Add bsv-20 put option.

src/contracts/bsv20Option.ts → src/contracts/bsv20CallOption.ts

@@ -11,7 +11,7 @@ import {
     Utils,
 } from 'scrypt-ts'
 
-export class Bsv20Option extends BSV20V2 {
+export class Bsv20CallOption extends BSV20V2 {
     @prop()
     grantor: PubKey
 

src/contracts/bsv20PutOption.ts

@@ -0,0 +1,163 @@
+import { BSV20V2 } from 'scrypt-ord'
+import {
+    assert,
+    ByteString,
+    byteString2Int,
+    hash256,
+    method,
+    prop,
+    PubKey,
+    pubKey2Addr,
+    Sig,
+    slice,
+    Utils,
+} from 'scrypt-ts'
+import { RabinPubKey, RabinSig, RabinVerifier } from 'scrypt-ts-lib'
+
+export class Bsv20PutOption extends BSV20V2 {
+    @prop()
+    grantor: PubKey
+
+    @prop(true)
+    grantee: PubKey
+
+    @prop()
+    tokenAmt: bigint
+
+    @prop()
+    strikePrice: bigint
+
+    @prop()
+    expirationTime: bigint
+
+    @prop(true)
+    forSale: boolean
+
+    @prop(true)
+    premium: bigint
+
+    @prop()
+    oraclePubKey: RabinPubKey
+
+    constructor(
+        id: ByteString,
+        sym: ByteString,
+        max: bigint,
+        dec: bigint,
+        grantor: PubKey,
+        grantee: PubKey,
+        tokenAmt: bigint,
+        strikePrice: bigint,
+        expirationTime: bigint,
+        forSale: boolean,
+        premium: bigint,
+        oraclePubKey: RabinPubKey
+    ) {
+        super(id, sym, max, dec)
+        this.init(...arguments)
+
+        this.grantor = grantor
+        this.grantee = grantee
+        this.tokenAmt = tokenAmt
+        this.strikePrice = strikePrice
+        this.expirationTime = expirationTime
+        this.forSale = forSale
+        this.premium = premium
+        this.oraclePubKey = oraclePubKey
+    }
+
+    @method()
+    public exercise(
+        sigGrantee: Sig,
+        oracleSig: RabinSig,
+        oracleMsg: ByteString
+    ) {
+        // Check oracle signature.
+        assert(
+            RabinVerifier.verifySig(oracleMsg, oracleSig, this.oraclePubKey),
+            'oracle sig verify failed'
+        )
+
+        // Check that we're unlocking the UTXO specified in the oracles message.
+        assert(
+            slice(this.prevouts, 0n, 36n) == slice(oracleMsg, 0n, 36n),
+            'first input is not spending specified ordinal UTXO'
+        )
+
+        // Get token amount held by the UTXO from oracle message.
+        const utxoTokenAmt = byteString2Int(slice(oracleMsg, 36n, 44n))
+
+        // Check token amount is correct.
+        assert(utxoTokenAmt == this.tokenAmt, 'invalid token amount')
+
+        // Check grantee sig.
+        assert(this.checkSig(sigGrantee, this.grantee), 'invalid sig grantee')
+
+        // Ensure grantor gets payed tokens.
+        let outputs = BSV20V2.buildTransferOutput(
+            pubKey2Addr(this.grantor),
+            this.id,
+            this.tokenAmt
+        )
+
+        // Ensure grantee gets payed satoshis.
+        const satAmt = this.strikePrice * this.tokenAmt
+        outputs += Utils.buildAddressOutput(pubKey2Addr(this.grantee), satAmt)
+
+        outputs += this.buildChangeOutput()
+
+        // Enforce outputs in call tx.
+        assert(hash256(outputs) == this.ctx.hashOutputs, 'hashOutputs mismatch')
+    }
+
+    @method()
+    public buy(newGrantee: PubKey) {
+        // Check if option is up for sale.
+        assert(this.forSale, 'option is not up for sale')
+
+        // Set new grantee.
+        const prevGrantee = this.grantee
+        this.grantee = newGrantee
+
+        // Toggle for sale flag.
+        this.forSale = false
+
+        // Propagate contract.
+        let outputs = this.buildStateOutput(this.ctx.utxo.value)
+
+        // Make sure premium is payed to previous grantee / holder.
+        outputs += Utils.buildAddressOutput(
+            pubKey2Addr(prevGrantee),
+            this.premium
+        )
+
+        outputs += this.buildChangeOutput()
+        assert(hash256(outputs) == this.ctx.hashOutputs, 'hashOutputs mismatch')
+    }
+
+    @method()
+    public listForSale(sigGrantee: Sig, premium: bigint) {
+        // Check grantee sig.
+        assert(this.checkSig(sigGrantee, this.grantee), 'invalid sig grantee')
+
+        // Store premium value in property.
+        this.premium = premium
+
+        // Toggle for sale flag.
+        this.forSale = true
+
+        // Propagate contract.
+        let outputs = this.buildStateOutput(this.ctx.utxo.value)
+        outputs += this.buildChangeOutput()
+        assert(hash256(outputs) == this.ctx.hashOutputs, 'hashOutputs mismatch')
+    }
+
+    @method()
+    public expiry(sigGrantor: Sig) {
+        // Check grantor sig.
+        assert(this.checkSig(sigGrantor, this.grantor), 'invalid sig grantor')
+
+        // Check if expired.
+        assert(this.timeLock(this.expirationTime), 'option has not yet expired')
+    }
+}

src/contracts/bsv20SellLimitOrder.ts

@@ -56,7 +56,7 @@ export class BSV20SellLimitOrder extends BSV20V2 {
     }
 
     @method()
-    public buy(amount: bigint, buyerAddr: Addr) {
+    public buy(amount: bigint) {
         // Check token amount doesn't exceed total.
         assert(
             this.tokenAmtSold + amount < this.tokenAmt,