From 9e9c1b21569faeabd33716e4153a881e2eed7134 Mon Sep 17 00:00:00 2001
From: Filip Wandzio <contact@philw.dev>
Date: Sun, 1 Mar 2026 17:45:00 +0100
Subject: Separate quiz logic from main function fo dedicated module

Signed-off-by: Filip Wandzio <contact@philw.dev>
---
 src/utils.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 104 insertions(+), 21 deletions(-)

(limited to 'src/utils.c')

diff --git a/src/utils.c b/src/utils.c
index c139929..2e26e8e 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -1,34 +1,117 @@
 #include "utils.h"
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 
-void print_line(void) {
-  printf("--------------------------------------------------\n");
+#define SEPARATOR_CHAR '-'
+#define SEPARATOR_WIDTH 50
+#define NEWLINE_CHAR '\n'
+#define INPUT_BUFFER_SIZE 16
+#define TIME_FORMAT_STRING "%Y-%m-%d %H:%M:%S"
+#define ASK_YES_NO_PROMPT "Please enter 'y' or 'n': "
+
+/** Clear leftover input from stdin */
+static void flush_stdin(void)
+{
+	int input_char;
+	do
+		input_char = getchar();
+	while (input_char != NEWLINE_CHAR && input_char != EOF);
+}
+
+/** Print a horizontal separator line for the quiz UI */
+static void print_separator_line(void)
+{
+	for (size_t current_column = 0; current_column < SEPARATOR_WIDTH;
+	     ++current_column)
+		putchar(SEPARATOR_CHAR);
+
+	putchar(NEWLINE_CHAR);
 }
 
-void wait_enter(const char *msg) {
-  if (msg)
-    printf("%s", msg);
-  int c;
-  while ((c = getchar()) != '\n' && c != EOF)
-    ;
+/** Print a horizontal separator line */
+void print_line(void)
+{
+	print_separator_line();
 }
 
-char ask_yes_no(const char *msg) {
-  char c = 'n';
-  printf("%s", msg);
-  if (scanf(" %c", &c) != 1)
-    c = 'n';
-  int flush;
-  while ((flush = getchar()) != '\n' && flush != EOF)
-    ;
-  return c;
+/**
+ * Pause until the user presses ENTER
+ *
+ * @param prompt Optional message to display before waiting
+ */
+void wait_for_enter(const char* prompt)
+{
+	if (prompt != NULL)
+		fputs(prompt, stdout);
+
+	flush_stdin();
+}
+
+/**
+ * Ask a yes/no question and return a boolean answer
+ *
+ * @param prompt Question message to display
+ * @return true if user answered 'y' or 'Y', false if 'n', default false
+ */
+bool ask_yes_no(const char* prompt)
+{
+	char input_line[INPUT_BUFFER_SIZE];
+
+	while (1) {
+		if (prompt != NULL)
+			fputs(prompt, stdout);
+
+		if (fgets(input_line, sizeof(input_line), stdin) == NULL)
+			return false;
+
+		const char first_char = input_line[0];
+
+		if (first_char == 'y' || first_char == 'Y')
+			return true;
+
+		if (first_char == 'n' || first_char == 'N')
+			return false;
+
+		fputs(ASK_YES_NO_PROMPT, stdout);
+	}
 }
 
-void now_str(char *buf, size_t size) {
-  time_t t = time(NULL);
-  strftime(buf, size, "%Y-%m-%d %H:%M:%S", localtime(&t));
+/**
+ * Get the current timestamp for recording when a question was answered
+ *
+ * @param answer_time_buffer Buffer to store the formatted timestamp
+ * @param buffer_capacity Size of the buffer in bytes
+ */
+void get_answer_timestamp(char* answer_time_buffer,
+			  const size_t buffer_capacity)
+{
+	if (answer_time_buffer == NULL || buffer_capacity == 0)
+		return;
+
+	const time_t current_time = time(NULL);
+	const struct tm* local_time = localtime(&current_time);
+	if (local_time != NULL)
+		strftime(answer_time_buffer,
+			 buffer_capacity,
+			 TIME_FORMAT_STRING,
+			 local_time);
 }
 
-size_t rand_index(size_t max) { return max ? (size_t)(rand() % max) : 0; }
+/**
+ * Get a random question index in the quiz (thread-safe)
+ *
+ * @param seed Pointer to an unsigned int seed (per-thread)
+ * @param total_questions Number of questions in the current quiz session
+ * @return Random index in the range [0, total_questions-1]
+ */
+size_t get_random_question_index(unsigned int* seed,
+				 const size_t total_questions)
+{
+	if (total_questions == 0 || seed == NULL)
+		return 0;
+
+	const unsigned long random_value = (unsigned long)rand_r(seed);
+	return random_value % total_questions;
+}
-- 
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