title RanStateChangeManager R5

participant Caller as C
participant RanStateChange\nManager as SCM
participant Rnib\nDataService as RNIB
participant Rnib\nWriter as WR
participant SDL
participant RanList\nHandler as LH
participant RanAlarm\nHandler as AH

C->SCM: ChangeState(nodeb, nextState)
note over SCM: According to source and target states,\ndetermine one of these raw events:\n CONNECTED\n DISCONNECTED\n NONE
note over SCM: If evenet != NONE,\nprefix raw event with RanId:\ni.e. <RanId>_CONNECTED
SCM->SCM: Set Nodeb's state,\n in memory 
alt event=CONNECTED/DISCONNECTED
    SCM->+RNIB: [NEW] UpdateNodebConnectivityState(nodeb, event)
    RNIB->+WR: [NEW] UpdateNodebConnectivityState(nodeb, event)
    note over WR: Pre-configured CHANNEL
    WR->+SDL: SetAndPublish({CHANNEL,event}, {key:nodeb})
else event=NONE
    SCM->RNIB: UpdateNodebInfo(nodeb)
    RNIB->WR: UpdateNodebInfo(nodeb)
    WR->SDL: Set({key:nodeb})
end
SDL-->-WR: ok/err
WR-->-RNIB: ok/err
RNIB-->-SCM: ok/err
alt rNib error
    note over SCM: log and stop...
    SCM->C: error
else success
    note over SCM: proceed...
end

SCM->+LH: UpdateRanState(nodeb)
note over LH: TBD...
LH-->-SCM: ok/err
note over SCM: log error and proceed...

alt event=CONNECTED/DISCONNECTED
    SCM->+AH: SetAlarm(nodeb)
    note over AH: TBD...
    AH-->-SCM: ok/err
    note over SCM: In case of error,\nlog and proceed...
else event=NONE
    note over SCM: No alarm...
end
SCM->C: ok