2021 01 15 dlc refactors (#2518)

* Kill DigitDecomp.isSigned

* Create TLVEndpoint, TLVMidpoint ADT. Also add helper method OutcomePayoutPoint.toTlvPoint

app/oracle-server/src/main/scala/org/bitcoins/oracle/server/OracleRoutes.scala

@@ -142,11 +142,13 @@ case class OracleRoutes(oracle: DLCOracle)(implicit
                     }
                     outcomes.map(num => Num(num.toDouble))
                   case decomp: DigitDecompositionEventDescriptorV0TLV =>
-                    val sign = if (decomp.isSigned) {
-                      Vector(Str("+"), Str("-"))
-                    } else {
-                      Vector.empty
+                    val sign = decomp match {
+                      case _: UnsignedDigitDecompositionEventDescriptor =>
+                        Vector.empty
+                      case _: SignedDigitDecompositionEventDescriptor =>
+                        Vector(Str("+"), Str("-"))
                     }
+
                     val digits = 0.until(decomp.numDigits.toInt).map { _ =>
                       0
                         .until(decomp.base.toInt)

core/src/main/scala/org/bitcoins/core/protocol/dlc/DLCMessage.scala

@@ -293,12 +293,7 @@ object DLCMessage {
     }
 
     override lazy val toTLV: ContractInfoV1TLV = {
-      val tlvPoints = outcomeValueFunc.points.map { point =>
-        TLVPoint(point.outcome,
-                 point.roundedPayout,
-                 point.extraPrecision,
-                 point.isEndpoint)
-      }
+      val tlvPoints = outcomeValueFunc.points.map(_.toTlvPoint)
 
       ContractInfoV1TLV(base, numDigits, totalCollateral, tlvPoints)
     }
@@ -312,6 +307,7 @@ object DLCMessage {
       val points = tlv.points.map { point =>
         val payoutWithPrecision =
           point.value.toLong + (BigDecimal(point.extraPrecision) / (1 << 16))
+
         OutcomePayoutPoint(point.outcome, payoutWithPrecision, point.isEndpoint)
       }
 

core/src/main/scala/org/bitcoins/core/protocol/dlc/DLCPayoutCurve.scala

@@ -1,6 +1,7 @@
 package org.bitcoins.core.protocol.dlc
 
 import org.bitcoins.core.currency.Satoshis
+import org.bitcoins.core.protocol.tlv.TLVPoint
 import org.bitcoins.core.util.{Indexed, NumberUtil}
 
 import scala.math.BigDecimal.RoundingMode
@@ -15,15 +16,26 @@ case class DLCPayoutCurve(points: Vector[OutcomePayoutPoint]) {
   /** These points (and their indices in this.points) represent the endpoints
     * between which interpolation happens.
     * In other words these endpoints define the pieces of the piecewise function.
+    *
+    * It's important to note that the index returned here is relative to the _entire_
+    * set of points, not the index relative to the set of endpoints.
     */
-  lazy val endpoints: Vector[Indexed[OutcomePayoutPoint]] =
-    Indexed(points).filter(_.element.isEndpoint)
+  lazy val endpoints: Vector[Indexed[OutcomePayoutEndpoint]] = {
+    val endpoints = points.zipWithIndex.collect {
+      case (o: OutcomePayoutEndpoint, idx) => (o, idx)
+    }
+    Indexed.fromGivenIndex(endpoints)
+  }
 
   /** This Vector contains the function pieces between the endpoints */
   lazy val functionComponents: Vector[DLCPayoutCurveComponent] = {
-    endpoints.init.zip(endpoints.tail).map { // All pairs of adjacent endpoints
+    val zipped: Vector[
+      (Indexed[OutcomePayoutEndpoint], Indexed[OutcomePayoutEndpoint])] =
+      endpoints.init.zip(endpoints.tail)
+    zipped.map { // All pairs of adjacent endpoints
       case (Indexed(_, index), Indexed(_, nextIndex)) =>
-        DLCPayoutCurveComponent(points.slice(index, nextIndex + 1))
+        val slice = points.slice(index, nextIndex + 1)
+        DLCPayoutCurveComponent(slice)
     }
   }
 
@@ -70,7 +82,13 @@ case class DLCPayoutCurve(points: Vector[OutcomePayoutPoint]) {
 sealed trait OutcomePayoutPoint {
   def outcome: Long
   def payout: BigDecimal
-  def isEndpoint: Boolean
+
+  def isEndPoint: Boolean = {
+    this match {
+      case _: OutcomePayoutEndpoint => true
+      case _: OutcomePayoutMidpoint => false
+    }
+  }
 
   def roundedPayout: Satoshis = {
     Satoshis(payout.setScale(0, RoundingMode.FLOOR).toLongExact)
@@ -89,6 +107,22 @@ sealed trait OutcomePayoutPoint {
       case OutcomePayoutMidpoint(_, _) => OutcomePayoutMidpoint(outcome, payout)
     }
   }
+
+  /** Converts our internal representation to a TLV that can be sent over the wire */
+  def toTlvPoint: TLVPoint = {
+    this match {
+      case _: OutcomePayoutEndpoint =>
+        TLVPoint(outcome = outcome,
+                 value = roundedPayout,
+                 extraPrecision = extraPrecision,
+                 isEndpoint = true)
+      case _: OutcomePayoutMidpoint =>
+        TLVPoint(outcome = outcome,
+                 value = roundedPayout,
+                 extraPrecision = extraPrecision,
+                 isEndpoint = false)
+    }
+  }
 }
 
 object OutcomePayoutPoint {
@@ -114,7 +148,6 @@ object OutcomePayoutPoint {
 
 case class OutcomePayoutEndpoint(outcome: Long, payout: BigDecimal)
     extends OutcomePayoutPoint {
-  override val isEndpoint: Boolean = true
 
   def toMidpoint: OutcomePayoutMidpoint = OutcomePayoutMidpoint(outcome, payout)
 }
@@ -128,7 +161,6 @@ object OutcomePayoutEndpoint {
 
 case class OutcomePayoutMidpoint(outcome: Long, payout: BigDecimal)
     extends OutcomePayoutPoint {
-  override val isEndpoint: Boolean = false
 
   def toEndpoint: OutcomePayoutEndpoint = OutcomePayoutEndpoint(outcome, payout)
 }
@@ -179,9 +211,9 @@ sealed trait DLCPayoutCurveComponent {
 object DLCPayoutCurveComponent {
 
   def apply(points: Vector[OutcomePayoutPoint]): DLCPayoutCurveComponent = {
-    require(points.head.isEndpoint && points.last.isEndpoint,
+    require(points.head.isEndPoint && points.last.isEndPoint,
             s"First and last points must be endpoints, $points")
-    require(points.tail.init.forall(!_.isEndpoint),
+    require(points.tail.init.forall(!_.isEndPoint),
             s"Endpoint detected in middle, $points")
 
     points match {
@@ -320,9 +352,10 @@ case class OutcomePayoutCubic(
 /** A polynomial interpolating points and defining a piece of a larger payout curve */
 case class OutcomePayoutPolynomial(points: Vector[OutcomePayoutPoint])
     extends DLCPayoutCurveComponent {
-  require(points.head.isEndpoint && points.last.isEndpoint,
+  require(points.head.isInstanceOf[OutcomePayoutEndpoint] && points.last
+            .isInstanceOf[OutcomePayoutEndpoint],
           s"First and last points must be endpoints, $points")
-  require(points.tail.init.forall(!_.isEndpoint),
+  require(points.tail.init.forall(!_.isInstanceOf[OutcomePayoutEndpoint]),
           s"Endpoint detected in middle, $points")
 
   override lazy val leftEndpoint: OutcomePayoutEndpoint =

core/src/main/scala/org/bitcoins/core/protocol/tlv/TLV.scala

@@ -603,9 +603,6 @@ sealed trait DigitDecompositionEventDescriptorV0TLV
   require(numDigits > UInt16.zero,
           s"Number of digits must be positive, got $numDigits")
 
-  /** Whether the outcome can be negative */
-  def isSigned: Boolean
-
   /** The number of digits that the oracle will sign */
   def numDigits: UInt16
 
@@ -613,22 +610,32 @@ sealed trait DigitDecompositionEventDescriptorV0TLV
 
   private lazy val maxDigit: NormalizedString = (base.toInt - 1).toString
 
-  override lazy val max: Vector[NormalizedString] = if (isSigned) {
-    NormalizedString("+") +: Vector.fill(numDigits.toInt)(maxDigit)
-  } else {
-    Vector.fill(numDigits.toInt)(maxDigit)
+  override lazy val max: Vector[NormalizedString] = {
+    this match {
+      case _: SignedDigitDecompositionEventDescriptor =>
+        NormalizedString("+") +: Vector.fill(numDigits.toInt)(maxDigit)
+      case _: UnsignedDigitDecompositionEventDescriptor =>
+        Vector.fill(numDigits.toInt)(maxDigit)
+
+    }
   }
 
-  override lazy val minNum: BigInt = if (isSigned) {
-    -maxNum
-  } else {
-    0
+  override lazy val minNum: BigInt = {
+    this match {
+      case _: SignedDigitDecompositionEventDescriptor =>
+        -maxNum
+      case _: UnsignedDigitDecompositionEventDescriptor =>
+        0
+    }
   }
 
-  override lazy val min: Vector[NormalizedString] = if (isSigned) {
-    NormalizedString("-") +: Vector.fill(numDigits.toInt)(maxDigit)
-  } else {
-    Vector.fill(numDigits.toInt)("0")
+  override lazy val min: Vector[NormalizedString] = {
+    this match {
+      case _: SignedDigitDecompositionEventDescriptor =>
+        NormalizedString("-") +: Vector.fill(numDigits.toInt)(maxDigit)
+      case _: UnsignedDigitDecompositionEventDescriptor =>
+        Vector.fill(numDigits.toInt)("0")
+    }
   }
 
   override lazy val step: UInt16 = UInt16.one
@@ -637,16 +644,26 @@ sealed trait DigitDecompositionEventDescriptorV0TLV
     DigitDecompositionEventDescriptorV0TLV.tpe
 
   override lazy val value: ByteVector = {
-    base.bytes ++
-      boolBytes(isSigned) ++
-      strBytes(unit) ++
+    val start = base.bytes
+    val signByte = this match {
+      case _: UnsignedDigitDecompositionEventDescriptor =>
+        boolBytes(false)
+      case _: SignedDigitDecompositionEventDescriptor =>
+        boolBytes(true)
+    }
+    val end = strBytes(unit) ++
       precision.bytes ++
       numDigits.bytes
+    start ++ signByte ++ end
   }
 
   override def noncesNeeded: Int = {
-    if (isSigned) numDigits.toInt + 1
-    else numDigits.toInt
+    this match {
+      case _: SignedDigitDecompositionEventDescriptor =>
+        numDigits.toInt + 1
+      case _: UnsignedDigitDecompositionEventDescriptor =>
+        numDigits.toInt
+    }
   }
 }
 
@@ -656,9 +673,7 @@ case class SignedDigitDecompositionEventDescriptor(
     numDigits: UInt16,
     unit: NormalizedString,
     precision: Int32)
-    extends DigitDecompositionEventDescriptorV0TLV {
-  override val isSigned: Boolean = true
-}
+    extends DigitDecompositionEventDescriptorV0TLV
 
 /** Represents a large range event that is unsigned */
 case class UnsignedDigitDecompositionEventDescriptor(
@@ -666,9 +681,7 @@ case class UnsignedDigitDecompositionEventDescriptor(
     numDigits: UInt16,
     unit: NormalizedString,
     precision: Int32)
-    extends DigitDecompositionEventDescriptorV0TLV {
-  override val isSigned: Boolean = false
-}
+    extends DigitDecompositionEventDescriptorV0TLV
 
 object DigitDecompositionEventDescriptorV0TLV
     extends TLVFactory[DigitDecompositionEventDescriptorV0TLV] {
@@ -895,7 +908,11 @@ object TLVPoint extends Factory[TLVPoint] {
     val outcome = BigSizeUInt(bytes.tail)
     val value = UInt64(bytes.drop(1 + outcome.byteSize).take(8))
     val extraPrecision = UInt16(bytes.drop(9 + outcome.byteSize).take(2)).toInt
-    TLVPoint(outcome.toLong, Satoshis(value.toLong), extraPrecision, isEndpoint)
+
+    TLVPoint(outcome = outcome.toLong,
+             value = Satoshis(value.toLong),
+             extraPrecision = extraPrecision,
+             isEndpoint = isEndpoint)
   }
 }
 

core/src/main/scala/org/bitcoins/core/util/Indexed.scala

@@ -1,10 +1,20 @@
 package org.bitcoins.core.util
 
-case class Indexed[T](element: T, index: Int)
+case class Indexed[+T](element: T, index: Int)
 
 object Indexed {
 
   def apply[T](vec: Vector[T]): Vector[Indexed[T]] = {
     vec.zipWithIndex.map { case (elem, index) => Indexed(elem, index) }
   }
+
+  /** Takes in a given vector of T's with their corresponding index
+    * and returns a Vector[Indexed[T]].
+    *
+    * This is useful in situations where you want to preserve the initial
+    * index in a set of elements, but have performed subsequent collection operations (like .filter, .filterNot, .collect etc)
+    */
+  def fromGivenIndex[T](vec: Vector[(T, Int)]): Vector[Indexed[T]] = {
+    vec.map { case (t, idx) => Indexed(t, idx) }
+  }
 }

dlc-oracle/src/main/scala/org/bitcoins/dlc/oracle/DLCOracle.scala

@@ -300,12 +300,14 @@ case class DLCOracle(private val extPrivateKey: ExtPrivateKeyHardened)(implicit
       oracleEventTLV: OracleEventTLV,
       num: Long): Future[OracleEvent] = {
 
-    val eventDescriptorTLV = oracleEventTLV.eventDescriptor match {
-      case _: EnumEventDescriptorV0TLV | _: RangeEventDescriptorV0TLV =>
-        throw new IllegalArgumentException(
-          "Must have a DigitDecomposition event descriptor use signEvent instead")
-      case decomp: DigitDecompositionEventDescriptorV0TLV =>
-        decomp
+    val eventDescriptorTLV: DigitDecompositionEventDescriptorV0TLV = {
+      oracleEventTLV.eventDescriptor match {
+        case _: EnumEventDescriptorV0TLV | _: RangeEventDescriptorV0TLV =>
+          throw new IllegalArgumentException(
+            "Must have a DigitDecomposition event descriptor use signEvent instead")
+        case decomp: DigitDecompositionEventDescriptorV0TLV =>
+          decomp
+      }
     }
 
     // Make this a vec so it is easier to add on
@@ -338,9 +340,12 @@ case class DLCOracle(private val extPrivateKey: ExtPrivateKeyHardened)(implicit
                                           eventDescriptorTLV.base.toInt,
                                           eventDescriptorTLV.numDigits.toInt)
 
-    val nonces =
-      if (eventDescriptorTLV.isSigned) oracleEventTLV.nonces.tail
-      else oracleEventTLV.nonces
+    val nonces = eventDescriptorTLV match {
+      case _: UnsignedDigitDecompositionEventDescriptor =>
+        oracleEventTLV.nonces
+      case _: SignedDigitDecompositionEventDescriptor =>
+        oracleEventTLV.nonces.tail
+    }
 
     val digitSigFs = nonces.zipWithIndex.map {
       case (nonce, index) =>

dlc-oracle/src/main/scala/org/bitcoins/dlc/oracle/util/EventDbUtil.scala

@@ -60,7 +60,12 @@ trait EventDbUtil {
             Vector.empty
         }
 
-        val digitNonces = if (decomp.isSigned) nonces.tail else nonces
+        val digitNonces = decomp match {
+          case _: UnsignedDigitDecompositionEventDescriptor =>
+            nonces
+          case _: SignedDigitDecompositionEventDescriptor =>
+            nonces.tail
+        }
 
         val digitDbs = digitNonces.flatMap { nonce =>
           0.until(decomp.base.toInt).map { num =>