/*
 * (c) Copyright 2019 Palantir Technologies Inc. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.palantir.baseline.errorprone;

import com.google.auto.service.AutoService;
import com.google.errorprone.BugPattern;
import com.google.errorprone.BugPattern.SeverityLevel;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.matchers.method.MethodMatchers;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;

@AutoService(BugChecker.class)
@BugPattern(
        name = "DangerousStringInternUsage",
        link = "https://github.com/palantir/gradle-baseline#baseline-error-prone-checks",
        linkType = BugPattern.LinkType.CUSTOM,
        severity = SeverityLevel.WARNING,
        summary = "Disallow String.intern() invocations.")
public final class DangerousStringInternUsage extends BugChecker implements BugChecker.MethodInvocationTreeMatcher {
    private static final String MESSAGE = "Should not use String.intern(). "
            + "Java string intern is complex and unpredictable. In most cases intern performs worse than pure-java "
            + "implementations such as Guava Interners "
            + "(https://guava.dev/releases/27.0.1-jre/api/docs/com/google/common/collect/Interners.html). If you are "
            + "confident that String.intern is the correct tool, please make sure you fully understand the "
            + "consequences."
            + "\nFrom https://shipilev.net/jvm/anatomy-quarks/10-string-intern/"
            + "\n> For OpenJDK, String.intern() is the gateway to native JVM String table, and it comes with"
            + "\n> caveats: throughput, memory footprint, pause time problems will await the users. It is very"
            + "\n> easy to underestimate the impact of these caveats. Hand-rolled deduplicators/interners are working"
            + "\n> much more reliably, because they are working on Java side, are just the regular Java objects,"
            + "\n> generally better sized/resized, and also can be thrown away completely when not needed anymore."
            + "\n> GC-assisted String deduplication does alleviate things even more."
            + "\n> In almost every project we were taking care of, removing String.intern() from the hotpaths, "
            + "\n> or optionally replacing it with a handrolled deduplicator, was the very profitable performance"
            + "\n> optimization. Do not use String.intern() without thinking very hard about it, okay?";
    private static final long serialVersionUID = 1L;

    private static final Matcher<ExpressionTree> STRING_INTERN_METHOD_MATCHER =
            MethodMatchers.instanceMethod()
                    .onExactClass(String.class.getName())
                    .named("intern")
                    .withParameters();

    @Override
    public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
        if (STRING_INTERN_METHOD_MATCHER.matches(tree, state)) {
            return buildDescription(tree)
                    .setMessage(MESSAGE)
                    .build();
        }
        return Description.NO_MATCH;
    }
}

@@ -1449,208 +1449,8 @@
 ry =
- %22Disallow String.intern() invocations.%22)%0Apublic final class DangerousStringInternUsage extends BugChecker implements BugChecker.MethodInvocationTreeMatcher %7B%0A    private static final String MESSAGE =
  %22Sh
@@ -1481,16 +1481,20 @@
 rn(). %22%0A
+    
         
@@ -1614,16 +1614,20 @@
         
+   
+ 
 + %22imple
@@ -1663,16 +1663,20 @@
 rners %22%0A
+    
         
@@ -1784,14 +1784,14 @@
 you 
-are %22%0A
+%22%0A    
     
@@ -1801,16 +1801,20 @@
      + %22
+are 
 confiden
@@ -1911,16 +1911,20 @@
         
+   
+ 
 + %22conse
@@ -1933,16 +1933,20 @@
 ences.%22%0A
+    
         
@@ -2026,24 +2026,28 @@
             
+  
+  
 + %22%5Cn%3E For O
@@ -2132,16 +2132,20 @@
 s with%22%0A
+    
         
@@ -2256,24 +2256,28 @@
             
+ 
+   
 + %22%5Cn%3E easy 
@@ -2365,18 +2365,14 @@
  are
- working%22%0A
+%22%0A    
     
@@ -2385,16 +2385,24 @@
   + %22%5Cn%3E
+ working
  much mo
@@ -2482,19 +2482,12 @@
 Java
- objects,
 %22%0A
+  
     
@@ -2494,22 +2494,33 @@
         
+  
 + %22%5Cn%3E
+ objects,
  general
@@ -2602,19 +2602,14 @@
 eded
- anymore.%22%0A
+%22%0A    
     
@@ -2622,16 +2622,25 @@
   + %22%5Cn%3E
+ anymore.
  GC-assi
@@ -2707,24 +2707,28 @@
             
+  
+  
 + %22%5Cn%3E In al
@@ -2816,16 +2816,20 @@
 aths, %22%0A
+    
         
@@ -2939,32 +2939,36 @@
 ce%22%0A            
+ 
+   
 + %22%5Cn%3E optimizat
@@ -3042,17 +3042,134 @@
 , okay?%22
-;
+)%0Apublic final class DangerousStringInternUsage extends BugChecker implements BugChecker.MethodInvocationTreeMatcher %7B
 %0A    pri
@@ -3670,99 +3670,26 @@
 urn 
-buildDescription(tree)%0A                    .setMessage(MESSAGE)%0A                    .build(
+describeMatch(tree
 );%0A 

Move DangerousStringInternUsage message to BugPattern.summary annotation (#1036)