From 446fa704ccc4c82eaa36b7d611c7255b9d316fbb Mon Sep 17 00:00:00 2001
From: Wesley Irvin <wesley@wesirvin.com>
Date: Sat, 10 Feb 2024 13:59:43 -0500
Subject: [PATCH] Log File

Added in the ability to write logs to a log file as well. For now the
logs write to ./quantum.log. All new log entries append onto the end of
the log. Also added timestamps in front of all log entries that are
generated when the log entry is made.
---
 quantum/src/logger/logger.c | 35 ++++++++++++++++++++++++++++++-----
 1 file changed, 30 insertions(+), 5 deletions(-)

diff --git a/quantum/src/logger/logger.c b/quantum/src/logger/logger.c
index 8514868..52400b6 100644
--- a/quantum/src/logger/logger.c
+++ b/quantum/src/logger/logger.c
@@ -4,6 +4,7 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
+#include <time.h>
 
 typedef enum level_color {
   COLOR_FATAL,
@@ -20,16 +21,37 @@ void send_to_console(const char *message, level_color color) {
 }
 
 void send_to_error_log(const char *message) {
-  // TODO: Add in file handling here so that we can write the log messages
-  // to file as well instead of just to console
+  // First we need to open up our log file to append to it
+  FILE *log_file = fopen("./quantum.log", "a");
 
-  printf("send_to_error_log() called...\n");
+  // Lets make sure we actually opened the file, and if not we return
+  if (log_file == NULL) {
+    send_to_console("[ERROR]: Could not open log file.", COLOR_ERROR);
+    return;
+  }
+
+  // Now we just need to write our message to the file
+  int chars_written = fprintf(log_file, "%s\n", message);
+
+  // fprintf returns a negative number on an error so let's check for that and
+  // display an error message
+  if (chars_written < 0) {
+    send_to_console("[ERROR]: Could not write to log file.", COLOR_ERROR);
+  }
+
+  // Now we need to make sure we close the file so that we do not leak
+  fclose(log_file);
 }
 
 void log_output(log_level level, const char *message, ...) {
   const char *level_strings[] = {
       "[FATAL]: ", "[ERROR]: ", "[WARN]: ", "[INFO]: ", "[DEBUG]: "};
 
+  // We are going to want to put a timestamp on our logs so lets get the current
+  // time and convert it into localtime
+  time_t cur_time = time(NULL);
+  struct tm local_time = *localtime(&cur_time);
+
   // We are going to impose a 32K char limit on a single log entry
   // we will hold this in format_message as a place to collect all
   // the variadic arguments and process them together. We make sure
@@ -45,9 +67,12 @@ void log_output(log_level level, const char *message, ...) {
   vsnprintf(format_message, msg_length, message, arg_ptr);
   va_end(arg_ptr);
 
-  // Now we prepend the message with our message level
+  // Now we prepend the message with a timestamp and our message level
   char log_message[msg_length];
-  sprintf(log_message, "%s%s", level_strings[level], format_message);
+  sprintf(log_message, "[%02d-%02d-%d %02d:%02d:%02d]%s%s",
+          local_time.tm_mon + 1, local_time.tm_mday, local_time.tm_year + 1900,
+          local_time.tm_hour, local_time.tm_min, local_time.tm_sec,
+          level_strings[level], format_message);
 
   // Now we call the appropriate function depending on the level
   if (level <= 1) {