From e583481074e628617c6c088bbf34e1de346300b9 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Mon, 13 May 2019 18:09:25 +0200
Subject: [PATCH] java completion: disprefer already called builder methods
 (IDEA-211080)

GitOrigin-RevId: 5a579dbd900505da03b987041f58c45104997d8f
---
 .../completion/JavaCompletionSorting.java     | 36 ++++++++++++++++---
 .../DispreferAlreadyCalledBuilderMethods.java | 13 +++++++
 .../NormalCompletionOrderingTest.groovy       |  4 +++
 3 files changed, 48 insertions(+), 5 deletions(-)
 create mode 100644 java/java-tests/testData/codeInsight/completion/normalSorting/DispreferAlreadyCalledBuilderMethods.java

diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionSorting.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionSorting.java
index 241b7c0ff5da..643b0a1ef7a5 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionSorting.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionSorting.java
@@ -19,16 +19,14 @@ import com.intellij.psi.javadoc.PsiDocComment;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiUtil;
 import com.intellij.psi.util.TypeConversionUtil;
+import com.intellij.util.ObjectUtils;
 import com.intellij.util.SmartList;
 import com.intellij.util.containers.ContainerUtil;
 import gnu.trove.THashSet;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
+import java.util.*;
 
 import static com.intellij.patterns.PsiJavaPatterns.psiElement;
 
@@ -58,9 +56,13 @@ public class JavaCompletionSorting {
     } else if (PsiTreeUtil.getParentOfType(position, PsiReferenceList.class) == null) {
       sorter = ((CompletionSorterImpl)sorter).withClassifier("liftShorterClasses", true, new LiftShorterClasses(position));
     }
+
+    List<LookupElementWeigher> afterPriority = new ArrayList<>();
+    ContainerUtil.addIfNotNull(afterPriority, dispreferPreviousChainCalls(position));
     if (smart) {
-      sorter = sorter.weighAfter("priority", new PreferDefaultTypeWeigher(expectedTypes, parameters, false));
+      afterPriority.add(new PreferDefaultTypeWeigher(expectedTypes, parameters, false));
     }
+    sorter = sorter.weighAfter("priority", afterPriority.toArray(new LookupElementWeigher[0]));
 
     List<LookupElementWeigher> afterStats = new ArrayList<>();
     afterStats.add(new PreferByKindWeigher(type, position, expectedTypes));
@@ -85,6 +87,30 @@ public class JavaCompletionSorting {
     return result.withRelevanceSorter(sorter);
   }
 
+  @Nullable
+  private static LookupElementWeigher dispreferPreviousChainCalls(PsiElement position) {
+    Set<PsiMethod> previousChainCalls = new HashSet<>();
+    if (position.getParent() instanceof PsiReferenceExpression) {
+      PsiMethodCallExpression qualifier = getCallQualifier((PsiReferenceExpression)position.getParent());
+      while (qualifier != null) {
+        ContainerUtil.addIfNotNull(previousChainCalls, qualifier.resolveMethod());
+        qualifier = getCallQualifier(qualifier.getMethodExpression());
+      }
+    }
+    return previousChainCalls.isEmpty() ? null : new LookupElementWeigher("dispreferPreviousChainCalls") {
+      @Override
+      public Comparable weigh(@NotNull LookupElement element, @NotNull WeighingContext context) {
+        //noinspection SuspiciousMethodCalls
+        return previousChainCalls.contains(element.getPsiElement());
+      }
+    };
+  }
+
+  @Nullable
+  private static PsiMethodCallExpression getCallQualifier(PsiReferenceExpression ref) {
+    return ObjectUtils.tryCast(ref.getQualifier(), PsiMethodCallExpression.class);
+  }
+
   @NotNull
   private static ExpectedTypeInfo[] getExpectedTypesWithDfa(CompletionParameters parameters, PsiElement position) {
     if (psiElement().beforeLeaf(psiElement().withText(".")).accepts(position)) {
diff --git a/java/java-tests/testData/codeInsight/completion/normalSorting/DispreferAlreadyCalledBuilderMethods.java b/java/java-tests/testData/codeInsight/completion/normalSorting/DispreferAlreadyCalledBuilderMethods.java
new file mode 100644
index 000000000000..b47d7b71a49a
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/normalSorting/DispreferAlreadyCalledBuilderMethods.java
@@ -0,0 +1,13 @@
+class Test {
+  {
+    MyBuilder b;
+    b.a().b().<caret>
+  }
+}
+
+interface MyBuilder {
+  MyBuilder a();
+  MyBuilder b();
+  MyBuilder c();
+  MyBuilder d();
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionOrderingTest.groovy b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionOrderingTest.groovy
index b321057381c6..f7c7c618b1b6 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionOrderingTest.groovy
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/NormalCompletionOrderingTest.groovy
@@ -871,6 +871,10 @@ class Foo {
     checkPreferredItems 1, 'Intf', 'IntfImpl'
   }
 
+  void testDispreferAlreadyCalledBuilderMethods() {
+    checkPreferredItems 0, 'c', 'd'
+  }
+
   void testPreferPrintln() {
     myFixture.configureByText 'a.java', 'class Foo { { System.out.pri<caret>x } }'
     myFixture.completeBasic()