From 1cb17733c6435e2bf773f244dbe7bf433c4120df Mon Sep 17 00:00:00 2001
From: "Veronica K. B. Olsen" <1619840+vkbo@users.noreply.github.com>
Date: Sun, 5 Jul 2020 16:55:31 +0200
Subject: [PATCH] Adding a numberToRoman function for converting integers to
 Roman number strings

---
 nw/core/__init__.py |  8 +++-----
 nw/core/tools.py    | 33 +++++++++++++++++++++++++++++----
 2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/nw/core/__init__.py b/nw/core/__init__.py
index 0107dac2..91616302 100644
--- a/nw/core/__init__.py
+++ b/nw/core/__init__.py
@@ -3,13 +3,10 @@
 from nw.core.document import NWDoc
 from nw.core.index import NWIndex
 from nw.core.project import NWProject
-from nw.core.spellcheck import NWSpellCheck
-from nw.core.spellcheck import NWSpellEnchant
-from nw.core.spellcheck import NWSpellSimple
+from nw.core.spellcheck import NWSpellCheck, NWSpellEnchant, NWSpellSimple
 from nw.core.tokenizer import Tokenizer
 from nw.core.tohtml import ToHtml
-from nw.core.tools import countWords
-from nw.core.tools import numberToWord
+from nw.core.tools import countWords, numberToRoman, numberToWord
 
 __all__ = [
     "NWDoc",
@@ -21,5 +18,6 @@ __all__ = [
     "Tokenizer",
     "ToHtml",
     "countWords",
+    "numberToRoman",
     "numberToWord",
 ]
diff --git a/nw/core/tools.py b/nw/core/tools.py
index 5c352fe7..c4455ff1 100644
--- a/nw/core/tools.py
+++ b/nw/core/tools.py
@@ -34,9 +34,9 @@ from os import path, unlink, rmdir
 
 logger = logging.getLogger(__name__)
 
-# =========================================================================== #
+# =============================================================================================== #
 #  Simple Word Counter
-# =========================================================================== #
+# =============================================================================================== #
 
 def countWords(theText):
     """Count words in a piece of text, skipping special syntax and
@@ -84,9 +84,34 @@ def countWords(theText):
 
     return charCount, wordCount, paraCount
 
-# =========================================================================== #
+# =============================================================================================== #
+#  Convert an Integer to a Roman Number
+# =============================================================================================== #
+
+def numberToRoman(numVal, isLower=False):
+    """Convert an integer to a roman number.
+    """
+    if numVal < 1 or numVal > 4999:
+        return "NAN"
+
+    theValues  = [
+        (1000, "M"), (900, "CM"), (500, "D"), (400, "CD"), (100, "C"), (90, "XC"),
+        (50, "L"), (40, "XL"), (10, "X"), (9, "IX"), (5, "V"), (4, "IV"), (1, "I"),
+    ]
+
+    romNum = ""
+    for theDiv, theSym in theValues:
+        for _ in range(numVal//theDiv):
+            romNum += theSym
+            numVal -= theDiv
+        if numVal <= 0:
+            break
+
+    return romNum.lower if isLower else romNum
+
+# =============================================================================================== #
 #  Convert an Integer to a Word Number
-# =========================================================================== #
+# =============================================================================================== #
 
 def numberToWord(numVal, theLanguage):
     """Wrapper for converting numbers to words for chapter headings.