key} "${val}"]`)
-      .sort()
-      .join("\n");
-
-    return [header, moves].join("\n\n");
-  }
-
   loadPGN(pgn: string) {
-    this.game.load_pgn(this.cleanPGN(pgn));
+    this.game.load_pgn(cleanPGN(pgn));
     this.game.delete_comments();
     this.moves = this.game.history({ verbose: true });
     this.currentPly = 0;

src/game/PGNHelpers.ts

@@ -0,0 +1,79 @@
+import { Chess } from "chess.js";
+
+const PGN_KEYS_TO_SHORT = {
+  Event: "E",
+  Site: "S",
+  White: "W",
+  Black: "B",
+  Date: "D",
+  Result: "R",
+  FEN: "F",
+};
+
+const PGN_KEYS = Object.keys(PGN_KEYS_TO_SHORT);
+
+const PGN_KEYS_TO_LONG = Object.fromEntries(
+  Object.entries(PGN_KEYS_TO_SHORT).map(([long, short]) => [short, long])
+);
+
+const cleanPGN = (pgn: string) => {
+  const game = new Chess();
+  game.load_pgn(pgn);
+  game.delete_comments();
+  const [_, moves] = game.pgn().split("\n\n");
+
+  const header = Object.entries(game.header())
+    .filter(([key]) => PGN_KEYS.includes(key))
+    .map(([key, val]) => `[${key} "${val}"]`)
+    .sort()
+    .join("\n");
+
+  return [header, moves].join("\n\n");
+};
+
+const compressPGN = (pgn: string) => {
+  const game = new Chess();
+  game.load_pgn(pgn);
+
+  const moves = game.history().join(" ");
+
+  const header = Object.entries(game.header())
+    .filter(([key]) => PGN_KEYS.includes(key))
+    .map(([key, val]) => `${key[0].toUpperCase()} ${val}`)
+    .sort()
+    .join("\n");
+
+  return btoa([header, moves].join("\n\n"));
+};
+
+const decompressPGN = (compressedPGN: string) => {
+  const [headerRaw, movesRaw] = atob(compressedPGN).split("\n\n");
+
+  let result;
+
+  const header = headerRaw
+    .split("\n")
+    .map((entry) => {
+      const [shortKey, ...data] = entry.split(" ");
+      const value = data.join(" ");
+
+      if (shortKey === "R") {
+        result = value;
+      }
+
+      return `[${PGN_KEYS_TO_LONG[shortKey]} "${value}"]`;
+    })
+    .join("\n");
+
+  const moves =
+    movesRaw
+      .split(" ")
+      .map((move, index) =>
+        index % 2 === 0 ? `${index / 2 + 1}. ${move}` : move
+      )
+      .join(" ") + ` ${result}`;
+
+  return [header, moves].join("\n\n");
+};
+
+export { cleanPGN, compressPGN, decompressPGN };