# MG2: Messages
## State Machine
```
+-------------+ placementPhase +------------------+
| Lobby state +--------------------->| Placement state |
+-------------+ +-------+----------+
^ |
| |
| |
| | gameStart
| |
| |
| |
| v
| gameOver +---------------+
+-----------------------------+ Running state |
+---------------+
```
## Datatypes
### ServerState (Struct)
| Field | Type | Explanation |
| - | - | - |
| teamShips | ShipState[] | |
| actionPoints | int | Action points per player |
| visibleHostileShips | Coordinate[] | Visible hostile ships |
### Config (Struct)
| Field | Type | Explanation |
| - | - | - |
| serverName | String | Server Name
| shipBalancings | ShipBalancing[2][] | |
| shipsPerTeam | ShipType[2][] | |
| N | int | Board size |
| actionPointsGain | int | Action point gain per turn |
| teamSizes | int[2] | Team sizes |
### ShipState (Struct)
| Field | Type | Explanation |
| - | - | - |
| shipType | ShipType | |
| position | Coord | |
| currentHealth | int | Current health of the ship |
| remainingCooldown | int | Remaining cooldown of the ship |
| owner | String | Owner of the ship |
### Coordinate (Struct)
| Field | Type | Explanation |
| - | - | - |
| x | int | x coordinate |
| y | int | y coodinate |
### PlayerLobbyState (Struct)
| Field | Type | Explanation |
| - | - | - |
| ready | bool | Is player ready |
| playerID | int | Unique player ID |
| name | String | Player name |
### Costs (Struct)
| Field | Type | Explanation |
| - | - | - |
| cooldown | int | Number of rounds needed for cooldown |
| actionPoints | int | Action points the action requires |
### CommonBalancing (Struct)
| Field | Type | Explanation |
| - | - | - |
| shootCosts | Costs | |
| shootRange | int | |
| movementCosts | Costs | |
| movementSpeed | int | |
| abilityCosts | Costs | |
| visionRange | int | |
| initialHealth | int | |
### ShipBalancing (Struct)
| Field | Type | Explanation |
| - | - | - |
| shipType | ShipTypeWithBalancing | - |
| commonBalancing | CommonBalancing | - |
### ShipType (Struct)
| Values |
| - |
| CARRIER |
| BATTLESHIP|
| CRUISER |
| SUBMARINE|
| DESTROYER|
### ShipTypeWithBalancing (Enum)
| Values |
| - |
| CARRIER(ability: ScoutBalancing) |
| BATTLESHIP (ability: MultiMissleBalancing)|
| CRUISER(ability: EngineBoostBalancing) |
| SUBMARINE(ability: TorpedoBalancing) |
| DESTROYER(ability: PredatorMissileBalancing) |
### ScoutBalancing (Enum)
| Field | Type | Explanation
| - | - | - |
| range | int | Range of the scout ability |
| radius | int | Radius of scout ability |
### MultiMissleBalancing (Enum)
| Field | Type | Explanation
| - | - | - |
| radius | int | Radius of missle ability |
| damage | int | The damage of each rocket |
### PredatorMissileBalancing (Enum)
| Field | Type | Explanation
| - | - | - |
| range | int | Range of the scout ability |
| radius | int | Radius of scout ability |
| damage | int | Damage of predator missile ability |
### EngineBoostBalancing (Struct)
| Field | Type | Explanation
| - | - | - |
| steps | int | The ammount of fields the ship moves |
### TorpedoBalancing (Struct)
| Field | Type | Explanation
| - | - | - |
| range | int | Range of the torpedo ability |
| damage | int | The damage of the torpedo ability |
### ShipAction (enum)
| Values |
| - |
| MOVE(moveProps: MoveProperties) |
| SHOOT(shootProps: ShootProperties) |
| ROTATE(rotateProps: RotateProperties) |
| TORPEDO(torpedoProps: TorpedoProperties) |
| SCOUT_PLANE(scoutProps: ScoutPlaneProperties) |
| MULTI_MISSILE(multiMissileProps: MultiMissileProperties) |
| PREDATOR(predatorProps: PredatorProperties) |
| ENGINE_BOOST |
### MoveProperties (Struct)
| Field | Type | Explanation |
| - | - | - |
| direction | MoveDirection | Direction to move
### ShootProperties (Struct)
| Field | Type | Explanation |
| - | - | - |
| target | Coordinate | Target of Attack |
### RotateProperties (Struct)
| Field | Type | Explanation |
| - | - | - |
| roatation | RoatationDirection | |
### TorpedoProperties (Struct)
| Field | Type | Explanation |
| - | - | - |
| direction | Direction | Direction to shoot torpedo towards |
### ScoutPlaneProperties (Struct)
| Field | Type | Explanation |
| - | - | - |
| center | Coordinate | Center point of scout ability |
### MultiMissileProperties (Struct)
| Field | Type | Explanation |
| - | - | - |
| positions | Coordinate[3] | Positions to shoot at |
### PredatorMissileProperties (Struct)
| Field | Type | Explanation |
| - | - | - |
| center | Coordinate | center of missile impact |
### Direction (Enum)
| Values |
| - |
| NORTH |
| EAST |
| SOUTH |
| WEST |
### MoveDirection (Enum)
| Values |
| - |
| FORWARD |
| BACKWARD |
### RotationDirection (Enum)
| Values |
| - |
| COUNTER_CLOCKWISE |
| CLOCKWISE |
### GameEndReason (Enum)
| Values |
| - |
| DISCONNECT |
| REGULAR(is_winner: bool) |
### ShipAssignment (Struct)
| Field | Type | Explanation |
| - | - | - |
| shipNumber | int | |
| coordinate | Coordinate | coordinate of ship origin |
| direction | Direction | direction of ship |
## Error Codes
| Number | Reason |
| - | - |
## Messages
### Errors
Responses can either be:
- A success
- A failure with a error code and an optional error message
A response always contains the response type and, iff successfull all fields of the specific response. If the response is non-successfull it instead contains an error code and a optional error message.
The equivalent rust type would be:
```rust
enum Response<T> {
Ok(T),
Error(int, Option<String>)
}
```
### Serverbound
#### Discovery
##### serverConfigRequest
Every client can request the config of the server, even before joining the lobby.
| Field | Type | Explanation |
| - | - | - |
##### joinRequest
Sent by the client to get to the server lobby.
| Field | Type | Explanation |
| - | - | - |
| username | String | |
#### Lobby
##### teamSwitchRequest
| Field | Type | Explanation |
| - | - | - |
##### setReadyStateRequest
| Field | Type | Explanation |
| - | - | - |
| readyState | bool | New ready state |
#### Placement
##### setPlacementRequest
| Field | Type | Explanation |
| - | - | - |
| assignments | ShipAssignment[] | Assignments |
#### Game
##### serverStateRequest
| Field | Type | Explanation |
| - | - | - |
##### shipActionRequest
| Field | Type | Explanation |
| - | - | - |
| shipNumber | int | Origin of action |
### Clientbound
#### Discovey
##### serverAdvertisment
Sent via multicast to every device in the local network at a regular interval while the server is in the lobby state.
| Field | Type | Explanation |
| - | - | - |
| address | String | Adress of server |
##### joinResponse: Response to joinRequest
Response to the client who requested to join the lobby.
| Field | Type | Explanation |
| - | - | - |
| playerId | int | Unique server assigned player id |
##### serverConfigResponse: Response to serverConfigRequest
Response to the client who requested the server config.
| Field | Type | Explanation |
| - | - | - |
| config | Config | Configuration of the server |
#### Lobby
##### teamSwitchResponse: Response to teamSwitchRequest
Response to the client who requested to switch teams.
| Field | Type | Explanation |
| - | - | - |
##### setReadyStateResponse: Response to setReadyStateRequest
Response to the client who requested a ready state change.
| Field | Type | Explanation |
| - | - | - |
##### lobbyChangeEvent
Sent to every client connected to the lobby to inform them about a change in the members of a team / the ready state of players.
| Field | Type | Explanation |
| - | - | - |
| teams | PlayerLobbyState[2][] | |
#### Placement
##### placementPhase
Sent to every client who is connected to the lobby when everyone is in the ready state and the team sizes are not violated.
| Field | Type | Explanation |
| - | - | - |
| corner | Coordinate | Coordinate of the bottom left corner |
##### placementResponse: Response to placementRequest
Sent to the client who requested to place his ships.
| Field | Type | Explanation |
| - | - | - |
#### Game
##### gameStart
Note: This method moves the client from the Placement Phase to the Game Phase
Sent to every client connected to the server once every player has sent a valid ship placement.
| Field | Type | Explanation |
| - | - | - |
| state | ServerState | |
##### serverStateResponse: Response to serverStateRequest
Sent to the client who requested the state of the game the server has.
| Field | Type | Explanation |
| - | - | - |
| state | ServerState | |
##### shipActionResponse: Response to shipActionRequest
Sent to the client who requested one of the ship actions.
| Field | Type | Explanation |
| - | - | - |
##### nextTurn
Sent to every player in the game to indicate that it is now the turn of another player.
| Field | Type | Explanation |
| - | - | - |
| nextPlayerId | int | The id of the next Player |
| positionInQueue | int | turns remaining |
##### hitEvent
Sent to the team of the player who performed the hit and the team of the player who received the hit.
| Field | Type | Explanation |
| - | - | - |
| coordinate | Coordinate | Coordinate of the hit |
| damage | int | Damage dealt |
##### destructionEvent
Sent to the team of the player who performed the destructive shot and the team of the player who received the destructive shot.
| Field | Type | Explanation |
| - | - | - |
| coordinate | Coordinate | Coordinate of destructive hit |
TODO: Ask if destruction should display whole ship
- (shipType)
- (position)
- (orientation)
##### visionEvent
Sent to the players of a team once their collective vision changes.
| Field | Type | Explanation |
| - | - | - |
| isShip | bool | Whether a ship is visible at the coordinate. When a ship gets out of vision, server sends a isShip=false and the client decides whether to draw fog of war or water |
| coordinate | Coordinate | Where the vision event occured |
##### shipActionEvent
Sent to the team of the player who performed the ship action.
| Field | Type | Explanation |
| - | - | - |
| action | ShipAction | Ship Action |
| shipNumber | int | Origin of action |
##### gameOverEvent
Sent to every player in the game once a team won or a player left the game.
| Field | Type | Explanation |
| - | - | - |
| reason | GameEndReason | |
## Example
P is the current player
E is a enemy of P
T is a teammate of P
S is the server
### Successfull torpedo attack
1. (P -> S) shipActionRequest { action: TORPEDO::({Direction::NORTH}), ship_number: 2 }
2. (S -> P) Response::OK ({ shipActionResponse { } }
3. (S -> P,T) shipActionEvent { action: TORPEDO::({Direction::NORTH}), ship_number: 2 }
4. (S -> P,T,E) hitEvent { coordinate: (21, 16), damage: 400 }
5. (S -> P,T,E) destructionEvent { coordinate: (21, 16) }
### Failed torpedo attack
1. (P -> S) shipActionRequest { action: TORPEDO::({Direction::NORTH}), ship_number: 2 }
2. (S -> P) Response::Error { error_code: 501, error_msg: "Cruiser cant shoot torpedo" }
## Tasks
| Tasks | Assigned
| - | -
| Consider all Request Response Pairs and add Error Codes to the Error table for possible errors|
| Explain the Error Mechanism for Responses|
| Specify all Client-Bound Discovery Messages in the RFC|
| Specify all Client-Bound Lobby Messages in the RFC|
| Specify all Client-Bound Placement Messages in the RFC|MG2
| Specify all Client-Bound Game Messages in the RFC |
| Specify all Server-Bound Discovery Messages in the RFC|
| Specify all Server-Bound Lobby Messages in the RFC|
| Specify all Server-Bound Placement Messages in the RFC|
| Specify all Server-Bound Game Messages in the RFC |
|ServerState, ShipState, ShipType
|ShipBalancing, ShipTypeWithBalancing, CommonBalancing, Costs
|Config, PlayerLobbyState, Coordinate, ShipAssignment
|ScoutBalancing, MultiMissileBalancing, PredatorBalancing, EngineBoostBalancing, TorpedoBalancing
|MoveProperties, ShootProperties, RotateProperties, ScoutProperties, MultiMissileProperties, PredatorProperties, EngineBoostProperties, TorpedoProperties
|Direction, MoveDirection, RotationDirection, GameEndReason| MG2
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