workflow.puml

@startuml

title Postbox monitor workflow



start

:Determine wake reason;

if (ESP_SLEEP_WAKEUP_EXT1) then (Sensor event)
  if (Which sensor?) then (Door)
    if (What state?) then (Open)
      :**Send message**:\n"RETRIEVED";
      :Set trigger event:\n"Door Closed";
    else (Closed)
      :Set trigger event:\n"Flap Open";
    endif
  else (Flap)
    :**Send message**:\n"DELIVERED";
    :Set trigger event:\n"Door Open";
  endif
elseif (ESP_SLEEP_WAKEUP_TIMER) then (Ping or event retry timer)
  :Increment the\nretry counter;
  :**Send message**:\n(Last unsent message type);
  :Set trigger event:\n(Active trigger event);
else (Hard boot)
  :**Send message**:\n"BOOT";
  :Set trigger event:\n"Flap Open";
endif

if (Any unsent messages?) then (Yes)
  :Schedule a send retry;
else (No)
  :Schedule the next\nPING event;
endif

:Flush all Serial data;
:Force WiFi disconnect;
:Enter deep sleep;
stop


partition "Send message" {
    if (Connect to WiFi) then (success)
        :Read sensors;
        :Build JSON payload;
        :POST to remote endpoint;
        if (HTTP response code) then (200 OK)
          :Clear the retry flag;
          end
        else (Not 200 OK)
          :Schedule a send retry;
        endif
    else (failure)
        :Schedule a send retry;
    endif

    :Enter deep sleep;
    end
}
@enduml