From 67447e4e5e4f3470a33e9cfc1ddc2e5b2c908f8c Mon Sep 17 00:00:00 2001
From: Alex P <dtk077@gmail.com>
Date: Thu, 2 Oct 2025 00:08:42 +0300
Subject: [PATCH] [WIP] Updates: reduce PR complexity

---
 internal/audio/c/audio_common.c | 81 +++++++++++++++++++++++++++++++++
 internal/audio/c/audio_common.h | 57 +++++++++++++++++++++++
 2 files changed, 138 insertions(+)
 create mode 100644 internal/audio/c/audio_common.c
 create mode 100644 internal/audio/c/audio_common.h

diff --git a/internal/audio/c/audio_common.c b/internal/audio/c/audio_common.c
new file mode 100644
index 00000000..0b7b14ec
--- /dev/null
+++ b/internal/audio/c/audio_common.c
@@ -0,0 +1,81 @@
+/*
+ * JetKVM Audio Common Utilities
+ *
+ * Shared functions used by both audio input and output servers
+ */
+
+#include "audio_common.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+
+// ============================================================================
+// GLOBAL STATE FOR SIGNAL HANDLER
+// ============================================================================
+
+// Pointer to the running flag that will be set to 0 on shutdown
+static volatile sig_atomic_t *g_running_ptr = NULL;
+
+// ============================================================================
+// SIGNAL HANDLERS
+// ============================================================================
+
+static void signal_handler(int signo) {
+    if (signo == SIGTERM || signo == SIGINT) {
+        printf("Audio server: Received signal %d, shutting down...\n", signo);
+        if (g_running_ptr != NULL) {
+            *g_running_ptr = 0;
+        }
+    }
+}
+
+void audio_common_setup_signal_handlers(volatile sig_atomic_t *running) {
+    g_running_ptr = running;
+
+    struct sigaction sa;
+    memset(&sa, 0, sizeof(sa));
+    sa.sa_handler = signal_handler;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = 0;
+
+    sigaction(SIGTERM, &sa, NULL);
+    sigaction(SIGINT, &sa, NULL);
+
+    // Ignore SIGPIPE (write to closed socket should return error, not crash)
+    signal(SIGPIPE, SIG_IGN);
+}
+
+// ============================================================================
+// CONFIGURATION PARSING
+// ============================================================================
+
+int audio_common_parse_env_int(const char *name, int default_value) {
+    const char *str = getenv(name);
+    if (str == NULL || str[0] == '\0') {
+        return default_value;
+    }
+    return atoi(str);
+}
+
+const char* audio_common_parse_env_string(const char *name, const char *default_value) {
+    const char *str = getenv(name);
+    if (str == NULL || str[0] == '\0') {
+        return default_value;
+    }
+    return str;
+}
+
+int audio_common_is_trace_enabled(void) {
+    const char *pion_trace = getenv("PION_LOG_TRACE");
+    if (pion_trace == NULL) {
+        return 0;
+    }
+
+    // Check if "audio" is in comma-separated list
+    if (strstr(pion_trace, "audio") != NULL) {
+        return 1;
+    }
+
+    return 0;
+}
diff --git a/internal/audio/c/audio_common.h b/internal/audio/c/audio_common.h
new file mode 100644
index 00000000..ae8b9a10
--- /dev/null
+++ b/internal/audio/c/audio_common.h
@@ -0,0 +1,57 @@
+/*
+ * JetKVM Audio Common Utilities
+ *
+ * Shared functions used by both audio input and output servers
+ */
+
+#ifndef JETKVM_AUDIO_COMMON_H
+#define JETKVM_AUDIO_COMMON_H
+
+#include <signal.h>
+
+// ============================================================================
+// SIGNAL HANDLERS
+// ============================================================================
+
+/**
+ * Setup signal handlers for graceful shutdown.
+ * Handles SIGTERM and SIGINT by setting the running flag to 0.
+ * Ignores SIGPIPE to prevent crashes on broken pipe writes.
+ *
+ * @param running Pointer to the volatile running flag to set on shutdown
+ */
+void audio_common_setup_signal_handlers(volatile sig_atomic_t *running);
+
+// ============================================================================
+// CONFIGURATION PARSING
+// ============================================================================
+
+/**
+ * Parse integer from environment variable.
+ * Returns default_value if variable is not set or empty.
+ *
+ * @param name Environment variable name
+ * @param default_value Default value if not set
+ * @return Parsed integer value or default
+ */
+int audio_common_parse_env_int(const char *name, int default_value);
+
+/**
+ * Parse string from environment variable.
+ * Returns default_value if variable is not set or empty.
+ *
+ * @param name Environment variable name
+ * @param default_value Default value if not set
+ * @return Environment variable value or default (not duplicated)
+ */
+const char* audio_common_parse_env_string(const char *name, const char *default_value);
+
+/**
+ * Check if trace logging is enabled for audio subsystem.
+ * Looks for "audio" in PION_LOG_TRACE comma-separated list.
+ *
+ * @return 1 if enabled, 0 otherwise
+ */
+int audio_common_is_trace_enabled(void);
+
+#endif // JETKVM_AUDIO_COMMON_H