From b327bbd4695008bfc2bd93609cf90d98a9f368b5 Mon Sep 17 00:00:00 2001
From: CodingEnthusiast <CodingEnthusiast@protonmail.com>
Date: Thu, 8 Aug 2024 13:55:22 +0330
Subject: [PATCH] Add new properties to IChain

---
 Src/Autarkysoft.Bitcoin/Blockchain/Chain.cs  | 15 +++++++++++++++
 Src/Autarkysoft.Bitcoin/Blockchain/IChain.cs | 12 ++++++++++++
 Src/Tests/Bitcoin/Blockchain/MockChain.cs    | 14 ++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/Src/Autarkysoft.Bitcoin/Blockchain/Chain.cs b/Src/Autarkysoft.Bitcoin/Blockchain/Chain.cs
index 2694e91..1741200 100644
--- a/Src/Autarkysoft.Bitcoin/Blockchain/Chain.cs
+++ b/Src/Autarkysoft.Bitcoin/Blockchain/Chain.cs
@@ -115,6 +115,8 @@ public Chain(IFileManager fileMan, IBlockVerifier blockVerifier, IConsensus c, I
         public IClientTime Time { get; }
         /// <inheritdoc/>
         public int Height { get; private set; }
+        /// <inheritdoc/>
+        public int HeaderCount => headerList.Count;
 
         private BlockchainState _state = BlockchainState.None;
         /// <inheritdoc/>
@@ -141,6 +143,11 @@ public BlockchainState State
         /// <inheritdoc/>
         public Digest256 Tip { get; private set; }
 
+        /// <inheritdoc/>
+        public BlockHeader LastHeader => headerList[^1];
+
+        /// <inheritdoc/>
+        public event EventHandler NewHeaderEvent;
         /// <inheritdoc/>
         public event EventHandler HeaderSyncEndEvent;
         /// <inheritdoc/>
@@ -597,11 +604,19 @@ public bool ProcessHeaders(BlockHeader[] headers, INodeStatus nodeStatus)
                         {
                             AppendHeadrs(headers.AsSpan().Slice(arrIndex, count).ToArray(), count);
                             nodeStatus.AddBigViolation();
+                            if (count != 0)
+                            {
+                                NewHeaderEvent?.Invoke(this, EventArgs.Empty);
+                            }
                             return false;
                         }
                     }
 
                     AppendHeadrs(headers.AsSpan()[arrIndex..].ToArray(), count);
+                    if (count != 0)
+                    {
+                        NewHeaderEvent?.Invoke(this, EventArgs.Empty);
+                    }
 
                     return true;
                 }
diff --git a/Src/Autarkysoft.Bitcoin/Blockchain/IChain.cs b/Src/Autarkysoft.Bitcoin/Blockchain/IChain.cs
index cab065e..8c4a251 100644
--- a/Src/Autarkysoft.Bitcoin/Blockchain/IChain.cs
+++ b/Src/Autarkysoft.Bitcoin/Blockchain/IChain.cs
@@ -22,14 +22,26 @@ public interface IChain
         /// </summary>
         int Height { get; }
         /// <summary>
+        /// Returns number of headers (should be higher than or equal to <see cref="Height"/>)
+        /// </summary>
+        int HeaderCount { get; }
+        /// <summary>
         /// Hash of the last block in the chain
         /// </summary>
         Digest256 Tip { get; }
         /// <summary>
+        /// Returns last header
+        /// </summary>
+        BlockHeader LastHeader { get; }
+        /// <summary>
         /// Gets or sets the current blockchain state
         /// </summary>
         public BlockchainState State { get; set; }
         /// <summary>
+        /// An event to be raised when a new block header is received (useful for UI updates, miner, etc).
+        /// </summary>
+        event EventHandler NewHeaderEvent;
+        /// <summary>
         /// An event to be raised when the initial header sync is over (signals start of adding new nodes, 
         /// downloading missing blocks, etc).
         /// </summary>
diff --git a/Src/Tests/Bitcoin/Blockchain/MockChain.cs b/Src/Tests/Bitcoin/Blockchain/MockChain.cs
index 655ff2f..e94e405 100644
--- a/Src/Tests/Bitcoin/Blockchain/MockChain.cs
+++ b/Src/Tests/Bitcoin/Blockchain/MockChain.cs
@@ -37,6 +37,7 @@ public BlockchainState State
             }
         }
 
+        public event EventHandler NewHeaderEvent;
         public event EventHandler HeaderSyncEndEvent;
         public event EventHandler BlockSyncEndEvent;
 
@@ -50,9 +51,22 @@ public int Height
             }
         }
 
+        internal int _hdrCount = -1;
+        public int HeaderCount
+        {
+            get
+            {
+                Assert.True(_hdrCount != -1, UnexpectedCall);
+                return _hdrCount;
+            }
+        }
+
         internal Digest256 _tip;
         public Digest256 Tip => _tip;
 
+        internal BlockHeader _lastHdr;
+        public BlockHeader LastHeader => _lastHdr;
+
         internal Target? targetToReturn;
         public Target GetNextTarget(in BlockHeader hdr)
         {