merge: 피드 아티스트 중복 제거

Feature/#122 피드 아티스트 중복 제거

src/main/java/play/pluv/progress/domain/MusicTransferContext.java

@@ -1,9 +1,15 @@
 package play.pluv.progress.domain;
 
-import static java.util.stream.Collectors.joining;
+import static java.util.Comparator.comparing;
+import static java.util.function.Function.identity;
+import static java.util.stream.Collectors.counting;
+import static java.util.stream.Collectors.groupingBy;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
 import lombok.Builder;
 import lombok.Getter;
 import play.pluv.feed.domain.Feed;
@@ -67,12 +73,19 @@ public Feed createFeed(final String creatorName) {
         .creatorName(creatorName)
         .artistNames(artistNames)
         .thumbNailUrl(thumbNailUrl)
+        .songCount(transferredMusics.size())
         .build();
   }
 
   private String extractArtistNames(final List<TransferredMusicInContext> transferredMusics) {
-    return transferredMusics.stream()
+    final Map<String, Long> artistCountMap = transferredMusics.stream()
         .map(TransferredMusicInContext::getArtistNames)
-        .collect(joining(","));
+        .filter(artistNames -> !artistNames.isBlank())
+        .map(artistNames -> artistNames.split(","))
+        .flatMap(Arrays::stream)
+        .collect(groupingBy(identity(), counting()));
+    return artistCountMap.keySet().stream()
+        .sorted(comparing(artistCountMap::get).reversed())
+        .collect(Collectors.joining(","));
   }
 }

src/test/java/play/pluv/fixture/TransferContextFixture.java

@@ -37,11 +37,11 @@ public static MusicTransferContext musicTransferContext(
     return List.of(
         new TransferredMusicInContext(new HistoryMusicId(APPLE, "a"), "사랑하게 될거야", "한로로", "imageUrl",
             "isrc"),
-        new TransferredMusicInContext(new HistoryMusicId(APPLE, "b"), "자처", "한로로", "imageUrl",
+        new TransferredMusicInContext(new HistoryMusicId(APPLE, "b"), "자처", "한로로,창모", "imageUrl",
             "abcd"),
-        new TransferredMusicInContext(new HistoryMusicId(APPLE, "c"), "ㅈㅣㅂ", "한로로", "imageUrl",
+        new TransferredMusicInContext(new HistoryMusicId(APPLE, "c"), "ㅈㅣㅂ", "아이유", "imageUrl",
             null),
-        new TransferredMusicInContext(new HistoryMusicId(APPLE, "d"), "금붕어", "한로로", "imageUrl",
+        new TransferredMusicInContext(new HistoryMusicId(APPLE, "d"), "금붕어", "한로로,아이유", "imageUrl",
             null)
     );
   }

src/test/java/play/pluv/progress/domain/MusicTransferContextTest.java

@@ -0,0 +1,49 @@
+package play.pluv.progress.domain;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static play.pluv.fixture.TransferContextFixture.이전한_음악_목록;
+import static play.pluv.playlist.domain.MusicStreaming.APPLE;
+import static play.pluv.playlist.domain.MusicStreaming.SPOTIFY;
+import static play.pluv.playlist.domain.MusicStreaming.YOUTUBE;
+
+import java.util.List;
+import org.junit.jupiter.api.Test;
+import play.pluv.history.domain.HistoryMusicId;
+
+class MusicTransferContextTest {
+
+  @Test
+  void 피드를_생성할수_있다() {
+    final List<TransferredMusicInContext> 이전한_음악_목록 = 이전한_음악_목록();
+    final MusicTransferContext context = new MusicTransferContext(
+        10L, List.of(), 10, "imageUrl", "이전 중", APPLE, SPOTIFY
+    );
+    context.addTransferredMusics(이전한_음악_목록);
+
+    final String actual = context.createFeed("creator").getArtistNames();
+    final String expected = "한로로,아이유,창모";
+
+    assertThat(actual)
+        .isEqualTo(expected);
+  }
+
+  @Test
+  void 피드를_생성할떄_가수이름이없는경우() {
+    final List<TransferredMusicInContext> 이전한_음악_목록 = List.of(
+        new TransferredMusicInContext(new HistoryMusicId(YOUTUBE, "c"), "ㅈㅣㅂ", "", "imageUrl",
+            null),
+        new TransferredMusicInContext(new HistoryMusicId(YOUTUBE, "d"), "금붕어", "", "imageUrl",
+            null)
+    );
+
+    final MusicTransferContext context = new MusicTransferContext(
+        10L, List.of(), 10, "imageUrl", "이전 중", APPLE, SPOTIFY
+    );
+    context.addTransferredMusics(이전한_음악_목록);
+
+    final String actual = context.createFeed("creator").getArtistNames();
+
+    assertThat(actual)
+        .isBlank();
+  }
+}