core: Move ssb.swapWithServerIdentity() to C.

src/ssb.db.c

@@ -2953,3 +2953,52 @@ void tf_ssb_db_get_blocks(sqlite3* db, void (*callback)(const char* id, double t
 		sqlite3_finalize(statement);
 	}
 }
+
+char* tf_ssb_db_swap_with_server_identity(sqlite3* db, const char* user, const char* user_id, const char* server_id)
+{
+	tf_printf("SWAP user=%s user_id=%s server_id=%s\n", user, user_id, server_id);
+	char* result = NULL;
+	char* error = NULL;
+	if (sqlite3_exec(db, "BEGIN TRANSACTION", NULL, NULL, &error) == SQLITE_OK)
+	{
+		sqlite3_stmt* statement = NULL;
+		if (sqlite3_prepare_v2(db, "UPDATE identities SET user = ? WHERE user = ? AND '@' || public_key = ?", -1, &statement, NULL) == SQLITE_OK)
+		{
+			if (sqlite3_bind_text(statement, 1, user, -1, NULL) == SQLITE_OK && sqlite3_bind_text(statement, 2, ":admin", -1, NULL) == SQLITE_OK &&
+				sqlite3_bind_text(statement, 3, server_id, -1, NULL) == SQLITE_OK && sqlite3_step(statement) == SQLITE_DONE && sqlite3_changes(db) == 1 &&
+				sqlite3_reset(statement) == SQLITE_OK && sqlite3_bind_text(statement, 1, ":admin", -1, NULL) == SQLITE_OK &&
+				sqlite3_bind_text(statement, 2, user, -1, NULL) == SQLITE_OK && sqlite3_bind_text(statement, 3, user_id, -1, NULL) == SQLITE_OK &&
+				sqlite3_step(statement) == SQLITE_DONE && sqlite3_changes(db) == 1)
+			{
+				char* commit_error = NULL;
+				if (sqlite3_exec(db, "COMMIT TRANSACTION", NULL, NULL, &commit_error) != SQLITE_OK)
+				{
+					result = commit_error ? tf_strdup(commit_error) : tf_strdup(sqlite3_errmsg(db));
+				}
+				if (commit_error)
+				{
+					sqlite3_free(commit_error);
+				}
+			}
+			else
+			{
+				result = tf_strdup(sqlite3_errmsg(db) ? sqlite3_errmsg(db) : "swap failed");
+			}
+			sqlite3_finalize(statement);
+		}
+		else
+		{
+			result = tf_strdup(sqlite3_errmsg(db));
+		}
+	}
+	else
+	{
+		result = error ? tf_strdup(error) : tf_strdup(sqlite3_errmsg(db));
+	}
+	if (error)
+	{
+		sqlite3_free(error);
+	}
+
+	return result;
+}