refactor: migrate to gRPC [wip]

lib/utils/utils.dart

@@ -25,6 +25,74 @@ import '../models/github/latest.dart';
 class Utils {
   static final Random random = Random();
 
+  static String genAuroraEid(int uid) {
+    if (uid == 0) {
+      return ''; // Return null for a UID of 0
+    }
+
+    // 1. Convert UID to a byte array.
+    List<int> midByte = utf8.encode(uid.toString());
+    List<int> resultByte = List<int>.filled(midByte.length, 0);
+
+    // 2. XOR each byte with the corresponding byte from the key.
+    const key = 'ad1va46a7lza';
+    for (int i = 0; i < midByte.length; i++) {
+      resultByte[i] = midByte[i] ^ key.codeUnitAt(i % key.length);
+    }
+
+    // 3. Perform Base64 encoding without padding.
+    String base64Encoded =
+        base64.encode(resultByte).replaceAll('=', ''); // Remove padding
+
+    // Return the resulting x-bili-aurora-eid.
+    return base64Encoded;
+  }
+
+  static String genRandomString(int length) {
+    const characters = '0123456789abcdefghijklmnopqrstuvwxyz';
+    Random random = Random();
+    return List.generate(
+            length, (index) => characters[random.nextInt(characters.length)])
+        .join();
+  }
+
+  static String genTraceId() {
+    // 1. Generate a 32-character random string (random_id).
+    String randomId = genRandomString(32);
+
+    // 2. Take the first 24 characters of random_id as random_trace_id.
+    StringBuffer randomTraceId = StringBuffer(randomId.substring(0, 24));
+
+    // 3. Initialize an array b_arr with a length of 3, initial values are 0.
+    List<int> bArr = List.filled(3, 0);
+
+    // Get the current timestamp.
+    int ts = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+
+    // Using a loop to traverse b_arr from high to low.
+    for (int i = 2; i >= 0; i--) {
+      ts >>= 8; // Right shift ts by 8 bits.
+      bArr[i] = (ts ~/ 128) % 2 == 0
+          ? (ts % 256)
+          : (ts % 256) - 256; // Assign value based on condition.
+    }
+
+    // 4. Convert each element in b_arr to a two-digit hexadecimal string and append to random_trace_id.
+    for (int value in bArr) {
+      randomTraceId
+          .write(value.toRadixString(16).padLeft(2, '0')); // Convert to hex.
+    }
+
+    // 5. Append the 31st and 32nd characters of random_id to random_trace_id.
+    randomTraceId.write(randomId.substring(30, 32));
+
+    // 6. Finally, concatenate as '{random_trace_id}:{random_trace_id[16..32]}:0:0'.
+    String randomTraceIdFinal =
+        '${randomTraceId.toString()}:${randomTraceId.toString().substring(16, 32)}:0:0';
+
+    return randomTraceIdFinal;
+  }
+
   static void viewBangumi({
     dynamic seasonId,
     dynamic epId,