From 1d87754f53d7627549cee2d5d920e0fcd7550236 Mon Sep 17 00:00:00 2001
From: Malte Tammena <malte.tammena@gmx.de>
Date: Fri, 20 Oct 2017 13:24:11 +0200
Subject: [PATCH] Did commenting

---
 src/player/malte/MalteAI.java | 82 ++++++++++++++++++++++++++++++++++-
 1 file changed, 80 insertions(+), 2 deletions(-)

diff --git a/src/player/malte/MalteAI.java b/src/player/malte/MalteAI.java
index 6ea639a..bcd1f3d 100644
--- a/src/player/malte/MalteAI.java
+++ b/src/player/malte/MalteAI.java
@@ -7,18 +7,42 @@ import java.util.Arrays;
 
 import player.Player;
 
+/**
+ * Maltes artificial intelligence for playing a game of Connect Four
+ */
 public class MalteAI implements Player{
 
+    /**
+     * Name of the player.
+     */
     private String name;
+
+    /**
+     * Random Object.
+     */
     private Random ran;
+
+    /**
+     * The players ID.
+     */
     private int id;
+
+    /**
+     * The enemy's ID.
+     */
     private int enemyID;
 
+    /**
+     * Constructor.
+     *
+     * @param name The name for the player.
+     */
     public MalteAI(String name){
         this.name = name;
         this.ran = new Random();
     }
 
+    @Override
     public void setPlayerID(int id) {
         this.id = id;
         this.enemyID = id == 1 ? 2: 1;
@@ -28,29 +52,40 @@ public class MalteAI implements Player{
         this.enemyID = enemyID;
     }
 
+    @Override
     public int move(int[][] board){
+        // Create a set of all possible options.
         Set<Integer> options = new HashSet<>(Arrays.asList(0,1,2,3,4,5,6));
+        // Remove impossible options.
         for (Integer i: copySet(options)) {
             if (board[i][0] != 0) {
                 options.remove(i);
             }
         }
+        // Get options which would lead to instant win.
         Set<Integer> winningOptions = getRowCompletionOptions(options, board, id);
         for (Integer i: winningOptions) {
             return i.intValue();
         }
-
+        // Get options which would prevent an instant win of the enemy.
         Set<Integer> preventionsOptions = getRowCompletionOptions(options, board, enemyID);
         for (Integer i: preventionsOptions) {
+            // Only accept options, that would not cause a winning opportunity for the enemy.
             int[][] fakeBoard = makeMove(copyBoard(board), i, id);
             if (getRowCompletionOptions(options, fakeBoard, enemyID).size() == 0) {
                 return i.intValue();
             }
         }
-
+        // If nothing applies, take a random valied one.
         return takeRandom(options).intValue();
     }
 
+    /**
+     * Copies the given board.
+     *
+     * @param board The board to be copied.
+     * @return A deep copy of the board.
+     */
     private int[][] copyBoard(int[][] board) {
         int[][] copy = new int[board.length][board[0].length];
         for (int i = 0; i < board.length; i++) {
@@ -61,25 +96,56 @@ public class MalteAI implements Player{
         return copy;
     }
 
+    /**
+     * Makes a move on the given board.
+     * Makes a move on the given board, no winning check or anything,
+     * just a fake move on the given board. Necessary for confirming that
+     * a chosen move will not give the enemy an instant win.
+     *
+     * @param board The board on which the move is made.
+     * @param choice The column to play in.
+     * @param id The player's id.
+     * @return The modified board.
+     */
     private int[][] makeMove(int[][] board, int choice, int id) {
         int column = 0;
+        // If the column is full, do nothing.
         if (board[choice][column] != 0) {
             return board;
         }
+        // Find the last empty row.
         while (board[choice][column + 1] == 0) {
             column++;
         }
+        // Add the players piece.
         board[choice][column] = id;
         return board;
     }
 
+    /**
+     * Instant winning options.
+     * Returns a set of options for the player to choose from. If any one is choosen and
+     * played by the player with the given id, a win is certain.
+     *
+     * @param options The options, that are valid, a subset is returned.
+     * @param board The current game's board.
+     * @param id The players id.
+     * @return A subset of options which would lead to a win.
+     */
     private Set<Integer> getRowCompletionOptions(Set<Integer> options, int[][] board, int id) {
+        // Get winning patterns from Generator.
         Set<Pattern> pats = PatternGenerator.winningPatterns(id);
+        // Get patterns, that match anywhere on the board.
         Set<Pattern> matches = Pattern.matchingPatterns(pats, board);
+        // Create set to be returned.
         Set<Integer> ret = new HashSet<>();
+        // Iterate over all matches.
         for (Pattern p: matches) {
+            // Get all positions, this pattern matches.
             Set<Position> positions = p.matches(board);
+            // Get empty spaces in the pattern.
             for (Item i: p.getZeros()) {
+                // Add all options to the set.
                 for(Position pos: positions) {
                     ret.add(new Integer(i.getPosX() + pos.getPosX()));
                 }
@@ -88,10 +154,19 @@ public class MalteAI implements Player{
         return ret;
     }
 
+    /**
+     * Copies a set of Integer.
+     */
     private Set<Integer> copySet(Set<Integer> s) {
         return new HashSet<Integer>(s);
     }
 
+    /**
+     * Takes a random Integer from a set of Integer.
+     *
+     * @param s The set to take from.
+     * @return A random element of s.
+     */
     private Integer takeRandom(Set<Integer> s) {
         int item = ran.nextInt(s.size());
         int i = 0;
@@ -105,6 +180,9 @@ public class MalteAI implements Player{
         return 0;
     }
 
+    /**
+     * Get the player's name.
+     */
     public String getName(){
         return this.name;
     }