user-journey.seqdiag

# View on web:
# https://www.websequencediagrams.com/files/render?link=2uX8ikm5zlbU2MY91kkCRsc8H0volTlZQdJDxleaiJPq1LDh7s6xGRSo2oRicmDt

# Or in VS Code:
# https://marketplace.visualstudio.com/items?itemName=AleksandarDev.vscode-sequence-diagrams

MusicianA->Server: visit home
Note over Server: Use WS connection for\n- WebRTC singaling\n- central clock?
Server->MusicianA: Establish websocket connection
Server->MusicianA: new jam session hash
MusicianA-->MusicianB: send session link

Note over MusicianB: B visits session URL
Server->MusicianB: Establish websocket connection

Note over Server: WebRTC signalling\n(simplified)
MusicianA->Server: send SDP offer\n(websocket)
Server->MusicianB: forward SDP offer to B\n(websocket)
MusicianB->Server: send SDP offer response\n(websocket)
Server->MusicianA: forward SDP offer response to A\n(websocket)

Note over Server: WebRTC signalling\ncomplete
Note over MusicianA: now A and B can connect\ndirectly over WebRTC
MusicianA -> MusicianB:  WebRTC data channel
MusicianB -> MusicianA: between A and B

Note left of MusicianA: Jam Session begins
Note over MusicianB: B plays a note on\ntheir instrument
MusicianB->MusicianA: Send MIDI 'NOTE_ON'\n(data channel)
Note over MusicianA: MIDI note plays for A
MusicianB->MusicianA: Send MIDI 'NOTE_OFF'\n(data channel)
MusicianA->MusicianB: Send MIDI 'NOTE_ON'\n(data channel)
Note over MusicianB: MIDI note plays for B
MusicianA->MusicianB: Send MIDI 'NOTE_OFF'\n(data channel)