[300 SigmaUSD] Vote for update(pool) command

[greenhat]

Should be done after #45 is merged.

To vote for the pool box update as per https://github.com/ergoplatform/eips/blob/bd7a6098db78d67ac2ca9ada4c09bfe709d5ac03/eip-0023.md#vote-for-update (with updates introduced in v2.0a, e.g reward tokens were moved from the refresh box to the pool box) add a new command line option --vote-update-pool with the following parameters:

• new pool box hash (blake2b256);
• height of the update box;

If the ballot token is locked in the existing ballot box (i.e. output of the previous update tx) it should be spent to create the new ballot box.

[kettlebell]

I will work on this.

[kettlebell]

Hi @greenhat I have a question about this issue:

Should the owner of the ballot token have their group element stored in the oracle config? Seems like it since we will need to implement transfer ballot token.

• An idea: we could do away with storing it in the config by scanning for local ballot box as follows:
  • Get all wallet addresses from node /wallet/addresses endpoint. For each address a, perform a scan for the box with the ballot_token_id and the group element of a in R4.

What do you reckon? Thanks.

[greenhat]

Hi @greenhat I have a question about this issue:

Should the owner of the ballot token have their group element stored in the oracle config? Seems like it since we will need to implement transfer ballot token.

* An idea: we could do away with storing it in the config by scanning for local ballot box as follows:
  
  * Get all wallet addresses from node `/wallet/addresses` endpoint. For each address `a`, perform a scan for the box with the `ballot_token_id` and the group element of `a` in `R4`.

What do you reckon? Thanks.

I think it's ok to store it in the config. Scanning for it seems way more complex. Let's try a simple solution first. :)

[greenhat]

There is an updated (with v2.0a changes) version of the EIP - ergoplatform/eips#41

[kettlebell]

Got it, thanks!

[kettlebell]

I'm almost done with this issue but I ran into a problem with the case where we're spending an existing ballot box. I got the following error:
TxSigningError(ProverError(EvalError(Misc("ByIndex: index Int(0) out of bounds for collection size 0")), 0))

I tracked it down and the problem originates in this line of the contract. Now I believe we need to amend the contract because for the vote for update command there's only one fixed input (the existing ballot box) as specified in the EIP, and so INPUTS(1) has no guarantee to contain any token.

So I amended the contract by removing the line with val otherTokenId = INPUTS(1).tokens(0)._1 and replacing update with:

val update = INPUTS.size > 1                           &&
             INPUTS(1).tokens.size > 0                 &&
             INPUTS(1).tokens(0)._1 == updateNFT       && // can only update when update box is the 2nd input
             output.R4[GroupElement].get == selfPubKey && // public key is preserved
             output.value >= SELF.value                && // value preserved or increased
             ! (output.R5[Any].isDefined)                 // no more registers; prevents box from being reused as a valid vote 

Then the test passes (playground link) Am I doing this correctly?

[greenhat]

@kettlebell Good call! I agree.
@scalahub Please check and approve the proposed update to the ballot contract above. The reason for the update is that val otherTokenId = INPUTS(1).tokens(0)._1 throws on voting, i.e. spending the ballot box without the update box.