feat: load and store in CSV file

Author: falkoschumann

api-app/.gitignore

@@ -1,3 +1,4 @@
+/testdata
 /application.yml
 /application.yaml
 /application.properties

api-app/Makefile

@@ -4,6 +4,7 @@ all: dist check
 
 clean:
 	./gradlew clean
+	rm -rf testdata
 
 distclean: clean
 	rm -rf .gradle

api-app/build.gradle.kts

@@ -29,6 +29,7 @@ dependencyManagement {
 }
 
 dependencies {
+  implementation("org.apache.commons:commons-csv:1.14.0")
   implementation("com.azure.spring:spring-cloud-azure-starter-active-directory")
   implementation("com.azure.spring:spring-cloud-azure-starter-actuator")
   implementation("org.springframework.boot:spring-boot-starter-actuator")

api-app/src/main/java/de/muspellheim/activitysampling/api/infrastructure/CsvActivitiesRepository.java

@@ -0,0 +1,2 @@
+  // TODO Handle row number as ID
+

api-app/src/test/java/de/muspellheim/activitysampling/api/integration/CsvActivitiesRepositoryTests.java

@@ -0,0 +1,52 @@
+// Copyright (c) 2025 Falko Schumann. All rights reserved. MIT license.
+
+package de.muspellheim.activitysampling.api.integration;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import de.muspellheim.activitysampling.api.infrastructure.ActivityDto;
+import de.muspellheim.activitysampling.api.infrastructure.CsvActivitiesRepository;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.time.Instant;
+import java.util.List;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class CsvActivitiesRepositoryTests {
+
+  private static final Path TEST_FILE = Paths.get("testdata", "activities.csv");
+
+  @BeforeEach
+  void setUp() throws Exception {
+    Files.deleteIfExists(TEST_FILE);
+    Files.createDirectories(TEST_FILE.getParent());
+  }
+
+  @Test
+  void createsEmptyRepository() {
+    var repository = new CsvActivitiesRepository(TEST_FILE);
+
+    assertEquals(List.of(), repository.findAll());
+  }
+
+  @Test
+  void findsByTimestampGreaterThanEqualOrderByTimestampDesc() {
+    var repository = new CsvActivitiesRepository(TEST_FILE);
+    repository.save(
+        ActivityDto.createTestInstance().withTimestamp(Instant.parse("2023-01-01T11:00:00Z")));
+    var activity2 =
+        repository.save(
+            ActivityDto.createTestInstance().withTimestamp(Instant.parse("2023-01-01T12:00:00Z")));
+    var activity3 =
+        repository.save(
+            ActivityDto.createTestInstance().withTimestamp(Instant.parse("2023-01-01T13:00:00Z")));
+
+    var activities =
+        repository.findByTimestampGreaterThanEqualOrderByTimestampDesc(
+            Instant.parse("2023-01-01T12:00:00Z"));
+
+    assertEquals(List.of(activity3, activity2), activities);
+  }
+}