/*
 * 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.
 */

/* $Id$ */

package org.apache.fop.render.afp.modca;

import java.awt.Color;
import java.io.IOException;
import java.io.OutputStream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.fop.render.afp.fonts.AFPFont;
import org.apache.fop.render.afp.tools.StringUtils;

/**
 * A data stream is a continuous ordered stream of data elements and objects
 * conforming to a given format. Application programs can generate data streams
 * destined for a presentation service, archive library, presentation device or
 * another application program. The strategic presentation data stream
 * architectures used is Mixed Object Document Content Architecture (MO:DCA�).
 *
 * The MO:DCA architecture defines the data stream used by applications to
 * describe documents and object envelopes for interchange with other
 * applications and application services. Documents defined in the MO:DCA format
 * may be archived in a database, then later retrieved, viewed, annotated and
 * printed in local or distributed systems environments. Presentation fidelity
 * is accommodated by including resource objects in the documents that reference
 * them.
 *
 */
public class AFPDataStream {

    /**
     * Static logging instance
     */
    protected static Log log = LogFactory.getLog("org.apache.fop.render.afp.modca");

    /**
     * Boolean completion indicator
     */
    private boolean complete = false;

    /**
     * The application producing the AFP document
     */
// not used
//    private String producer = null;

    /**
     * The AFP document object
     */
    private Document document = null;

    /**
     * The current page group object
     */
    private PageGroup currentPageGroup = null;

    /**
     * The current page object
     */
    private PageObject currentPageObject = null;

    /**
     * The current overlay object
     */
    private Overlay currentOverlay = null;

    /**
     * The current page
     */
    private AbstractPageObject currentPage = null;

    /**
     * The page count
     */
    private int pageCount = 0;

    /**
     * The page group count
     */
// not used
//    private int pageGroupCount = 0;

    /**
     * The overlay count
     */
    private int ovlCount = 0;

    /**
     * The portrait rotation
     */
    private int portraitRotation = 0;

    /**
     * The landscape rotation
     */
    private int landscapeRotation = 270;

    /**
     * The x offset
     */
    private int xOffset = 0;

    /**
     * The y offset
     */
    private int yOffset = 0;

    /**
     * The rotation
     */
    private int rotation;

    /**
     * The outputstream for the data stream
     */
    private OutputStream outputStream = null;

    /**
     * Default constructor for the AFPDataStream.
     */
    public AFPDataStream() {
    }

    /**
     * The document is started by invoking this method which creates an instance
     * of the AFP Document object.
     *
     * @param docOutputStream
     *            the outputStream which the document is written to.
     */
    public void startDocument(OutputStream docOutputStream) {

        if (document != null) {
            String msg = "Invalid state - document already started.";
            log.warn("startDocument():: " + msg);
            throw new IllegalStateException(msg);
        }

        this.document = new Document();
        this.outputStream = docOutputStream;

    }

    /**
     * The document is ended by invoking this method which creates an instance
     * of the AFP Document object and registers the start with a validation map
     * which ensures that methods are not invoked out of the correct sequence.
     *
     * @throws java.io.IOException
     *             throws an I/O exception of some sort has occurred
     */
    public void endDocument() throws IOException {

        if (complete) {
            String msg = "Invalid state - document already ended.";
            log.warn("endDocument():: " + msg);
            throw new IllegalStateException(msg);
        }

        if (currentPageObject != null) {
            // End the current page if necessary
            endPage();
        }

        if (currentPageGroup != null) {
            // End the current page group if necessary
            endPageGroup();
        }

        document.endDocument();
        document.writeDataStream(this.outputStream);
        this.outputStream.flush();

        complete = true;

        document = null;

        this.outputStream = null;
    }

    /**
     * Start a new page. When processing has finished on the current page, the
     * {@link #endPage()}method must be invoked to mark the page ending.
     *
     * @param pageWidth
     *            the width of the page
     * @param pageHeight
     *            the height of the page
     * @param pageRotation
     *            the rotation of the page
     * @param pageWidthResolution
     *            the width resolution of the page
     * @param pageHeightResolution
     *            the height resolution of the page
     */
    public void startPage(int pageWidth, int pageHeight, int pageRotation,
            int pageWidthResolution, int pageHeightResolution) {

        String pageName = "PGN"
                + StringUtils.lpad(String.valueOf(pageCount++), '0', 5);

        currentPageObject = new PageObject(pageName, pageWidth, pageHeight,
                pageRotation, pageWidthResolution, pageHeightResolution);
        currentPage = currentPageObject;
        currentOverlay = null;
        setOffsets(0, 0, 0);
    }

    /**
     * Start a new overlay. When processing has finished on the current overlay,
     * the {@link #endOverlay()}method must be invoked to mark the overlay
     * ending.
     *
     * @param overlayX
     *            the x position of the overlay on the page
     * @param overlayY
     *            the y position of the overlay on the page
     * @param overlayWidth
     *            the width of the overlay
     * @param overlayHeight
     *            the height of the overlay
     * @param overlayWidthResolution
     *            the width resolution of the overlay
     * @param overlayHeightResolution
     *            the height resolution of the overlay
     * @param overlayRotation
     *            the rotation of the overlay
     */
    public void startOverlay(int overlayX, int overlayY, int overlayWidth,
            int overlayHeight, int overlayWidthResolution,
            int overlayHeightResolution, int overlayRotation) {

        String overlayName = "OVL"
                + StringUtils.lpad(String.valueOf(ovlCount++), '0', 5);

        currentOverlay = new Overlay(overlayName, overlayWidth, overlayHeight,
                overlayWidthResolution, overlayHeightResolution,
                overlayRotation);
        currentPageObject.addOverlay(currentOverlay);
        currentPageObject.createIncludePageOverlay(overlayName, overlayX,
                overlayY, 0);
        currentPage = currentOverlay;
        setOffsets(0, 0, 0);
    }

    /**
     * Helper method to mark the end of the current overlay.
     */
    public void endOverlay() {

        currentOverlay.endPage();
        currentOverlay = null;
        currentPage = currentPageObject;

    }

    /**
     * Helper method to save the current page.
     *
     * @return current page object that was saved
     */
    public PageObject savePage() {

        PageObject pageObject = currentPageObject;
        if (currentPageGroup != null) {
            currentPageGroup.addPage(currentPageObject);
        } else {
            document.addPage(currentPageObject);
        }
        currentPageObject = null;
        currentPage = null;
        return pageObject;

    }

    /**
     * Helper method to restore the current page.
     *
     * @param pageObject
     *            page object
     */
    public void restorePage(PageObject pageObject) {

        currentPageObject = pageObject;
        currentPage = pageObject;

    }

    /**
     * Helper method to mark the end of the current page.
     *
     * @throws java.io.IOException
     *             thrown when an I/O exception of some sort has occurred
     */
    public void endPage() throws IOException {

        currentPageObject.endPage();
        if (currentPageGroup != null) {
            currentPageGroup.addPage(currentPageObject);
        } else {
            document.addPage(currentPageObject);
            document.writeDataStream(this.outputStream);
        }

        currentPageObject = null;
        currentPage = null;

    }

    /**
     * Sets the offsets to be used for element positioning
     *
     * @param xOff
     *            the offset in the x direction
     * @param yOff
     *            the offset in the y direction
     * @param rot
     *            the rotation
     */
    public void setOffsets(int xOff, int yOff, int rot) {
        this.xOffset = xOff;
        this.yOffset = yOff;
        this.rotation = rot;
    }

    /**
     * Helper method to create a map coded font object on the current page, this
     * method delegates the construction of the map coded font object to the
     * active environment group on the current page.
     *
     * @param fontReference
     *            the font number used as the resource identifier
     * @param font
     *            the font
     * @param size
     *            the point size of the font
     */
    public void createFont(byte fontReference, AFPFont font, int size) {

        currentPage.createFont(fontReference, font, size);

    }

    /**
     * Helper method to create text on the current page, this method delegates
     * to the current presentation text object in order to construct the text.
     *
     * @param fontNumber
     *            the font number used as the resource identifier
     * @param x
     *            the x coordinate of the text
     * @param y
     *            the y coordinate of the text
     * @param col
     *            the text color
     * @param vsci
     *            The variable space character increment.
     * @param ica
     *            The inter character adjustment.
     * @param data
     *            the text data to create
     */
    public void createText(int fontNumber, int x, int y, Color col, int vsci,
            int ica, byte[] data) {

        currentPage.createText(fontNumber, x + xOffset, y + yOffset, rotation,
                col, vsci, ica, data);

    }

    /**
     * Returns an ImageObject used to create an image in the datastream.
     *
     * @param x
     *            the x position of the image
     * @param y
     *            the y position of the image
     * @param w
     *            the width of the image
     * @param h
     *            the height of the image
     * @param wr
     *            the width resolution of the image
     * @param hr
     *            the height resolution of the image
     * @return ImageObject used to create an image in the datastream
     */
    public ImageObject getImageObject(int x, int y, int w, int h, int wr, int hr) {

        int xOrigin;
        int yOrigin;
        int width;
        int height;
        int widthResolution;
        int heightResolution;

        switch (rotation) {
        case 90:
            xOrigin = currentPage.getWidth() - y - yOffset;
            yOrigin = x + xOffset;
            width = h;
            height = w;
            widthResolution = hr;
            heightResolution = wr;
            break;
        case 180:
            xOrigin = currentPage.getWidth() - x - xOffset;
            yOrigin = currentPage.getHeight() - y - yOffset;
            width = w;
            height = h;
            widthResolution = wr;
            heightResolution = hr;
            break;
        case 270:
            xOrigin = y + yOffset;
            yOrigin = currentPage.getHeight() - x - xOffset;
            width = h;
            height = w;
            widthResolution = hr;
            heightResolution = wr;
            break;
        default:
            xOrigin = x + xOffset;
            yOrigin = y + yOffset;
            width = w;
            height = h;
            widthResolution = wr;
            heightResolution = hr;
            break;
        }
        ImageObject io = currentPage.getImageObject();
        io.setImageViewport(xOrigin, yOrigin, width, height, rotation,
                widthResolution, heightResolution);
        return io;

    }

    /**
     * Method to create a line on the current page.
     *
     * @param x1
     *            the first x coordinate of the line
     * @param y1
     *            the first y coordinate of the line
     * @param x2
     *            the second x coordinate of the line
     * @param y2
     *            the second y coordinate of the line
     * @param thickness
     *            the thickness of the line
     * @param col
     *            The text color.
     */
    public void createLine(int x1, int y1, int x2, int y2, int thickness,
            Color col) {

        currentPage.createLine(x1 + xOffset, y1 + yOffset, x2 + xOffset, y2
                + yOffset, thickness, rotation, col);

    }

    /**
     * This method will create shading on the page using the specified
     * coordinates (the shading contrast is controlled via the red, green, blue
     * parameters, by converting this to grey scale).
     *
     * @param x
     *            the x coordinate of the shading
     * @param y
     *            the y coordinate of the shading
     * @param w
     *            the width of the shaded area
     * @param h
     *            the height of the shaded area
     * @param red
     *            the red value
     * @param green
     *            the green value
     * @param blue
     *            the blue value
     */
    public void createShading(int x, int y, int w, int h, int red, int green,
            int blue) {

        currentPage.createShading(x + xOffset, y + xOffset, w, h, red, green,
                blue);

    }

    /**
     * Helper method which allows creation of the MPO object, via the AEG. And
     * the IPO via the Page. (See actual object for descriptions.)
     *
     * @param name
     *            the name of the static overlay
     */
    public void createIncludePageOverlay(String name) {

        currentPageObject.createIncludePageOverlay(name, 0, 0, rotation);
        ActiveEnvironmentGroup aeg = currentPageObject
                .getActiveEnvironmentGroup();
        aeg.createOverlay(name);

    }

    /**
     * Helper method which allows creation of the IMM object.
     *
     * @param name
     *            the name of the medium map
     */
    public void createInvokeMediumMap(String name) {

        if (currentPageGroup == null) {
            startPageGroup();
        }
        currentPageGroup.createInvokeMediumMap(name);

    }

    /**
     * Creates an IncludePageSegment on the current page.
     *
     * @param name
     *            the name of the include page segment
     * @param x
     *            the x coordinate for the overlay
     * @param y
     *            the y coordinate for the overlay
     */
    public void createIncludePageSegment(String name, int x, int y) {

        int xOrigin;
        int yOrigin;
        switch (rotation) {
        case 90:
            xOrigin = currentPage.getWidth() - y - yOffset;
            yOrigin = x + xOffset;
            break;
        case 180:
            xOrigin = currentPage.getWidth() - x - xOffset;
            yOrigin = currentPage.getHeight() - y - yOffset;
            break;
        case 270:
            xOrigin = y + yOffset;
            yOrigin = currentPage.getHeight() - x - xOffset;
            break;
        default:
            xOrigin = x + xOffset;
            yOrigin = y + yOffset;
            break;
        }
        currentPage.createIncludePageSegment(name, xOrigin, yOrigin);

    }

    /**
     * Creates a TagLogicalElement on the current page.
     *
     * @param attributes
     *            the array of key value pairs.
     */
    public void createPageTagLogicalElement(TagLogicalElementBean[] attributes) {

        for (int i = 0; i < attributes.length; i++) {
            String name = (String) attributes[i].getKey();
            String value = (String) attributes[i].getValue();
            currentPage.createTagLogicalElement(name, value);
        }

    }

    /**
     * Creates a TagLogicalElement on the current page group.
     *
     * @param attributes
     *            the array of key value pairs.
     */
    public void createPageGroupTagLogicalElement(
            TagLogicalElementBean[] attributes) {

        for (int i = 0; i < attributes.length; i++) {
            String name = (String) attributes[i].getKey();
            String value = (String) attributes[i].getValue();
            currentPageGroup.createTagLogicalElement(name, value);
        }

    }

    /**
     * Creates a TagLogicalElement on the current page or page group
     *
     * @param name
     *            The tag name
     * @param value
     *            The tag value
     */
    public void createTagLogicalElement(String name, String value) {

        if (currentPageGroup != null) {
            currentPageGroup.createTagLogicalElement(name, value);
        } else {
            currentPage.createTagLogicalElement(name, value);
        }

    }

    /**
     * Creates a NoOperation item
     *
     * @param content
     *            byte data
     */
    public void createNoOperation(String content) {
        currentPage.createNoOperation(content);
    }

    /**
     * Start a new page group. When processing has finished on the current page
     * group the {@link #endPageGroup()}method must be invoked to mark the page
     * group ending.
     */
    public void startPageGroup() {

        String pageGroupName = "PGP"
                + StringUtils.lpad(String.valueOf(pageCount++), '0', 5);

        currentPageGroup = new PageGroup(pageGroupName);

    }

    /**
     * Helper method to mark the end of the page group.
     * @throws IOException thrown if an I/O exception of some sort has occurred
     */
    public void endPageGroup() throws IOException {

        currentPageGroup.endPageGroup();
        document.addPageGroup(currentPageGroup);
        document.writeDataStream(outputStream);
        currentPageGroup = null;

    }

    /**
     * Sets the rotation to be used for portrait pages, valid values are 0
     * (default), 90, 180, 270.
     *
     * @param pageRotation
     *            The rotation in degrees.
     */
    public void setPortraitRotation(int pageRotation) {

        if (pageRotation == 0 || pageRotation == 90 || pageRotation == 180
                || pageRotation == 270) {
            this.portraitRotation = pageRotation;
        } else {
            throw new IllegalArgumentException(
                    "The portrait rotation must be one of the values 0, 90, 180, 270");
        }

    }

    /**
     * Sets the rotation to be used for landscape pages, valid values are 0, 90,
     * 180, 270 (default).
     *
     * @param pageRotation
     *            The rotation in degrees.
     */
    public void setLandscapeRotation(int pageRotation) {

        if (pageRotation == 0 || pageRotation == 90 || pageRotation == 180
                || pageRotation == 270) {
            this.landscapeRotation = pageRotation;
        } else {
            throw new IllegalArgumentException(
                    "The landscape rotation must be one of the values 0, 90, 180, 270");
        }

    }

}