/*
 * Copyright 1999-2005 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.apps;

// Java
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.List;
import java.util.Map;

// avalon configuration
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;

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

// FOP
import org.apache.fop.fo.ElementMapping;
import org.apache.fop.fo.FOEventHandler;
import org.apache.fop.layoutmgr.LayoutManagerMaker;
import org.apache.fop.pdf.PDFEncryptionParams;
import org.apache.fop.render.Renderer;
import org.apache.fop.render.XMLHandlerRegistry;

/**
 * The User Agent for fo.
 * This user agent is used by the processing to obtain user configurable
 * options.
 * <p>
 * Renderer specific extensions (that do not produce normal areas on
 * the output) will be done like so:
 * <br>
 * The extension will create an area, custom if necessary
 * <br>
 * this area will be added to the user agent with a key
 * <br>
 * the renderer will know keys for particular extensions
 * <br>
 * eg. bookmarks will be held in a special hierarchical area representing
 * the title and bookmark structure
 * <br>
 * These areas may contain resolvable areas that will be processed
 * with other resolvable areas
 */
public class FOUserAgent {

    /** Defines the default resolution (72dpi) for FOP */
    public static final float DEFAULT_PX2MM = (25.4f / 72); //dpi (=25.4/dpi) 
    
    /** Registry for XML handlers */
    private XMLHandlerRegistry xmlHandlers = new XMLHandlerRegistry();
    
    private String baseURL;
    private PDFEncryptionParams pdfEncryptionParams;
    private float px2mm = DEFAULT_PX2MM;
    private Map rendererOptions = new java.util.HashMap();
    private InputHandler inputHandler = null;
    private File outputFile = null;
    private Renderer rendererOverride = null;
    private FOEventHandler foEventHandlerOverride = null;
    private LayoutManagerMaker lmMakerOverride = null;
    /* user configuration */
    private Configuration userConfig = null;
    private Log log = LogFactory.getLog("FOP");
    
    /* FOP has the ability, for some FO's, to continue processing even if the
     * input XSL violates that FO's content model.  This is the default  
     * behavior for FOP.  However, this flag, if set, provides the user the
     * ability for FOP to halt on all content model violations if desired.   
     */ 
    private boolean strictValidation = true;

    /* Additional fo.ElementMapping subclasses set by user */
    private List additionalElementMappings = null;

    /** Producer:  Metadata element for the system/software that produces
     * the document. (Some renderers can store this in the document.)
     */
    protected String producer = "Apache FOP Version " + Fop.getVersion();

    /** Creator:  Metadata element for the user that created the
     * document. (Some renderers can store this in the document.)
     */
    protected String creator = null;

    /** Creation Date:  Override of the date the document was created. 
     * (Some renderers can store this in the document.)
     */
    protected Date creationDate = null;
    
    /** Author of the content of the document. */
    protected String author = null;
    /** Title of the document. */
    protected String title = null;
    /** Set of keywords applicable to this document. */
    protected String keywords = null;
    
    /**
     * Sets the InputHandler object for this process
     * @param inputHandler holding input file name information
     */
    public void setInputHandler(InputHandler inputHandler) {
        this.inputHandler = inputHandler;
    }

    /**
     * Returns the apps.InputHandler object created during command-line
     * processing
     * @return InputHandler object
     */
    public InputHandler getInputHandler() {
        return inputHandler;
    }

    /**
     * Add the element mapping with the given class name.
     * @param elementMapping the class name representing the element mapping.
     */
    public void addElementMapping(ElementMapping elementMapping) {
        if (additionalElementMappings == null) {
            additionalElementMappings = new java.util.ArrayList();
        }
        additionalElementMappings.add(elementMapping);
    }

    /**
     * Returns the List of user-added ElementMapping class names
     * @return List of Strings holding ElementMapping names.
     */
    public List getAdditionalElementMappings() {
        return additionalElementMappings;
    }

    /**
     * Sets an explicit renderer to use which overrides the one defined by the 
     * render type setting.  
     * @param renderer the Renderer instance to use
     */
    public void setRendererOverride(Renderer renderer) {
        this.rendererOverride = renderer;
    }

    /**
     * Returns the overriding Renderer instance, if any.
     * @return the overriding Renderer or null
     */
    public Renderer getRendererOverride() {
        return rendererOverride;
    }

    /**
     * Sets an explicit FOEventHandler instance which overrides the one
     * defined by the render type setting.  
     * @param handler the FOEventHandler instance
     */
    public void setFOEventHandlerOverride(FOEventHandler handler) {
        this.foEventHandlerOverride = handler;
    }

    /**
     * Returns the overriding FOEventHandler instance, if any.
     * @return the overriding FOEventHandler or null
     */
    public FOEventHandler getFOEventHandlerOverride() {
        return this.foEventHandlerOverride;
    }

    /**
     * Activates strict XSL content model validation for FOP
     * Default is false (FOP will continue processing where it can)
     * @param validateStrictly true to turn on strict validation
     */
    public void setStrictValidation(boolean validateStrictly) {
        this.strictValidation = validateStrictly;
    }

    /**
     * Returns whether FOP is strictly validating input XSL
     * @return true of strict validation turned on, false otherwise
     */
    public boolean validateStrictly() {
        return strictValidation;
    }

    /**
     * Sets an explicit LayoutManagerMaker instance which overrides the one
     * defined by the AreaTreeHandler.
     * @param lmMaker the LayoutManagerMaker instance
     */
    public void setLayoutManagerMakerOverride(LayoutManagerMaker lmMaker) {
        this.lmMakerOverride = lmMaker;
    }

    /**
     * Returns the overriding LayoutManagerMaker instance, if any.
     * @return the overriding LayoutManagerMaker or null
     */
    public LayoutManagerMaker getLayoutManagerMakerOverride() {
        return this.lmMakerOverride;
    }

    /**
     * Sets the producer of the document.  
     * @param producer source of document
     */
    public void setProducer(String producer) {
        this.producer = producer;
    }

    /**
     * Returns the producer of the document
     * @return producer name
     */
    public String getProducer() {
        return producer;
    }

    /**
     * Sets the creator of the document.  
     * @param creator of document
     */
    public void setCreator(String creator) {
        this.creator = creator;
    }

    /**
     * Returns the creator of the document
     * @return creator name
     */
    public String getCreator() {
        return creator;
    }

    /**
     * Sets the creation date of the document.  
     * @param creationDate date of document
     */
    public void setCreationDate(Date creationDate) {
        this.creationDate = creationDate;
    }

    /**
     * Returns the creation date of the document
     * @return creation date of document
     */
    public Date getCreationDate() {
        return creationDate;
    }

    /**
     * Sets the author of the document.  
     * @param author of document
     */
    public void setAuthor(String author) {
        this.author = author;
    }

    /**
     * Returns the author of the document
     * @return author name
     */
    public String getAuthor() {
        return author;
    }

    /**
     * Sets the title of the document. This will override any title coming from
     * an fo:title element.  
     * @param title of document
     */
    public void setTitle(String title) {
        this.title = title;
    }

    /**
     * Returns the title of the document
     * @return title name
     */
    public String getTitle() {
        return title;
    }

    /**
     * Sets the keywords for the document.  
     * @param keywords for the document
     */
    public void setKeywords(String keywords) {
        this.keywords = keywords;
    }

    /**
     * Returns the keywords for the document
     * @return the keywords
     */
    public String getKeywords() {
        return keywords;
    }

    /**
     * Returns the renderer options
     * @return renderer options
     */
    public Map getRendererOptions() {
        return rendererOptions;
    }

    /**
     * Set the user configuration.
     * @param userConfig configuration
     */
    public void setUserConfig(Configuration userConfig) {
        this.userConfig = userConfig;
    }

    /**
     * Get the user configuration.
     * @return the user configuration
     */
    public Configuration getUserConfig() {
        return userConfig;
    }

    /**
     * Returns the configuration subtree for a specific renderer.
     * @param mimeType MIME type of the renderer
     * @return the requested configuration subtree, null if there's no configuration
     */
    public Configuration getUserRendererConfig (String mimeType) {

        if (userConfig == null || mimeType == null) {
            return null;
        }

        Configuration userRendererConfig = null;

        Configuration[] cfgs
            = userConfig.getChild("renderers").getChildren("renderer");
        for (int i = 0; i < cfgs.length; ++i) {
            Configuration cfg = cfgs[i];
            try {
                if (cfg.getAttribute("mime").equals(mimeType)) {
                    userRendererConfig = cfg;
                    break;
                }
            } catch (ConfigurationException e) {
                // silently pass over configurations without mime type
            }
        }
        log.debug((userRendererConfig == null ? "No u" : "U")
                  + "ser configuration found for MIME type " + mimeType);
        return userRendererConfig;
    }

    /**
     * Sets the base URL.
     * @param baseURL base URL
     */
    public void setBaseURL(String baseURL) {
        this.baseURL = baseURL;
    }

    /**
     * Returns the base URL.
     * @return the base URL
     */
    public String getBaseURL() {
        if ((this.baseURL == null) || (this.baseURL.trim().equals(""))) {
            return "file:.";
        } else {
            return this.baseURL;
        }
    }

    /**
     * Returns the parameters for PDF encryption.
     * @return the PDF encryption parameters, null if not applicable
     */
    public PDFEncryptionParams getPDFEncryptionParams() {
        return pdfEncryptionParams;
    }

    /**
     * Sets the parameters for PDF encryption.
     * @param pdfEncryptionParams the PDF encryption parameters, null to
     * disable PDF encryption
     */
    public void setPDFEncryptionParams(PDFEncryptionParams pdfEncryptionParams) {
        this.pdfEncryptionParams = pdfEncryptionParams;
    }


    /**
     * Get an input stream for a reference.
     * Temporary solution until API better.
     * @param uri URI to access
     * @return InputStream for accessing the resource.
     * @throws IOException in case of an I/O problem
     */
    public InputStream getStream(String uri) throws IOException {
        return null;
    }

    /**
     * Sets the output File.
     * @param the output File
     */
    public void setOutputFile(File f){
        this.outputFile = f;
    }

    /**
     * Gets the output File.
     * @return the output File
     */
    public File getOutputFile(){
        return outputFile;
    }

    /**
     * Returns the conversion factor from pixel units to millimeters. This
     * depends on the desired reolution.
     * @return float conversion factor
     */
    public float getPixelUnitToMillimeter() {
        return this.px2mm;
    }

    /**
     * Sets the resolution in dpi.
     * @param dpi resolution in dpi
     */
    public void setResolution(int dpi) {
        this.px2mm = (float)(25.4 / dpi);
    }

    /**
     * If to create hot links to footnotes and before floats.
     * @return True if hot links should be created
     */
    public boolean linkToFootnotes() {
        return true;
    }

    /**
     * @return the XML handler registry
     */
    public XMLHandlerRegistry getXMLHandlerRegistry() {
        return this.xmlHandlers;
    }
    
    
}