From 12e2a91ca78dcd32ee3adb431e2c9c133ec75ca3 Mon Sep 17 00:00:00 2001
From: Carl Niklas Rydberg <carlniklasrydberg@gmail.com>
Date: Sun, 21 Dec 2025 21:09:01 +0100
Subject: [PATCH] Added the snapshot/epoch type and getter in the public API,
 plus the store wrapper implementation:

---
 include/amduat/tgk/store.h  | 6 ++++++
 src/tgk_stack/store/store.c | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/amduat/tgk/store.h b/include/amduat/tgk/store.h
index 527911a..5ba6278 100644
--- a/include/amduat/tgk/store.h
+++ b/include/amduat/tgk/store.h
@@ -20,6 +20,8 @@ typedef enum {
   GS_ERR_INTEGRITY = 4
 } amduat_tgk_graph_error_t;
 
+typedef uint64_t amduat_tgk_snapshot_id_t;
+
 typedef struct {
   amduat_tgk_edge_type_id_t *types;
   size_t types_len;
@@ -83,6 +85,7 @@ typedef struct {
 
 typedef struct {
   bool (*get_config)(void *ctx, amduat_tgk_store_config_t *out_config);
+  bool (*snapshot_id)(void *ctx, amduat_tgk_snapshot_id_t *out_id);
   amduat_tgk_graph_error_t (*resolve_edge)(void *ctx,
                                            amduat_reference_t ref,
                                            amduat_tgk_edge_body_t *out_body);
@@ -124,6 +127,9 @@ void amduat_tgk_store_init(amduat_tgk_store_t *store,
 bool amduat_tgk_store_get_config(amduat_tgk_store_t *store,
                                  amduat_tgk_store_config_t *out_config);
 
+bool amduat_tgk_store_snapshot_id(amduat_tgk_store_t *store,
+                                  amduat_tgk_snapshot_id_t *out_id);
+
 amduat_tgk_graph_error_t amduat_tgk_store_resolve_edge(
     amduat_tgk_store_t *store,
     amduat_reference_t ref,
diff --git a/src/tgk_stack/store/store.c b/src/tgk_stack/store/store.c
index 8320a6c..8bbf659 100644
--- a/src/tgk_stack/store/store.c
+++ b/src/tgk_stack/store/store.c
@@ -31,6 +31,14 @@ bool amduat_tgk_store_get_config(amduat_tgk_store_t *store,
   return store->ops.get_config(store->ctx, out_config);
 }
 
+bool amduat_tgk_store_snapshot_id(amduat_tgk_store_t *store,
+                                  amduat_tgk_snapshot_id_t *out_id) {
+  if (store == NULL || store->ops.snapshot_id == NULL) {
+    return false;
+  }
+  return store->ops.snapshot_id(store->ctx, out_id);
+}
+
 amduat_tgk_graph_error_t amduat_tgk_store_resolve_edge(
     amduat_tgk_store_t *store,
     amduat_reference_t ref,