Add BSV-20 option.

src/contracts/bsv20Option.ts

@@ -0,0 +1,95 @@
+import { BSV20V2 } from 'scrypt-ord'
+import {
+    assert,
+    ByteString,
+    hash256,
+    method,
+    prop,
+    PubKey,
+    pubKey2Addr,
+    Sig,
+    Utils,
+} from 'scrypt-ts'
+
+export class Bsv20Option extends BSV20V2 {
+    @prop()
+    grantor: PubKey
+
+    @prop(true)
+    grantee: PubKey
+
+    @prop()
+    tokenAmt: bigint
+
+    @prop()
+    strikePrice: bigint
+
+    @prop()
+    expirationTime: bigint
+
+    constructor(
+        id: ByteString,
+        sym: ByteString,
+        max: bigint,
+        dec: bigint,
+        grantor: PubKey,
+        grantee: PubKey,
+        tokenAmt: bigint,
+        strikePrice: bigint,
+        expirationTime: bigint
+    ) {
+        super(id, sym, max, dec)
+        this.init(...arguments)
+
+        this.grantor = grantor
+        this.grantee = grantee
+        this.tokenAmt = tokenAmt
+        this.strikePrice = strikePrice
+        this.expirationTime = expirationTime
+    }
+
+    @method()
+    public exercise(sigGrantee: Sig) {
+        // Check grantee sig.
+        assert(this.checkSig(sigGrantee, this.grantee), 'invalid sig grantee')
+
+        // Ensure grantee gets payed tokens.
+        let outputs = BSV20V2.buildTransferOutput(
+            pubKey2Addr(this.grantee),
+            this.id,
+            this.tokenAmt
+        )
+
+        // Ensure grantor gets payed satoshis.
+        const satAmt = this.strikePrice * this.tokenAmt
+        outputs += Utils.buildAddressOutput(pubKey2Addr(this.grantor), satAmt)
+
+        outputs += this.buildChangeOutput()
+
+        // Enforce outputs in call tx.
+        assert(hash256(outputs) == this.ctx.hashOutputs, 'hashOutputs mismatch')
+    }
+
+    @method()
+    public transfer(sigGrantee: Sig, newGrantee: PubKey) {
+        // Check grantee sig.
+        assert(this.checkSig(sigGrantee, this.grantee), 'invalid sig grantee')
+
+        // Set new grantee.
+        this.grantee = newGrantee
+
+        // Propagate contract.
+        let outputs = this.buildStateOutputFT(this.tokenAmt)
+        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')
+    }
+}