package com.javaranch.dynadto;

import java.util.*;
import org.apache.commons.beanutils.*;

/**
 * DynaBean implementation for DynaDTOs.  Contains an implementation of
 * <tt>equals()</tt> which checks for content equality between
 * <tt>DynaDTODynaBean</tt> objects.
 * @author Jason Menard
 * @version 1.0, 08 SEP 2003
 */
public class DynaDTODynaBean extends BasicDynaBean {

    /**
     * Constructor
     * @param dynaClass <tt>DynaClass</tt> for this <tt>DynaBean</tt>
     */
    public DynaDTODynaBean(DynaClass dynaClass) {
        super(dynaClass);
    }

    /**
     * Tests for content equality between DynaDTODynaBean objects.
     * @param o an object to test for equality
     * @return <b>true</b> if <tt>o</tt> is a <tt>DynaDTODynaBean</tt>
     * containing only the same properties as the <tt>DynaDTODynaBean</tt> being
     * tested against and all values of those properties have their
     * <tt>equals()</tt> methods also evaluate to <b>true</b>.  Any property
     * which is a <tt>Collection</tt> will have each element checked for
     * equality as well (with <tt>Collections</tt> of <tt>Collections</tt>
     * being recursively checked as well).  Otherwise returns <b>false</b>.
     */
    public boolean equals(Object o) {
        if (o == this) {
            return true;
        }
        if (!(o instanceof DynaDTODynaBean)) {
            return false;
        }
        DynaDTODynaBean oBean = (DynaDTODynaBean)o;
        return dynaBeanEquals(this, oBean);
    }

    /**
     * Returns a hash code value for the object.
     * @return a hash code value for this object.
     */
    public int hashCode() {
        int result = 17;
        DynaProperty[] props = this.getDynaClass().getDynaProperties();
        for (int i = 0; i < props.length; i++) {
            int propHashCode = props[i].getName().hashCode() ^
                               props[i].getType().hashCode();
            Object propVal = get(props[i].getName());
            int valHashCode = (propVal == null ? 0 : propVal.hashCode());
            int c = propHashCode ^ valHashCode;
            result = 37 * result + c;
        }
        return result;
    }

    /**
     * Returns a String representation of this object.
     * @return a String representation of this object.
     */
    public String toString() {
        StringBuffer out = new StringBuffer();
        out.append("[" + this.getDynaClass().getName() + ": ");
        DynaProperty[] properties = getDynaClass().getDynaProperties();
        for (int i = 0; i < properties.length; i++) {
            String propName = properties[i].getName();
            String propType = properties[i].getType().getName();
            Object propValue = this.get(propName);
            out.append("name=" + properties[i].getName());
            out.append(" type=" + properties[i].getType());
            if (propValue instanceof Collection) {
                Collection collection = (Collection)propValue;
                for (Iterator it = collection.iterator(); it.hasNext(); ) {
                    out.append(" value=" + it.next());
                }
            } else {
                out.append(" value=" + propValue);
            }
            if (i < properties.length - 1) {
                out.append(", ");
            }
        }
        out.append("]");
        return out.toString();
    }

    private boolean dynaBeanEquals(DynaBean bean1, DynaBean bean2) {
        if (bean1 == bean2) {
            return true;
        }
        if (bean1 == null || bean2 == null) {
            return false;
        }
        DynaClass dynaClass1 = bean1.getDynaClass();
        DynaProperty[] props1 = dynaClass1.getDynaProperties();
        if (props1.length != bean2.getDynaClass().getDynaProperties().length) {
            return false;
        }
        boolean isEqual = true;
        int i = 0;
        while (i < props1.length && isEqual) {
            DynaProperty prop1 = props1[i];
            DynaProperty prop2 =
                    bean2.getDynaClass().getDynaProperty(prop1.getName());
            isEqual = dynaPropertyEquals(prop1,
                                         prop2,
                                         bean1.get(prop1.getName()),
                                         bean2.get(prop2.getName()));
            i++;
        }
        return isEqual;
    }

    private boolean dynaPropertyEquals(DynaProperty prop1,
                                       DynaProperty prop2,
                                       Object value1,
                                       Object value2) {
        if (prop1 == prop2) {
            return true;
        }
        if (prop1 == null || prop2 == null) {
            return false;
        }
        String name1 = prop1.getName();
        String name2 = prop2.getName();
        Class type1 = prop1.getType();
        Class type2 = prop2.getType();
        if (name1.equals(name2) && type1.equals(type2)) {
            return valueEquals(value1, value2);
        }
        return false;
    }

    private boolean valueEquals(Object value1, Object value2) {
        if (value1 == value2) {
            return true;
        }
        if (value1 == null) {
            return false;
        }
        return value1.equals(value2);
    }
}