/*
 * Copyright (C) 2005-2011 Alfresco Software Limited.
 *
 * This file is part of Alfresco
 *
 * Alfresco is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Alfresco is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 */
package org.alfresco.util.schemacomp.model;

import org.alfresco.util.schemacomp.ComparisonUtils;
import org.alfresco.util.schemacomp.DbProperty;
import org.alfresco.util.schemacomp.DefaultComparisonUtils;
import org.alfresco.util.schemacomp.DiffContext;
import org.alfresco.util.schemacomp.Result.Strength;
import org.alfresco.util.schemacomp.Results;

/**
 * Useful base class for many, if not all the {@link DbObject} implementations.
 * 
 * @author Matt Ward
 */
public abstract class AbstractDbObject implements DbObject
{
    private DbObject parent;
    private String name;
    /** How differences in the name field should be reported */
    private Strength nameStrength = Strength.ERROR;
    protected ComparisonUtils comparisonUtils = new DefaultComparisonUtils();
    

    /**
     * Instantiate, giving the object a parent and a name.
     * 
     * @param parent
     * @param name
     */
    public AbstractDbObject(DbObject parent, String name)
    {
        this.parent = parent;
        this.name = name;
    }

    /**
     * @return the name
     */
    public String getName()
    {
        return this.name;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name)
    {
        this.name = name;
    }
    
    /**
     * @return the nameStrength
     */
    public Strength getNameStrength()
    {
        return this.nameStrength;
    }

    /**
     * @param nameStrength the nameStrength to set
     */
    public void setNameStrength(Strength nameStrength)
    {
        this.nameStrength = nameStrength;
    }

    @Override
    public boolean sameAs(DbObject other)
    {
        if (getName() != null && other != null && other.getName() != null)
        {
            return getName().equals(other.getName());
        }
        else
        {
            // Only other way we can know if they are the same is if they are
            // the exact same object reference.
            return this == other;
        }
    }

    @Override
    public int hashCode()
    {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((this.name == null) ? 0 : this.name.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj)
    {
        if (this == obj) return true;
        if (obj == null) return false;
        if (getClass() != obj.getClass()) return false;
        AbstractDbObject other = (AbstractDbObject) obj;
        if (this.name == null)
        {
            if (other.name != null) return false;
        }
        else if (!this.name.equals(other.name)) return false;
        return true;
    }
    
    @Override
    public String toString()
    {
        StringBuffer sb = new StringBuffer();
        sb.append(getClass().getSimpleName());
        sb.append("[name=");
        
        if (getName() != null)
        {
            sb.append(getName());
        }
        else
        {
            sb.append("null");
        }
        
        sb.append("]");
        
        return sb.toString();
    }

    /**
     * Provides an implementation of {@link DbObject#diff(DbObject, Results)}. The template
     * method {@link #doDiff(DbObject, Results)} provides the subclass specific diffing logic,
     * whilst this method handles the workflow required in most cases: set the path's prefix that will be
     * used to explain where differences occur; compare the name fields of the two objects; delegate to the
     * subclass specific diffing (if any); remove the last path addition ready for the next object to perform
     * its diff correctly.
     */
    @Override
    public void diff(DbObject right, DiffContext ctx, Strength strength)
    {   
        DbProperty leftNameProp = new DbProperty(this, "name");
        DbProperty rightNameProp = new DbProperty(right, "name");
        
        comparisonUtils.compareSimple(leftNameProp, rightNameProp, ctx, getNameStrength());
        
        doDiff(right, ctx, strength);
    }
    
    
    @Override
    public DbObject getParent()
    {
        return parent;
    }
    
    
    @Override
    public void setParent(DbObject parent)
    {
        this.parent = parent;
    }

    
    /**
     * Override this method to provide subclass specific diffing logic.
     * 
     * @param right
     * @param differences
     * @param strength
     */
    protected void doDiff(DbObject right, DiffContext ctx, Strength strength)
    {
    }
    

    /**
     * If a ComparisonUtils other than the default is required, then this setter can be used.
     * Useful for testing, where a mock can be injected.
     * 
     * @param comparisonUtils the comparisonUtils to set
     */
    public void setComparisonUtils(ComparisonUtils comparisonUtils)
    {
        this.comparisonUtils = comparisonUtils;
    }
}