From d711f33721255e02222899748b126ae100bd0ef8 Mon Sep 17 00:00:00 2001
From: Pol Henarejos <pol.henarejos@cttc.es>
Date: Sun, 31 May 2026 18:54:22 +0200
Subject: [PATCH] Add signals

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>
---
 src/main.c     | 43 +++++++++++++++++++++++++++++++++++++++++++
 src/picokeys.h | 29 +++++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/src/main.c b/src/main.c
index fe7b339..477f662 100644
--- a/src/main.c
+++ b/src/main.c
@@ -50,6 +50,9 @@ app_t *current_app = NULL;
 
 const uint8_t *ccid_atr = NULL;
 
+signal_t signals[MAX_SIGNALS] = {0};
+uint8_t num_signals = 0;
+
 bool app_exists(const uint8_t *aid, size_t aid_len) {
     for (int a = 0; a < num_apps; a++) {
         if (aid_len >= apps[a].aid[0] && !memcmp(apps[a].aid + 1, aid, apps[a].aid[0])) {
@@ -215,3 +218,43 @@ int main(void) {
 
     return 0;
 }
+
+int signal_add(signal_code_t code, signal_flag_t flags, signal_handler_t handler) {
+    if (num_signals >= MAX_SIGNALS) {
+        return -1;
+    }
+    signals[num_signals].code = code;
+    signals[num_signals].flags = flags;
+    signals[num_signals].handler = handler;
+    num_signals++;
+    return 0;
+}
+
+int signal_remove(signal_code_t code, signal_handler_t handler) {
+    for (int i = 0; i < num_signals; i++) {
+        if (signals[i].code == code && signals[i].handler == handler) {
+            for (int j = i; j < num_signals - 1; j++) {
+                signals[j] = signals[j + 1];
+            }
+            num_signals--;
+            return 0;
+        }
+    }
+    return -1;
+}
+
+int signal_emit_param(signal_code_t code, void *data) {
+    for (int i = 0; i < num_signals; i++) {
+        if (signals[i].code == code) {
+            int ret = signals[i].handler(code, data);
+            if (ret != 0 && (signals[i].flags & SIGNAL_FLAG_ERROR_CONTINUE) == 0) {
+                return ret;
+            }
+        }
+    }
+    return 0;
+}
+
+int signal_emit(signal_code_t code) {
+    return signal_emit_param(code, NULL);
+}
diff --git a/src/picokeys.h b/src/picokeys.h
index e160c61..782ae1e 100644
--- a/src/picokeys.h
+++ b/src/picokeys.h
@@ -172,4 +172,33 @@ extern bool is_req_button_pending(void);
 
 extern int set_atr(void);
 
+
+#define MAX_SIGNALS 32
+typedef enum {
+    SIGNAL_NONE = 0,
+    SIGNAL_BOOT = 1,
+    SIGNAL_USB_MOUNTED = 2,
+    SIGNAL_BUTTON_PRESS = 3,
+    SIGNAL_BUTTON_RELEASE = 4,
+    SIGNAL_USER_PRESENCE_REQUEST = 5,
+} signal_code_t;
+
+typedef enum {
+    SIGNAL_FLAG_NONE = 0x0,
+    SIGNAL_FLAG_ERROR_CONTINUE = 0x1,
+} signal_flag_t;
+
+typedef int (*signal_handler_t)(signal_code_t, void *);
+
+typedef struct {
+    signal_code_t code;
+    signal_flag_t flags;
+    signal_handler_t handler;
+} signal_t;
+
+extern int signal_add(signal_code_t code, signal_flag_t flags, signal_handler_t handler);
+extern int signal_remove(signal_code_t code, signal_handler_t handler);
+extern int signal_emit_param(signal_code_t code, void *data);
+extern int signal_emit(signal_code_t code);
+
 #endif