@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 -> broker : Establish TLS session with the MQTT Broker
application -> mqtt : Initialize MQTT
application -> mqtt : Establish an MQTT connection

activate mqtt
mqtt -> broker: Establish MQTT Connection
mqtt -> application : Return from MQTT library
deactivate mqtt

application -> shadow : Get the shadow delete response topic strings using macros from the shadow library:\n\
    If classic shadow:\n\
    SHADOW_TOPIC_STR_DELETE_ACC( "testShadow", SHADOW_NAME_CLASSIC )\n\
    SHADOW_TOPIC_STR_DELETE_REJ( "testShadow", SHADOW_NAME_CLASSIC )\n\
    If named shadow:\n\
    SHADOW_TOPIC_STR_DELETE_ACC( "testShadow", "namedShadow" )\n\
    SHADOW_TOPIC_STR_DELETE_REJ( "testShadow", "namedShadow" )\n

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

application -> mqtt : Subscribe to the shadow delete response topics ( SubscribeToTopic )

activate mqtt
mqtt -> broker: Subscribe to the shadow delete response topics
mqtt -> application : Return Success
deactivate mqtt

application -> shadow : Get the shadow delete operation topic string using the macro from the shadow library\n\
    If classic shadow:\n\
    SHADOW_TOPIC_STR_DELETE( "testShadow", SHADOW_NAME_CLASSIC )\n\
    If named shadow:\n\
    SHADOW_TOPIC_STR_DELETE( "testShadow", "namedShadow" )

activate shadow
shadow -> application : Return the assembled shadow topic
deactivate shadow

application -> mqtt : Publish an empty message on the shadow delete topic to delete the shadow if it exists

activate mqtt
mqtt -> broker : Publish message on the shadow delete topic to the broker
mqtt <- broker : Incoming message
mqtt -> callback : Call Callback
activate callback
callback -> shadow : Parse the topic ( Shadow_MatchTopicString )
activate shadow
shadow -> callback : Return the parsed result ( ShadowMessageType_t )
deactivate shadow
callback -> mqtt : Return from the callback
deactivate callback
mqtt -> application : Return from MQTT library
deactivate mqtt

application -> mqtt : Unsubscribe from the shadow delete response topics ( UnsubscribeFromTopic )
activate mqtt
mqtt -> broker : Unsubscribe from the shadow delete response topics
mqtt -> application : Return from MQTT library
deactivate mqtt

application -> shadow : Get the following shadow topic strings using macros from the shadow library:\n\
    If classic shadow:\n\
    SHADOW_TOPIC_STR_UPDATE_DELTA( "testShadow", SHADOW_NAME_CLASSIC )\n\
    SHADOW_TOPIC_STR_UPDATE_ACC( "testShadow", SHADOW_NAME_CLASSIC )\n\
    SHADOW_TOPIC_STR_UPDATE_REJ( "testShadow", SHADOW_NAME_CLASSIC )\n\
    If named shadow:\n\
    SHADOW_TOPIC_STR_UPDATE_DELTA( "testShadow", "namedShadow" )\n\
    SHADOW_TOPIC_STR_UPDATE_ACC( "testShadow", "namedShadow" )\n\
    SHADOW_TOPIC_STR_UPDATE_REJ( "testShadow", "namedShadow" )

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 topics
mqtt -> application : Return Success
deactivate mqtt

application -> shadow : Get the shadow update operation topic string using macro from shadow library:\n\
    If classic shadow:\n\
    SHADOW_TOPIC_STR_UPDATE( "testShadow", SHADOW_NAME_CLASSIC )\n\
    If named shadow:\n\
    SHADOW_TOPIC_STR_UPDATE( "testShadow", "namedShadow" )
activate shadow
shadow -> application : Return the assembled shadow topic
deactivate shadow

application -> mqtt : Publish powerOn:1 in the message on the shadow update topic ( PublishToTopic )

activate mqtt
mqtt -> broker : Publish message on the shadow update topic to the broker
mqtt <- broker : Incoming message
mqtt -> callback : Call Callback
activate callback
callback -> shadow : Parse the topic ( Shadow_MatchTopicString )
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 from the subscribed shadow update topics ( UnsubscribeFromTopic )
activate mqtt
mqtt -> broker : Unsubscribe from the subscribed shadow update 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 -> application : Return from MQTT library
deactivate mqtt

application -> broker : TLS disconnect from the broker

deactivate application

@enduml