add toUpdateDeckPayload

index.ts

-import { countItems } from './src/utils';
+import { BufferWriter, countItems } from './src/utils';
 import { Base64 } from 'js-base64';
 
 export default class YGOProDeck {
@@ -13,14 +13,9 @@ export default class YGOProDeck {
 
   toUint8Array() {
     const counted = [this.main, this.extra, this.side].map(countItems);
-    const buf = new Uint8Array(counted.reduce((a, b) => a + b.size * 4, 0));
-    let pointer = 0;
-    const writeUint32LE = (value: number) => {
-      buf[pointer++] = value & 0xff;
-      buf[pointer++] = (value >> 8) & 0xff;
-      buf[pointer++] = (value >> 16) & 0xff;
-      buf[pointer++] = (value >> 24) & 0xff;
-    };
+    const writer = new BufferWriter(
+      counted.reduce((a, b) => a + b.size * 4, 0),
+    );
     const writeCards = (countMap: Map<number, number>, type: number) => {
       // each card: 28 bits for id, 2 bits(0, 1, 2, 3) for type(0: main, 1: extra, 2: side, 3: unknown), 2 bits for count (0: 1, 1: 2, 2: 3, 3: 4)
       for (const [id, count] of countMap.entries()) {
@@ -28,11 +23,11 @@ export default class YGOProDeck {
           throw new Error(`Too many cards: ${id}`);
         }
         const value = (id & 0xfffffff) | (type << 28) | ((count - 1) << 30);
-        writeUint32LE(value);
+        writer.writeUint32LE(value);
       }
     };
     counted.forEach(writeCards);
-    return buf;
+    return writer.buffer;
   }
 
   toEncodedString() {
@@ -66,7 +61,7 @@ export default class YGOProDeck {
     return this.fromUint8Array(Base64.toUint8Array(str));
   }
 
-  static fromEncodedString(str: string) { 
+  static fromEncodedString(str: string) {
     return new YGOProDeck().fromEncodedString(str);
   }
 
@@ -106,4 +101,13 @@ export default class YGOProDeck {
   static fromYdkString(str: string) {
     return new YGOProDeck().fromYdkString(str);
   }
+
+  toUpdateDeckPayload() {
+    const cards = [...this.main, ...this.extra, ...this.side];
+    const writer = new BufferWriter(cards.length * 4 + 8)
+      .writeUint32LE(this.main.length + this.extra.length)
+      .writeUint32LE(this.side.length);
+    cards.forEach((id) => writer.writeUint32LE(id));
+    return writer.buffer;
+  }
 }

src/utils.ts

@@ -5,3 +5,50 @@ export function countItems<T>(arr: T[]) {
   }
   return map;
 }
+
+export class BufferWriter {
+  buffer: Uint8Array;
+  pointer = 0;
+  constructor(length: number) {
+    this.buffer = new Uint8Array(length);
+  }
+  writeUint32LE(value: number) {
+    this.buffer[this.pointer++] = value & 0xff;
+    this.buffer[this.pointer++] = (value >> 8) & 0xff;
+    this.buffer[this.pointer++] = (value >> 16) & 0xff;
+    this.buffer[this.pointer++] = (value >> 24) & 0xff;
+    return this;
+  }
+
+  writeUint32BE(value: number) {
+    this.buffer[this.pointer++] = (value >> 24) & 0xff;
+    this.buffer[this.pointer++] = (value >> 16) & 0xff;
+    this.buffer[this.pointer++] = (value >> 8) & 0xff;
+    this.buffer[this.pointer++] = value & 0xff;
+    return this;
+  }
+
+  writeUint16LE(value: number) {
+    this.buffer[this.pointer++] = value & 0xff;
+    this.buffer[this.pointer++] = (value >> 8) & 0xff;
+    return this;
+  }
+
+  writeUint16BE(value: number) {
+    this.buffer[this.pointer++] = (value >> 8) & 0xff;
+    this.buffer[this.pointer++] = value & 0xff;
+    return this;
+  }
+
+  writeUint8(value: number) {
+    this.buffer[this.pointer++] = value & 0xff;
+    return this;
+  }
+
+  writeString(str: string) {
+    for (let i = 0; i < str.length; i++) {
+      this.buffer[this.pointer++] = str.charCodeAt(i);
+    }
+    return this;
+  }
+}

tests/sample.spec.ts

@@ -18,6 +18,24 @@ describe('Sample test.', () => {
       encoded.replace(/[-_]/g, (m0) => (m0 == '-' ? '+' : '/')),
       'base64',
     );
+    expect(buf.readUInt32LE(0) & 0xfffffff).toBe(123);
+    expect((buf.readUInt32LE(0) >> 28) & 0x3).toBe(0);
+    expect(((buf.readUInt32LE(0) >> 30) & 0x3) + 1).toBe(3);
+    expect(buf.readUInt32LE(4) & 0xfffffff).toBe(456);
+    expect((buf.readUInt32LE(4) >> 28) & 0x3).toBe(0);
+    expect(((buf.readUInt32LE(4) >> 30) & 0x3) + 1).toBe(2);
+    expect(buf.readUInt32LE(8) & 0xfffffff).toBe(789);
+    expect((buf.readUInt32LE(8) >> 28) & 0x3).toBe(0);
+    expect(((buf.readUInt32LE(8) >> 30) & 0x3) + 1).toBe(1);
+    expect(buf.readUInt32LE(12) & 0xfffffff).toBe(1234);
+    expect((buf.readUInt32LE(12) >> 28) & 0x3).toBe(1);
+    expect(((buf.readUInt32LE(12) >> 30) & 0x3) + 1).toBe(1);
+    expect(buf.readUInt32LE(16) & 0xfffffff).toBe(5678);
+    expect((buf.readUInt32LE(16) >> 28) & 0x3).toBe(1);
+    expect(((buf.readUInt32LE(16) >> 30) & 0x3) + 1).toBe(1);
+    expect(buf.readUInt32LE(20) & 0xfffffff).toBe(12345);
+    expect((buf.readUInt32LE(20) >> 28) & 0x3).toBe(2);
+    expect(((buf.readUInt32LE(20) >> 30) & 0x3) + 1).toBe(1);
     expect(buf.length).toBe(24);
     const decoded = new YGOProDeck().fromEncodedString(encoded);
     expect(decoded.main).toStrictEqual(deck.main);