1 files changed, 47 insertions, 0 deletions
diff --git a/src/log.c b/src/log.c
new file mode 100644
index 0000000..b3ebc49
--- /dev/null
+++ b/src/log.c
@@ -0,0 +1,47 @@
+#include "../include/log.h"
+
+#include <stdio.h>
+#include <stdarg.h>
+
+#define GSR_LOG_MESSAGE_MAX_SIZE 4096
+
+static const char* log_level_to_string(gsr_log_level level) {
+    switch(level) {
+        case GSR_LOG_LEVEL_DEBUG:   return "debug";
+        case GSR_LOG_LEVEL_INFO:    return "info";
+        case GSR_LOG_LEVEL_WARNING: return "warning";
+        case GSR_LOG_LEVEL_ERROR:   return "error";
+    }
+    return "unknown";
+}
+
+static void gsr_log_default_handler(gsr_log_level level, const char *message, void *userdata) {
+    (void)userdata;
+    fprintf(stderr, "gsr %s: %s\n", log_level_to_string(level), message);
+}
+
+static gsr_log_level log_level = GSR_LOG_LEVEL_INFO;
+static gsr_log_handler log_handler = gsr_log_default_handler;
+static void *log_handler_userdata = NULL;
+
+void gsr_log(gsr_log_level level, const char *fmt, ...) {
+    if(level < log_level)
+        return;
+
+    char message[GSR_LOG_MESSAGE_MAX_SIZE];
+    va_list args;
+    va_start(args, fmt);
+    vsnprintf(message, sizeof(message), fmt, args);
+    va_end(args);
+
+    log_handler(level, message, log_handler_userdata);
+}
+
+void gsr_log_set_level(gsr_log_level level) {
+    log_level = level;
+}
+
+void gsr_log_set_handler(gsr_log_handler handler, void *userdata) {
+    log_handler = handler ? handler : gsr_log_default_handler;
+    log_handler_userdata = userdata;
+}