matrix-spec/drafts/client_server_use_cases.log

#1: Lightweight IM client (no perm storage)
#2: Mobile IM client (perm storage)
#3: MIDI client
#4: Animatrix client
#5: Unity object trees
#6: Forum
#7: Social Network ("Walls", PMs, groups)
#8: Minecraft-clone
#9: Bug Tracking Software
#10: Global 'Like' widget, which links through to a room.

================

#1: Lightweight IM client (no perm storage)
-------------------------------------------
Description: 
  An IM client (think web client) with no way of persisting data beyond
  a session (the instance a person is using the app).
Features: 
  Recent activity, Room screen (member list, etc), User page, just like
  the web client.
Actions:
 - Send a one-to-one message to someone.
 - Accept an invite.
 - Populate recent activity (all rooms joined with latest message + room names/aliases, rooms invited to + room names/aliases)
 - Populate scrollback if click on room
 - Populate member list if click on room + get presence updates for them
 - Populate room name / topic if click on room
 - Create an empty room.
 - Join a room from an alias.
 

---

Action: 
  Send a one-to-one message to someone.
How: 
  Enter their username and hit Message. Taken to room page with invited user.
  History displays that I've invited someone / joined the room. Enter a message
  and hit send. Message appears in window.

::

  Client                    Server
       -- @user:domain -->
       <--- room ID, ACK--
       <-historical msgs--
       -- msg,room ID --->
       <--- ACK ----------

---

Action: 
  Accept an invite.
How: 
  Get list of invites. Click one of them to 'accept' it. May or may not want
  room content.

::

  Client                    Server
       ---- req invites ->
       <--- [inv,inv] ----
       ---- accept inv -->
       <--- ACK ----------
       <--- room content-- (optional)
       
---

Action: 
  Populate recent activity (all rooms joined with latest message + room names/aliases, rooms invited to + room names/aliases)
How: 
  Request joined rooms with latest message and room name. Request rooms invited to. Possibly extra info like # joined members.

::

  Client                    Server
       ---- req sync ---->
       <---joined rooms--- {msg,name,alias,#members?}
       <---invited rooms-- {name,alias}
       
---

Action: 
  Populate scrollback if click on room.
How: 
  Request scrollback for room.

::

  Client                    Server
       ---- room id ----->
       <--- scrollback ---
       
---

Action: 
  Populate member list if click on room + get presence updates for them.
How: 
  Click on room. Member list with names/presence/pics appears. May not want
  pic.

::

  Client                    Server
       ---- req mem list ->
       <--- members ------- {name,pic,presence}
       - monitor presence->
              ...
       <- presence change--
       <- presence change--
              ...
       -- stop presence --->
       
---

Action: 
  Populate room name / topic if click on room.
How: 
  Click on room. Room name and topic with aliases appears. May not want topic
  (eg screen size).

::

  Client                    Server
       ---- req room info->
       <--- room info ----- {name,topic,aliases}
       
---

Action: 
  Create an empty room.
How: 
  Type in room config (desired name, public/private, etc). Hit Create. Room is
  created. Possibly get room info.

::

  Client                    Server
       ---- mkroom{config}->
       <--ACK{room_id}------
       <-- room info ------- (optional)
       
---

Action: 
  Join a room from an alias.
How: 
  Type in alias. Hit Join. Room is joined. Possibly get room info.

::

  Client                    Server
       -- join{alias} ----->
       <--ACK{room_id}------
       <--room info--------- (optional)
       
       
===========================

#2: Mobile IM client (perm storage)
-----------------------------------
Description: 
  An IM client (think android/ios) which persists data on a database.
Features: 
  Recent activity, Room screen (member list, etc), User page, just like
  the web client.
Actions:
 - Send a one-to-one message to someone.
 - Accept a stored invite.
 - Populate recent activity (all rooms joined with latest message + room names/aliases, rooms invited to + room names/aliases)
 - Populate scrollback if click on room
 - Populate member list if click on room + get presence updates for them
 - Populate room name / topic if click on room
 - Create an empty room.
 - Join a room from an alias.
 

---

Action: 
  Send a one-to-one message to someone (single room).
How: 
  Enter their username and hit Message. Taken to room page with invited user if no room exists,
  else takes to existing room. History displays that I've invited someone or scrollback. Enter 
  a message and hit send. Message appears in window.

::

  Client                    Server
       -- @user:domain -->
       <--- room ID, ACK--
       <-historical msgs-- (optional; not if existing room)
       -- msg,room ID ---> 
       <--- ACK ----------

---

Action: 
  Accept a stored invite.
How: 
  Send invite to server. Get room content (or NO-OP if already joined).

::

  Client                    Server
       ---- accept inv -->
       <--- ACK ----------
       <--- room content-- (optional)
       
---

Action: 
  Populate recent activity (all rooms joined with latest message + room names/aliases, rooms invited to + room names/aliases)
  incrementally.
How: 
  Request recent activity diff. Get updated msg/name/#members for changed values only.

::

  Client                    Server
       - req sync{token}->
       <---diff{rooms}---- {msg,name,alias,#members?}
       
---

Action: 
  Populate scrollback if click on room. 
How: 
  Request scrollback for room. Either a diff or a page of scrollback
  depending on cached data.

::

  Client                        Server
       -room id{latest event}-> {max msgs}
       <--- scrollback -------- {fresh/incremental flag}
       
---

Action: 
  Populate member list if click on room + get presence updates for them.
How: 
  Click on room. Member list with names/presence/pics appears. May not want
  pic.

::

  Client                    Server
       ---- req mem list ->
       <--- members ------- {name,pic,presence}
       - monitor presence->
              ...
       <- presence change--
       <- presence change--
              ...
       -- stop presence --->
       
---

Action: 
  Populate room name / topic if click on room.
How: 
  Click on room. Room name and topic with aliases appears. May not want topic
  (eg screen size). Display cached info until updated.

::

  Client                    Server
       ---- req room info->
       <--- room info ----- {name,topic,aliases}
       
---

Action: 
  Create an empty room.
How: 
  Type in room config (desired name, public/private, etc). Hit Create. Room is
  created. Possibly get room info.

::

  Client                    Server
       ---- mkroom{config}->
       <--ACK{room_id}------
       <-- room info ------- (optional)

---

Action: 
  Join a room from an alias.
How: 
  Type in alias. Hit Join. Room is joined. Possibly get room info.

::

  Client                    Server
       -- join{alias} ----->
       <--ACK{room_id}------
       <--room info--------- (optional)