/*******************************************************************************
 * Copyright (c) 2007 Oracle Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Cameron Bateman/Oracle - initial API and implementation
 *    
 ********************************************************************************/
package org.eclipse.jst.jsf.common.util;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.Signature;
import org.eclipse.jst.jsf.common.JSFCommonPlugin;

/**
 * Represents a single bean property backed by JDT data
 * 
 * This class may not be sub-classed by clients.
 * 
 * @author cbateman
 *
 */
public class JDTBeanProperty 
{
	/**
	 * the IMethod for the accessor  (either is or get)
	 */
	private IMethod   _getter;
	
	/**
	 * the IMethod for a "set" accessor method
	 */
	private IMethod   _setter;

	/**
	 * The IType that this property belongs to
	 */
	protected final IType    _type;
    
    /**
     * @param type
     */
    protected JDTBeanProperty(IType type)
    {
        _type = type;
    }

    /**
	 * @return true if this property is readable
	 */
	public boolean isReadable()
	{
		return  _getter != null;
	}
	
	/**
	 * @return true if this property is writable
	 */
	public boolean isWritable()
	{
		return _setter != null;
	}
	
	
	/**
	 * @return the get accessor IMethod or null if none
	 */
	public IMethod getGetter() {
		return _getter;
	}

	
	/**
	 * Set the get accessor IMethod
	 * @param getter -- may be null to indicate none
	 */
	void setGetter(IMethod getter) {
		_getter = getter;
	}


	/**
	 * @return the set mutator IMethod or null if none
	 */
	public IMethod getSetter() {
		return _setter;
	}

	/**
	 * @param setter
	 */
	void setSetter(IMethod setter) {
		_setter = setter;
	}
	
    /**
     * @return the IType for this property's type or null if it
     * cannot determined.  Note that null does not necessarily indicate an error
     * since some types like arrays of things do not have corresponding JDT IType's
     * If typeSignature represents an array, the base element IType is returned
     * if possible
     */
    public IType getType()
    {
        final String typeSignature = Signature.getElementType(getTypeSignature());
        return TypeUtil.resolveType(_type, typeSignature);
    }
	
    /**
     * @return the number of array nesting levels in typeSignature.
     * Returns 0 if not an array.
     */
    public int getArrayCount()
    {
        return Signature.getArrayCount(getTypeSignature());
    }
    
    /**
     * @return true if property is an enum type, false otherwise or if cannot be resolved
     */
    public boolean isEnumType()
    {
        return TypeUtil.isEnumType(getType());
    }
    
	/**
	 * Fully equivalent to:
	 * 
	 * getTypeSignature(true)
	 * 
	 * @return the fully resolved (if possible) type signature for
     * the property or null if unable to determine.
     * 
     * NOTE: this is the "type erasure" signature, so any type parameters
     * will be removed and only the raw type signature will be returned.
	 */
	public String getTypeSignature()
    {
	    return getTypeSignature(true);
    }
	
	
    /**
     * @param eraseTypeParameters if true, the returned type has type parameters
     * erased. If false, template types are resolved. 
     * 
     * @see org.eclipse.jst.jsf.common.util.TypeUtil#resolveTypeSignature(IType, String, boolean)
     * for more information on how specific kinds of unresolved generics are resolved
     * 
     * @return the fully resolved (if possible) type signature for
     * the property or null if unable to determine.
     */
    public String getTypeSignature(boolean eraseTypeParameters)
    {
        try
        {
            String unResolvedSig = getUnresolvedType();
            return TypeUtil.resolveTypeSignature(_type, unResolvedSig, eraseTypeParameters);
        }
        catch (JavaModelException jme)
        {
            JSFCommonPlugin.log(jme, "Error resolving bean property type signature"); //$NON-NLS-1$
            return null;
        }
    }
    
	/**
	 * For example, if this property was formed from: List<String> getListOfStrings()
	 * then the list would consist of the signature "Ljava.lang.String;".  All 
	 * nested type paramters are resolved
	 * 
     * @see org.eclipse.jst.jsf.common.util.TypeUtil#resolveTypeSignature(IType, String, boolean)
     * for more information on how specific kinds of unresolved generics are resolved
	 * 
	 * @return a list of type signatures (fully resolved if possible)
	 * of this property's bounding type parameters.
	 */
	public List<String> getTypeParameterSignatures()
	{
	    List<String>  signatures = new ArrayList<String>();
	    
	    try
	    {
	        final String[] typeParameters = Signature.getTypeArguments(getUnresolvedType());
	        //System.err.println(getUnresolvedType());
	        for (String parameter : typeParameters)
	        {
	            //System.out.println(parameter);
	            signatures.add(TypeUtil.resolveTypeSignature(_type, parameter, false));
	        }
	    }
	    catch (JavaModelException jme)
	    {
            JSFCommonPlugin.log(jme, "Error resolving bean property type signature"); //$NON-NLS-1$
            // fall-through and return empty array
	    }

	    return signatures;
	}

//	public Map<String, String> getTypeParameterSignatureMap()
//	{
//	    Map<String, String>  signatures = new HashMap<String, String>();
//        
//        try
//        {
//            final String[] typeParameters = Signature.getTypeArguments(getUnresolvedType());
//            
//            for (String parameter : typeParameters)
//            {
//                signatures.add(TypeUtil.resolveTypeSignature(_type, parameter, false));
//            }
//        }
//        catch (JavaModelException jme)
//        {
//            JSFCommonPlugin.log(jme, "Error resolving bean property type signature"); //$NON-NLS-1$
//            // fall-through and return empty array
//        }
//
//        return signatures;
//	}
	
    private String getUnresolvedType() throws JavaModelException
    {
        String   typeSig = null;
        
        // first decide which method to use; getter always gets precendence
        if (_getter != null)
        {
            typeSig = _getter.getReturnType();
        }
        // TODO: if no getter or setter could we have been created?
        // use setter
        else
        {
            typeSig = _setter.getParameterTypes()[0];
        }
        
        return typeSig;
    }
}