Add bridge backend for sync

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/iam/scim/bridge_runner_backoff.go

@@ -0,0 +1,48 @@
+// Copyright (c) 2025 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package scim
+
+import "time"
+
+const (
+	// DefaultMaxConsecutiveFailures is the maximum number of consecutive failures
+	// before a bridge is disabled.
+	DefaultMaxConsecutiveFailures = 10
+
+	// DefaultMaxBackoff is the maximum backoff duration between retries.
+	DefaultMaxBackoff = 24 * time.Hour
+
+	// DefaultStaleSyncThreshold is the time after which a SYNCING bridge is
+	// considered stale and can be recovered by another runner.
+	DefaultStaleSyncThreshold = 10 * time.Minute
+)
+
+func (r *BridgeRunner) calculateBackoff(consecutiveFailures int) time.Duration {
+	if consecutiveFailures <= 0 {
+		return r.cfg.Interval
+	}
+
+	backoff := r.cfg.Interval * time.Duration(1<<consecutiveFailures)
+
+	if backoff > r.cfg.MaxBackoff {
+		return r.cfg.MaxBackoff
+	}
+
+	return backoff
+}
+
+func (r *BridgeRunner) shouldDisable(consecutiveFailures int) bool {
+	return consecutiveFailures >= r.cfg.MaxConsecutiveFailures
+}