From c9d676efb40677527c1b6268ada09a4124d0db76 Mon Sep 17 00:00:00 2001
From: Sky Young <sky@alexandria.io>
Date: Mon, 14 May 2018 16:38:03 -0700
Subject: [PATCH] Update Difficulty Calculations

---
 lib/blockchain/chain.js   | 45 ++++++++++++++++++++++++++-------------
 lib/protocol/consensus.js | 10 +++++++--
 lib/protocol/networks.js  | 34 ++++++++++++++++++++++++++++-
 3 files changed, 71 insertions(+), 18 deletions(-)

diff --git a/lib/blockchain/chain.js b/lib/blockchain/chain.js
index 4a31dfcf..01122e0c 100644
--- a/lib/blockchain/chain.js
+++ b/lib/blockchain/chain.js
@@ -2301,16 +2301,20 @@ Chain.prototype.getTarget = async function getTarget(time, prev) {
     return prev.bits;
   }
 
-  // Back 2 weeks
-  var back = pow.retargetInterval - 1;
-  
-  if (prev.height + 1 !== pow.retargetInterval)
-    back = pow.retargetInterval;
-  
-  const height = prev.height - back;
-  assert(height >= 0);
+  // Back 6 block
+  var back = pow.averagingInterval - 1;
+
+  
+  if (prev.height + 1 !== pow.averagingInterval)
+    back = pow.averagingInterval;
+
+  
+  let first = prev;
+  for (let i = 0; i < back; i++){
+    if (first)
+      first = await this.getPrevious(first)
+  }
 
-  const first = await this.getAncestor(prev, height);
   assert(first);
 
   return this.retarget(prev, first);
@@ -2327,19 +2331,30 @@ Chain.prototype.getTarget = async function getTarget(time, prev) {
 Chain.prototype.retarget = function retarget(prev, first) {
   const pow = this.network.pow;
   const targetTimespan = pow.targetTimespan;
+  const averagingIntervalTimespan = pow.averagingIntervalTimespan;
+  const targetSpacing = pow.targetSpacing;
+  const adjustUp = pow.adjustUp;
+  const adjustDown = pow.adjustDown;
 
   if (pow.noRetargeting)
     return prev.bits;
 
-  const target = consensus.fromCompact(prev.bits);
-
   let actualTimespan = prev.time - first.time;
 
-  if (actualTimespan < targetTimespan / 4 | 0)
-    actualTimespan = targetTimespan / 4 | 0;
 
-  if (actualTimespan > targetTimespan * 4)
-    actualTimespan = targetTimespan * 4;
+  let minActualTimespan = Math.floor(averagingIntervalTimespan * (100 - adjustUp) / 100)
+  let maxActualTimespan = Math.floor(averagingIntervalTimespan * (100 + adjustDown) / 100)
+
+  if (actualTimespan < minActualTimespan)
+    actualTimespan = minActualTimespan;
+
+
+  if (actualTimespan > maxActualTimespan)
+    actualTimespan = maxActualTimespan;
+
+  // Retarget
+  let target = consensus.fromCompact(prev.bits);
+
 
   target.imuln(actualTimespan);
   target.idivn(targetTimespan);
diff --git a/lib/protocol/consensus.js b/lib/protocol/consensus.js
index 9a7dc9c4..a1f3061c 100644
--- a/lib/protocol/consensus.js
+++ b/lib/protocol/consensus.js
@@ -24,7 +24,7 @@ exports.COIN = 100000000;
 
 /**
  * Maximum amount of money in satoshis:
- * `21million * 1btc` (consensus).
+ * `160million * 1flo` (consensus).
  * @const {Amount}
  * @default
  */
@@ -330,7 +330,13 @@ exports.getReward = function getReward(height, interval) {
   if (halvings === 0)
     return exports.BASE_REWARD;
 
-  return exports.HALF_REWARD >>> (halvings - 1);
+  let rewardValue = exports.BASE_REWARD;
+
+  for (let i = 0; i < halvings; i++){
+    rewardValue /= 2;
+  }
+
+  return rewardValue;
 };
 
 /**
diff --git a/lib/protocol/networks.js b/lib/protocol/networks.js
index 312fa461..3e6bb99e 100644
--- a/lib/protocol/networks.js
+++ b/lib/protocol/networks.js
@@ -217,7 +217,7 @@ main.pow = {
    * @default
    */
 
-  targetTimespan: 1 * 24 * 60 * 60,
+  targetTimespan: 6 * 40,
 
   /**
    * Average block time.
@@ -235,6 +235,38 @@ main.pow = {
 
   retargetInterval: 1,
 
+  /**
+   * Average retarget interval in blocks.
+   * @const {Number}
+   * @default
+   */
+
+  averagingInterval: 6,
+
+  /**
+   * Average retarget interval in blocks.
+   * @const {Number}
+   * @default
+   */
+
+  averagingIntervalTimespan: 6 * 40,
+
+  /**
+   * Adjust Target Timespan Max.
+   * @const {Number}
+   * @default
+   */
+
+  adjustUp: 2,
+
+  /**
+   * Adjust Target Timespan Min.
+   * @const {Number}
+   * @default
+   */
+
+  adjustDown: 3,
+
   /**
    * Whether to reset target if a block
    * has not been mined recently.