refactor roman to arabic algorithm, update few options, able to work with program

2 files changed, 79 insertions, 22 deletions

diff --git a/snc.c b/snc.c
index 58aea38..3585141 100644
--- a/snc.c
+++ b/snc.c
@@ -26,7 +26,12 @@
 
 void usage()
 {
-	printf("Simple numbers converter\n"
+	printf("SNC (Simple numbers converter)\n"
+			"Copyright (C) 2021 Aleksandr D. Goncharov\n"
+			"SNC is free software; you can redistribute it and/or modify\n"
+			"it under the terms of the GNU General Public License as\n"
+			"published by the Free SoftwareFoundation; either version\n"
+			"2 of the License, or (at your option) any later version.\n"
 			"\n"
 			"Synopsis: snc [OPTION] ... [NUMBER]\n"
 			"Option:\n"
@@ -37,14 +42,15 @@ void usage()
 			"\t-o, --output\n"
 			"\t\t****\n"
 			"\t-a, --alphabet\n"
-			"\t\t****\n"
+			"\t\tOutput numeral system. Arabic is used by default\n"
 			"\t-A, --list-alphabets\n"
-			"\t\t****\n");
+			"\t\tPrint valid alphabets\n");
 }
 
 int getRomanValue(char symbol)
 {
-	switch(symbol) {
+	switch(symbol)
+	{
 		case 'I': return SNC_ROMAN_I; // have triple notation
 		case 'V': return SNC_ROMAN_V;
 		case 'X': return SNC_ROMAN_X; // have triple notation
@@ -52,8 +58,8 @@ int getRomanValue(char symbol)
 		case 'C': return SNC_ROMAN_C; // have triple notation
 		case 'D': return SNC_ROMAN_D;
 		case 'M': return SNC_ROMAN_M; // have triple notation
+		default: return 0;
 	}
-	return 0;
 }
 
 int romanToArabic(char *str)
@@ -66,8 +72,16 @@ int romanToArabic(char *str)
 		int cur_value = getRomanValue(*str);
 		if(cur_value == 0)
 			return -1;
-		else if(last_value == cur_value || last_value == 0) {
+
+		if(last_value == cur_value || last_value == 0) {
+			if(amount_char >= 3)
+				return -1;
 			answer += cur_value;
+			if(cur_value == SNC_ROMAN_V || cur_value == SNC_ROMAN_L
+					|| cur_value == SNC_ROMAN_D) {
+				if(amount_char > 1) return -1;
+			}
+
 			amount_char++;
 		}
 		else if(last_value > cur_value) {
@@ -75,26 +89,19 @@ int romanToArabic(char *str)
 			amount_char = 1;
 		}
 		else if(last_value < cur_value) {
+			if(amount_char > 1)
+				return -1;
 			if(last_value * 10 < cur_value)
 				return -1;
-			else if(last_value == SNC_ROMAN_V ||
-					last_value == SNC_ROMAN_L || last_value == SNC_ROMAN_D)
+			if(last_value == SNC_ROMAN_V || last_value == SNC_ROMAN_L
+					|| last_value == SNC_ROMAN_D)
 				return -1;
-			
+
 			answer += cur_value - 2 * last_value;
-			if(amount_char > 1)
-				return -1;
 			amount_char = 1;
 		}
 		last_value = cur_value;
 
-		if(amount_char > 3)
-			return -1;
-		else if(cur_value == SNC_ROMAN_V ||
-				cur_value == SNC_ROMAN_L || cur_value == SNC_ROMAN_D) {
-			if(amount_char > 1) return -1;
-		}
-
 		str++;
 	}
 
@@ -138,10 +145,15 @@ int main(int argc, char *argv[])
 		{"input", required_argument, NULL, 'i'},
 		{"output", required_argument, NULL, 'o'},
 		{"alphabet", required_argument, NULL, 'a'},
-		{"list-alphabets", required_argument, NULL, 'A'},
+		{"list-alphabets", no_argument, NULL, 'A'},
 		{NULL, 0, NULL, 0}
 	};
 
+	int convert_from;
+	int convert_to = SNC_ARABIC;
+	//int input_base = 10;
+	//int output_base = 10;
+
 	while((result = getopt_long(argc, argv, short_options,
 		long_options, NULL)) != -1) {
 		switch(result) {
@@ -156,14 +168,57 @@ int main(int argc, char *argv[])
 			break;
 		}
 		case 'a': {
-			break;
+			if(strcmp(optarg, "roman") == 0) {
+				convert_to = SNC_ROMAN;
+				break;
+			}
+			else if(strcmp(optarg, "arabic") == 0) {
+				convert_to = SNC_ARABIC;
+				break;
+			}
+			// else print all available alphabets
 		}
 		case 'A': {
-			break;
+			printf("Valid alphabets are: roman, arabic\n");
+			return 0;
 		}
 		default: break;
 		}
 	}
 
+	char *str_number = argv[optind];
+	if(!str_number) {
+		usage();
+		return 1;
+	}
+
+	if(atoi(argv[optind]) == 0)
+		convert_from = SNC_ROMAN;
+	else
+		convert_from = SNC_ARABIC;
+
+	if(convert_to != convert_from) {
+		if(convert_to == SNC_ROMAN) {
+			char *answer = arabicToRoman(str_number);
+			if(!answer) {
+				printf("%s is not correct arabic number.\n", str_number);
+				return 1;
+			}
+			printf("%s\n", answer);
+			free(answer);
+		}
+		else {
+			int answer = romanToArabic(str_number);
+			if(answer == -1) {
+				printf("%s is not correct roman number.\n", str_number);
+				return 1;
+			}
+			printf("%d\n", answer);
+		}
+	}
+	else {
+		printf("%s\n", str_number);
+	}
+
 	return 0;
-}
\ No newline at end of file
+}
diff --git a/snc.h b/snc.h
index 9b02b51..c7bd7c3 100644
--- a/snc.h
+++ b/snc.h
@@ -21,6 +21,8 @@
 ***/
 
 enum {
+	SNC_ARABIC,
+	SNC_ROMAN,
 	SNC_ROMAN_I = 1,
 	SNC_ROMAN_V = 5,
 	SNC_ROMAN_X = 10,