Translate the json data representing the diagram data into a plantuml script considering:

1. The participants' shape must be translated in their plantuml counterpart using the following conversion rules :
    - "rectangle" shape  must be translated into  plantuml's "rectangle"
    - "circle" shape  must be translated into  plantuml's "circle"
    - "person" or  "stickman" shape  must be translated into  plantuml's  "actor"
    - "oval" or "ellipse"  shape  must be translated into  plantuml's  "usecase"
    - "cylinder" shape  must be translated into  plantuml's  "database"
    - "diamond" shape  must be translated into  plantuml's "hexagon"
2. Each recognised participant must be written in the form: "<participant plantuml shape>"  "<name>" as <camel case name><<description>>
3. Relations must be the arrow that connect participants
4. Put diagram description in the legend of the diagram in the form:
    legend
    <description with a bullet point for each steps>
    end legend
5. Put  diagram title in the form:
     title "<diagram title>"

diagram data:
 {{diagram_description}}
