fix(indexer): L1/L2 independent resyncing (#8735)

* allow l1 & l2 to be re-synced independently

* sent_message should cascade the delete

* nit

indexer/migrations/20230523_create_schema.sql

@@ -120,8 +120,8 @@ CREATE TABLE IF NOT EXISTS l2_transaction_withdrawals (
     initiated_l2_event_guid VARCHAR NOT NULL UNIQUE REFERENCES l2_contract_events(guid) ON DELETE CASCADE,
 
     -- Multistep (bedrock) process of a withdrawal
-    proven_l1_event_guid    VARCHAR UNIQUE REFERENCES l1_contract_events(guid) ON DELETE CASCADE,
-    finalized_l1_event_guid VARCHAR UNIQUE REFERENCES l1_contract_events(guid) ON DELETE CASCADE,
+    proven_l1_event_guid    VARCHAR UNIQUE REFERENCES l1_contract_events(guid) ON DELETE SET NULL ON UPDATE CASCADE,
+    finalized_l1_event_guid VARCHAR UNIQUE REFERENCES l1_contract_events(guid) ON DELETE SET NULL ON UPDATE CASCADE,
     succeeded               BOOLEAN,
 
     -- transaction data
@@ -145,7 +145,7 @@ CREATE TABLE IF NOT EXISTS l1_bridge_messages(
     transaction_source_hash VARCHAR NOT NULL UNIQUE REFERENCES l1_transaction_deposits(source_hash) ON DELETE CASCADE,
 
     sent_message_event_guid    VARCHAR NOT NULL UNIQUE REFERENCES l1_contract_events(guid) ON DELETE CASCADE,
-    relayed_message_event_guid VARCHAR UNIQUE REFERENCES l2_contract_events(guid) ON DELETE CASCADE,
+    relayed_message_event_guid VARCHAR UNIQUE REFERENCES l2_contract_events(guid) ON DELETE SET NULL ON UPDATE CASCADE,
 
     -- sent message
     from_address VARCHAR NOT NULL,
@@ -167,7 +167,7 @@ CREATE TABLE IF NOT EXISTS l2_bridge_messages(
     transaction_withdrawal_hash VARCHAR NOT NULL UNIQUE REFERENCES l2_transaction_withdrawals(withdrawal_hash) ON DELETE CASCADE,
 
     sent_message_event_guid    VARCHAR NOT NULL UNIQUE REFERENCES l2_contract_events(guid) ON DELETE CASCADE,
-    relayed_message_event_guid VARCHAR UNIQUE REFERENCES l1_contract_events(guid) ON DELETE CASCADE,
+    relayed_message_event_guid VARCHAR UNIQUE REFERENCES l1_contract_events(guid) ON DELETE SET NULL ON UPDATE CASCADE,
 
     -- sent message
     from_address VARCHAR NOT NULL,

indexer/processors/bridge.go

@@ -182,7 +182,7 @@ func (b *BridgeProcessor) onL2Data(latestL2Header *types.Header) (errs error) {
 		}
 
 		// Finalized L2 Events (on L1)
-		if b.LastFinalizedL1Header == nil || b.LastFinalizedL1Header.Timestamp < latestL2Header.Time {
+		if b.LastL2Header != nil && (b.LastFinalizedL1Header == nil || b.LastFinalizedL1Header.Timestamp < latestL2Header.Time) {
 			if err := b.processFinalizedL1Events(latestL2Header); err != nil {
 				errs = errors.Join(errs, fmt.Errorf("failed processing finalized l1 events: %w", err))
 			}