/*
    * Copyright 2004-2022 the original author or authors.
    *
    * 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
    *
    *    https://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.ibatis.common.beans;
  
  import java.lang.reflect.Constructor;
  import java.lang.reflect.Field;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.lang.reflect.ReflectPermission;
  import java.lang.reflect.UndeclaredThrowableException;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Date;
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.Hashtable;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Set;
  import java.util.TreeMap;
  import java.util.TreeSet;
  import java.util.Vector;
  import java.util.concurrent.ConcurrentHashMap;
  
  /**
   * This class represents a cached set of class definition information that allows for easy mapping between property
   * names and getter/setter methods.
   */
  public class ClassInfo {
  
    /** The cache enabled. */
    private static boolean cacheEnabled = true;
  
    /** The Constant EMPTY_STRING_ARRAY. */
    private static final String[] EMPTY_STRING_ARRAY = new String[0];
  
    /** The Constant SIMPLE_TYPE_SET. */
    private static final Set SIMPLE_TYPE_SET = new HashSet();
  
    /** The Constant CLASS_INFO_MAP. */
    private static final Map<Class, ClassInfo> CLASS_INFO_MAP = new ConcurrentHashMap<Class, ClassInfo>();
  
    /** The class name. */
    private String className;
  
    /** The readable property names. */
    private String[] readablePropertyNames = EMPTY_STRING_ARRAY;
  
    /** The writeable property names. */
    private String[] writeablePropertyNames = EMPTY_STRING_ARRAY;
  
    /** The set methods. */
    private HashMap setMethods = new HashMap();
  
    /** The get methods. */
    private HashMap getMethods = new HashMap();
  
    /** The set types. */
    private HashMap setTypes = new HashMap();
  
    /** The get types. */
    private HashMap getTypes = new HashMap();
  
    /** The default constructor. */
    private Constructor defaultConstructor;
  
    static {
      SIMPLE_TYPE_SET.add(String.class);
      SIMPLE_TYPE_SET.add(Byte.class);
      SIMPLE_TYPE_SET.add(Short.class);
      SIMPLE_TYPE_SET.add(Character.class);
      SIMPLE_TYPE_SET.add(Integer.class);
      SIMPLE_TYPE_SET.add(Long.class);
      SIMPLE_TYPE_SET.add(Float.class);
      SIMPLE_TYPE_SET.add(Double.class);
      SIMPLE_TYPE_SET.add(Boolean.class);
      SIMPLE_TYPE_SET.add(Date.class);
      SIMPLE_TYPE_SET.add(Class.class);
      SIMPLE_TYPE_SET.add(BigInteger.class);
      SIMPLE_TYPE_SET.add(BigDecimal.class);
 
     SIMPLE_TYPE_SET.add(Collection.class);
     SIMPLE_TYPE_SET.add(Set.class);
     SIMPLE_TYPE_SET.add(Map.class);
     SIMPLE_TYPE_SET.add(List.class);
     SIMPLE_TYPE_SET.add(HashMap.class);
     SIMPLE_TYPE_SET.add(TreeMap.class);
     SIMPLE_TYPE_SET.add(ArrayList.class);
     SIMPLE_TYPE_SET.add(LinkedList.class);
     SIMPLE_TYPE_SET.add(HashSet.class);
     SIMPLE_TYPE_SET.add(TreeSet.class);
     SIMPLE_TYPE_SET.add(Vector.class);
     SIMPLE_TYPE_SET.add(Hashtable.class);
     SIMPLE_TYPE_SET.add(Enumeration.class);
   }
 
   /**
    * Instantiates a new class info.
    *
    * @param clazz
    *          the clazz
    */
   private ClassInfo(Class clazz) {
     className = clazz.getName();
     addDefaultConstructor(clazz);
     addGetMethods(clazz);
     addSetMethods(clazz);
     addFields(clazz);
     readablePropertyNames = (String[]) getMethods.keySet().toArray(new String[getMethods.keySet().size()]);
     writeablePropertyNames = (String[]) setMethods.keySet().toArray(new String[setMethods.keySet().size()]);
   }
 
   /**
    * Adds the default constructor.
    *
    * @param clazz
    *          the clazz
    */
   private void addDefaultConstructor(Class clazz) {
     Constructor[] consts = clazz.getDeclaredConstructors();
     for (int i = 0; i < consts.length; i++) {
       Constructor constructor = consts[i];
       if (constructor.getParameterTypes().length == 0) {
         if (canAccessPrivateMethods()) {
           try {
             constructor.setAccessible(true);
           } catch (Exception e) {
             // Ignored. This is only a final precaution, nothing we can do.
           }
         }
         if (constructor.isAccessible()) {
           this.defaultConstructor = constructor;
         }
       }
     }
   }
 
   /**
    * Adds the get methods.
    *
    * @param cls
    *          the cls
    */
   private void addGetMethods(Class cls) {
     Method[] methods = getClassMethods(cls);
     for (int i = 0; i < methods.length; i++) {
       Method method = methods[i];
       String name = method.getName();
       if (name.startsWith("get") && name.length() > 3) {
         if (method.getParameterTypes().length == 0) {
           name = dropCase(name);
           addGetMethod(name, method);
         }
       } else if (name.startsWith("is") && name.length() > 2) {
         if (method.getParameterTypes().length == 0) {
           name = dropCase(name);
           addGetMethod(name, method);
         }
       }
     }
   }
 
   /**
    * Adds the get method.
    *
    * @param name
    *          the name
    * @param method
    *          the method
    */
   private void addGetMethod(String name, Method method) {
     getMethods.put(name, new MethodInvoker(method));
     getTypes.put(name, method.getReturnType());
   }
 
   /**
    * Adds the set methods.
    *
    * @param cls
    *          the cls
    */
   private void addSetMethods(Class cls) {
     Map conflictingSetters = new HashMap();
     Method[] methods = getClassMethods(cls);
     for (int i = 0; i < methods.length; i++) {
       Method method = methods[i];
       String name = method.getName();
       if (name.startsWith("set") && name.length() > 3) {
         if (method.getParameterTypes().length == 1) {
           name = dropCase(name);
           // /------------
           addSetterConflict(conflictingSetters, name, method);
           // addSetMethod(name, method);
           // /------------
         }
       }
     }
     resolveSetterConflicts(conflictingSetters);
   }
 
   /**
    * Adds the setter conflict.
    *
    * @param conflictingSetters
    *          the conflicting setters
    * @param name
    *          the name
    * @param method
    *          the method
    */
   private void addSetterConflict(Map conflictingSetters, String name, Method method) {
     List list = (List) conflictingSetters.get(name);
     if (list == null) {
       list = new ArrayList();
       conflictingSetters.put(name, list);
     }
     list.add(method);
   }
 
   /**
    * Resolve setter conflicts.
    *
    * @param conflictingSetters
    *          the conflicting setters
    */
   private void resolveSetterConflicts(Map conflictingSetters) {
     for (Iterator propNames = conflictingSetters.keySet().iterator(); propNames.hasNext();) {
       String propName = (String) propNames.next();
       List setters = (List) conflictingSetters.get(propName);
       Method firstMethod = (Method) setters.get(0);
       if (setters.size() == 1) {
         addSetMethod(propName, firstMethod);
       } else {
         Class expectedType = (Class) getTypes.get(propName);
         if (expectedType == null) {
           throw new RuntimeException("Illegal overloaded setter method with ambiguous type for property " + propName
               + " in class " + firstMethod.getDeclaringClass() + ".  This breaks the JavaBeans "
               + "specification and can cause unpredicatble results.");
         } else {
           Iterator methods = setters.iterator();
           Method setter = null;
           while (methods.hasNext()) {
             Method method = (Method) methods.next();
             if (method.getParameterTypes().length == 1 && expectedType.equals(method.getParameterTypes()[0])) {
               setter = method;
               break;
             }
           }
           if (setter == null) {
             throw new RuntimeException("Illegal overloaded setter method with ambiguous type for property " + propName
                 + " in class " + firstMethod.getDeclaringClass() + ".  This breaks the JavaBeans "
                 + "specification and can cause unpredicatble results.");
           }
           addSetMethod(propName, setter);
         }
       }
     }
   }
 
   /**
    * Adds the set method.
    *
    * @param name
    *          the name
    * @param method
    *          the method
    */
   private void addSetMethod(String name, Method method) {
     setMethods.put(name, new MethodInvoker(method));
     setTypes.put(name, method.getParameterTypes()[0]);
   }
 
   /**
    * Adds the fields.
    *
    * @param clazz
    *          the clazz
    */
   private void addFields(Class clazz) {
     Field[] fields = clazz.getDeclaredFields();
     for (int i = 0; i < fields.length; i++) {
       Field field = fields[i];
       if (canAccessPrivateMethods()) {
         try {
           field.setAccessible(true);
         } catch (Exception e) {
           // Ignored. This is only a final precaution, nothing we can do.
         }
       }
       if (field.isAccessible()) {
         if (!setMethods.containsKey(field.getName())) {
           addSetField(field);
         }
         if (!getMethods.containsKey(field.getName())) {
           addGetField(field);
         }
       }
     }
     if (clazz.getSuperclass() != null) {
       addFields(clazz.getSuperclass());
     }
   }
 
   /**
    * Adds the set field.
    *
    * @param field
    *          the field
    */
   private void addSetField(Field field) {
     setMethods.put(field.getName(), new SetFieldInvoker(field));
     setTypes.put(field.getName(), field.getType());
   }
 
   /**
    * Adds the get field.
    *
    * @param field
    *          the field
    */
   private void addGetField(Field field) {
     getMethods.put(field.getName(), new GetFieldInvoker(field));
     getTypes.put(field.getName(), field.getType());
   }
 
   /**
    * This method returns an array containing all methods declared in this class and any superclass. We use this method,
    * instead of the simpler Class.getMethods(), because we want to look for private methods as well.
    *
    * @param cls
    *          The class
    *
    * @return An array containing all methods in this class
    */
   private Method[] getClassMethods(Class cls) {
     HashMap uniqueMethods = new HashMap();
     Class currentClass = cls;
     while (currentClass != null) {
       addUniqueMethods(uniqueMethods, currentClass.getDeclaredMethods());
 
       // we also need to look for interface methods -
       // because the class may be abstract
       Class[] interfaces = currentClass.getInterfaces();
       for (int i = 0; i < interfaces.length; i++) {
         addUniqueMethods(uniqueMethods, interfaces[i].getMethods());
       }
 
       currentClass = currentClass.getSuperclass();
     }
 
     Collection methods = uniqueMethods.values();
 
     return (Method[]) methods.toArray(new Method[methods.size()]);
   }
 
   /**
    * Adds the unique methods.
    *
    * @param uniqueMethods
    *          the unique methods
    * @param methods
    *          the methods
    */
   private void addUniqueMethods(HashMap uniqueMethods, Method[] methods) {
     for (Method currentMethod : methods) {
       if (!currentMethod.isBridge()) {
         String signature = getSignature(currentMethod);
         // check to see if the method is already known
         // if it is known, then an extended class must have
         // overridden a method
         if (!uniqueMethods.containsKey(signature)) {
           if (canAccessPrivateMethods()) {
             try {
               currentMethod.setAccessible(true);
             } catch (Exception e) {
               // Ignored. This is only a final precaution, nothing we can do.
             }
           }
 
           uniqueMethods.put(signature, currentMethod);
         }
       }
     }
   }
 
   /**
    * Gets the signature.
    *
    * @param method
    *          the method
    *
    * @return the signature
    */
   private String getSignature(Method method) {
     StringBuilder sb = new StringBuilder();
     sb.append(method.getName());
     Class[] parameters = method.getParameterTypes();
 
     for (int i = 0; i < parameters.length; i++) {
       if (i == 0) {
         sb.append(':');
       } else {
         sb.append(',');
       }
       sb.append(parameters[i].getName());
     }
 
     return sb.toString();
   }
 
   /**
    * Drop case.
    *
    * @param name
    *          the name
    *
    * @return the string
    */
   private static String dropCase(String name) {
     if (name.startsWith("is")) {
       name = name.substring(2);
     } else if (name.startsWith("get") || name.startsWith("set")) {
       name = name.substring(3);
     } else {
       throw new ProbeException("Error parsing property name '" + name + "'.  Didn't start with 'is', 'get' or 'set'.");
     }
 
     if (name.length() == 1 || (name.length() > 1 && !Character.isUpperCase(name.charAt(1)))) {
       name = name.substring(0, 1).toLowerCase(Locale.US) + name.substring(1);
     }
 
     return name;
   }
 
   /**
    * Can access private methods.
    *
    * @return true, if successful
    */
   private static boolean canAccessPrivateMethods() {
     try {
       SecurityManager securityManager = System.getSecurityManager();
       if (null != securityManager) {
         securityManager.checkPermission(new ReflectPermission("suppressAccessChecks"));
       }
     } catch (SecurityException e) {
       return false;
     }
     return true;
   }
 
   /**
    * Gets the name of the class the instance provides information for.
    *
    * @return The class name
    */
   public String getClassName() {
     return className;
   }
 
   /**
    * Instantiate class.
    *
    * @return the object
    */
   public Object instantiateClass() {
     if (defaultConstructor != null) {
       try {
         return defaultConstructor.newInstance(null);
       } catch (Exception e) {
         throw new RuntimeException("Error instantiating class. Cause: " + e, e);
       }
     } else {
       throw new RuntimeException("Error instantiating class.  There is no default constructor for class " + className);
     }
   }
 
   /**
    * Gets the setter for a property as a Method object.
    *
    * @param propertyName
    *          - the property
    *
    * @return The Method
    */
   public Method getSetter(String propertyName) {
     Invoker method = (Invoker) setMethods.get(propertyName);
     if (method == null) {
       throw new ProbeException(
           "There is no WRITEABLE property named '" + propertyName + "' in class '" + className + "'");
     }
     if (!(method instanceof MethodInvoker)) {
       throw new ProbeException(
           "Can't get setter method because '" + propertyName + "' is a field in class '" + className + "'");
     }
     return ((MethodInvoker) method).getMethod();
   }
 
   /**
    * Gets the getter for a property as a Method object.
    *
    * @param propertyName
    *          - the property
    *
    * @return The Method
    */
   public Method getGetter(String propertyName) {
     Invoker method = (Invoker) getMethods.get(propertyName);
     if (method == null) {
       throw new ProbeException(
           "There is no READABLE property named '" + propertyName + "' in class '" + className + "'");
     }
     if (!(method instanceof MethodInvoker)) {
       throw new ProbeException(
           "Can't get getter method because '" + propertyName + "' is a field in class '" + className + "'");
     }
     return ((MethodInvoker) method).getMethod();
   }
 
   /**
    * Gets the sets the invoker.
    *
    * @param propertyName
    *          the property name
    *
    * @return the sets the invoker
    */
   public Invoker getSetInvoker(String propertyName) {
     Invoker method = (Invoker) setMethods.get(propertyName);
     if (method == null) {
       throw new ProbeException(
           "There is no WRITEABLE property named '" + propertyName + "' in class '" + className + "'");
     }
     return method;
   }
 
   /**
    * Gets the gets the invoker.
    *
    * @param propertyName
    *          the property name
    *
    * @return the gets the invoker
    */
   public Invoker getGetInvoker(String propertyName) {
     Invoker method = (Invoker) getMethods.get(propertyName);
     if (method == null) {
       throw new ProbeException(
           "There is no READABLE property named '" + propertyName + "' in class '" + className + "'");
     }
     return method;
   }
 
   /**
    * Gets the type for a property setter.
    *
    * @param propertyName
    *          - the name of the property
    *
    * @return The Class of the propery setter
    */
   public Class getSetterType(String propertyName) {
     Class clazz = (Class) setTypes.get(propertyName);
     if (clazz == null) {
       throw new ProbeException(
           "There is no WRITEABLE property named '" + propertyName + "' in class '" + className + "'");
     }
     return clazz;
   }
 
   /**
    * Gets the type for a property getter.
    *
    * @param propertyName
    *          - the name of the property
    *
    * @return The Class of the propery getter
    */
   public Class getGetterType(String propertyName) {
     Class clazz = (Class) getTypes.get(propertyName);
     if (clazz == null) {
       throw new ProbeException(
           "There is no READABLE property named '" + propertyName + "' in class '" + className + "'");
     }
     return clazz;
   }
 
   /**
    * Gets an array of the readable properties for an object.
    *
    * @return The array
    */
   public String[] getReadablePropertyNames() {
     return readablePropertyNames;
   }
 
   /**
    * Gets an array of the writeable properties for an object.
    *
    * @return The array
    */
   public String[] getWriteablePropertyNames() {
     return writeablePropertyNames;
   }
 
   /**
    * Check to see if a class has a writeable property by name.
    *
    * @param propertyName
    *          - the name of the property to check
    *
    * @return True if the object has a writeable property by the name
    */
   public boolean hasWritableProperty(String propertyName) {
     return setMethods.keySet().contains(propertyName);
   }
 
   /**
    * Check to see if a class has a readable property by name.
    *
    * @param propertyName
    *          - the name of the property to check
    *
    * @return True if the object has a readable property by the name
    */
   public boolean hasReadableProperty(String propertyName) {
     return getMethods.keySet().contains(propertyName);
   }
 
   /**
    * Tells us if the class passed in is a knwon common type.
    *
    * @param clazz
    *          The class to check
    *
    * @return True if the class is known
    */
   public static boolean isKnownType(Class clazz) {
     if (SIMPLE_TYPE_SET.contains(clazz)) {
       return true;
     } else if (Collection.class.isAssignableFrom(clazz)) {
       return true;
     } else if (Map.class.isAssignableFrom(clazz)) {
       return true;
     } else if (List.class.isAssignableFrom(clazz)) {
       return true;
     } else if (Set.class.isAssignableFrom(clazz)) {
       return true;
     } else if (Iterator.class.isAssignableFrom(clazz)) {
       return true;
     } else {
       return false;
     }
   }
 
   /**
    * Gets an instance of ClassInfo for the specified class.
    *
    * @param clazz
    *          The class for which to lookup the method cache.
    *
    * @return The method cache for the class
    */
   public static ClassInfo getInstance(Class clazz) {
     if (cacheEnabled) {
       ClassInfo cached = (ClassInfo) CLASS_INFO_MAP.get(clazz);
       if (cached == null) {
         cached = new ClassInfo(clazz);
         CLASS_INFO_MAP.put(clazz, cached);
       }
       return cached;
     } else {
       return new ClassInfo(clazz);
     }
   }
 
   /**
    * Sets the cache enabled.
    *
    * @param cacheEnabled
    *          the new cache enabled
    */
   public static void setCacheEnabled(boolean cacheEnabled) {
     ClassInfo.cacheEnabled = cacheEnabled;
   }
 
   /**
    * Examines a Throwable object and gets it's root cause.
    *
    * @param t
    *          - the exception to examine
    *
    * @return The root cause
    */
   public static Throwable unwrapThrowable(Throwable t) {
     Throwable t2 = t;
     while (true) {
       if (t2 instanceof InvocationTargetException) {
         t2 = ((InvocationTargetException) t).getTargetException();
       } else if (t2 instanceof UndeclaredThrowableException) {
         t2 = ((UndeclaredThrowableException) t).getUndeclaredThrowable();
       } else {
         return t2;
       }
     }
   }
 
 }