package com.qianwen.smart.core.auto.common;


import java.util.ArrayList;
import java.util.List;
import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.Element;
import javax.lang.model.element.QualifiedNameable;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.util.Types;

public class TypeHelper {
  private final ProcessingEnvironment env;
  
  private final Types types;
  
  public TypeHelper(ProcessingEnvironment env) {
    this.env = env;
    this.types = env.getTypeUtils();
  }
  
  public String getType(Element element) {
    return getType((element != null) ? element.asType() : null);
  }
  
  public String getType(AnnotationMirror annotation) {
    return getType((annotation != null) ? annotation.getAnnotationType() : null);
  }
  
  public String getType(TypeMirror type) {
    if (type == null)
      return null; 
    if (type instanceof DeclaredType) {
      DeclaredType declaredType = (DeclaredType)type;
      Element enclosingElement = declaredType.asElement().getEnclosingElement();
      if (enclosingElement != null && enclosingElement instanceof javax.lang.model.element.TypeElement)
        return getQualifiedName(enclosingElement) + "$" + declaredType.asElement().getSimpleName().toString(); 
      return getQualifiedName(declaredType.asElement());
    } 
    return type.toString();
  }
  
  private String getQualifiedName(Element element) {
    if (element instanceof QualifiedNameable)
      return ((QualifiedNameable)element).getQualifiedName().toString(); 
    return element.toString();
  }
  
  public Element getSuperClass(Element element) {
    List<? extends TypeMirror> superTypes = this.types.directSupertypes(element.asType());
    if (superTypes.isEmpty())
      return null; 
    return this.types.asElement(superTypes.get(0));
  }
  
  public List<Element> getDirectInterfaces(Element element) {
    List<? extends TypeMirror> superTypes = this.types.directSupertypes(element.asType());
    List<Element> directInterfaces = new ArrayList<>();
    if (superTypes.size() > 1)
      for (int i = 1; i < superTypes.size(); i++) {
        Element e = this.types.asElement(superTypes.get(i));
        if (e != null)
          directInterfaces.add(e); 
      }  
    return directInterfaces;
  }
  
  public List<? extends AnnotationMirror> getAllAnnotationMirrors(Element e) {
    return this.env.getElementUtils().getAllAnnotationMirrors(e);
  }
}