Komodo Airdrop

This Airdrop crate makes it easy to perform an airdrop from a Komodo Platform Assetchain, using KMD or any other assetchain.

extern crate komodo_airdrop;    

fn main() {    
    let snapshot = komodo_airdrop::Snapshot::builder()
        .on_chain(Chain::CHAIN)
        .exclude_addresses(vec![
            String::from("REbwjC5mfQBRevH78CuRjcvQudxa3ii5Ma"),
            String::from("RU9F2EdDzUNK4LUMgjLTMDmtCmDK1a9vrY"),
            String::from("RYEufBcEUsofxwt4bGUdroRGmAQxBR8aJG")
        ])
        .using_threshold(1.0) // only include addresses that contain at least 1 CHAIN
        .build()
        .unwrap();
    
    let airdrop = komodo_airdrop::Airdrop::builder()
        .using_chain(Chain::KMD)
        .include_interest(true)
        .using_snapshot(&snapshot)
        .fund_address("RQT7m4jcnWQxwqQQzh77WKNCuZotkRkAuk")
        .payout_ratio(0.75)
        .build()
        .unwrap();
}

If an airdrop happens from a multisig address (starts with b):

let signing_string = airdrop.signing_string(Some(String::from("<redeem_script here>")));
println!("{}", signing_string);

If not:

let signing_string = airdrop.signing_string(None);
println!("{}", signing_string);   

signing_string creates a raw transaction from the inputs of all utxos in the fund_address, and uses the resulting hex (a running daemon of the fund_address blockchain is required) to create a string that can be used as parameter string for the signrawtransaction daemon RPC, where in case of a multisig, a private key (WIF) needs to be supplied manually by the signer.

notes:

• ratio is applied to both balance and interest. any change includes interest against the same ratio

todo:

• documentation
  • why this airdrop crate is needed: KMD platform addresses are the same etc, so the only differentiator is an AC
• define static payout amount in addition to ratio
• let the builder pattern work with Results (trait type?) impossible, checking is done in build() now
• send back any remainders and/or interest to fund_address
• add P2SH inputs to support multisig airdrop
• airdrop take a reference to snapshot
• use JSON file as input to Airdrop
• only include necessary utxos as input to the transaction, to prevent using all utxos when it's not needed since the required amount to airdrop has been reached.
  • what about interest? if KMD && interest_included then spend all inputs to include all interest.
  • else spend only required utxos
    • with some kind of ordering of utxos to only use largest utxos
• use a global komodod daemon client instead of instantiating it a couple of times.
• use an Enum for ratio and amount in Airdrop
• Enum: add nonexhaustive to not have a breaking change when adding a new Enum variant

scenarios tested

• Multisig yes/no
• Ratio
• Amount
  • payout full amount
• Interest included

long term maybe's:

• serialize multisig raw tx for easy multiparty signing
  • would likely be separate crate