lbryio/chainquery

package e2e

import (
    "github.com/btcsuite/btcd/btcjson"
    "github.com/lbryio/lbry.go/v2/extras/errors"
)

type outputFinder struct {
    unspent     []btcjson.ListUnspentResult
    lastChecked int
}

func newOutputFinder(unspentResults []btcjson.ListUnspentResult) *outputFinder {
    return &outputFinder{unspent: unspentResults, lastChecked: -1}
}

func (f *outputFinder) nextBatch(minAmount float64) ([]btcjson.ListUnspentResult, error) {
    var batch []btcjson.ListUnspentResult
    var lbcBatched float64
    for i, unspent := range f.unspent {
        if i > f.lastChecked {
            if unspent.Spendable {
                batch = append(batch, unspent)
                lbcBatched = lbcBatched + unspent.Amount
            }
        }
        if lbcBatched >= minAmount {
            f.lastChecked = i
            break
        }
        if i == len(f.unspent)-1 {
            return nil, errors.Err("Not enough unspent outputs to spend %d on supports.", minAmount)
        }
    }

    return batch, nil
}