@startuml
skinparam ParticipantPadding 20
skinparam BoxPadding 20

title Libsovrin Agent to Agent communucation API
scale 0.9

box "Sender Agent" #LightBlue
actor "Sender Agent" as SA
participant "Sender Libsovrin" as SL
participant "Sender Wallet" as SW
participant "Sender Socket" as SS
endbox

box "Receiver Agent" #LightBlue
actor "Receiver Agent" as RA
participant "Receiver Libsovrin" as RL
participant "Receiver Wallet" as RW
participant "Receiver Socket" as RS
endbox

participant "Ledger" as L

=== Start listening ==

RA -> RL: <b>1. sovrin_create_and_store_my_did
RL -> RW: Store receiver keys

RA -> RL: <b>2. sovrin_agent_listen
RL -> RS: Start listening
RL -> RA: Listener handle (cb)

=== Establish connection ==

SA -> SL: <b>3. sovrin_create_and_store_my_did
SL -> SW: Store sender keys

SA -> SL: <b>4. sovrin_agent_connect
SL -> SW: Get sender keys
SW -> SL: Sender keys
SL -> L: GET_NYM/GET_DDO
L -> SL: Receiver keys and endpoint
SL -> SW: Store receiver keys and endpoint

SL -> SS: Receiver did, keys and endpoint. Sender did, keys

SS -> RS: PairwiseCurveCP Hello message
RS -> RL: Keys lookup request
RL -> RW: Get keys and did for request
RW -> RL: Receiver keys and did
RL -> RS: Receiver keys
RS -> SS: PairwiseCurveCP Welcome message

SS -> RS: Next PairwiseCurveCP handshake messages
RS -> SS: PairwiseCurveCP handshake messages answers

SS -> SL: PairwiseCurveCP connection established

SL -> SS: DID message
SS -> RS: DID message
RS -> RL: Sender did and public key
RL -> L: GET_NYM/GET_DDO
L -> RL: Sender keys and did (from Ledger)
RL -> RL: Connection verification
RL -> RS: DID message answer
RS -> SS: DID message answer
SS -> SL: DID message answer
SL -> SA: Connection handle (cb)
RL -> RA: Connection handle (cb)

=== Exchange messages ==

SA -> SL: <b>4. sovrin_agent_send
SL -> SS: Message
SS -> RS: Message
RS -> RL: Message
RL -> RA: Message (cb)

RA -> RL: <b>5. sovrin_agent_send
RL -> RS: Message
RS -> SS: Message
SS -> SL: Message
SL -> SA: Message (cb)

=== Clean up ==

SA -> SL:  <b>5. sovrin_agent_close_connection
SL -> SS: Close socket

RA -> RL: <b>5. sovrin_agent_close_listener
RL -> RS: Close socket

@enduml