add getCreateRoomPasswd

src/api/mycard/room.ts

@@ -18,24 +18,68 @@ export function getEncryptedPasswd(
 ): string {
   const optionsBuffer = new Uint8Array(6);
   optionsBuffer[1] = 3 << 4;
+
+  encryptBuffer(optionsBuffer, external_id);
+
+  const base64String = btoa(String.fromCharCode(...optionsBuffer));
+
+  return base64String + roomID;
+}
+
+// 获取创建房间的密码
+export function getCreateRoomPasswd(
+  options: Options,
+  roomID: string,
+  external_id: number,
+  _private: boolean = false,
+) {
+  // ref: https://docs.google.com/document/d/1rvrCGIONua2KeRaYNjKBLqyG9uybs9ZI-AmzZKNftOI/edit
+  const optionsBuffer = new Uint8Array(6);
+  optionsBuffer[1] =
+    ((_private ? 2 : 1) << 4) |
+    (options.duel_rule << 1) |
+    (options.auto_death ? 0x1 : 0);
+
+  optionsBuffer[2] =
+    (options.rule << 5) |
+    (options.mode << 3) |
+    (options.no_check_deck ? 1 << 1 : 0) |
+    (options.no_shuffle_deck ? 1 : 0);
+  writeUInt16LE(optionsBuffer, 3, options.start_lp);
+  optionsBuffer[5] = (options.start_hand << 4) | options.draw_count;
+
+  encryptBuffer(optionsBuffer, external_id);
+  const base64String = btoa(String.fromCharCode(...optionsBuffer));
+
+  return base64String + roomID;
+}
+
+// 填充校验码和加密
+function encryptBuffer(buffer: Uint8Array, external_id: number) {
   let checksum = 0;
 
-  for (let i = 1; i < optionsBuffer.length; i++) {
-    checksum -= optionsBuffer[i];
+  for (let i = 1; i < buffer.length; i++) {
+    checksum -= buffer[i];
   }
 
-  optionsBuffer[0] = checksum & 0xff;
+  buffer[0] = checksum & 0xff;
 
   const secret = (external_id % 65535) + 1;
 
-  for (let i = 0; i < optionsBuffer.length; i += 2) {
-    const value = (optionsBuffer[i + 1] << 8) | optionsBuffer[i];
+  for (let i = 0; i < buffer.length; i += 2) {
+    const value = readUInt16LE(buffer, i);
     const xorResult = value ^ secret;
-    optionsBuffer[i + 1] = (xorResult >> 8) & 0xff;
-    optionsBuffer[i] = xorResult & 0xff;
+    writeUInt16LE(buffer, i, xorResult);
   }
+}
 
-  const base64String = btoa(String.fromCharCode(...optionsBuffer));
+/* 一些辅助函数 */
 
-  return base64String + roomID;
+function readUInt16LE(buffer: Uint8Array, offset: number): number {
+  return (buffer[offset + 1] << 8) | buffer[offset];
+}
+
+function writeUInt16LE(buffer: Uint8Array, offset: number, value: number) {
+  buffer[offset] = value & 0xff;
+  buffer[offset + 1] = (value >> 8) & 0xff;
 }