@startuml
skinparam dpi 300
skinparam classFontSize 8
skinparam classFontName Helvetica
autonumber

box "Application" #LightGreen
    participant "Application" as application
    participant "Callback" as callback
end box

box "Libraries" #LightBlue
    participant "JSON" as json

    participant "Shadow" as shadow

    participant "MQTT" as mqtt

end box

box "AWS IoT Broker" #Yellow
    participant "AWS IoT Broker" as broker
end box

activate application
application -> mqtt : EstablishMqttSession with callback function ( EstablishMqttSession )


activate mqtt
mqtt -> broker : Establish TLS session with server & client credential
mqtt -> mqtt : Initialization with the callback
mqtt -> broker: Establish MQTT Connection
mqtt -> application : Return from MQTT library
deactivate mqtt

application -> shadow : Get the following shadow topics:\n$aws/things/testShadow/shadow/update/delta SHADOW_TOPIC_STRING_UPDATE_DELTA( "testShadow" )\n$aws/things/testShadow/shadow/update/accepted SHADOW_TOPIC_STRING_UPDATE_ACCEPTED( "testShadow" )\n$aws/things/testShadow/shadow/update/rejected SHADOW_TOPIC_STRING_UPDATE_REJECTED( "testShadow" )

activate shadow
shadow -> application : Return assembled shadow topics
deactivate shadow

application -> mqtt : MQTT_Subscribe subscribes to those shadow topics ( SubscribeToTopic )

activate mqtt
mqtt -> broker: Subscribe to the shadow topic to the broker
mqtt -> application : Return Success
deactivate mqtt

application -> shadow : Get the $aws/things/testShadow/shadow/update by\nSHADOW_TOPIC_STRING_UPDATE( "testShadow" )
activate shadow
shadow -> application : Return the assembled shadow topic
deactivate shadow

application -> mqtt : Publish powerOn:1 in the message on the topic $aws/things/testShadow/shadow/update ( PublishToTopic )

activate mqtt
mqtt -> broker : Publish message on the shadow topic to the broker
mqtt <- broker : Incoming message
mqtt -> callback : Call Callback
activate callback
callback -> shadow : Parse the topic ( Shadow_MatchTopic )
activate shadow
shadow -> callback : Return the parsed result ( ShadowMessageType_t )
deactivate shadow
callback -> json : Parse powerOn/value from shadow topic payload ( JSON_Search )
activate json
json -> callback : Return parsed powerOn/value
deactivate json
callback -> mqtt : Return from the callback
deactivate callback
mqtt -> application : Return from MQTT library
deactivate mqtt

application -> mqtt : Unsubscribe thosed subscribed topics ( UnsubscribeFromTopic )
activate mqtt
mqtt -> broker : Unsubscribe to those subscribed topics
mqtt -> application : Return from MQTT library
deactivate mqtt

application -> mqtt : Disconnect from connection ( DisconnectMqttSession )
activate mqtt
mqtt -> broker : MQTT disconnect from the broker
mqtt -> broker : TLS disconnect from the broker
mqtt -> application : Return from MQTT library
deactivate mqtt

deactivate application

@enduml