/*
 * Copyright 1999-2004 The Apache Software Foundation.
 * 
 * Licensed 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.
 */

/* $Id$ */

package org.apache.fop.render.rtf.rtflib.rtfdoc;

// Java
import java.io.IOException;
import java.io.Writer;
import java.util.List;
import java.util.Iterator;
import java.util.ListIterator;

// FOP
import org.apache.fop.render.rtf.rtflib.rtfdoc.RtfExternalGraphic;

/** 
 * Class which contains a linear text run. It has methods to add attributes, 
 * text, paragraph breaks....
 * @author Peter Herweg, pherweg@web.de
 */
public class RtfTextrun extends RtfContainer {
    private boolean bSuppressLastPar = false;
    private RtfListItem rtfListItem;
    
    /** Manager for handling space-* property. */
    private RtfSpaceManager rtfSpaceManager = new RtfSpaceManager();
    
    /**  Class which represents the opening of a RTF group mark.*/
    private class RtfOpenGroupMark extends RtfElement {
                
        RtfOpenGroupMark(RtfContainer parent, Writer w, RtfAttributes attr)
                throws IOException {
            super(parent, w, attr);
        }
        
        /**
         * @return true if this element would generate no "useful" RTF content
         */
        public boolean isEmpty() {
            return false;
        }
        
        /**
         * write RTF code of all our children
         * @throws IOException for I/O problems
         */
        protected void writeRtfContent() throws IOException {
            writeGroupMark(true);
            writeAttributes(getRtfAttributes(), null);
        }
    }
    
    /**  Class which represents the closing of a RTF group mark.*/
    private class RtfCloseGroupMark extends RtfElement {
        
        RtfCloseGroupMark(RtfContainer parent, Writer w)
                throws IOException {
            super(parent, w);
        }
        
        /**
         * @return true if this element would generate no "useful" RTF content
         */
        public boolean isEmpty() {
            return false;
        }
        
        /**
         * write RTF code of all our children
         * @throws IOException for I/O problems
         */
        protected void writeRtfContent() throws IOException {
            writeGroupMark(false);
        }
    }

    /**  Class which represents a paragraph break.*/
    private class RtfParagraphBreak extends RtfElement {
        
        RtfParagraphBreak(RtfContainer parent, Writer w)
                throws IOException {
            super(parent, w);
        }
    
        /**
         * @return true if this element would generate no "useful" RTF content
         */
        public boolean isEmpty() {
            return false;
        }
    
        /**
         * write RTF code of all our children
         * @throws IOException for I/O problems
         */
        protected void writeRtfContent() throws IOException {
            writeControlWord("par");
        }
    }
              
    /** Create an RTF container as a child of given container */
    RtfTextrun(RtfContainer parent, Writer w, RtfAttributes attrs) throws IOException {
        super(parent, w, attrs);
    }
    
    
    /**
     * Adds instance of <code>OpenGroupMark</code> as a child with attributes.
     * 
     * @param attrs  attributes to add
     * @throws IOException for I/O problems
     */
    private void addOpenGroupMark(RtfAttributes attrs) throws IOException {
        RtfOpenGroupMark r = new RtfOpenGroupMark(this, writer, attrs);
    }

    /**
     * Adds instance of <code>CloseGroupMark</code> as a child.
     * 
     * @throws IOException for I/O problems
     */
    private void addCloseGroupMark() throws IOException {
        RtfCloseGroupMark r = new RtfCloseGroupMark(this, writer);
    }
    
    /**
     * Pushes block attributes, notifies all opened blocks about pushing block 
     * attributes, adds <code>OpenGroupMark</code> as a child.
     * 
     * @param attrs  the block attributes to push
     * @throws IOException for I/O problems
     */
    public void pushBlockAttributes(RtfAttributes attrs) throws IOException {
        rtfSpaceManager.stopUpdatingSpaceBefore();
        RtfSpaceSplitter splitter = rtfSpaceManager.pushRtfSpaceSplitter(attrs);
        addOpenGroupMark(splitter.getCommonAttributes());
    }
    
    /**
     * Pops block attributes, notifies all opened blocks about pushing block 
     * attributes, adds <code>CloseGroupMark</code> as a child.
     * 
     * @throws IOException for I/O problems
     */
    public void popBlockAttributes() throws IOException {
        rtfSpaceManager.popRtfSpaceSplitter();
        rtfSpaceManager.stopUpdatingSpaceBefore();
        addCloseGroupMark();
    }

    /**
     * Pushes inline attributes.
     * 
     * @param attrs  the inline attributes to push
     * @throws IOException for I/O problems
     */
    public void pushInlineAttributes(RtfAttributes attrs) throws IOException {
        rtfSpaceManager.pushInlineAttributes(attrs);
        addOpenGroupMark(attrs);
    }

    /**
     * Pop inline attributes.
     * 
     * @throws IOException for I/O problems
     */
    public void popInlineAttributes() throws IOException {
        rtfSpaceManager.popInlineAttributes();
        addCloseGroupMark();
    }
    
    /**
     * Add string to children list.
     * 
     * @param s  string to add
     * @throws IOException for I/O problems
     */
    public void addString(String s) throws IOException {
        if (s.equals("")) {
            return;
        }
        RtfAttributes attrs = rtfSpaceManager.getLastInlineAttribute();
        //add RtfSpaceSplitter to inherit accumulated space
        rtfSpaceManager.pushRtfSpaceSplitter(attrs);
        rtfSpaceManager.setCandidate(attrs);
        RtfString r = new RtfString(this, writer, s);
        rtfSpaceManager.popRtfSpaceSplitter();
    }
    
    /**
     * Inserts a footnote.
     * 
     * @return inserted footnote
     * @throws IOException for I/O problems
     */
    public RtfFootnote addFootnote() throws IOException {
        return new RtfFootnote(this, writer);
    }
    
    /**
     * Inserts paragraph break before all close group marks.
     * 
     * @throws IOException  for I/O problems
     */
    public void addParagraphBreak() throws IOException {
        // get copy of children list
        List children = getChildren();

        // delete all previous CloseGroupMark
        int deletedCloseGroupCount = 0;

        ListIterator lit = children.listIterator(children.size());
        while (lit.hasPrevious()
                && (lit.previous() instanceof RtfCloseGroupMark)) {
            lit.remove();
            deletedCloseGroupCount++;
        }

        if (children.size() != 0) {
            // add paragraph break and restore all deleted close group marks
            setChildren(children);
            new RtfParagraphBreak(this, writer);
            for (int i = 0; i < deletedCloseGroupCount; i++) {
                addCloseGroupMark();
            }
        }
    }
    
    /**
     * Inserts a page number.
     * @param attr Attributes for the page number to insert.
     * @throws IOException for I/O problems
     */
    public void addPageNumber(RtfAttributes attr) throws IOException {
        RtfPageNumber r = new RtfPageNumber(this, writer, attr);
    }
    
    /**
     * Inserts a hyperlink.
     * @param attr Attributes for the hyperlink to insert.
     * @return inserted hyperlink
     * @throws IOException for I/O problems
     */
    public RtfHyperLink addHyperlink(RtfAttributes attr) throws IOException {
        return new RtfHyperLink(this, writer, attr);
    }
    
    /**
     * Inserts a bookmark.
     * @param id Id for the inserted bookmark
     * @throws IOException for I/O problems
     */
    public void addBookmark(String id) throws IOException {
       if (id != "") {
            // if id is not empty, add boormark
           new RtfBookmark(this, writer, id);
       }
    }

    /**
     * Inserts an image.
     * @return inserted image
     * @throws IOException for I/O problems
     */
    public RtfExternalGraphic newImage() throws IOException {
        return new RtfExternalGraphic(this, writer);
    }

    /**
     * Adds a new RtfTextrun to the given container if necessary, and returns it.
     * @param container RtfContainer, which is the parent of the returned RtfTextrun
     * @param writer Writer of the given RtfContainer
     * @param attrs RtfAttributes which are to write at the beginning of the RtfTextrun
     * @return new or existing RtfTextrun object.
     * @throws IOException for I/O problems
     */
    public static RtfTextrun getTextrun(RtfContainer container, Writer writer, RtfAttributes attrs)
            throws IOException {

        List list = container.getChildren();
                
        if (list.size() == 0) {
            //add a new RtfTextrun
            RtfTextrun textrun = new RtfTextrun(container, writer, attrs);
            list.add(textrun);

            return textrun;
        }
        
        Object obj = list.get(list.size() - 1);

        if (obj instanceof RtfTextrun) {
            //if the last child is a RtfTextrun, return it
            return (RtfTextrun) obj;
        }

        //add a new RtfTextrun as the last child
        RtfTextrun textrun = new RtfTextrun(container, writer, attrs);
        list.add(textrun);
        
        return textrun;
    }
   
    /**
     * specify, if the last paragraph control word (\par) should be suppressed.
     * @param bSuppress true, if the last \par should be suppressed
     */    
    public void setSuppressLastPar(boolean bSuppress) {
        bSuppressLastPar = bSuppress;
    }
   
    /**
     * write RTF code of all our children
     * @throws IOException for I/O problems
     */
    protected void writeRtfContent() throws IOException {
        /**
         *TODO: The textrun's children are iterated twice:
         * 1. To determine the last RtfParagraphBreak
         * 2. To write the children
         * Maybe this can be done more efficient.
         */
        
        boolean bHasTableCellParent =
            this.getParentOfClass(RtfTableCell.class) != null;
        RtfAttributes attrBlockLevel = new RtfAttributes();

        //determine, if this RtfTextrun is the last child of its parent
        boolean bLast = false;
        for (Iterator it = parent.getChildren().iterator(); it.hasNext();) {
            if (it.next() == this) {
                bLast = !it.hasNext();
                break;
            }
        }
        
        //get last RtfParagraphBreak, which is not followed by any visible child
        RtfParagraphBreak lastParagraphBreak = null;
        if (bLast) {
            for (Iterator it = getChildren().iterator(); it.hasNext();) {
                final RtfElement e = (RtfElement)it.next();
                if (e instanceof RtfParagraphBreak) {
                    lastParagraphBreak = (RtfParagraphBreak)e;
                } else {
                    if (!(e instanceof RtfOpenGroupMark)
                            && !(e instanceof RtfCloseGroupMark)
                            && e.isEmpty()) {
                        lastParagraphBreak = null;
                    }
                }
            }
        }
        
        //may contain for example \intbl
        writeAttributes(attrib, null);
        
        if (rtfListItem != null) {
            rtfListItem.getRtfListStyle().writeParagraphPrefix(this);
        }

        //write all children
        boolean bPrevPar = false;
        boolean bFirst = true;
        for (Iterator it = getChildren().iterator(); it.hasNext();) {
            final RtfElement e = (RtfElement)it.next();
            final boolean bRtfParagraphBreak = (e instanceof RtfParagraphBreak);

            if (bHasTableCellParent) {
                attrBlockLevel.set(e.getRtfAttributes());
            }
            
            
            /**
             * -Write RtfParagraphBreak only, if the previous visible child
             * was't also a RtfParagraphBreak.
             * -Write RtfParagraphBreak only, if it is not the first visible
             * child.
             * -If the RtfTextrun is the last child of its parent, write a
             * RtfParagraphBreak only, if it is not the last child.
             */
            boolean bHide = false;
            bHide = bRtfParagraphBreak;
            bHide = bHide 
                && (bPrevPar 
                    || bFirst 
                    || (bSuppressLastPar && bLast && lastParagraphBreak != null 
                        && e == lastParagraphBreak));
                
            if (!bHide) {
                newLine();
                e.writeRtf(); 
                
                if (rtfListItem != null && e instanceof RtfParagraphBreak) {
                    rtfListItem.getRtfListStyle().writeParagraphPrefix(this);
                }
            }
            
            if (e instanceof RtfParagraphBreak) {
                bPrevPar = true;
            } else if (e instanceof RtfCloseGroupMark) {
                //do nothing
            } else if (e instanceof RtfOpenGroupMark) {
                //do nothing
            } else {
                bPrevPar = bPrevPar && e.isEmpty();
                bFirst = bFirst && e.isEmpty();
            }
        } //for (Iterator it = ...)
        
        //
        if (bHasTableCellParent) {
            writeAttributes(attrBlockLevel, null);
        }
        
    }
    
    /**
     * Set the parent list-item of the textrun.
     * 
     * @param listItem parent list-item of the textrun
     */
    public void setRtfListItem(RtfListItem listItem) {
        rtfListItem = listItem;
    }
    
    /**
     * Gets the parent list-item of the textrun. 
     * 
     * @return parent list-item of the textrun
     */
    public RtfListItem getRtfListItem() {
        return rtfListItem;
    }
}