# Wheel

The better name which will be helpful for Google seacrh is "Fortune Wheel".
Here, we call this game is just wheel, in which user pay for a turn of the
wheel to get some reward.

## Code name

`wheel`.

## Rules

- User must place a bet to turn the wheel for one round.
- User will win the money by the score of the wheel

So, technically:

- User must always pay first. They will always win, but the winning price might
be smaller that the price they have paid.

## Consideration

The wheel should be configurable. Visually aspect, the wheel score can
distribtued evenly:


Or non even


Thus, following things should be configurable **per partner**:

- Number of segments.
- Weight of each segment.
- Score or the money that user can get for each segment
- Display of segments (background color, icons, images ...)
- Price that user must pay per turn.

## Technical design

### DB

3 tables main:

- `wheel_config`:

- Should ref `partner_id`, for partner to enable this game and config the
- `id`, `ctime`, `mtime`, `status`
- `bg_sound`: `sound/bg.wav`
- `win_sound`: `sound/win.wav`
- `bet_sound`: `sound/bet.wav`
- `bet_amount`: `400`
- `theme`: ``,

- `wheel_segment_config`:

- `id`, `ctime`, `mtime`, `status`
- `label`: `abc`
- `bg_color`: `#121212`
- `reward_amount`: `400`
- `icon`: `icon1.avg`
- `order_number`: `2`,
- `angle`: `10 degree`
- `wheel_config_id`: ref to `wheel_config`

- `wheel_game_record`
- Should ref `user_id`, `transaction`, `wallet`, ...
- `id`, `ctime`: read-only, hence, no `mtime`
- `user_id`
- `partner_id`
- `reward_amount`
- `wheel_type`:
- `result_type`: `UserWin` (1), `UserLost` (2), `Draw` (3)
- `bet_amount`: a bet money configure by partner API
`api/game/wheel_config`

### Staff API

- Create: should avoid conflict, as each partner ca only have 1 records in
`wheel_config` table.

RPC `/api/game/wheel_config

Request:

{
  "bg_sound": "sound/bg.wav",
  "win_sound": "sound/win.wav",
  "bet_sound": "sound/bet.wav",
  "bet_amount": 400,
  "theme": "theme_default.png"
}

Response:

{
  "id": 1,
  "bg_sound": "sound/bg.wav",
  "win_sound": "sound/win.wav",
  "bet_sound": "sound/bet.wav",
  "bet_amount": 400,
  "theme": "theme_default.png"
}

RPC `/api/game/wheel_segment_config`

Request:

[
  {
    "wheel_config_id": 1,
    "label": "abc",
    "bg_color": "#121212",
    "icon": "icon1.svg",
    "order_number": 2,
    "angle": 10,
    "reward_amount": 200
  },
  {
    "wheel_config_id": 1,
    "label": "efg",
    "bg_color": "#131313",
    "icon": "icon2.svg",
    "order_number": 1,
    "angle": 10,
    "reward_amount": 200
  }
]

- Update
- Read
- Delete: disable the game for the partner

### User API

2 API

- `/api/game/wheel_config`, RPC style.

- Input: nothing, we only need auth cookie to know which user, then find the
`partner_id` and from that, find the correct record in
`wheel_config`.
- Output: `wheel_config` for partner.

- `/api/game/wheel_segment_config`, RPC style.

- Input: nothing, we only need auth cookie to know which user, then find the
`partner_id` and from that, find the correct record in
`wheel_segment_config`.
- Output: `wheel_segment_config` for partner.

RPC `/api/game/wheel/bet`

Request: empty

Response format for `UserLost` case:

{
  "type": 2,
  "bet_amount": 100
}

### Implementation

RPC `/api/game/wheel/bet`

After client submit bet, the server should generate the result and
calculate reward for user, then:

- 2 new transactions should be created:

- The first one is type `BET`, subtracts user balance by the amount their
bet.
- The second one is type `REWARD`, increase user balance by the winning
amount.

RPC `/api/game/wheel_config`

The server save request common config game wheel from partner to DB.

RPC `/api/game/wheel_segment_config`

- The server processing request config segment of wheel and
save it to DB.
- The sum of `angle` less than or equal 360 degree

### Optimization

> Optional for now, just make sure that the game work correctly.

- `wheel_config` can be loaded and cached on first user of each partner.
- When staff edit the config for any partner, we will refresh their cache, and
also send a push notification to client to refresh their game config. For
now, the client will just call `api/games/wheel_config` when
init the game GUI.