Implement snowflakes

lib/structs/Snowflake.dart

@@ -0,0 +1,69 @@
+class Snowflake implements Comparable<Snowflake> {
+  /// Discord Epoch
+  static final DiscordEpoch = DateTime.utc(2015, 1, 1, 0, 0, 0);
+
+  /// Aria's Creations Epoch
+  static final ACEpoch = DateTime.utc(2024, 7, 9, 23, 0, 0);
+
+  final DateTime epoch;
+  final int value;
+  static final ZERO = Snowflake(epoch: DiscordEpoch, value: 0);
+
+  Snowflake({required this.epoch, required this.value});
+
+  DateTime get timestamp =>
+      epoch.add(Duration(milliseconds: millisecondsSinceEpoch));
+
+  int get millisecondsSinceEpoch => value >> 22;
+
+  int get workerId => (value & 0x3E0000) >> 17;
+
+  int get processId => (value & 0x1F000) >> 12;
+
+  int get increment => value & 0xFFF;
+
+  bool get isZero => value == 0;
+
+  factory Snowflake.parse(dynamic value, DateTime epoch) {
+    int val = int.parse(value.toString());
+    return Snowflake(epoch: epoch, value: val);
+  }
+
+  factory Snowflake.now(DateTime epoch) =>
+      Snowflake.fromDateTime(DateTime.now(), epoch);
+
+  factory Snowflake.fromDateTime(DateTime dt, DateTime epoch) {
+    return Snowflake(
+        epoch: epoch, value: dt.difference(epoch).inMilliseconds << 22);
+  }
+
+  bool isBefore(Snowflake other) => timestamp.isBefore(other.timestamp);
+
+  bool isAfter(Snowflake other) => timestamp.isAfter(other.timestamp);
+
+  bool isAtSameMomentAs(Snowflake other) =>
+      timestamp.isAtSameMomentAs(other.timestamp);
+
+  Snowflake operator +(Duration duration) =>
+      Snowflake.fromDateTime(timestamp.add(duration), epoch);
+
+  Snowflake operator -(Duration duration) =>
+      Snowflake.fromDateTime(timestamp.subtract(duration), epoch);
+
+  @override
+  int compareTo(Snowflake other) => value.compareTo(other.value);
+
+  bool operator <(Snowflake other) => isBefore(other);
+
+  bool operator >(Snowflake other) => isAfter(other);
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) || (other is Snowflake && other.value == value);
+
+  @override
+  int get hashCode => value.hashCode;
+
+  @override
+  String toString() => value.toString();
+}