From 1c977bd5dd591c3b994ed1d0b9292e1c90635139 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Sat, 13 May 2017 07:48:27 +0200
Subject: [PATCH] IDEA-170406 Prefer expected enum constants in annotation
 attribute, despite statistics

---
 .../completion/JavaCompletionStatistician.java      | 13 +++++++++++++
 ...erExpectedEnumConstantInAnnotationAttribute.java |  3 +++
 .../completion/NormalCompletionOrderingTest.groovy  |  9 +++++++++
 3 files changed, 25 insertions(+)
 create mode 100644 java/java-tests/testData/codeInsight/completion/normalSorting/PreferExpectedEnumConstantInAnnotationAttribute.java

diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionStatistician.java b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionStatistician.java
index 0156a5fb1a07..762ee099f40c 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionStatistician.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionStatistician.java
@@ -22,6 +22,8 @@ import com.intellij.patterns.ElementPattern;
 import com.intellij.psi.*;
 import com.intellij.psi.statistics.JavaStatisticsManager;
 import com.intellij.psi.statistics.StatisticsInfo;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.psi.util.PsiUtil;
 import org.jetbrains.annotations.Nullable;
 
 import static com.intellij.patterns.PsiJavaPatterns.psiElement;
@@ -50,12 +52,23 @@ public class JavaCompletionStatistician extends CompletionStatistician{
     }
 
     ExpectedTypeInfo firstInfo = getExpectedTypeInfo(location);
+    if (firstInfo != null && isInEnumAnnotationParameter(position, firstInfo)) {
+      return StatisticsInfo.EMPTY;
+    }
+    
     if (o instanceof PsiClass) {
       return getClassInfo((PsiClass)o, position, firstInfo);
     }
     return getFieldOrMethodInfo((PsiMember)o, element, firstInfo);
   }
 
+  private static boolean isInEnumAnnotationParameter(PsiElement position, ExpectedTypeInfo firstInfo) {
+    if (PsiTreeUtil.getParentOfType(position, PsiNameValuePair.class) == null) return false;
+    
+    PsiClass expectedClass = PsiUtil.resolveClassInType(firstInfo.getType());
+    return expectedClass != null && expectedClass.isEnum();
+  }
+
   @Nullable
   private static ExpectedTypeInfo getExpectedTypeInfo(CompletionLocation location) {
     ExpectedTypeInfo[] infos = JavaCompletionUtil.EXPECTED_TYPES.getValue(location);
diff --git a/java/java-tests/testData/codeInsight/completion/normalSorting/PreferExpectedEnumConstantInAnnotationAttribute.java b/java/java-tests/testData/codeInsight/completion/normalSorting/PreferExpectedEnumConstantInAnnotationAttribute.java
new file mode 100644
index 000000000000..38f2222fc098
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/normalSorting/PreferExpectedEnumConstantInAnnotationAttribute.java
@@ -0,0 +1,3 @@
+@interface Anno { MyEnum value(); }
+enum MyEnum { foo, bar }
+@Anno(value=<caret>)
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionOrderingTest.groovy b/java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionOrderingTest.groovy
index 0b49e6240790..247d98e605c6 100644
--- a/java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionOrderingTest.groovy
+++ b/java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionOrderingTest.groovy
@@ -781,4 +781,13 @@ class ContainerUtil extends ContainerUtilRt {
     checkPreferredItems 0, 'Point.JSON', 'JSON'
   }
 
+  void testPreferExpectedEnumConstantInAnnotationAttribute() {
+    checkPreferredItems 0, 'MyEnum.bar', 'MyEnum', 'MyEnum.foo'
+    def unrelatedItem = myFixture.lookupElementStrings.findIndexOf { it.contains('Throwable') }
+    incUseCount(lookup, unrelatedItem)
+    //nothing should change
+    assertPreferredItems 0, 'MyEnum.bar', 'MyEnum', 'MyEnum.foo'
+    
+  }
+
 }