feat(Board): generate random fish distribution on game board

plugin/src/main/kotlin/sc/plugin2023/Board.kt

@@ -3,6 +3,8 @@ package sc.plugin2023
 import com.thoughtworks.xstream.annotations.XStreamAlias
 import com.thoughtworks.xstream.annotations.XStreamImplicit
 import sc.api.plugins.*
+import kotlin.math.min
+import kotlin.math.roundToInt
 import sc.framework.deepCopy
 import kotlin.random.Random
 import sc.plugin2023.util.PenguinConstants as Constants
@@ -11,7 +13,7 @@ import sc.plugin2023.util.PenguinConstants as Constants
 @XStreamAlias(value = "board")
 class Board(
     @XStreamImplicit(itemFieldName = "row")
-    override val gameField: MutableTwoDBoard<Field> = generateFields()
+    override val gameField: MutableTwoDBoard<Field> = generateFields(),
 ): RectangularBoard<Field>(), IBoard {
 
     constructor(board: Board): this(board.gameField.deepCopy())
@@ -69,9 +71,10 @@ class Board(
     companion object {
         /** Generiert ein neues Spielfeld mit zufällig auf dem Spielbrett verteilten Fischen. */
         private fun generateFields(seed: Int = Random.nextInt()): MutableTwoDBoard<Field> {
-            var remainingFish = Constants.BOARD_SIZE * Constants.BOARD_SIZE
             val random = Random(seed)
-            println("Board Seed: $seed")
+            println("Board seed: $seed")
+
+            var remainingFish = Constants.BOARD_SIZE * Constants.BOARD_SIZE
             var maxholes = 5
             // Pro Hälfte 32 Felder, mind. 27 Schollen
             // Maximal (64-20)/2 = 22 2-Fisch-Schollen,
@@ -95,5 +98,78 @@ class Board(
             }
         }
 
+        private fun generateFieldsRandom(seed: Int = Random.nextInt()): MutableTwoDBoard<Field> {
+            val random = Random(seed)
+            println("Board seed: $seed")
+
+            val length = Constants.BOARD_SIZE
+            val width = Constants.BOARD_SIZE
+            val weightedInts =
+                listOf(Field(0) to 0.1f, Field(1) to 0.2f, Field(2) to 0.4f, Field(3) to 0.2f, Field(4) to 0.1f)
+            val totalSum = length * width
+            val halfWidth = width / 2
+            val halfEnforcedOnes = Constants.BOARD_SIZE / 2
+            val fields: TwoDBoard<Field> = Array(length) { Array(width) { Field(0) } }
+            var countOne = 0
+
+            for(i in 0 until length) {
+                for(j in 0 until halfWidth) {
+                    if(i * halfWidth + j < halfEnforcedOnes) {
+                        fields[i][j] = Field(1)
+                        countOne += 1
+                        continue
+                    }
+
+                    val currentSum = fields.sumOf { it -> it.sumOf { it.fish } }
+                    val notFilled = totalSum - (i * halfWidth + j)
+
+                    val weightedSum = weightedInts.sumOf { it.second.toDouble() }
+                    if(weightedSum.roundToInt() != 1) {
+                        throw IllegalArgumentException("The sum of the probabilities must be 1. It is $weightedSum")
+                    }
+
+                    val lowestPossible = weightedInts.filter { it.first.fish >= (totalSum - currentSum) / notFilled }
+                        .minOf { it.first.fish }
+                    val highestPossible = min(totalSum - currentSum, weightedInts.maxOf { it.first.fish })
+
+                    val possibleValues =
+                        weightedInts.filter { it.first.fish in lowestPossible..highestPossible }.map { it.first.fish }
+                    val possibleWeights =
+                        weightedInts.filter { it.first.fish in lowestPossible..highestPossible }.map { it.second }
+
+                    val value = random.nextFloat()
+                    var cumulativeWeight = 0f
+                    var index = 0
+                    while(index < possibleValues.size && cumulativeWeight + possibleWeights[index] < value) {
+                        cumulativeWeight += possibleWeights[index]
+                        index++
+                    }
+
+                    fields[i][j] = Field(possibleValues[index])
+                    countOne += if(fields[i][j].fish == 1) 1 else 0
+                }
+            }
+
+            for(i in 0 until length) {
+                for(j in 0 until halfWidth) {
+                    val x = random.nextInt(length)
+                    val y = random.nextInt(halfWidth)
+                    fields[i][j] = fields[x][y].also { fields[x][y] = fields[i][j] }
+                }
+            }
+
+            for(i in 0 until length) {
+                for(j in 0 until halfWidth) {
+                    // TODO ??
+                    //  fields[i] += fields[length - i - 1][halfWidth - j - 1]
+                }
+            }
+
+            return fields.let {
+                it + it.reversedArray().map { list ->
+                    Array(Constants.BOARD_SIZE) { index -> list[Constants.BOARD_SIZE - index - 1].deepCopy() }
+                }
+            }
+        }
     }
 }