1 files changed, 203 insertions, 0 deletions

diff --git a/src/quiz.c b/src/quiz.c
new file mode 100644
index 0000000..7bc31b2
--- /dev/null
+++ b/src/quiz.c
@@ -0,0 +1,203 @@
+#include "../include/quiz.h"
+#include "../include/utils.h"
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+
+#define INPUT_BUFFER_SIZE 64
+#define QUIZ_DATA_DIRECTORY "data"
+#define QUESTIONS_FILE_NAME "questions.txt"
+#define RESULTS_FILE_NAME "results.csv"
+#define CSV_TIMESTAMP_BUFFER 32
+#define FILE_PATH_BUFFER 256
+#define PERMISSIONS_DATA_DIRECTORY 0755
+#define TIME_UNLIMITED 0
+#define BASE_VALUE 10
+
+static const char* START_PROMPT = "Press ENTER to start...";
+static const char* DONE_PROMPT = "Press ENTER when done...";
+static const char* TIME_LIMIT_PROMPT = "Time limit (sec, 0 = unlimited): ";
+static const char* CORRECT_PROMPT = "Correct? (y/n): ";
+static const char* NEXT_QUESTION_PROMPT = "Next? (y/n): ";
+static const char* TIME_EXCEEDED_MESSAGE = "Time exceeded!\n";
+static const char* CSV_OPEN_ERROR_MESSAGE = "CSV open";
+static const char* QUESTIONS_LOAD_ERROR = "Error: cannot load questions file\n";
+static const char* DATA_DIR_ERROR = "Error: cannot create data directory\n";
+
+static bool ensure_data_directory_exists(void)
+{
+        struct stat st = {0};
+        if (stat(QUIZ_DATA_DIRECTORY, &st) == -1) {
+#ifdef _WIN32
+                return _mkdir(QUIZ_DATA_DIRECTORY) == 0;
+#else
+                return mkdir(QUIZ_DATA_DIRECTORY, PERMISSIONS_DATA_DIRECTORY)
+                       == 0;
+#endif
+        }
+        return true;
+}
+
+static int read_time_limit(void)
+{
+        char buffer[INPUT_BUFFER_SIZE];
+        printf("%s", TIME_LIMIT_PROMPT);
+
+        if (!fgets(buffer, sizeof buffer, stdin))
+                return TIME_UNLIMITED;
+
+        errno = 0;
+        char* end = NULL;
+        long value = strtol(buffer, &end, BASE_VALUE);
+
+        if (errno == ERANGE || end == buffer)
+                return TIME_UNLIMITED;
+        if (value < 0)
+                value = 0;
+        if (value > INT_MAX)
+                value = INT_MAX;
+
+        return (int)value;
+}
+
+static void write_csv_result(FILE* csv,
+                             const char* timestamp,
+                             const char* general_q,
+                             const char* major_q,
+                             const bool correct_answer,
+                             const double duration)
+{
+        static const char* CSV_FORMAT = "\"%s\",\"%s\",\"%s\",%c,%.0f\n";
+        fprintf(csv,
+                CSV_FORMAT,
+                timestamp,
+                general_q,
+                major_q,
+                correct_answer ? 'y' : 'n',
+                duration);
+}
+
+void print_score(const size_t correct, size_t total)
+{
+        double percentage = 0.0;
+        if (total != 0)
+                percentage = (double)correct / total * PERCENT_MULTIPLIER;
+
+        printf(SCORE_FORMAT, correct, total, percentage);
+}
+
+void print_final_score(const QuizSession* session)
+{
+        double final_percentage = 0.0;
+        if (session->total_answered > 0)
+                final_percentage = (double)session->total_correct
+                                   / session->total_answered
+                                   * PERCENT_MULTIPLIER;
+
+        printf("\nSession score: %.1f%%\n", final_percentage);
+}
+
+// ------------------------
+// Initialization & Cleanup
+// ------------------------
+bool initialize_quiz_session(QuizSession* session)
+{
+        session->seed = (unsigned int)time(NULL);
+        srand(session->seed);
+
+        if (!ensure_data_directory_exists()) {
+                fprintf(stderr, "%s", DATA_DIR_ERROR);
+                return false;
+        }
+
+        char questions_path[FILE_PATH_BUFFER];
+        snprintf(questions_path,
+                 sizeof questions_path,
+                 "%s/%s",
+                 QUIZ_DATA_DIRECTORY,
+                 QUESTIONS_FILE_NAME);
+
+        char results_path[FILE_PATH_BUFFER];
+        snprintf(results_path,
+                 sizeof results_path,
+                 "%s/%s",
+                 QUIZ_DATA_DIRECTORY,
+                 RESULTS_FILE_NAME);
+
+        if (load_questions(questions_path, &session->questions)
+            != EXIT_SUCCESS) {
+                fprintf(stderr, "%s", QUESTIONS_LOAD_ERROR);
+                return false;
+        }
+
+        session->csv = fopen(results_path, "a");
+        if (!session->csv) {
+                perror(CSV_OPEN_ERROR_MESSAGE);
+                free_questions(&session->questions);
+                return false;
+        }
+
+        session->total_answered = 0;
+        session->total_correct = 0;
+        session->time_limit = read_time_limit();
+
+        return true;
+}
+
+void cleanup_session(QuizSession* session)
+{
+        fclose(session->csv);
+        free_questions(&session->questions);
+}
+
+// ------------------------
+// Single Quiz Iteration
+// ------------------------
+bool quiz_iteration(QuizSession* session)
+{
+        const size_t general_index = get_random_question_index(
+            &session->seed, session->questions.general_count);
+        const size_t major_index = get_random_question_index(
+            &session->seed, session->questions.major_count);
+
+        const char* general_question =
+            session->questions.general[general_index];
+        const char* major_question = session->questions.major[major_index];
+
+        print_line();
+        printf(
+            "GENERAL:\n%s\n\nMAJOR:\n%s\n", general_question, major_question);
+        print_line();
+
+        wait_for_enter(START_PROMPT);
+        const time_t start_time = time(NULL);
+
+        wait_for_enter(DONE_PROMPT);
+        const double duration_seconds = difftime(time(NULL), start_time);
+
+        if (session->time_limit > 0 && duration_seconds > session->time_limit)
+                printf("%s", TIME_EXCEEDED_MESSAGE);
+
+        const bool correct = ask_yes_no(CORRECT_PROMPT);
+        if (correct)
+                session->total_correct++;
+        session->total_answered++;
+
+        char timestamp[CSV_TIMESTAMP_BUFFER];
+        get_answer_timestamp(timestamp, sizeof timestamp);
+
+        write_csv_result(session->csv,
+                         timestamp,
+                         general_question,
+                         major_question,
+                         correct,
+                         duration_seconds);
+
+        print_score(session->total_correct, session->total_answered);
+
+        return ask_yes_no(NEXT_QUESTION_PROMPT);
+}