From 9bc4ca38705025bba39de9a55d78a576a4599ad5 Mon Sep 17 00:00:00 2001
From: Sebastian Korotkiewicz <skorotkiewicz@gmail.com>
Date: Tue, 6 Feb 2024 05:43:57 +0100
Subject: [PATCH] Initial commit

---
 .gitignore |  5 ++++
 decode.js  | 28 ++++++++++++++++++++
 encode.js  | 47 ++++++++++++++++++++++++++++++++++
 index.js   | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 155 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 decode.js
 create mode 100644 encode.js
 create mode 100644 index.js

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..acc2ddb
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+a.js
+b.js
+c.js
+d.js
+decode_d.js
\ No newline at end of file
diff --git a/decode.js b/decode.js
new file mode 100644
index 0000000..fb9395d
--- /dev/null
+++ b/decode.js
@@ -0,0 +1,28 @@
+function decodeSnowflake(idStr) {
+    const id = BigInt(idStr);
+    const binary = id.toString(2).padStart(64, '0');
+
+    const timestampShift = 22n;
+    const machineIdShift = 12n;
+    const sequenceMask = 0xFFFn; // 12 bitów na sekwencję
+
+    const timestamp = (id >> (timestampShift + machineIdShift)) & 0x1FFFFFFFFFFn;
+    const machineId = (id >> machineIdShift) & 0x3FFn; // 10 bitów na ID maszyny
+    const sequence = id & sequenceMask;
+
+    // Upewnij się, że epoka jest taka sama, jak użyta do generowania Snowflake IDs
+    const epoch = BigInt(1288834974657); // Powinna być taka sama, jak w generatorze
+    const date = new Date(Number(epoch + (timestamp * 1000n)));
+
+    return {
+        timestamp: date,
+        machineId: machineId.toString(),
+        sequence: sequence.toString(),
+    };
+}
+
+// Użycie
+const idStr = '7160488856901390336'; // Przykładowy identyfikator Snowflake
+const decoded = decodeSnowflake(idStr);
+console.log(decoded);
+
diff --git a/encode.js b/encode.js
new file mode 100644
index 0000000..0013b90
--- /dev/null
+++ b/encode.js
@@ -0,0 +1,47 @@
+class Snowflake {
+    constructor(machineId) {
+        if (machineId < 0 || machineId >= 1024) {
+            throw new Error('Machine ID must be in the range 0-1023.');
+        }
+
+        this.machineId = BigInt(machineId);
+        this.sequence = BigInt(0);
+        this.lastTimestamp = BigInt(-1);
+
+        // Konfiguracja bitów: 41 bitów na czas, 10 bitów na ID maszyny, 12 bitów na sekwencję
+        this.timestampShift = 22n;
+        this.machineIdShift = 12n;
+        this.sequenceMask = 0xFFFn; // 4095 w dziesiętnym, BigInt
+    }
+
+    generate() {
+        let timestamp = BigInt(Date.now());
+
+        if (timestamp === this.lastTimestamp) {
+            this.sequence = (this.sequence + 1n) & this.sequenceMask;
+
+            if (this.sequence === 0n) {
+                while (timestamp <= this.lastTimestamp) {
+                    timestamp = BigInt(Date.now());
+                }
+            }
+        } else {
+            this.sequence = 0n;
+        }
+
+        this.lastTimestamp = timestamp;
+
+        const id = ((timestamp & 0x1FFFFFFFFFFn) << this.timestampShift) |
+                    (this.machineId << this.machineIdShift) |
+                    this.sequence;
+
+        return id.toString(); // Zwraca string, ponieważ BigInt może być zbyt duży dla niektórych zastosowań
+    }
+}
+
+// Użycie
+const machineId = 1; // ID maszyny (0-1023)
+const snowflake = new Snowflake(machineId);
+
+const id1 = snowflake.generate();
+console.log(id1);
diff --git a/index.js b/index.js
new file mode 100644
index 0000000..f2afc74
--- /dev/null
+++ b/index.js
@@ -0,0 +1,75 @@
+class Snowflake {
+  constructor(machineId) {
+    if (machineId < 0 || machineId >= 1024) {
+      throw new Error("Machine ID must be in the range 0-1023.");
+    }
+
+    this.machineId = BigInt(machineId);
+    this.sequence = BigInt(0);
+    this.lastTimestamp = BigInt(-1);
+
+    // Konfiguracja bitów: 41 bitów na czas, 10 bitów na ID maszyny, 12 bitów na sekwencję
+    this.timestampShift = 22n;
+    this.machineIdShift = 12n;
+    this.sequenceMask = 0xfffn; // 4095 w dziesiętnym, BigInt
+  }
+
+  generate() {
+    let timestamp = BigInt(Date.now());
+
+    if (timestamp === this.lastTimestamp) {
+      this.sequence = (this.sequence + 1n) & this.sequenceMask;
+
+      if (this.sequence === 0n) {
+        while (timestamp <= this.lastTimestamp) {
+          timestamp = BigInt(Date.now());
+        }
+      }
+    } else {
+      this.sequence = 0n;
+    }
+
+    this.lastTimestamp = timestamp;
+
+    const id =
+      ((timestamp & 0x1ffffffffffn) << this.timestampShift) |
+      (this.machineId << this.machineIdShift) |
+      this.sequence;
+
+    return id.toString(); // Zwraca string, ponieważ BigInt może być zbyt duży dla niektórych zastosowań
+  }
+}
+
+function decodeSnowflake(idStr) {
+  const id = BigInt(idStr);
+  const binary = id.toString(2).padStart(64, "0");
+
+  const timestampShift = 22n;
+  const machineIdShift = 12n;
+  const sequenceMask = 0xfffn; // 12 bitów na sekwencję
+
+  const timestamp = (id >> (timestampShift + machineIdShift)) & 0x1ffffffffffn;
+  const machineId = (id >> machineIdShift) & 0x3ffn; // 10 bitów na ID maszyny
+  const sequence = id & sequenceMask;
+
+  // Upewnij się, że epoka jest taka sama, jak użyta do generowania Snowflake IDs
+  const epoch = BigInt(1288834974657); // Powinna być taka sama, jak w generatorze
+  const date = new Date(Number(epoch + timestamp * 1000n));
+
+  return {
+    timestamp: date,
+    machineId: machineId.toString(),
+    sequence: sequence.toString(),
+  };
+}
+
+// Użycie
+const machineId = 1; // ID maszyny (0-1023)
+const snowflake = new Snowflake(machineId);
+
+const id1 = snowflake.generate();
+console.log("encodeID", id1);
+
+const idStr = id1; // Przykładowy identyfikator Snowflake
+const decoded = decodeSnowflake(idStr);
+console.log("decodeID", decoded);