@startuml implementation-layers
skinparam componentStyle rectangle
skinparam shadowing false
skinparam defaultTextAlignment center
top to bottom direction

component "Public API\n\nSegmentIndex\nIndexConfiguration" as API

component "Session and lifecycle\ncore.session\n\nSegmentIndexImpl\nSegmentIndexOperationGate\nSegmentIndexSessionResources" as SESSION

component "Lifecycle and lock state\ncore.session\n\nSegmentIndexStateMachine\nIndexCloseCoordinator\nIndexDirectoryLock" as SESSION_STATE

component "Operation access\n\nIndexOperationCoordinator\nSegmentIndexMaintenanceSessionAdapter" as FACADES

component "Runtime opening\ncore.session\n\nSegmentIndexBootstrapOperation\nSegmentIndexSessionAssembler" as RUNTIME

component "Topology runtime\ncore.routing + core.split + core.execution\n\nSegmentTopology\nSplitService\nSegmentStreamingService" as TOPOLOGY_RUNTIME

component "Core storage\ncore.storage\n\nStorageService\nStorageService.create(...)\nCoreStorageRuntime\nIndexWalCoordinatorDelegate" as CORE_STORAGE

component "Split runtime\ncore.split\n\nSplitService\nSplitExecutionCoordinator\nSplitPolicyCoordinator\nRouteSplitCoordinator\nRouteSplitPublishCoordinator" as SPLIT_RUNTIME

component "WAL runtime\nwal\n\nWalRuntime.open(...)\nWalRuntime" as WAL_RUNTIME

component "Point operation orchestration\ncore.execution\n\nIndexOperationCoordinator" as OPERATIONS

component "Route and segment lease access\ncore.routing\n\nSegmentLeaseService\nSegmentLease\nSegmentSplitLease" as ACCESS

component "Stable segment operations\ncore.execution\n\nStableSegmentOperationGateway\nSegmentStreamingService\nSegmentsIterator" as STABLE_ACCESS

component "Route state\n\nKeyToSegmentMap\nSegmentTopology" as ROUTE

component "Registry and segment handle\norg.hestiastore.index.segmentregistry\n\nSegmentRegistry\nBlockingSegment\n(segment handler/handle)" as REGISTRY

component "Segment engine\norg.hestiastore.index.segment\n\nSegment\nSegmentImpl\nSegmentCore\nSegmentSearcher\nSegmentCompacter" as SEGMENT

database "Segment files\n\nmain data\ndelta cache\nsparse index\nBloom filter" as FILES

API --> RUNTIME : create/open helpers
API --> SESSION : live index calls
SESSION --> SESSION_STATE : lifecycle and lock ownership
SESSION --> FACADES : maintenance API entry point
SESSION --> OPERATIONS : point put/get/delete
SESSION --> TOPOLOGY_RUNTIME : iterators and split scans
RUNTIME --> CORE_STORAGE : assemble storage service
RUNTIME --> TOPOLOGY_RUNTIME : create topology services
TOPOLOGY_RUNTIME --> SPLIT_RUNTIME : own split runtime
RUNTIME --> WAL_RUNTIME : open WAL runtime
OPERATIONS --> ACCESS : route key and load segment
OPERATIONS --> CORE_STORAGE : WAL append and applied LSN
CORE_STORAGE --> WAL_RUNTIME : active WAL coordination
TOPOLOGY_RUNTIME --> STABLE_ACCESS : iterator access
STABLE_ACCESS --> ACCESS : route segment iterators
SPLIT_RUNTIME --> ACCESS : drain split candidates
SPLIT_RUNTIME --> ROUTE : publish route changes
ACCESS --> REGISTRY : loaded segment handle
STABLE_ACCESS --> REGISTRY : stable segment handle
REGISTRY --> SEGMENT : retry-aware segment calls
SEGMENT --> FILES : persisted structures

ACCESS --> ROUTE : route snapshot and lease
TOPOLOGY_RUNTIME --> ROUTE : split and topology coordination
CORE_STORAGE --> ROUTE : persisted route map

note right of ACCESS
This is where routed SegmentIndex
operations and split drains combine
SegmentRouteMap, RouteTopology,
and SegmentRegistry.
end note

note right of REGISTRY
The current code calls the handler
layer BlockingSegment.
end note

@enduml