@startuml seq_check
title Flux CHECK — Peer A ↔ Peer B via oc-discovery

skinparam sequenceMessageAlign center
skinparam sequence {
    ArrowColor          #333333
    LifeLineBorderColor #888888
    GroupBorderColor    #777777
    GroupBackgroundColor #FAFAFA
    NoteBackgroundColor #FFFDE7
    NoteBorderColor     #CCAA00
    BoxBorderColor      #555555
}
skinparam ParticipantBackgroundColor #FFFFFF

box "Peer A" #EAF3FB
    participant "oc-scheduler A" as SA
    participant "oc-discovery A" as DA
end box

box "Peer B" #EAF9EE
    participant "oc-discovery B" as DB
    participant "oc-scheduler B" as SB
end box

participant "Client" as Client

' ══════════════════════════════════════════════════════
== Alimentation continue du PlannerCache (fond permanent) ==
' ══════════════════════════════════════════════════════

note over SA, SB
  Déclenché par : démarrage de SB, booking local créé,
  TTL planner expiré → refreshSelfPlanner()
end note

SB  ->  DB  : **NATS PUB** · PROPALGATION_EVENT\nPB_PLANNER { peer_id, schedule, capacities }
DB  --> DA  : **STREAM** · PropalgationMessage\n{ action: PB_PLANNER }
DA  ->  SA  : **NATS SUB** · PROPALGATION_EVENT\n[ FromApp = "oc-discovery" ]
SA  ->  SA  : storePlanner(PeerB.PeerID, planner)\n→ PlannerCache[PeerB.PeerID] = p

' ══════════════════════════════════════════════════════
== Flux CHECK (POST /oc/:wfID/check) ==
' ══════════════════════════════════════════════════════

Client ->  SA  : POST /oc/:wfID/check\n?as_possible=true&preemption=false

group ① Résolution du workflow
    SA -> SA : workflow.LoadOne(wfID)
    SA -> SA : collectBookingResources(wf)\n→ [ { peerID=B, resourceID, instanceID } ]
end

group ② Vérification locale contre le cache
    SA -> SA : checkResourceAvailability()\nPlannerCache[PeerB.PeerID].Check(res, inst, start, end)

    alt slot disponible
        SA -> SA : available = true
    else slot occupé
        SA -> SA : findNextSlot(window=5h, pas=15min)\n→ next_slot
    end
end

SA -> Client : **CheckResult**\n{ available, start, end, next_slot, warnings }

note over Client, SB
  Aucun appel réseau pendant le check :
  tout est résolu depuis le PlannerCache local de A.
  oc-discovery n'intervient qu'en amont (fond continu).
end note

@enduml