package com.onaro.util.jfc.grouping;

import org.apache.commons.lang3.StringUtils;

import com.onaro.sanscreen.client.view.tabular.value.NumberValue;

/**
 * Average the values in a specific column for the rows in a group and all its descendants.
 */
public class AverageNumberSummarizer implements Summarizer {
	
    /**
     * The column to put the average in.
     */
    private int column;

    /**
     * Defined the format-name used by {@link NumberValue} to format the number.
     */
    private String format;
    
    /**
     * If true, don't show anything if a child row has a blank value
     */
    protected boolean showIfAnyBlanks;

    /**
     * Initialize a summarizer for the given column.
     * @param column the column to put the average in
     */
    public AverageNumberSummarizer(int column) {
    	this(column, NumberValue.FORMAT_DEFAULT);
    }
    
    /**
     * Initialize a summarizer for the given column. Assumes default of showIfAnyBlanks = true.
     * @param column the column to put the average in
     * @param format Format to be used; blank/null results in NumberValue.FORMAT_DEFAULT being used
     */
    public AverageNumberSummarizer(int column, String format) {
    	this(column, format, true);
    }

    /**
     * Initialize a summarizer for the given column.
     * @param column the column to put the average in
     * @param format Format to be used; blank/null results in NumberValue.FORMAT_DEFAULT being used
     * @param showIfAnyBlanks if true, include null node values in the count divisor; otherwise return a null if any child node values are null
     */
    public AverageNumberSummarizer(int column, String format, boolean showIfAnyBlanks) {
    	this.column = column;
    	this.format = StringUtils.isBlank(format) ? NumberValue.FORMAT_DEFAULT : format;
        this.showIfAnyBlanks = showIfAnyBlanks;
    }

    /**
     * Average the values of the column set for this summarizer in all the rows of the
     * given node and all its descendants.
     * @param node the node
     */
	public void updateSummary(Node node) {
        double sum = 0;
        String unitsText = null;
        boolean hasBlankChildValue = false;

        for (int i = 0; i < node.getChildCount(); ++i) {
            Node child = node.getChild(i);
            Object value = child.getValueAt(column);
            if (value instanceof Number) {
                sum += ((Number)value).doubleValue();
            } else if (value instanceof NumberValue) {
                NumberValue numberValue = ((NumberValue) value);
                sum += numberValue.getNumber();
                if (unitsText==null)
                    unitsText = numberValue.getUnitsText();
            }
            else if(value == null) {
                hasBlankChildValue = true;
            }
        }

        // Show the value if we are showing even if there are blank values or we don't have blanks
        if(showIfAnyBlanks || !hasBlankChildValue) {
            double average = sum / node.getChildCount();

            node.setValueAt(column, new NumberValue(average, unitsText, null, format));
        }
        else {
            node.setValueAt(column, null);
        }
	}

}