[CORE] Sparkline optimisation

shared/crypto/presentation/src/commonMain/kotlin/dev/ohoussein/cryptoapp/crypto/presentation/core/Math.kt

@@ -0,0 +1,18 @@
+package dev.ohoussein.cryptoapp.crypto.presentation.core
+
+fun List<Double>.averageValues(maxValues: Int = 20): List<Double> {
+    if (size <= maxValues) {
+        return this
+    }
+
+    val groupSize = size / maxValues
+    val averagedPrices = mutableListOf<Double>()
+
+    for (i in indices step groupSize) {
+        val group = subList(i, minOf(i + groupSize, size))
+        val avgPrice = group.average()
+        averagedPrices.add(avgPrice)
+    }
+
+    return averagedPrices
+}

shared/crypto/presentation/src/commonMain/kotlin/dev/ohoussein/cryptoapp/crypto/presentation/mapper/DomainModelMapper.kt

@@ -5,9 +5,11 @@ import dev.ohoussein.cryptoapp.core.formatter.PriceFormatter
 import dev.ohoussein.cryptoapp.crypto.domain.model.CryptoDetailsModel
 import dev.ohoussein.cryptoapp.crypto.domain.model.CryptoModel
 import dev.ohoussein.cryptoapp.crypto.domain.model.Locale
+import dev.ohoussein.cryptoapp.crypto.presentation.core.averageValues
 import dev.ohoussein.cryptoapp.crypto.presentation.model.*
 import dev.ohoussein.cryptoapp.designsystem.graph.model.GraphPoint
 
+private const val SPARKLINE_7D_MAX_VALUES = 7 * 4
 class DomainModelMapper(
     private val priceFormatter: PriceFormatter,
     private val percentFormatter: PercentFormatter,
@@ -31,7 +33,7 @@ class DomainModelMapper(
             priceChangePercentIn24h = domain.priceChangePercentIn24h?.let {
                 LabelValue(it, percentFormatter(it / 100.0))
             },
-            sparkline7d = domain.sparkLine7d?.mapIndexed { index, value ->
+            sparkline7d = domain.sparkLine7d?.averageValues(SPARKLINE_7D_MAX_VALUES)?.mapIndexed { index, value ->
                 GraphPoint(index.toDouble(), value)
             }
         )

shared/crypto/presentation/src/commonTest/kotlin/dev/ohoussein/cryptoapp/crypto/presentation/core/MathTest.kt

@@ -0,0 +1,37 @@
+package dev.ohoussein.cryptoapp.crypto.presentation.core
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class MathTest {
+
+    @Test
+    fun `Given values less than max value When call averageValues it it should return the same list`() {
+        val prices = listOf(100.0, 110.0, 105.0)
+        val result = prices.averageValues(maxValues = 20)
+        val expected = listOf(100.0, 110.0, 105.0)
+
+        assertEquals(expected, result)
+    }
+
+    @Test
+    fun `Given values When call averageValues it it should return the average values`() {
+        val prices = (1..40).map { it.toDouble() }
+        val result = prices.averageValues(maxValues = 20)
+        val expected = listOf(
+            1.5, 3.5, 5.5, 7.5, 9.5, 11.5, 13.5, 15.5, 17.5, 19.5,
+            21.5, 23.5, 25.5, 27.5, 29.5, 31.5, 33.5, 35.5, 37.5, 39.5
+        )
+
+        assertEquals(expected, result)
+    }
+
+    @Test
+    fun `Given empty values When call averageValues it it should return an empty list`() {
+        val prices = emptyList<Double>()
+        val result = prices.averageValues(maxValues = 20)
+        val expected = emptyList<Double>()
+
+        assertEquals(expected, result)
+    }
+}