zec

const (
	// MinimumTxOverhead
	// 4 header + 4 nVersionGroup + 1 varint input count + 1 varint output count
	// + 4 lockTime + 4 nExpiryHeight + 8 valueBalanceSapling + 1 varint nSpendsSapling
	// + 1 varint nOutputsSapling + 1 varint nJoinSplit
	MinimumTxOverhead = 29

	InitTxSizeBase = MinimumTxOverhead + btc.P2PKHOutputSize + btc.P2SHOutputSize // 29 + 34 + 32 = 95
	InitTxSize     = InitTxSizeBase + btc.RedeemP2PKHInputSize                    // 95 + 149 = 244

	// LegacyFeeRate returns a standard 10 zats / byte. Prior to ZIP-0317, Zcash
	// used a standard tx fee of 1000 zats, regardless of tx size. We don't
	// handle fees correctly yet though, so just use a fee / byte that
	// guarantees a tx fee of > 1000 zats. A single input spending a p2pkh
	// output is 149 bytes, so 10 zats / byte should be sufficient for any tx.
	//
	// However, zcashd v5.5 begins making stricter fee requirements for both
	// relay and block inclusion. The release notes state that relay by default
	// still works with 1000 zat fee txns, but it may be adjusted by operators,
	// and it may need to be set to the higher ZIP 317 rate. For mining, there
	// is a small allowance on the number of "unpaid actions" allowed in a
	// block, so we should take care to pay the ZIP 317 "conventional" rate,
	// which is multiples of 5000 zats, and a minimum of 10000. To ensure we
	// have no unpaid actions in our (transparent) transactions, we need a
	// higher rate. For a 242 byte transaction, like a swap init, we can emulate
	// this with about 42 zats/byte. Even with 100 zats/byte, our typical redeem
	// of ~342 bytes would pay 34200 zats, which is only about a penny, so to
	// ensure our transactions are relayed and mined, we go with a high rate.
	LegacyFeeRate = 84
)

const (
	VersionPreOverwinter = 2
	VersionOverwinter    = 3
	VersionSapling       = 4
	VersionNU5           = 5
	MaxExpiryHeight      = 499999999 // https://zips.z.cash/zip-0203

)