From 3364337b1420afbc501984002f8e5bfa7c44096e Mon Sep 17 00:00:00 2001
From: EpicKnarvik97 <kristian.knarvik@knett.no>
Date: Sun, 29 Aug 2021 19:16:54 +0200
Subject: [PATCH] Adds a new helper class responsible for book formatting

---
 .../utility/BookFormatter.java                | 92 +++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 src/main/java/net/knarcraft/bookswithoutborders/utility/BookFormatter.java

diff --git a/src/main/java/net/knarcraft/bookswithoutborders/utility/BookFormatter.java b/src/main/java/net/knarcraft/bookswithoutborders/utility/BookFormatter.java
new file mode 100644
index 0000000..50f0f9b
--- /dev/null
+++ b/src/main/java/net/knarcraft/bookswithoutborders/utility/BookFormatter.java
@@ -0,0 +1,92 @@
+package net.knarcraft.bookswithoutborders.utility;
+
+import java.util.List;
+
+/**
+ * A class for formatting text to fit books
+ *
+ * <p>The book formatter</p>
+ */
+public class BookFormatter {
+
+    /**
+     * Formats the last page of a set of pages
+     *
+     * <p>If the last page is non-empty and has space, a newline is added. If the last two pages' contents can fit on
+     * the same page, they will be combined.</p>
+     *
+     * @param rawPages <p>A list of pages</p>
+     */
+    public static void formatLastPage(List<String> rawPages) {
+        int maxPageText = 256;
+        int fitsNewline = maxPageText - 2;
+
+        //Adds newline if the contents of the last page does not exceed page limit and is non-empty
+        formatLastPageAddNewline(rawPages, fitsNewline);
+
+        //Combines the two last pages if they can fit on one page
+        if (rawPages.size() > 1) {
+            formatLastPageCombinePages(rawPages, maxPageText);
+        }
+
+        //Splits the last page if it is too long
+        if (rawPages.get(rawPages.size() - 1).length() > maxPageText) {
+            formatLastPageSplitOverflow(rawPages, maxPageText, fitsNewline);
+        }
+    }
+
+    /**
+     * Splits the last page if it overflows
+     * @param rawPages <p>The raw pages to format</p>
+     * @param maxPageText <p>The max number of characters which fit on a page</p>
+     * @param fitsNewline <p>The max number of characters on a page which still fits a newline character</p>
+     */
+    public static void formatLastPageSplitOverflow(List<String> rawPages, int maxPageText, int fitsNewline) {
+        while (rawPages.get(rawPages.size() - 1).length() > maxPageText) {
+            int splitPosition;
+            String fittingText = rawPages.get(rawPages.size() - 1).substring(0, maxPageText);
+            int lastSpaceBeforePageBreak = fittingText.lastIndexOf(" ");
+
+            if (lastSpaceBeforePageBreak > -1) {
+                //Split at space if it exists
+                rawPages.add(rawPages.get(rawPages.size() - 1).substring(lastSpaceBeforePageBreak + 1));
+                splitPosition = lastSpaceBeforePageBreak;
+            } else {
+                //Split at text limit
+                rawPages.add(rawPages.get(rawPages.size() - 1).substring(maxPageText));
+                splitPosition = maxPageText;
+            }
+            //Adds newline if the contents of the last page does not exceed page limit and is non-empty
+            formatLastPageAddNewline(rawPages, fitsNewline);
+            //Removes excess page content
+            rawPages.set(rawPages.size() - 2, rawPages.get(rawPages.size() - 2).substring(0, splitPosition));
+        }
+    }
+
+    /**
+     * Combines the two last pages if they can fit on the same page
+     * @param rawPages <p>The raw pages to format</p>
+     * @param maxPageText <p>The max number of characters which fit on a page</p>
+     */
+    public static void formatLastPageCombinePages(List<String> rawPages, int maxPageText) {
+        int lastPageIndex = rawPages.size() - 1;
+        int nextToLastIndex = rawPages.size() - 2;
+        if (rawPages.get(nextToLastIndex).length() + rawPages.get(lastPageIndex).length() <= maxPageText) {
+            rawPages.set(nextToLastIndex, (rawPages.get(nextToLastIndex)) + (rawPages.get(lastPageIndex)));
+            rawPages.remove(lastPageIndex);
+        }
+    }
+
+    /**
+     * Adds newline if the contents of the last page does not exceed page limit and is non-empty
+     * @param rawPages <p>The raw pages to format</p>
+     * @param fitsNewline <p>The max number of characters on a page which still fits a newline character</p>
+     */
+    public static void formatLastPageAddNewline(List<String> rawPages, int fitsNewline) {
+        int pageIndex = rawPages.size() - 1;
+        if (rawPages.get(pageIndex).length() <= fitsNewline && !rawPages.get(pageIndex).isEmpty()) {
+            rawPages.set(pageIndex, (rawPages.get(pageIndex)) + "\n");
+        }
+    }
+
+}