prime-safe-liquidation.tapscript

//Liquidation: Treasury can Unlock all collateral
// with Attestation Price below the liquidation target price when Burning Fuji
//
// constructorInputs:
//      priceLevel: uint64
//      setupTimestamp: uint64
//      oraclePk: xonlypubkey
//      borrowAsset: asset
//      borrowAmount: value
//      treasuryPk: value
//      assetPair: bytes
//
// functionInputs:
//      currentPrice: uint64
//      timestamp: uint64
//      oracleSig: datasig
//      treasurySig: sig

// save $currentPrice
OP_DUP
// check $currentPrice < priceLevel
<$priceLevel>
OP_LESSTHAN64
OP_VERIFY
// copy $timestamp from the witness
OP_OVER
// make sure the $timestamp is after the contract setup time
<$setupTimestamp>
OP_GREATERTHANOREQUAL64
OP_VERIFY
// concatenate $currentPrice to the end of $timestamp
OP_CAT
// concatenate $assetPair to the end of $timestamp.$currentPrice
<$assetPair>
OP_CAT
// check that SHA2($timestamp.$currentPrice.$assetPair) was signed by the oracle
OP_SHA256
<$oraclePk>
OP_CHECKSIGFROMSTACKVERIFY
// get out 0 asset
<0>
OP_INSPECTOUTPUTASSET
// check that out 0 asset is explicit
<1>
OP_EQUALVERIFY
// check that out 0 asset is equal to $borrowAsset
<$borrowAsset>
OP_EQUALVERIFY
// get out 0 value
<0>
OP_INSPECTOUTPUTVALUE
// check that out 0 value is explicit
<1>
OP_EQUALVERIFY
// check that out 0 value is equal to $borrowAmount
<$borrowAmount>
OP_EQUALVERIFY
// take out 0 scriptpubkey
<0>
OP_INSPECTOUTPUTSCRIPTPUBKEY
// OP_RETURN is not a witness scriptPubKey, so its version will be -1
// check that the version is -1
<-1>
OP_EQUALVERIFY
// check that the out 0 scriptpubkey is really just OP_RETURN
<0x6a>
OP_SHA256
OP_EQUALVERIFY
// Check that the nonce on out 0 is empty
<0>
OP_INSPECTOUTPUTNONCE
<0>
OP_EQUALVERIFY
// Require authorization by Treasury
<$treasuryPk>
OP_CHECKSIG