/* Lotter Smart Contract in DVM-BASIC This lottery smart contract will give lottery wins every xth try. */ Function Lottery(value Uint64) Uint64 10 dim deposit_count,winner as Uint64 20 LET deposit_count = LOAD("deposit_count")+1 25 IF value == 0 THEN GOTO 110 // if deposit amount is 0, simply return 30 STORE("depositor_address" + (deposit_count-1), SIGNER()) // store address for later on payment 40 STORE("deposit_total", LOAD("deposit_total") + value ) 50 STORE("deposit_count",deposit_count) 60 IF LOAD("lotteryeveryXdeposit") > deposit_count THEN GOTO 110 // we will wait till X players join in // we are here means all players have joined in, roll the DICE, 70 LET winner = RANDOM() % deposit_count // we have a winner 80 SEND_DERO_TO_ADDRESS(LOAD("depositor_address" + winner) , LOAD("lotterygiveback")*LOAD("deposit_total")/10000) // re initialize for another round 90 STORE("deposit_count", 0) // initial players 100 STORE("deposit_total", 0) // total deposit of all players 110 RETURN 0 End Function // this function is used to initialize parameters during install time Function Initialize() Uint64 10 STORE("owner", SIGNER()) // store in DB ["owner"] = address 20 STORE("lotteryeveryXdeposit", 2) // lottery will reward every X deposits // how much will lottery giveback in 1/10000 parts, granularity .01 % 30 STORE("lotterygiveback", 9900) // lottery will give reward 99% of deposits, 1 % is accumulated for owner to withdraw 33 STORE("deposit_count", 0) // initial players 34 STORE("deposit_total", 0) // total deposit of all players 35 printf "Initialize executed" 40 RETURN 0 End Function // used to tune lottery parameters Function TuneLotteryParameters(input Uint64, lotteryeveryXdeposit Uint64, lotterygiveback Uint64) Uint64 10 dim key,stored_owner as String 20 dim value_uint64 as Uint64 30 IF ADDRESS_RAW(LOAD("owner")) == ADDRESS_RAW(SIGNER()) THEN GOTO 100 // check whether owner is real owner 40 RETURN 1 100 STORE("lotteryeveryXdeposit", lotteryeveryXdeposit) // lottery will reward every X deposits 130 STORE("lotterygiveback", value_uint64) // how much will lottery giveback in 1/10000 parts, granularity .01 % 140 RETURN 0 // return success End Function // this function is used to change owner // owner is an string form of address Function TransferOwnership(newowner String) Uint64 10 IF ADDRESS_RAW(LOAD("owner")) == ADDRESS_RAW(SIGNER()) THEN GOTO 30 20 RETURN 1 30 STORE("tmpowner",newowner) 40 RETURN 0 End Function // until the new owner claims ownership, existing owner remains owner Function ClaimOwnership() Uint64 10 IF ADDRESS_RAW(LOAD("tmpowner")) == ADDRESS_RAW(SIGNER()) THEN GOTO 30 20 RETURN 1 30 STORE("owner",SIGNER()) // ownership claim successful 40 RETURN 0 End Function // if signer is owner, withdraw any requested funds // if everthing is okay, thety will be showing in signers wallet Function Withdraw( amount Uint64) Uint64 10 IF ADDRESS_RAW(LOAD("owner")) == ADDRESS_RAW(SIGNER()) THEN GOTO 30 20 RETURN 1 30 SEND_DERO_TO_ADDRESS(SIGNER(),amount) 40 RETURN 0 End Function