/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id: RowGroupLayoutManager.java 1761020 2016-09-16 11:17:35Z ssteiner $ */

package org.apache.fop.layoutmgr.table;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.apache.fop.fo.Constants;
import org.apache.fop.fo.flow.table.EffRow;
import org.apache.fop.fo.flow.table.GridUnit;
import org.apache.fop.fo.flow.table.PrimaryGridUnit;
import org.apache.fop.fo.flow.table.TableColumn;
import org.apache.fop.fo.flow.table.TableRow;
import org.apache.fop.fo.properties.CommonBorderPaddingBackground;
import org.apache.fop.fo.properties.LengthRangeProperty;
import org.apache.fop.layoutmgr.ElementListObserver;
import org.apache.fop.layoutmgr.LayoutContext;
import org.apache.fop.traits.MinOptMax;
import org.apache.fop.util.BreakUtil;

class RowGroupLayoutManager {

    private static Log log = LogFactory.getLog(RowGroupLayoutManager.class);

    private static final MinOptMax MAX_STRETCH = MinOptMax.getInstance(0, 0, Integer.MAX_VALUE);

    private EffRow[] rowGroup;

    private TableLayoutManager tableLM;

    private TableStepper tableStepper;

    RowGroupLayoutManager(TableLayoutManager tableLM, EffRow[] rowGroup,
            TableStepper tableStepper) {
        this.tableLM = tableLM;
        this.rowGroup = rowGroup;
        this.tableStepper = tableStepper;
    }

    public LinkedList getNextKnuthElements(LayoutContext context, int alignment, int bodyType) {
        LinkedList returnList = new LinkedList();
        createElementsForRowGroup(context, alignment, bodyType, returnList);

        context.updateKeepWithPreviousPending(rowGroup[0].getKeepWithPrevious());
        context.updateKeepWithNextPending(rowGroup[rowGroup.length - 1].getKeepWithNext());

        int breakBefore = Constants.EN_AUTO;
        TableRow firstRow = rowGroup[0].getTableRow();
        if (firstRow != null) {
            breakBefore = firstRow.getBreakBefore();
        }
        context.setBreakBefore(BreakUtil.compareBreakClasses(breakBefore,
                rowGroup[0].getBreakBefore()));

        int breakAfter = Constants.EN_AUTO;
        TableRow lastRow = rowGroup[rowGroup.length - 1].getTableRow();
        if (lastRow != null) {
            breakAfter = lastRow.getBreakAfter();
        }
        context.setBreakAfter(BreakUtil.compareBreakClasses(breakAfter,
                rowGroup[rowGroup.length - 1].getBreakAfter()));

        return returnList;
    }

    
Creates Knuth elements for a row group (see TableRowIterator.getNextRowGroup()).
Params:
context – Active LayoutContext
alignment – alignment indicator
bodyType – Indicates what kind of body is being processed (BODY, HEADER or FOOTER)
returnList – List to received the generated elements/**
     * Creates Knuth elements for a row group (see TableRowIterator.getNextRowGroup()).
     * @param context Active LayoutContext
     * @param alignment alignment indicator
     * @param bodyType Indicates what kind of body is being processed (BODY, HEADER or FOOTER)
     * @param returnList List to received the generated elements
     */
    private void createElementsForRowGroup(LayoutContext context, int alignment,
            int bodyType, LinkedList returnList) {
        log.debug("Handling row group with " + rowGroup.length + " rows...");
        EffRow row;
        for (EffRow aRowGroup : rowGroup) {
            row = aRowGroup;
            for (Object o : row.getGridUnits()) {
                GridUnit gu = (GridUnit) o;
                if (gu.isPrimary()) {
                    PrimaryGridUnit primary = gu.getPrimary();
                    // TODO a new LM must be created for every new static-content
                    primary.createCellLM();
                    primary.getCellLM().setParent(tableLM);
                    //Calculate width of cell
                    int spanWidth = 0;
                    Iterator colIter = tableLM.getTable().getColumns().listIterator(
                            primary.getColIndex());
                    for (int i = 0, c = primary.getCell().getNumberColumnsSpanned(); i < c; i++) {
                        spanWidth += ((TableColumn) colIter.next()).getColumnWidth().getValue(
                                tableLM);
                    }
                    LayoutContext childLC = LayoutContext.newInstance();
                    childLC.setStackLimitBP(context.getStackLimitBP()); //necessary?
                    childLC.setRefIPD(spanWidth);

                    //Get the element list for the cell contents
                    List elems = primary.getCellLM().getNextKnuthElements(
                            childLC, alignment);
                    ElementListObserver.observe(elems, "table-cell", primary.getCell().getId());
                    primary.setElements(elems);
                }
            }
        }
        computeRowHeights();
        List elements = tableStepper.getCombinedKnuthElementsForRowGroup(context,
                rowGroup, bodyType);
        returnList.addAll(elements);
    }

    
Calculate the heights of the rows in the row group, see CSS21, 17.5.3 Table height
algorithms.
TODO this method will need to be adapted once clarification has been made by the
W3C regarding whether borders or border-separation must be included or not
/**
     * Calculate the heights of the rows in the row group, see CSS21, 17.5.3 Table height
     * algorithms.
     *
     * TODO this method will need to be adapted once clarification has been made by the
     * W3C regarding whether borders or border-separation must be included or not
     */
    private void computeRowHeights() {
        log.debug("rowGroup:");
        MinOptMax[] rowHeights = new MinOptMax[rowGroup.length];
        EffRow row;
        for (int rgi = 0; rgi < rowGroup.length; rgi++) {
            row = rowGroup[rgi];
            // The BPD of the biggest cell in the row
//            int maxCellBPD = 0;
            MinOptMax explicitRowHeight;
            TableRow tableRowFO = rowGroup[rgi].getTableRow();
            if (tableRowFO == null) {
                rowHeights[rgi] = MAX_STRETCH;
                explicitRowHeight = MAX_STRETCH;
            } else {
                LengthRangeProperty rowBPD = tableRowFO.getBlockProgressionDimension();
                rowHeights[rgi] = rowBPD.toMinOptMax(tableLM);
                explicitRowHeight = rowBPD.toMinOptMax(tableLM);
            }
            for (Object o : row.getGridUnits()) {
                GridUnit gu = (GridUnit) o;
                if (!gu.isEmpty() && gu.getColSpanIndex() == 0 && gu.isLastGridUnitRowSpan()) {
                    PrimaryGridUnit primary = gu.getPrimary();
                    int effectiveCellBPD = 0;
                    LengthRangeProperty cellBPD = primary.getCell().getBlockProgressionDimension();
                    if (!cellBPD.getMinimum(tableLM).isAuto()) {
                        effectiveCellBPD = cellBPD.getMinimum(tableLM).getLength()
                                .getValue(tableLM);
                    }
                    if (!cellBPD.getOptimum(tableLM).isAuto()) {
                        effectiveCellBPD = cellBPD.getOptimum(tableLM).getLength()
                                .getValue(tableLM);
                    }
                    if (gu.getRowSpanIndex() == 0) {
                        effectiveCellBPD = Math.max(effectiveCellBPD, explicitRowHeight.getOpt());
                    }
                    effectiveCellBPD = Math.max(effectiveCellBPD, primary.getContentLength());
                    int borderWidths = primary.getBeforeAfterBorderWidth();
                    int padding = 0;
                    CommonBorderPaddingBackground cbpb = primary.getCell()
                            .getCommonBorderPaddingBackground();
                    padding += cbpb.getPaddingBefore(false, primary.getCellLM());
                    padding += cbpb.getPaddingAfter(false, primary.getCellLM());
                    int effRowHeight = effectiveCellBPD + padding + borderWidths;
                    for (int prev = rgi - 1; prev >= rgi - gu.getRowSpanIndex(); prev--) {
                        effRowHeight -= rowHeights[prev].getOpt();
                    }
                    if (effRowHeight > rowHeights[rgi].getMin()) {
                        // This is the new height of the (grid) row
                        rowHeights[rgi] = rowHeights[rgi].extendMinimum(effRowHeight);
                    }
                }
            }

            row.setHeight(rowHeights[rgi]);
            row.setExplicitHeight(explicitRowHeight);
            // TODO re-enable and improve after clarification
            //See http://markmail.org/message/h25ycwwu7qglr4k4
//            if (maxCellBPD > row.getExplicitHeight().max) {
//old:
//                log.warn(FONode.decorateWithContextInfo(
//                        "The contents of row " + (row.getIndex() + 1)
//                        + " are taller than they should be (there is a"
//                        + " block-progression-dimension or height constraint
//                        + " on the indicated row)."
//                        + " Due to its contents the row grows"
//                        + " to " + maxCellBPD + " millipoints, but the row shouldn't get"
//                        + " any taller than " + row.getExplicitHeight() + " millipoints.",
//                        row.getTableRow()));
//new (with events):
//                BlockLevelEventProducer eventProducer = BlockLevelEventProducer.Factory.create(
//                        tableRow.getUserAgent().getEventBroadcaster());
//                eventProducer.rowTooTall(this, row.getIndex() + 1,
//                        maxCellBPD, row.getExplicitHeight().max, tableRow.getLocator());
//            }
        }
    }
}