From 876c71d89b5888059129af6e0469b436637a398f Mon Sep 17 00:00:00 2001
From: Andrew Cooper <andrew.cooper@nearmap.com>
Date: Tue, 16 Aug 2022 09:01:14 +1000
Subject: [PATCH] Add move logic

---
 67_One_Check/csharp/Board.cs | 34 ++++++++++++++++++++++++++++++----
 67_One_Check/csharp/Game.cs  | 28 +++++++++++++++++++++++++++-
 67_One_Check/csharp/Move.cs  | 13 +++++++++++++
 3 files changed, 70 insertions(+), 5 deletions(-)
 create mode 100644 67_One_Check/csharp/Move.cs

diff --git a/67_One_Check/csharp/Board.cs b/67_One_Check/csharp/Board.cs
index 213a54d7..7ae917be 100644
--- a/67_One_Check/csharp/Board.cs
+++ b/67_One_Check/csharp/Board.cs
@@ -2,17 +2,43 @@ namespace OneCheck;
 
 internal class Board
 {
-    private readonly int[][] _checkers;
+    private readonly bool[][] _checkers;
+    private int _count;
 
     public Board()
     {
         _checkers = 
             Enumerable.Range(0, 8)
                 .Select(r => Enumerable.Range(0, 8)
-                    .Select(c => r > 1 && r < 6 && c > 1 && c < 6 ? 0 : 1).ToArray())
+                    .Select(c => r <= 1 || r >= 6 || c <= 1 || c >= 6).ToArray())
                 .ToArray();
+        _count = 48;
     }
 
+    private bool this[int index]
+    {
+        get => _checkers[(index - 1) / 8][(index-1) % 8];
+        set => _checkers[(index - 1) / 8][(index-1) % 8] = value;
+    }
+
+    public int Count => _count;
+
+    public bool TryMove(Move move)
+    {
+        if (move.IsInRange && move.IsTwoSpacesDiagonally && IsPieceJumpingPieceToEmptySpace(move))
+        {
+            this[move.From] = false;
+            this[move.Jumped] = false;
+            this[move.To] = true;
+            _count--;
+            return true;
+        }
+
+        return false;
+    }
+
+    private bool IsPieceJumpingPieceToEmptySpace(Move move) => this[move.From] && this[move.Jumped] && !this[move.To];
+
     public override string ToString() => 
-        string.Join(Environment.NewLine, _checkers.Select(r => string.Join(" ", r.Select(c => $" {c}"))));
-}
\ No newline at end of file
+        string.Join(Environment.NewLine, _checkers.Select(r => string.Join(" ", r.Select(c => c ? " 1" : " 0"))));
+}
diff --git a/67_One_Check/csharp/Game.cs b/67_One_Check/csharp/Game.cs
index 924fc04c..49da9851 100644
--- a/67_One_Check/csharp/Game.cs
+++ b/67_One_Check/csharp/Game.cs
@@ -4,6 +4,7 @@ internal class Game
 {
     private readonly IReadWrite _io;
     private readonly Board _board;
+    private int _moveCount;
 
     public Game(IReadWrite io)
     {
@@ -15,6 +16,31 @@ internal class Game
     {
         _io.Write(Streams.Introduction);
         
-        _io.WriteLine(_board);
+        do
+        {
+            _io.WriteLine(_board);
+            _io.WriteLine();
+        } while (PlayMove());
+
+        _io.WriteLine(Formats.Results, _moveCount, _board.Count);
+    }
+
+    private bool PlayMove()
+    {
+        while (true)
+        {
+            var from = (int)_io.ReadNumber(Prompts.From);
+            if (from == 0) { return false; }
+
+            var move = new Move { From = from, To = (int)_io.ReadNumber(Prompts.To) };
+
+            if (_board.TryMove(move)) 
+            { 
+                _moveCount++;
+                return true; 
+            }
+
+            _io.Write(Streams.IllegalMove);
+        }
     }
 }
diff --git a/67_One_Check/csharp/Move.cs b/67_One_Check/csharp/Move.cs
new file mode 100644
index 00000000..b90f7c0b
--- /dev/null
+++ b/67_One_Check/csharp/Move.cs
@@ -0,0 +1,13 @@
+namespace OneCheck;
+
+internal class Move
+{
+    public int From { get; init; }
+    public int To { get; init; }
+    public int Jumped => (From + To) / 2;
+
+    public bool IsInRange => From >= 1 && From <= 64 && To >= 1 && To <= 64;
+    public bool IsTwoSpacesDiagonally => RowDelta == 2 && ColumnDelta == 2;
+    private int RowDelta => Math.Abs(From / 8 - To / 8);
+    private int ColumnDelta => Math.Abs(From % 8 - To % 8);
+}
\ No newline at end of file