content: /*
   * Copyright (C) 2015 Square, Inc.
   *
   * 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.squareup.javapoet;
  
  import static com.squareup.javapoet.Util.checkArgument;
  import static com.squareup.javapoet.Util.checkNotNull;
  
  import java.io.IOException;
  import java.lang.reflect.Type;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Set;
  
  import jdkx.lang.model.SourceVersion;
  import jdkx.lang.model.element.ElementKind;
  import jdkx.lang.model.element.ExecutableElement;
  import jdkx.lang.model.element.Modifier;
  import jdkx.lang.model.element.VariableElement;
  
  /** A generated parameter declaration. */
  public final class ParameterSpec {
    public final String name;
    public final List<AnnotationSpec> annotations;
    public final Set<Modifier> modifiers;
    public final TypeName type;
    public final CodeBlock javadoc;
  
    private ParameterSpec(Builder builder) {
      this.name = checkNotNull(builder.name, "name == null");
      this.annotations = Util.immutableList(builder.annotations);
      this.modifiers = Util.immutableSet(builder.modifiers);
      this.type = checkNotNull(builder.type, "type == null");
      this.javadoc = builder.javadoc.build();
    }
  
    public static Builder builder(Type type, String name, Modifier... modifiers) {
      return builder(TypeName.get(type), name, modifiers);
    }
  
    static List<ParameterSpec> parametersOf(ExecutableElement method) {
      List<ParameterSpec> result = new ArrayList<>();
      for (VariableElement parameter : method.getParameters()) {
        result.add(ParameterSpec.get(parameter));
      }
      return result;
    }
  
    public static ParameterSpec get(VariableElement element) {
      checkArgument(element.getKind().equals(ElementKind.PARAMETER), "element is not a parameter");
  
      TypeName type = TypeName.get(element.asType());
      String name = element.getSimpleName().toString();
      // Copying parameter annotations can be incorrect so we're deliberately not including them.
      // See https://github.com/square/javapoet/issues/482.
      return ParameterSpec.builder(type, name).addModifiers(element.getModifiers()).build();
    }
  
    public static Builder builder(TypeName type, String name, Modifier... modifiers) {
      checkNotNull(type, "type == null");
      checkArgument(isValidParameterName(name), "not a valid name: %s", name);
      return new Builder(type, name).addModifiers(modifiers);
    }
  
    private static boolean isValidParameterName(String name) {
      // Allow "this" for explicit receiver parameters
      // See https://docs.oracle.com/javase/specs/jls/se8/html/jls-8.html#jls-8.4.1.
      if (name.endsWith(".this")) {
        return SourceVersion.isIdentifier(name.substring(0, name.length() - ".this".length()));
      }
      return name.equals("this") || SourceVersion.isName(name);
    }
  
    public boolean hasModifier(Modifier modifier) {
      return modifiers.contains(modifier);
    }
  
    @Override
    public int hashCode() {
      return toString().hashCode();
    }
  
    @Override
    public boolean equals(Object o) {
      if (this == o) return true;
      if (o == null) return false;
      if (getClass() != o.getClass()) return false;
      return toString().equals(o.toString());
    }
  
    @Override
    public String toString() {
      StringBuilder out = new StringBuilder();
      try {
        CodeWriter codeWriter = new CodeWriter(out);
        emit(codeWriter, false);
        return out.toString();
      } catch (IOException e) {
        throw new AssertionError();
      }
    }
  
    void emit(CodeWriter codeWriter, boolean varargs) throws IOException {
      codeWriter.emitAnnotations(annotations, true);
      codeWriter.emitModifiers(modifiers);
      if (varargs) {
        TypeName.asArray(type).emit(codeWriter, true);
      } else {
        type.emit(codeWriter);
      }
      codeWriter.emit(" $L", name);
    }
  
    public Builder toBuilder() {
      return toBuilder(type, name);
    }
  
    Builder toBuilder(TypeName type, String name) {
      Builder builder = new Builder(type, name);
      builder.annotations.addAll(annotations);
      builder.modifiers.addAll(modifiers);
      return builder;
    }
  
    public static final class Builder {
      public final List<AnnotationSpec> annotations = new ArrayList<>();
      public final List<Modifier> modifiers = new ArrayList<>();
      private final TypeName type;
      private final String name;
      private final CodeBlock.Builder javadoc = CodeBlock.builder();
  
      private Builder(TypeName type, String name) {
        this.type = type;
        this.name = name;
      }
  
      public Builder addJavadoc(String format, Object... args) {
        javadoc.add(format, args);
        return this;
      }
  
      public Builder addJavadoc(CodeBlock block) {
        javadoc.add(block);
        return this;
      }
  
      public Builder addAnnotations(Iterable<AnnotationSpec> annotationSpecs) {
        checkArgument(annotationSpecs != null, "annotationSpecs == null");
        for (AnnotationSpec annotationSpec : annotationSpecs) {
          this.annotations.add(annotationSpec);
        }
        return this;
      }
  
      public Builder addAnnotation(AnnotationSpec annotationSpec) {
        this.annotations.add(annotationSpec);
        return this;
      }
  
      public Builder addAnnotation(Class<?> annotation) {
        return addAnnotation(ClassName.get(annotation));
      }
  
      public Builder addAnnotation(ClassName annotation) {
        this.annotations.add(AnnotationSpec.builder(annotation).build());
        return this;
      }
  
      public Builder addModifiers(Modifier... modifiers) {
        Collections.addAll(this.modifiers, modifiers);
        return this;
      }
  
      public Builder addModifiers(Iterable<Modifier> modifiers) {
        checkNotNull(modifiers, "modifiers == null");
        for (Modifier modifier : modifiers) {
          if (!modifier.equals(Modifier.FINAL)) {
            throw new IllegalStateException("unexpected parameter modifier: " + modifier);
          }
          this.modifiers.add(modifier);
        }
        return this;
      }
  
      public ParameterSpec build() {
        return new ParameterSpec(this);
      }
    }
  }
  