From fdb4a6d5660ffd85668b73818bccae719c44a491 Mon Sep 17 00:00:00 2001
From: Rob Greene <robgreene@gmail.com>
Date: Mon, 14 Mar 2022 20:15:51 -0500
Subject: [PATCH] Adding Range to better report a condensed description of
 differences.

---
 .../storage/compare/DiskDiff.java             | 24 +++--
 .../webcodepro/applecommander/util/Range.java | 89 +++++++++++++++++++
 .../applecommander/util/RangeTest.java        | 49 ++++++++++
 3 files changed, 157 insertions(+), 5 deletions(-)
 create mode 100644 lib/ac-api/src/main/java/com/webcodepro/applecommander/util/Range.java
 create mode 100644 lib/ac-api/src/test/java/com/webcodepro/applecommander/util/RangeTest.java

diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/compare/DiskDiff.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/compare/DiskDiff.java
index e580a93..ba3e9d2 100644
--- a/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/compare/DiskDiff.java
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/storage/compare/DiskDiff.java
@@ -24,12 +24,14 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
 import java.util.function.BiConsumer;
+import java.util.stream.Collectors;
 
 import com.webcodepro.applecommander.storage.Disk;
 import com.webcodepro.applecommander.storage.DiskGeometry;
 import com.webcodepro.applecommander.storage.DiskUnrecognizedException;
 import com.webcodepro.applecommander.storage.FormattedDisk;
 import com.webcodepro.applecommander.storage.physical.ImageOrder;
+import com.webcodepro.applecommander.util.Range;
 
 /**
  * Perform a disk comparison based on selected strategy.
@@ -123,12 +125,21 @@ public class DiskDiff {
                     orderA.getBlocksOnDevice(), orderB.getBlocksOnDevice());
             return;
         }
-        
+
+        List<Integer> unequalBlocks = new ArrayList<>();
         for (int block=0; block<orderA.getBlocksOnDevice(); block++) {
             byte[] blockA = orderA.readBlock(block);
             byte[] blockB = orderB.readBlock(block);
             if (!Arrays.equals(blockA, blockB)) {
-                results.addError("Block #%d does not match.", block);
+                unequalBlocks.add(block);
+            }
+        }
+        for (Range r : Range.from(unequalBlocks)) {
+            if (r.size() == 1) {
+                results.addError("Block #%s does not match.", r);
+            }
+            else {
+                results.addError("Blocks #%s do not match.", r);
             }
         }
     }
@@ -145,17 +156,20 @@ public class DiskDiff {
         }
         
         for (int track=0; track<orderA.getTracksPerDisk(); track++) {
-            List<String> unequalSectors = new ArrayList<>();
+            List<Integer> unequalSectors = new ArrayList<>();
             for (int sector=0; sector<orderA.getSectorsPerTrack(); sector++) {
                 byte[] sectorA = orderA.readSector(track, sector);
                 byte[] sectorB = orderB.readSector(track, sector);
                 if (!Arrays.equals(sectorA, sectorB)) {
-                    unequalSectors.add(Integer.toString(sector));
+                    unequalSectors.add(sector);
                 }
             }
             if (!unequalSectors.isEmpty()) {
                 results.addError("Track %d does not match on sectors %s", track,
-                        String.join(",", unequalSectors));
+                        Range.from(unequalSectors)
+                             .stream()
+                             .map(Range::toString)
+                             .collect(Collectors.joining(",")));
             }
         }
     }
diff --git a/lib/ac-api/src/main/java/com/webcodepro/applecommander/util/Range.java b/lib/ac-api/src/main/java/com/webcodepro/applecommander/util/Range.java
new file mode 100644
index 0000000..fcb5055
--- /dev/null
+++ b/lib/ac-api/src/main/java/com/webcodepro/applecommander/util/Range.java
@@ -0,0 +1,89 @@
+/*
+ * AppleCommander - An Apple ][ image utility.
+ * Copyright (C) 2002-2022 by Robert Greene and others
+ * robgreene at users.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or modify it 
+ * under the terms of the GNU General Public License as published by the 
+ * Free Software Foundation; either version 2 of the License, or (at your 
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but 
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along 
+ * with this program; if not, write to the Free Software Foundation, Inc., 
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package com.webcodepro.applecommander.util;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ *  Represents a range of numbers with helper methods to put them together. 
+ */
+public class Range {
+    private int first;
+    private int last;
+    
+    public Range(int first, int last) {
+        if (first < last) {
+            this.first = first;
+            this.last = last;
+        }
+        else {
+            this.first = last;
+            this.last = first;
+        }
+    }
+    
+    public int getFirst() {
+        return first;
+    }
+    public int getLast() {
+        return last;
+    }
+    public int size() {
+        return last - first + 1;
+    }
+    
+    @Override
+    public String toString() {
+        if (first == last) {
+            return String.format("%d", first);
+        }
+        else {
+            return String.format("%d-%d", first, last);
+        }
+    }
+
+    public static List<Range> from(List<Integer> numbers) {
+        List<Range> ranges = new ArrayList<>();
+        Collections.sort(numbers);
+        
+        int first = -1;
+        int last = -1;
+        for (int number : numbers) {
+            if (first == -1) {
+                first = last = number;
+            }
+            else if (number == last+1) {
+                last = number;
+            }
+            else {
+                ranges.add(new Range(first, last));
+                first = last = number;
+            }
+        }
+
+        if (first != -1) {
+            ranges.add(new Range(first, last));
+        }
+        
+        return ranges;
+    }
+}
diff --git a/lib/ac-api/src/test/java/com/webcodepro/applecommander/util/RangeTest.java b/lib/ac-api/src/test/java/com/webcodepro/applecommander/util/RangeTest.java
new file mode 100644
index 0000000..1e7f4bb
--- /dev/null
+++ b/lib/ac-api/src/test/java/com/webcodepro/applecommander/util/RangeTest.java
@@ -0,0 +1,49 @@
+/*
+ * AppleCommander - An Apple ][ image utility.
+ * Copyright (C) 2002-2022 by Robert Greene and others
+ * robgreene at users.sourceforge.net
+ *
+ * This program is free software; you can redistribute it and/or modify it 
+ * under the terms of the GNU General Public License as published by the 
+ * Free Software Foundation; either version 2 of the License, or (at your 
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but 
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along 
+ * with this program; if not, write to the Free Software Foundation, Inc., 
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package com.webcodepro.applecommander.util;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Arrays;
+
+import org.junit.Test;
+
+public class RangeTest {
+    @Test
+    public void testToString() {
+        assertEquals("1", new Range(1,1).toString());
+        assertEquals("1-5", new Range(1,5).toString());
+    }
+    
+    @Test
+    public void testFrom() {
+        assertEquals("[1-3, 5, 7, 9-12]", Range.from(Arrays.asList(1,2,3,5,7,9,10,11,12)).toString());
+    }
+
+    @Test
+    public void testFromUnordered() {
+        assertEquals("[1-3, 5, 7, 9-12]", Range.from(Arrays.asList(9,10,1,5,2,12,3,11,7)).toString());
+    }
+    
+    @Test
+    public void testFromEmpty() {
+        assertEquals("[]", Range.from(Arrays.asList()).toString());
+    }
+}