Swiss ready to be tested

webapp/src/main/kotlin/org/jeudego/pairgoth/model/Pairing.kt

@@ -12,9 +12,7 @@ import java.util.Random
 // TODO - this is only an early draft
 
 sealed class Pairing(val type: PairingType) {
-    companion object {
-        val rand = Random(/* seed from properties - TODO */)
-    }
+    companion object {}
     enum class PairingType { SWISS, MACMAHON, ROUNDROBIN }
 
     abstract fun pair(tournament: Tournament, round: Int, pairables: List<Pairable>): List<Game>
@@ -30,7 +28,7 @@ class Swiss(
         val history =
             if (tournament.games.isEmpty()) emptyList()
             else tournament.games.slice(0 until round).flatMap { it.values }
-        return SwissSolver(history, actualMethod).pair(pairables)
+        return SwissSolver(history, pairables, actualMethod).pair()
     }
 }
 

webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/Solver.kt

@@ -9,19 +9,23 @@ import org.jgrapht.alg.matching.blossom.v5.ObjectiveSense
 import org.jgrapht.graph.DefaultWeightedEdge
 import org.jgrapht.graph.SimpleWeightedGraph
 import org.jgrapht.graph.builder.GraphBuilder
+import java.util.*
 
-sealed class Solver(private val history: List<Game>) {
+sealed class Solver(protected val history: List<Game>, protected val pairables: List<Pairable>) {
+
+    companion object {
+        val rand = Random(/* seed from properties - TODO */)
+    }
 
     open fun sort(p: Pairable, q: Pairable): Int = 0 // no sort by default
     abstract fun weight(p: Pairable, q: Pairable): Double
 
-    fun pair(pairables: List<Pairable>): List<Game> {
+    fun pair(): List<Game> {
         // check that at this stage, we have an even number of pairables
         if (pairables.size % 2 != 0) throw Error("expecting an even number of pairables")
-        val sorted = pairables.sortedWith(::sort)
         val builder = GraphBuilder(SimpleWeightedGraph<Pairable, DefaultWeightedEdge>(DefaultWeightedEdge::class.java))
-        for (i in sorted.indices) {
-            for (j in i + 1 until sorted.size) {
+        for (i in sortedPairables.indices) {
+            for (j in i + 1 until n) {
                 val p = pairables[i]
                 val q = pairables[j]
                 builder.addEdge(p, q, weight(p, q))
@@ -38,6 +42,35 @@ sealed class Solver(private val history: List<Game>) {
         return result
     }
 
+    // Calculation parameters
+
+    val n = pairables.size
+
+    // pairables sorted using overloadable sort function
+    private val sortedPairables by lazy {
+        pairables.sortedWith(::sort)
+    }
+
+    // place (among sorted pairables)
+    val Pairable.place: Int get() = _place[id]!!
+    private val _place by lazy {
+        sortedPairables.mapIndexed { index, pairable ->
+            Pair(pairable.id, index)
+        }.toMap()
+    }
+
+    // placeInGroup (of same score) : Pair(place, groupSize)
+    val Pairable.placeInGroup: Pair<Int, Int> get() = _placeInGroup[id]!!
+    private val _placeInGroup by lazy {
+        sortedPairables.groupBy {
+            it.score
+        }.values.flatMap { group ->
+            group.mapIndexed { index, pairable ->
+                Pair(pairable.id, Pair(index, group.size))
+            }
+        }.toMap()
+    }
+
     // already paired players map
     fun Pairable.played(other: Pairable) = _paired.contains(Pair(id, other.id))
     private val _paired: Set<Pair<Int, Int>> by lazy {

webapp/src/main/kotlin/org/jeudego/pairgoth/pairing/SwissSolver.kt

@@ -3,9 +3,14 @@ package org.jeudego.pairgoth.pairing
 import org.jeudego.pairgoth.model.Game
 import org.jeudego.pairgoth.model.Pairable
 import org.jeudego.pairgoth.model.Swiss
+import org.jeudego.pairgoth.model.Swiss.Method.*
 import kotlin.math.abs
 
-class SwissSolver(history: List<Game>, method: Swiss.Method): Solver(history) {
+class SwissSolver(history: List<Game>, pairables: List<Pairable>, val method: Swiss.Method): Solver(history, pairables) {
+
+    val PLAYED_WEIGHT = 1_000_000.0 // weight if players already met
+    val SCORE_WEIGHT = 10_000.0     // weight per difference of score
+    val PLACE_WEIGHT = 1_000.0      // weight per difference of place
 
     override fun sort(p: Pairable, q: Pairable): Int =
         when (p.score) {
@@ -14,8 +19,20 @@ class SwissSolver(history: List<Game>, method: Swiss.Method): Solver(history) {
         }
 
     override fun weight(p: Pairable, q: Pairable) = when {
-        p.played(q) -> 100_000.0
-        p.score != q.score -> abs(p.score - q.score) * 10_000.0
-        else -> abs(p.rating - q.rating) * 10.0
+        p.played(q) -> PLAYED_WEIGHT
+        p.score != q.score -> {
+            val placeWeight =
+                if (p.score > q.score) (p.placeInGroup.second + q.placeInGroup.first) * PLACE_WEIGHT
+                else (q.placeInGroup.second + p.placeInGroup.first) * PLACE_WEIGHT
+            abs(p.score - q.score) * SCORE_WEIGHT + placeWeight
+        }
+        else -> when (method) {
+            SPLIT_AND_FOLD ->
+                if (p.placeInGroup.first > q.placeInGroup.first) abs(p.placeInGroup.first - (q.placeInGroup.second - q.placeInGroup.first)) * PLACE_WEIGHT
+                else abs(q.placeInGroup.first - (p.placeInGroup.second - p.placeInGroup.first)) * PLACE_WEIGHT
+            SPLIT_AND_RANDOM -> rand.nextDouble(p.placeInGroup.second.toDouble()) * PLACE_WEIGHT
+            SPLIT_AND_SLIP -> abs(abs(p.placeInGroup.first - q.placeInGroup.first) - p.placeInGroup.second) * PLACE_WEIGHT
+            else -> throw Error("unhandled case")
+        }
     }
 }