@startuml seq_schedule
title Flux SCHEDULE — 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

participant "Client" as Client

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

' ══════════════════════════════════════════════════════════════════
Client -> SA : POST /oc/:wfID

' ──────────────────────────────────────────────────────────────────
group ① Planification — synchrone (GetBuyAndBook)
    SA -> SA : workflow.LoadOne(wfID)\nwf.Planify(start, end, instances, …)\nexec.Buy()  → purchases [ DestPeerID = B ]\nexec.Book() → bookings  [ DestPeerID = B ]\n⇒ WorkflowExecution {\n     BookingsState:  { booking_id:  false }\n     PurchasesState: { purchase_id: false }\n   }
end

' ──────────────────────────────────────────────────────────────────
group ② Propagation vers Peer B — goroutines (errCh attend l'envoi NATS, pas la réception par B)

    SA  ->  DA  : **NATS PUB** · CREATE_RESOURCE\nPURCHASE_RESOURCE { DestPeerID=B, IsDraft=true }
    note right of DA : oc-discovery A est le\nrécepteur systématique\ndes émissions NATS de SA
    DA  --> DB  : **STREAM** · PropalgationMessage\n{ datatype: PURCHASE_RESOURCE }
    DB  ->  SB  : **NATS SUB** · CREATE_RESOURCE PURCHASE_RESOURCE

    SA  ->  DA  : **NATS PUB** · CREATE_RESOURCE\nBOOKING { DestPeerID=B, IsDraft=true }
    DA  --> DB  : **STREAM** · PropalgationMessage\n{ datatype: BOOKING }
    DB  ->  SB  : **NATS SUB** · CREATE_RESOURCE BOOKING

end

' ──────────────────────────────────────────────────────────────────
group ③ Peer B traite — async (ListenNATS goroutine de SB)

    SB  ->  SB  : StoreOne(purchase, IsDraft=true)\nAfterFunc(10 min → draftTimeout)

    SB  ->  DB  : **NATS PUB** · PROPALGATION_EVENT\nConsiders { DataType:PURCHASE_RESOURCE,\n  id=purchase_id, execution_id }
    note right of DB : SB émet sur son NATS local\nDB (oc-discovery B) reçoit
    DB  --> DA  : **STREAM** · PropalgationMessage\n{ action: Considers, DataType: PURCHASE_RESOURCE }
    DA  ->  SA  : **NATS SUB** · PROPALGATION_EVENT\n[ FromApp = "oc-discovery" ]
    SA  ->  SA  : updateExecutionState()\nPurchasesState[ purchase_id ] = true

    SB  ->  SB  : PlannerCache[self].Check(slot) ✓\nStoreOne(booking, IsDraft=true)\nAfterFunc(10 min → draftTimeout)\nrefreshSelfPlanner()

    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, p)

    SB  ->  DB  : **NATS PUB** · PROPALGATION_EVENT\nConsiders { DataType:BOOKING,\n  id=booking_id, execution_id }
    DB  --> DA  : **STREAM** · PropalgationMessage\n{ action: Considers, DataType: BOOKING }
    DA  ->  SA  : **NATS SUB** · PROPALGATION_EVENT\n[ FromApp = "oc-discovery" ]
    SA  ->  SA  : updateExecutionState()\nBookingsState[ booking_id ] = true\n→ tous true → State = SCHEDULED (DB)

end

' ──────────────────────────────────────────────────────────────────
group ④ Schedules() finalise — synchrone (concurrent avec ③)
    SA  ->  SA  : GenerateOrder(purchases, bookings)\nexec.PurgeDraft()\nexec.StoreDraftDefault() → State=SCHEDULED, IsDraft=false\nGenericStoreOne(exec)

    SA  ->  DA  : **NATS PUB** · PROPALGATION_EVENT  [goroutine]\nConsiders { DataType:WORKFLOW_EXECUTION,\n  execution, peer_ids:[ PeerB ] }
    note right of DA : oc-discovery A reçoit\net STREAM vers tous les\npairs listés dans peer_ids
    DA  --> DB  : **STREAM** · PropalgationMessage\n{ action: Considers, DataType: WORKFLOW_EXECUTION }
    DB  ->  SB  : **NATS SUB** · PROPALGATION_EVENT\n[ FromApp = "oc-discovery" ]
    SB  ->  SB  : confirmExecutionDrafts()\nconfirmResource(booking_id)\n  → Booking.IsDraft=false, State=SCHEDULED\nconfirmResource(purchase_id)\n  → Purchase.IsDraft=false

    SA  ->  Client : **{WorkflowSchedule, Workflow, Executions}**
end

note over SA, SB
  ③ et ④ sont concurrents.
  En pratique : GenerateOrder + écritures DB côté A
  laissent le temps à B de recevoir et stocker ses drafts
  avant que A émette le Considers/WORKFLOW_EXECUTION.
end note

@enduml