module Eventful.ProcessManager
( ProcessManager (..)
, ProcessManagerCommand (..)
, applyProcessManagerCommandsAndEvents
) where
import Control.Monad (forM_, void)
import Eventful.Aggregate
import Eventful.Projection
import Eventful.Store.Class
import Eventful.UUID
data ProcessManager state event command
= ProcessManager
{ processManagerProjection :: Projection state (VersionedStreamEvent event)
, processManagerPendingCommands :: state -> [ProcessManagerCommand event command]
, processManagerPendingEvents :: state -> [StreamEvent UUID () event]
}
data ProcessManagerCommand event command
= forall state. ProcessManagerCommand
{ processManagerCommandAggregateId :: UUID
, processManagerCommandAggregate :: Aggregate state event command
, processManagerCommandCommand :: command
}
instance (Show command, Show event) => Show (ProcessManagerCommand event command) where
show (ProcessManagerCommand uuid _ command) =
"ProcessManagerCommand{processManagerCommandAggregateId = " ++ show uuid ++
", processManagerCommandCommand = " ++ show command ++ "}"
applyProcessManagerCommandsAndEvents
:: (Monad m)
=> ProcessManager state event command
-> EventStoreWriter m event
-> VersionedEventStoreReader m event
-> state
-> m ()
applyProcessManagerCommandsAndEvents ProcessManager{..} writer reader state = do
forM_ (processManagerPendingCommands state) $ \(ProcessManagerCommand aggregateId aggregate command) ->
void $ commandStoredAggregate writer reader aggregate aggregateId command
forM_ (processManagerPendingEvents state) $ \(StreamEvent projectionId () event) ->
storeEvents writer AnyVersion projectionId [event]