@startuml
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left to right direction
!pragma layout elk


component "Mullvad daemon" as mullvad_daemon {
  () "Management interface" as management_interface
  () "Mullvad API" as mullvad_api

  node "Daemon" as daemon {
    [Settings] as settings #yellow
    [Account history] as account_history #yellow
    [Various state around tunnels and relays] #yellow
  }

  node "Tunnel state machine" as tsm {
    [Firewall] as firewall #yellow
    [DNS] as dns #yellow
    [Routing] as routing
    [Tunnel] as tunnel
    [Offline monitor] as offline_monitor
  }

  [Account manager] as account_manager
  [Mullvad API client] as rest_service
  [Relay list updater] as relay_list_updater
  [Version updater] as version_updater
  [Relay selector] as relay_selector #yellow
}

legend
  Yellow components are shared synchronously (via a mutex).
end legend


management_interface -> daemon : Incoming RPCs

daemon -> tsm : Sets target tunnel state
tsm -> daemon : "Notifies of changes to tunnel state, gets tunnel connection config"
tsm -> daemon : Get tunnel connection config
daemon -> relay_selector : Select a relay for a connection
daemon -> rest_service : Change API availability
daemon -> relay_list_updater : Force relay list update
daemon -> version_updater : Fetch current version
daemon -> account_manager : Fetch account data
daemon -> account_manager : Fetch device data and WG key

relay_list_updater -> relay_selector : Update relay list
account_manager -> daemon : Account/device events


rest_service -> relay_selector : Select bridge relay for API connection
rest_service -> tsm : Unblock API endpoint
rest_service -> mullvad_api : Send requests to our web service

relay_list_updater -> rest_service : Fetch relay list from API
version_updater -> rest_service : Fetch latest app versions
account_manager -> rest_service : Fetch account data
account_manager -> rest_service : Fetch device data, rotate keys


@enduml