2 files changed, 107 insertions, 0 deletions
diff --git a/movement/watch_faces/complications/totp_face.c b/movement/watch_faces/complications/totp_face.c
new file mode 100644
index 00000000..4aa1382a
--- /dev/null
+++ b/movement/watch_faces/complications/totp_face.c
@@ -0,0 +1,81 @@
+/**
+ * TODO:
+ * - Add support for UTC offset in settings?
+ * - Support for multiple codes
+ */
+#include <stdlib.h>
+#include <string.h>
+#include "totp_face.h"
+#include "watch.h"
+#include "watch_utility.h"
+#include "TOTP.h"
+
+// test key: JBSWY3DPEHPK3PXP
+// Use https://cryptii.com/pipes/base32-to-hex to convert base32 to hex
+// Use https://totp.danhersam.com/ to generate test codes for verification
+static uint8_t hmacKey[] = {0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x21, 0xde, 0xad, 0xbe, 0xef}; // Secret key
+
+
+static const uint8_t UTC_OFFSET = 5; // set to your current UTC offset
+static const uint32_t TIMESTEP = 30;
+
+void totp_face_setup(movement_settings_t *settings, void ** context_ptr) {
+    (void) settings;
+    if (*context_ptr == NULL) *context_ptr = malloc(sizeof(totp_state_t));
+    TOTP(hmacKey, sizeof(hmacKey), TIMESTEP);
+}
+
+void totp_face_activate(movement_settings_t *settings, void *context) {
+    (void) settings;
+    memset(context, 0, sizeof(totp_state_t));
+    totp_state_t *totp_state = (totp_state_t *)context;
+    totp_state->timestamp = watch_utility_date_time_to_unix_time(watch_rtc_get_date_time(), UTC_OFFSET);
+    totp_state->current_code = getCodeFromTimestamp(totp_state->timestamp);
+}
+
+bool totp_face_loop(movement_event_t event, movement_settings_t *settings, void *context) {
+    (void) settings;
+
+    totp_state_t *totp_state = (totp_state_t *)context;
+    char buf[14];
+    uint8_t valid_for;
+    div_t result;
+
+    switch (event.event_type) {
+        case EVENT_TICK:
+            totp_state->timestamp++;
+            // fall through
+        case EVENT_ACTIVATE:
+            result = div(totp_state->timestamp, TIMESTEP);
+            if (result.quot != totp_state->steps) {
+                totp_state->current_code = getCodeFromTimestamp(totp_state->timestamp);
+                totp_state->steps = result.quot;
+            }
+            valid_for = TIMESTEP - result.rem;
+            sprintf(buf, "2f%2d%06lu", valid_for, totp_state->current_code);
+
+            watch_display_string(buf, 0);
+            break;
+        case EVENT_MODE_BUTTON_UP:
+            movement_move_to_next_face();
+            break;
+        case EVENT_LIGHT_BUTTON_DOWN:
+            movement_illuminate_led();
+            break;
+        case EVENT_TIMEOUT:
+            movement_move_to_face(0);
+            break;
+        case EVENT_ALARM_BUTTON_DOWN:
+        case EVENT_ALARM_BUTTON_UP:
+        case EVENT_ALARM_LONG_PRESS:
+        default:
+            break;
+    }
+
+    return true;
+}
+
+void totp_face_resign(movement_settings_t *settings, void *context) {
+    (void) settings;
+    (void) context;
+}
diff --git a/movement/watch_faces/complications/totp_face.h b/movement/watch_faces/complications/totp_face.h
new file mode 100644
index 00000000..0527627a
--- /dev/null
+++ b/movement/watch_faces/complications/totp_face.h
@@ -0,0 +1,26 @@
+#ifndef TOTP_FACE_H_
+#define TOTP_FACE_H_
+
+#include "movement.h"
+
+typedef struct {
+    uint32_t timestamp;
+    uint8_t steps;
+    uint32_t current_code;
+
+} totp_state_t;
+
+void totp_face_setup(movement_settings_t *settings, void ** context_ptr);
+void totp_face_activate(movement_settings_t *settings, void *context);
+bool totp_face_loop(movement_event_t event, movement_settings_t *settings, void *context);
+void totp_face_resign(movement_settings_t *settings, void *context);
+
+static const watch_face_t totp_face = {
+    totp_face_setup,
+    totp_face_activate,
+    totp_face_loop,
+    totp_face_resign,
+    NULL
+};
+
+#endif // TOTP_FACE_H_