Issue #12: Basic implementation of transformation service

build.gradle.kts

@@ -69,6 +69,7 @@ dependencies {
     implementation("ca.uhn.hapi.fhir:hapi-fhir-base:${versions["hapi-fhir"]}")
     implementation("ca.uhn.hapi.fhir:hapi-fhir-structures-r4:${versions["hapi-fhir"]}")
     implementation("org.apache.httpcomponents.client5:httpclient5:${versions["httpclient5"]}")
+    implementation("com.jayway.jsonpath:json-path")
     runtimeOnly("org.mariadb.jdbc:mariadb-java-client")
     runtimeOnly("org.postgresql:postgresql")
     developmentOnly("org.springframework.boot:spring-boot-devtools")

src/main/kotlin/dev/dnpm/etl/processor/services/TransformationService.kt

@@ -0,0 +1,62 @@
+package dev.dnpm.etl.processor.services
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.jayway.jsonpath.JsonPath
+import com.jayway.jsonpath.PathNotFoundException
+import de.ukw.ccc.bwhc.dto.MtbFile
+
+class TransformationService(private val objectMapper: ObjectMapper) {
+    fun transform(mtbFile: MtbFile, vararg transformations: Transformation): MtbFile {
+        var json = objectMapper.writeValueAsString(mtbFile)
+
+        transformations.forEach { transformation ->
+            val jsonPath = JsonPath.parse(json)
+
+            try {
+                val before = transformation.path.substringBeforeLast(".")
+                val last = transformation.path.substringAfterLast(".")
+
+                val existingValue = if (transformation.existingValue is Number) transformation.existingValue else transformation.existingValue.toString()
+                val newValue = if (transformation.newValue is Number) transformation.newValue else transformation.newValue.toString()
+
+                jsonPath.set("$.$before.[?]$last", newValue, {
+                    it.item(HashMap::class.java)[last] == existingValue
+                })
+            } catch (e: PathNotFoundException) {
+                // Ignore
+            }
+
+            json = jsonPath.jsonString()
+        }
+
+        return objectMapper.readValue(json, MtbFile::class.java)
+    }
+
+}
+
+class Transformation private constructor(internal val path: String) {
+
+    lateinit var existingValue: Any
+        private set
+    lateinit var newValue: Any
+        private set
+
+    infix fun from(value: Any): Transformation {
+        this.existingValue = value
+        return this
+    }
+
+    infix fun to(value: Any): Transformation {
+        this.newValue = value
+        return this
+    }
+
+    companion object {
+
+        fun of(path: String): Transformation {
+            return Transformation(path)
+        }
+
+    }
+
+}

src/test/kotlin/dev/dnpm/etl/processor/services/TransformationServiceTest.kt

@@ -0,0 +1,83 @@
+package dev.dnpm.etl.processor.services
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import de.ukw.ccc.bwhc.dto.Consent
+import de.ukw.ccc.bwhc.dto.Diagnosis
+import de.ukw.ccc.bwhc.dto.Icd10
+import de.ukw.ccc.bwhc.dto.MtbFile
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+
+class TransformationServiceTest {
+
+    private lateinit var service: TransformationService
+
+    @BeforeEach
+    fun setup() {
+        this.service = TransformationService(ObjectMapper())
+    }
+
+    @Test
+    fun shouldTransformMtbFile() {
+        val transformations = arrayOf(
+            Transformation.of("diagnoses[*].icd10.version") from "2013" to "2014",
+        )
+
+        val mtbFile = MtbFile.builder().withDiagnoses(
+            listOf(
+                Diagnosis.builder().withId("1234").withIcd10(Icd10("F79.9").also {
+                    it.version = "2013"
+                }).build()
+            )
+        ).build()
+
+        val actual = this.service.transform(mtbFile, *transformations)
+
+        assertThat(actual).isNotNull
+        assertThat(actual.diagnoses[0].icd10.version).isEqualTo("2014")
+    }
+
+    @Test
+    fun shouldOnlyTransformGivenValues() {
+        val transformations = arrayOf(
+            Transformation.of("diagnoses[*].icd10.version") from "2013" to "2014",
+        )
+
+        val mtbFile = MtbFile.builder().withDiagnoses(
+            listOf(
+                Diagnosis.builder().withId("1234").withIcd10(Icd10("F79.9").also {
+                    it.version = "2013"
+                }).build(),
+                Diagnosis.builder().withId("5678").withIcd10(Icd10("F79.8").also {
+                    it.version = "2019"
+                }).build()
+            )
+        ).build()
+
+        val actual = this.service.transform(mtbFile, *transformations)
+
+        assertThat(actual).isNotNull
+        assertThat(actual.diagnoses[0].icd10.code).isEqualTo("F79.9")
+        assertThat(actual.diagnoses[0].icd10.version).isEqualTo("2014")
+        assertThat(actual.diagnoses[1].icd10.code).isEqualTo("F79.8")
+        assertThat(actual.diagnoses[1].icd10.version).isEqualTo("2019")
+    }
+
+    @Test
+    fun shouldTransformMtbFileWithConsentEnum() {
+        val transformations = arrayOf(
+            Transformation.of("consent.status") from Consent.Status.ACTIVE to Consent.Status.REJECTED,
+        )
+
+        val mtbFile = MtbFile.builder().withConsent(
+            Consent("123", "456", Consent.Status.ACTIVE)
+        ).build()
+
+        val actual = this.service.transform(mtbFile, *transformations)
+
+        assertThat(actual.consent).isNotNull
+        assertThat(actual.consent.status).isEqualTo(Consent.Status.REJECTED)
+    }
+
+}