package com.onaro.sanscreen.client.view.tabular.value;

import java.util.Comparator;

import org.apache.commons.lang3.StringUtils;

public class ComparatorTableValue implements TableValue{
    private final Comparator<Object> comparator;
    private final Object display;

    /**
     *
     * @param comparator should be able to handle null values.
     */
    public ComparatorTableValue(Comparator<Object> comparator, Object display) {
        this.comparator = comparator;
        this.display = display;
    }

    public Object getDisplay() {
        return display != null ? display : StringUtils.EMPTY;
    }

    @Override
    public int compareTo (TableValue o) {
        return comparator.compare(this.getDisplay(), o.getDisplay());
    }

    /**
     * Since this method is used by he grouping-table, it returns the display value.
     * @return Return's the same value as {@link TableValue#getDisplay} does
     */
    public String toString() {
        return getDisplay().toString();
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((comparator == null) ? 0 : comparator.hashCode());
        result = prime * result + ((display == null) ? 0 : display.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;
        ComparatorTableValue other = (ComparatorTableValue) obj;
        if (comparator == null) {
            if (other.comparator != null) return false;
        }
        else if (!comparator.equals(other.comparator)) return false;
        if (display == null) {
            if (other.display != null) return false;
        }
        else if (!display.equals(other.display)) return false;
        return true;
    }
}