/*
 * DynamicReports - Free Java reporting library for creating reports dynamically
 *
 * Copyright (C) 2010 - 2018 Ricardo Mariaca and the Dynamic Reports Contributors
 * http://www.dynamicreports.org
 *
 * This file is part of DynamicReports.
 *
 * DynamicReports 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.
 *
 * DynamicReports 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 DynamicReports. If not, see <http://www.gnu.org/licenses/>.
 */
package cn.myapps.report.examples.subtotal;

import cn.myapps.report.examples.Templates;
import net.sf.dynamicreports.report.base.expression.AbstractSimpleExpression;
import net.sf.dynamicreports.report.builder.column.TextColumnBuilder;
import net.sf.dynamicreports.report.builder.subtotal.AggregationSubtotalBuilder;
import net.sf.dynamicreports.report.builder.subtotal.CustomSubtotalBuilder;
import net.sf.dynamicreports.report.datasource.DRDataSource;
import net.sf.dynamicreports.report.definition.ReportParameters;
import net.sf.dynamicreports.report.exception.DRException;
import net.sf.jasperreports.engine.JRDataSource;

import java.math.BigDecimal;

import static net.sf.dynamicreports.report.builder.DynamicReports.col;
import static net.sf.dynamicreports.report.builder.DynamicReports.report;
import static net.sf.dynamicreports.report.builder.DynamicReports.sbt;
import static net.sf.dynamicreports.report.builder.DynamicReports.type;

/**
 * <p>CustomSubtotalReport class.</p>
 *
 * @author Ricardo Mariaca (r.mariaca@dynamicreports.org)
 * @version $Id: $Id
 */
public class CustomSubtotalReport {
    private AggregationSubtotalBuilder<Integer> quantitySum;
    private AggregationSubtotalBuilder<BigDecimal> priceSum;

    /**
     * <p>Constructor for CustomSubtotalReport.</p>
     */
    public CustomSubtotalReport() {
        build();
    }

    /**
     * <p>main.</p>
     *
     * @param args an array of {@link java.lang.String} objects.
     */
    public static void main(String[] args) {
        new CustomSubtotalReport();
    }

    private void build() {
        TextColumnBuilder<String> itemColumn = col.column("Item", "item", type.stringType());
        TextColumnBuilder<Integer> quantityColumn = col.column("Quantity", "quantity", type.integerType());
        TextColumnBuilder<BigDecimal> priceColumn = col.column("Price", "price", type.bigDecimalType());
        TextColumnBuilder<BigDecimal> unitPriceColumn = priceColumn.divide(2, quantityColumn).setTitle("Price / Quantity");

        quantitySum = sbt.sum(quantityColumn).setLabel("sum");
        priceSum = sbt.sum(priceColumn).setLabel("sum");
        CustomSubtotalBuilder<BigDecimal> unitPriceSbt = sbt.customValue(new UnitPriceSubtotal(), unitPriceColumn).setLabel("sum(price) / sum(quantity)").setDataType(type.bigDecimalType());

        try {
            report().setTemplate(Templates.reportTemplate)
                    .columns(itemColumn, quantityColumn, priceColumn, unitPriceColumn)
                    .subtotalsAtSummary(quantitySum, priceSum, unitPriceSbt)
                    .title(Templates.createTitleComponent("CustomSubtotal"))
                    .pageFooter(Templates.footerComponent)
                    .setDataSource(createDataSource())
                    .show();
        } catch (DRException e) {
            e.printStackTrace();
        }
    }

    private JRDataSource createDataSource() {
        DRDataSource dataSource = new DRDataSource("item", "quantity", "price");
        dataSource.add("Tablet", 3, new BigDecimal(330));
        dataSource.add("Tablet", 1, new BigDecimal(150));
        dataSource.add("Laptop", 3, new BigDecimal(900));
        dataSource.add("Smartphone", 8, new BigDecimal(720));
        dataSource.add("Smartphone", 6, new BigDecimal(720));
        return dataSource;
    }

    private class UnitPriceSubtotal extends AbstractSimpleExpression<BigDecimal> {
        private static final long serialVersionUID = 1L;

        @Override
        public BigDecimal evaluate(ReportParameters reportParameters) {
            Integer quantitySumValue = reportParameters.getValue(quantitySum);
            BigDecimal priceSumValue = reportParameters.getValue(priceSum);
            return priceSumValue.divide(new BigDecimal(quantitySumValue), 2, BigDecimal.ROUND_HALF_UP);
        }
    }
}
