public static bool Transfer(byte[] from, byte[] to, BigInteger amount)
{
if (!ValidateAddress(from) || !ValidateAddress(to))
{
throw new Exception("The parameters from and to SHOULD be 20-byte addresses.");
}
if (amount <= 0)
{
throw new Exception("The parameter amount MUST be greater than 0.");
}
if (!IsPayable(to))
{
throw new Exception("Receiver cannot receive.");
}
if (!Runtime.CheckWitness(from) && !from.Equals(ExecutionEngine.CallingScriptHash))
{
throw new Exception("No authorization.");
}
if (AssetStorage.Get(from) < amount)
{
throw new Exception("Insufficient balance.");
}
if (from == to)
{
return(true);
}
AssetStorage.Reduce(from, amount);
AssetStorage.Increase(to, amount);
OnTransfer(from, to, amount);
return(true);
}
public static bool Mint()
{
if (Runtime.InvocationCounter != 1)
{
throw new Exception("InvocationCounter must be 1.");
}
var notifications = Runtime.GetNotifications();
if (notifications.Length == 0)
{
throw new Exception("Contribution transaction not found.");
}
BigInteger neo = 0;
BigInteger gas = 0;
for (int i = 0; i < notifications.Length; i++)
{
var notification = notifications[i];
if (notification.ScriptHash == NeoToken)
{
neo += GetTransactionAmount(notification);
}
else if (notification.ScriptHash == GasToken)
{
gas += GetTransactionAmount(notification);
}
}
var totalSupply = TotalSupplyStorage.Get();
if (totalSupply <= 0)
{
throw new Exception("Contract not deployed.");
}
var avaliable_supply = MaxSupply - totalSupply;
var contribution = (neo * TokensPerNEO) + (gas * TokensPerGAS);
if (contribution <= 0)
{
throw new Exception("Contribution cannot be zero.");
}
if (contribution > avaliable_supply)
{
throw new Exception("Insufficient supply for mint tokens.");
}
Transaction tx = (Transaction)ExecutionEngine.ScriptContainer;
AssetStorage.Increase(tx.Sender, contribution);
TotalSupplyStorage.Increase(contribution);
OnTransfer(null, tx.Sender, contribution);
return(true);
}
public static bool Deploy()
{
if (!IsOwner())
{
throw new Exception("No authorization.");
}
if (TotalSupplyStorage.Get() > 0)
{
throw new Exception("Contract has been deployed.");
}
TotalSupplyStorage.Increase(InitialSupply);
AssetStorage.Increase(Owner, InitialSupply);
OnTransfer(null, Owner, InitialSupply);
return(true);
}