sequence_witnessing.plantuml

@startuml
box "Client"
  actor "Client" as client
  participant "dApp" as dapp
end box

box "Third party"
  control "Watcher" as watcher
end box

box "Smart contracts"
  entity "Pandora" as pandora << (C,#ADD1B2) >>
  entity "Cognitive\nJob\nContract" as job << (C,#ADD1B2) >>
  entity "Worker\nContracts" as workerContracts << (C,#ADD1B2) >>
  entity "Failed\nWorker\nContract" as failedContract << (C,#ADD1B2) >>
end box

box "Nodes"
  collections "Worker\nNodes" as workers
  participant "Failed\nWorker" as failedWorker
end box

== Relations ==

pandora --\\ job: 1 - to - many
job --\\ workerContracts: 1 - to - many
workerContracts //-- failedContract: one of

workers --\\ workerContracts: owner
failedWorker --\\ failedContract: owner

== Witnessing ==

activate job
workers -> job: reportProgress()

alt No internet connectivity
  |||
  failedWorker -->x failedContract
  |||
else Crash or turned off
  |||
  failedWorker -> failedWorker
  destroy failedWorker
  |||
else Decided to keep silence
  |||
  failedWorker -->x]
  |||
end

watcher -> job: reportWorkerFailure(failedWorker)
job -> job: check timeout
job -> failedContract: updateState(Offline)
job -> job: replaceWorker()
job -> pandora: penaltize(failedWorker)
activate pandora
deactivate job

pandora -> pandora: reduceStake(penalty)
pandora -> failedContract: updateState(InssufficientStake) if neccessary
pandora -> watcher: payReward()

deactivate pandora

== Restoring from failure ==

activate failedWorker
failedWorker -> failedContract: backOnline()
activate failedContract
deactivate failedWorker
failedContract -> failedContract: updateState(Idle)
deactivate failedContract

|||
@enduml