From ae6657a9d645df0ffbbf7ddac8535b794f98b266 Mon Sep 17 00:00:00 2001
From: Steve Brokenshire <sbrokenshire@xestia.co.uk>
Date: Sun, 17 Apr 2016 14:09:08 +0100
Subject: [PATCH] Added HexToInt function and unit tests for it.

HexToInt converts a value from a string to a integer. Pointers are used
to optimise the memory usage.
---
 source/common/text.cpp                        | 71 +++++++++++++++++++
 source/common/text.h                          |  3 +
 source/tests/xestiacalendar_commonfunctions.h | 61 ++++++++++++++++
 3 files changed, 135 insertions(+)

diff --git a/source/common/text.cpp b/source/common/text.cpp
index df64411..d223993 100644
--- a/source/common/text.cpp
+++ b/source/common/text.cpp
@@ -185,4 +185,75 @@ PropertyNameValue SplitNameValue(string InputData){
 	
 	return FinalNameValue;
 	
+}
+
+bool HexToInt(std::string *HexString, int *Number){
+	
+	// Check that each character in the string is a number
+	// or a letter (a-f/A-F).
+	
+	char Char = 0;
+	int CharNum = 0;
+	
+	for (int CharSeek = 0; 
+		CharSeek < HexString->size(); CharSeek++){
+		
+		// Check if character is a number (0-9).
+			
+		Char = HexString->at(CharSeek);
+		CharNum = Char;
+			
+		if (CharNum >= 48 &&
+			CharNum <= 57){
+		
+			continue;
+				
+		}
+		
+		// Check if character is a letter (A-F)
+		
+		if (CharNum >= 65 &&
+			CharNum <= 70){
+		
+			continue;
+				
+		}
+		
+		// Check if character is a letter (a-f).
+
+		if (CharNum >= 97 &&
+			CharNum <= 102){
+		
+			continue;
+				
+		}
+		
+		// Exit from subroutine as character is invalid.
+		
+		return false;
+		
+	}
+	
+	// Convert a Hex value that is in string to integer.
+	
+	try {
+	
+		*Number = stoi((*HexString), nullptr, 16);
+	
+	}
+	
+	catch (const std::invalid_argument &err){
+		
+		return false;
+		
+	}
+	
+	catch (const std::out_of_range &err){
+		
+		return false;
+		
+	}
+	
+	return true;
+	
 }
\ No newline at end of file
diff --git a/source/common/text.h b/source/common/text.h
index 0cc513a..f50113e 100644
--- a/source/common/text.h
+++ b/source/common/text.h
@@ -2,9 +2,11 @@
 #define __COMMON_TEXT_H__
 
 #include <string>
+#include <sstream>
 #include <vector>
 #include <map>
 #include <iostream>
+#include <stdexcept>
 
 struct PropertyNameValue{
 	std::string Name;
@@ -17,5 +19,6 @@ std::multimap<std::string, std::string> ProcessTextVectors(std::vector<std::stri
 	std::string Property);
 std::map<std::string, std::string> SplitValues(std::string InputData);
 PropertyNameValue SplitNameValue(std::string InputData);
+bool HexToInt(std::string *HexString, int *Number);
 
 #endif
\ No newline at end of file
diff --git a/source/tests/xestiacalendar_commonfunctions.h b/source/tests/xestiacalendar_commonfunctions.h
index 85ef33e..ce4fc7c 100644
--- a/source/tests/xestiacalendar_commonfunctions.h
+++ b/source/tests/xestiacalendar_commonfunctions.h
@@ -197,4 +197,65 @@ TEST(CommonFunctions, SplitNameValueTests){
 	ASSERT_EQ(PropertyName, "TEST");
 	ASSERT_EQ(PropertyValue, "OK");
 	
+}
+
+TEST(CommonFunctions, HexToInt){
+	
+	string Value1 = "10"; 		// 16
+	string Value2 = "50"; 		// 80
+	string Value3 = "4F"; 		// 79
+	string Value4 = "FF"; 		// 255
+	string Value5 = "FFF"; 		// 4095
+	string Value6 = "FFFF"; 	// 65535
+	string Value7 = "75AB"; 	// 30123
+	string Value8 = "2AC";		// 684
+	string Value9 = "!"; 		// Fail
+	string Value10 = "4BZ"; 	// Fail
+	string Value11 = "Z?!$";	// Fail
+	
+	int OutputValue = 0;
+	bool Result = false;
+	
+	Result = HexToInt(&Value1, &OutputValue);
+	
+	ASSERT_EQ(Result, true);
+	ASSERT_EQ(OutputValue, 16);
+
+	Result = HexToInt(&Value2, &OutputValue);	
+	ASSERT_EQ(Result, true);
+	ASSERT_EQ(OutputValue, 80);
+
+	Result = HexToInt(&Value3, &OutputValue);	
+	ASSERT_EQ(Result, true);
+	ASSERT_EQ(OutputValue, 79);
+	
+	Result = HexToInt(&Value4, &OutputValue);	
+	ASSERT_EQ(Result, true);
+	ASSERT_EQ(OutputValue, 255);
+	
+	Result = HexToInt(&Value5, &OutputValue);	
+	ASSERT_EQ(Result, true);
+	ASSERT_EQ(OutputValue, 4095);
+
+	Result = HexToInt(&Value6, &OutputValue);	
+	ASSERT_EQ(Result, true);
+	ASSERT_EQ(OutputValue, 65535);
+	
+	Result = HexToInt(&Value7, &OutputValue);	
+	ASSERT_EQ(Result, true);
+	ASSERT_EQ(OutputValue, 30123);
+	
+	Result = HexToInt(&Value8, &OutputValue);	
+	ASSERT_EQ(Result, true);
+	ASSERT_EQ(OutputValue, 684);
+	
+	Result = HexToInt(&Value9, &OutputValue);
+	ASSERT_EQ(Result, false);
+
+	Result = HexToInt(&Value10, &OutputValue);	
+	ASSERT_EQ(Result, false);
+	
+	Result = HexToInt(&Value11, &OutputValue);
+	ASSERT_EQ(Result, false);
+
 }
\ No newline at end of file
-- 
2.39.2