GAMBL

Development

Environment

Local

• $ solana config set --url localhost
• Run local ledger
  • $ anchor localnet
  • $ solana-test-validator if anchor not installed
  • $ solana-test-validator --reset if anchor not available and you need to reset the ledger

Compile

• $ anchor build or $ npm run build

Deploy

• $ anchor deploy or $ npm run deploy

Learning

This is by far the best tutorial in the world

Functionallity

Accounts

pub struct WheelOfFortune {
    pub timestamp: i64
    pub value: i8
}

pub struct WheelOfFortuneBet {
    pub author: Pubkey,
    pub game: Pubkey, // Which game is being bet on
    pub timestamp: i64,
    pub value: i8
}

Process

1. a game / WheelOfFortune account is instanciated by a user (fn: start_game)
   • This is a transaction with a instruction to create a new game. (
   • The rent for the game is 2 years to make the transaction exempt and the fee is carried by the owner (meaning ME!!)
     • currently the account is 11 bytes which is around 0,001 SOL for 2 years rent.
   • The game will initiate with 0 as value as this is the non-played state.
   • If a game is already running (value is not 0) a new game is not allowed to be created and the transaction will be rolled back.
2. a user can instanciate a bet WheelOfFortuneBet with the value the user is betting on.
   • Currently the bet is always 1 GAMBL coin TODO: this needs to be variable.
   • With instanciate a bet the betted GAMBL coins are transfered to the program owner (meaning ME!!)
   • The size of a bet account is 81 bytes which translates to 0,0015 SOL for 2 years / rent except.
   • The full fee of a bet is the rent exempt costs of the bet account (81 bytes) aswell as the rent exempt game account (11 bytes) itself.
     • This ensures that the game runs autonomous as the rent will always be payed.
     • This fee could theoretically be dropped to half a game account rent exempt since at least 2 people are needed for a game but this counts as profit for us.
   • If the game is not active (value > 0) the an error is thrown and the transaction is rolled back
3. Any user can at any point initiate the rolling of the WheelOfFortune game.
   • This is necessary since we can't schedule this automatically on the block chain as of right now.
   • Rolling does not create an account and is therefore free of charge.
   • The program will generate a random number 1-255 (0 is reserved for the non-played state).
   • After a value is determined the payout is calculated. TODO: Create nice math formulas for this.
     • If only one player bet correctly they get the full pool.
     • If more than one player bet on the correct value the split is calculated between them depending on their initial bet.
       • Each winning players percentage is caluclated by cumulating all winners bet and dividing it by their specific amount.
       • The players percentage is then calculated against the full pool to determine their winnings.
   • Each winners winnings is the tranferred to their wallet.
4. => Step 1

TODOS

• [] Block game creation if a game is active
• [] Block betting on old games
• [] Make the program owner (me) pay for game creation
• [] Increase the fee of a bet to make up for game creation fee
• [] Include the whole GAMBL token transfer functionallity