make product database entity, add new dependencies

build.gradle.kts

@@ -1,7 +1,9 @@
 plugins {
 	id("org.springframework.boot") version "3.2.4"
 	id("io.spring.dependency-management") version "1.1.4"
+
 	jacoco
+
 	kotlin("jvm") version "2.0.20"
 	kotlin("plugin.jpa") version "1.9.23"
 	kotlin("plugin.serialization") version "2.0.20"
@@ -20,15 +22,21 @@ repositories {
 }
 
 dependencies {
+	api("org.springframework.boot:spring-boot-starter-data-jdbc")
+
 	implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
 	implementation("org.flywaydb:flyway-core")
 	implementation("org.jetbrains.kotlin:kotlin-reflect")
 	implementation("org.jetbrains.kotlinx:kotlinx-serialization-json")
+	implementation("org.springframework.boot:spring-boot-starter-data-jpa")
 	implementation("org.springframework.boot:spring-boot-starter-jdbc")
 	implementation("org.springframework.boot:spring-boot-starter-mustache")
 	implementation("org.springframework.boot:spring-boot-starter-web")
+
 	developmentOnly("org.springframework.boot:spring-boot-devtools")
+
 	runtimeOnly("org.postgresql:postgresql")
+
 	testImplementation("org.jetbrains.kotlin:kotlin-test-junit5")
 	testImplementation("org.mockito.kotlin:mockito-kotlin:5.4.0")
 	testImplementation("org.springframework.boot:spring-boot-starter-test")

src/main/kotlin/com/example/demo/models/Customer.kt

@@ -12,5 +12,5 @@ data class Customer(val name: String, val city: City, val orders: List<Order>) {
 
     fun getOrderedProducts(): Set<Product> = orders.flatMap { order -> order.products }.toSet()
 
-    fun getTotalOrderPrice(): Double = orders.flatMap { ord -> ord.products }.sumOf { pr -> pr.price }
+    fun getTotalOrderPrice(): Double = orders.flatMap { ord -> ord.products }.sumOf { pr -> pr.getPriceDouble()}
 }

src/main/kotlin/com/example/demo/models/Product.kt

@@ -1,3 +1,31 @@
 package com.example.demo.models
 
-data class Product(val name: String, val price: Double)
+
+import com.example.demo.models.serializables.OffsetDateTimeSerialization
+import com.example.demo.models.serializables.UuidSerialization
+import com.example.demo.utils.roundTo
+import jakarta.persistence.Column
+import jakarta.persistence.Id
+import kotlinx.serialization.Serializable
+import org.springframework.data.relational.core.mapping.Table
+import java.time.OffsetDateTime
+import java.util.*
+
+@Table(value = "product", schema = "public")
+@Serializable
+data class Product(
+    @Id var id: Long,
+    @Serializable(with = UuidSerialization::class)
+    val guid: UUID,
+    val name: String,
+    val description: String?,
+    val price: Int,
+    @Serializable(with = OffsetDateTimeSerialization::class)
+    @Column(name = "created_at")
+    val createdAt: OffsetDateTime,
+    @Serializable(with = OffsetDateTimeSerialization::class)
+    @Column(name = "updated_at")
+    val updatedAt: OffsetDateTime?,
+) {
+    fun getPriceDouble(): Double = (price.toDouble() / 100).roundTo(2)
+}

src/main/kotlin/com/example/demo/models/serializables/OffsetDateTimeSerialization.kt

@@ -0,0 +1,22 @@
+package com.example.demo.models.serializables
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import java.time.OffsetDateTime
+import java.time.format.DateTimeFormatter
+
+class OffsetDateTimeSerialization: KSerializer<OffsetDateTime> {
+    override val descriptor = PrimitiveSerialDescriptor("Time", PrimitiveKind.STRING)
+
+    override fun deserialize(decoder: Decoder): OffsetDateTime {
+        return OffsetDateTime.parse(decoder.decodeString())
+    }
+
+    override fun serialize(encoder: Encoder, value: OffsetDateTime) {
+        encoder.encodeString(value.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME))
+
+    }
+}

src/main/kotlin/com/example/demo/models/serializables/UuidSerialization.kt

@@ -0,0 +1,21 @@
+package com.example.demo.models.serializables
+
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import java.util.*
+
+class UuidSerialization: KSerializer<UUID> {
+    override val descriptor = PrimitiveSerialDescriptor("UUID", PrimitiveKind.STRING)
+
+    override fun deserialize(decoder: Decoder): UUID {
+        return UUID.fromString(decoder.decodeString())
+    }
+
+    override fun serialize(encoder: Encoder, value: UUID) {
+        encoder.encodeString(value.toString())
+
+    }
+}

src/main/kotlin/com/example/demo/provider/MockedShopProvider.kt

@@ -1,28 +1,46 @@
 package com.example.demo.provider
 
 import com.example.demo.models.*
+import java.time.OffsetDateTime
+import java.util.*
 
 class MockedShopProvider: ShopProvider {
     override fun getRandomShop(): Shop? {
+        val productOne = makeProduct(id = 1, name = "one", price = 11.2)
+        val productTwo = makeProduct(id = 2, name = "two", price = 13.2)
+        val productThree = makeProduct(id = 3, name = "three", price = 15.2)
+        val productFour = makeProduct(id = 4, name = "four", price = 14.2)
+
         return Shop(name="shop", customers= listOf(
             Customer(
                 name = "Foo-1",
                 city = City(name= "Bar"),
                 orders = listOf(
-                    Order(products = listOf(Product(name = "one", price = 11.2)), isDelivered = false),
-                    Order(products = listOf(Product(name = "two", price = 13.2)), isDelivered = false),
-                    Order(products = listOf(Product(name = "three", price = 15.2)), isDelivered = true),
+                    Order(products = listOf(productOne, productTwo), isDelivered = true),
+                    Order(products = listOf(productThree), isDelivered = false),
                 )
             ),
             Customer(
                 name = "Foo-2",
                 city = City(name= "Bar"),
                 orders = listOf(
-                    Order(products = listOf(Product(name = "one", price = 12.2)), isDelivered = false),
-                    Order(products = listOf(Product(name = "two", price = 13.2)), isDelivered = true),
-                    Order(products = listOf(Product(name = "four", price = 14.2)), isDelivered = true),
+                    Order(products = listOf(productOne), isDelivered = false),
+                    Order(products = listOf(productTwo), isDelivered = true),
+                    Order(products = listOf(productFour), isDelivered = true),
                 )
             ),
         ))
     }
+
+    private fun makeProduct(id: Long, name: String, price: Double): Product {
+        return Product(
+            id = id,
+            guid = UUID.randomUUID(),
+            name = name,
+            description = null,
+            price = (price * 100).toInt(),
+            createdAt = OffsetDateTime.now(),
+            updatedAt = null,
+        )
+    }
 }

src/main/kotlin/com/example/demo/utils/Extensions.kt

@@ -0,0 +1,9 @@
+package com.example.demo.utils
+
+import kotlin.math.pow
+import kotlin.math.roundToInt
+
+fun Double.roundTo(numFractionDigits: Int): Double {
+    val factor = 10.0.pow(numFractionDigits.toDouble())
+    return (this * factor).roundToInt() / factor
+}