/*
 * [BuildImage.java]
 *
 * Summary: Not a macro. Used to generate <img src= HTML.
 *
 * Copyright: (c) 2008-2017 Roedy Green, Canadian Mind Products, http://mindprod.com
 *
 * Licence: This software may be copied and used freely for any purpose but military.
 *          http://mindprod.com/contact/nonmil.html
 *
 * Requires: JDK 1.8+
 *
 * Created with: JetBrains IntelliJ IDEA IDE http://www.jetbrains.com/idea/
 *
 * Version History:
 *  1.0 2008-08-03
 */
package com.mindprod.htmlmacros.support;

import com.mindprod.common18.ImageInfo;
import com.mindprod.common18.ST;
import com.mindprod.fastcat.FastCat;
import org.jetbrains.annotations.Nullable;

import java.io.File;
import java.util.HashMap;

import static com.mindprod.htmlmacros.macro.Global.configuration;

/**
 * Not a macro. Used to generate <img src= HTML.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.0 2008-08-03
 * @since 2008-08-03
 */
public class BuildImage
    {
    /**
     * capacity of HashMap to store dimensions of cached images
     */
    private static final int IMAGE_CACHE_CAPACITY = 4000;
    // TODO get rid of level numbers in all public methods.

    /**
     * to avoid work of checking image dimensions on disk, we cacheFIle results of good images found earlier
     * we store two shorts in the width x height.
     */
    private static final HashMap<String, Integer> doneBefore = new HashMap<>( IMAGE_CACHE_CAPACITY );

    /**
     * suffix for a tag
     */
    private static final String TAG_TAIL = configuration.getTagTail();

    /**
     * create a <img given just the unqualified filename in /image, no jump to link.  Image in project image tree.
     * e.g. <img class="plain" src="../image/icon32/x.png" width="32" height="32" alt="xx" />
     *
     * @param imageFilename        name of image file, e.g. dog.gif, or some html to create image in the image
     *                             directory tree
     * @param alt                  alternate text display, may contain html or entities.
     * @param align                alignment enum e.g. absmiddle, possibly null for none.
     * @param cssClassForImage     cssClass of the image itself
     * @param width                of the image in pixels.
     * @param height               of the image in pixels.
     *                             the file currently being processed.
     * @param fileBeingDistributed where this link will end up
     *
     * @return html for one img tag
     */
    private static String buildHTML4ImageTag( final String imageFilename,
                                              final String alt,
                                              final ImageAlignment align,
                                              final String cssClassForImage,
                                              final int width,
                                              final int height,
                                              final File fileBeingDistributed )
        {
        assert fileBeingDistributed != null : "null fileBeingDistributed";
        assert imageFilename != null : "null image filename";
        // we put field out in canonical order class src  alt (title longdesc) width height align border
        final FastCat sb = new FastCat( 20 );
        sb.append( "<img" );
        if ( cssClassForImage != null )
            {
            assert cssClassForImage.length() != 0 : "empty CSS class";
            sb.append( " class=\"" );
            sb.append( cssClassForImage );
            sb.append( "\"" );
            }
        sb.append( " src=\"" );
        sb.append( Tools.relativeURL( "image/" + imageFilename, fileBeingDistributed ) );
        sb.append( "\"\nalt=\"" );
        sb.append( Tools.stripHTMLTags( alt ) );
        sb.append( "\" width=\"", width );
        sb.append( "\" height=\"", height );
        sb.append( "\"" );
        // enum value is automatically legal.
        if ( align != ImageAlignment.none )
            {
            sb.append( " ", align.getStyle() );
            }
        sb.append( ">" );
        return sb.toString();
        }

    /**
     * create a <img given just the unqualified filename in /image, no jump to link.  Image in project image tree.
     * e.g. <img class="plain" src="../image/icon32/x.png" width="32" height="32" alt="x" />
     *
     * @param imageFilename        name of image file, e.g. dog.gif, or some html to create image in the image
     *                             directory tree
     * @param alt                  alternate text display, may contain html or entities.
     * @param align                alignment enum e.g. absmiddle, possibly null for none.
     * @param cssClassForImage     cssClass of the image itself
     * @param width                width of the image in pixels.
     * @param height               height of the image in pixels.
     *                             the file currently being processed.
     * @param fileBeingDistributed where this link will end up
     *
     * @return html for one img tag
     */
    private static String buildXHTMLImageTag( final String imageFilename,
                                              final String alt,
                                              final ImageAlignment align,
                                              final String cssClassForImage,
                                              final int width,
                                              final int height,
                                              final File fileBeingDistributed )
        {
        assert fileBeingDistributed != null : "null fileBeingDistributed";
        assert imageFilename != null : "null image filename";
        // we put field out in canonical order class src  alt (title longdesc) width height align border
        final FastCat sb = new FastCat( 20 );
        sb.append( "<img" );
        if ( cssClassForImage != null )
            {
            assert cssClassForImage.length() != 0 : "empty CSS class";
            sb.append( " class=\"" );
            sb.append( cssClassForImage );
            if ( align != ImageAlignment.none )
                {
                sb.append( " " );
                sb.append( align.toString() );
                }
            sb.append( "\"" );
            }
        else
            {
            if ( align != ImageAlignment.none )
                {
                sb.append( " class=\"" );
                sb.append( align.toString() );
                sb.append( "\"" );
                }
            }
        sb.append( " src=\"" );
        sb.append( Tools.relativeURL( "image/" + imageFilename, fileBeingDistributed ) );
        sb.append( "\"\nalt=\"" );
        sb.append( Tools.stripHTMLTags( alt ) );
        sb.append( "\" width=\"" );
        sb.append( width );
        sb.append( "\" height=\"" );
        sb.append( height );
        sb.append( "\">" );
        return sb.toString();
        }

    /**
     * create a relative filename given just the unqualified filename in /image for use in a  local style  reference.
     * e.g. ../image/icon32/x.png
     *
     * @param imageFilename        name of image file, e.g. dog.gif, stylesheet/open.png or some html to create
     *                             image, in the image directory tree
     *                             the file currently being processed.
     * @param fileBeingDistributed where this link will end up
     *
     * @return style="background-image: url(xxx) reference for image, just the xxx.
     */
    public static String buildImageRootForStyleRef( String imageFilename, File fileBeingDistributed )
        {
        assert fileBeingDistributed != null : "null fileBeingDistributed";
        assert imageFilename != null && imageFilename.length() > 0 : "null image filename";
        if ( imageFilename.endsWith( "jpg" ) | imageFilename.endsWith( "gif" ) | imageFilename.endsWith(
                "png" ) )
            {
            int[] dimensions = getProjectImageDimensions( imageFilename );
            final int width = dimensions[ 0 ];
            final int height = dimensions[ 1 ];
            if ( width == 0 || height == 0 )
                {
                // oops. problem with image file
                final File absFile = Tools.toFileFromUPath( "image/" + imageFilename );
                if ( absFile.exists() )
                    {
                    throw new IllegalArgumentException( "image file " + absFile + " is malformed (zero width/height)." );
                    }
                else
                    {
                    throw new IllegalArgumentException( "image file " + absFile + " does not exist." );
                    }
                }
            return Tools.relativeURL( "image/" + imageFilename, fileBeingDistributed );
            }
        else
            {
            throw new IllegalArgumentException( "image file " + imageFilename + " not png, gif or jpg" );
            }
        }

    /**
     * create a <img given just the unqualified filename in /image, no jump to link.  Image in project image tree.
     * e.g. <img class="plain" src="../image/icon32/x.png" width="32" height="32" alt="x">
     *
     * @param imageRelativeFilename name of image file, e.g. dog.gif, or some html to create image in the image
     *                              directory tree. Image local in image dir.
     *                              possibly empty or null
     * @param alt                   alternate text display, may contain html or entities.
     * @param align                 alignment enum e.g. absmiddle, possibly null for none.
     * @param cssClassForImage      cssClass of the image itself
     *                              the file currently being distributed. used to compute relative url of image.
     * @param fileBeingDistributed  where this link will end up
     *
     * @return html for one img tag, or "" for null image  from <img to >
     */
    public static String buildImgTag( final String imageRelativeFilename,
                                      final String alt,
                                      @Nullable ImageAlignment align,
                                      @Nullable final String cssClassForImage,
                                      final File fileBeingDistributed )
        {
        assert fileBeingDistributed != null : "null fileBeingDistributed";
        if ( ST.isEmpty( imageRelativeFilename ) )
            {
            return "";
            }
        if ( imageRelativeFilename.endsWith( "png" )
             | imageRelativeFilename.endsWith( "jpg" )
             | imageRelativeFilename.endsWith( "gif" )
             | imageRelativeFilename.endsWith( "webp" ) )
            {
            int[] dimensions = getProjectImageDimensions( imageRelativeFilename );
            final int width = dimensions[ 0 ];
            final int height = dimensions[ 1 ];
            if ( width == 0 )
                {
                // oops. problem with image file
                final File absFile = Tools.toFileFromUPath( "image/" + imageRelativeFilename );
                if ( absFile.exists() )
                    {
                    throw new IllegalArgumentException( "image file " + absFile + " is malformed." );
                    }
                else
                    {
                    throw new IllegalArgumentException( "image file " + absFile + " does not exist." );
                    }
                }
            if ( align == null )
                {
                align = ImageAlignment.none;
                }
            if ( configuration.isUsingXHTML() )
                {
                return buildXHTMLImageTag( imageRelativeFilename,
                        alt,
                        align,
                        cssClassForImage,
                        width,
                        height,
                        fileBeingDistributed );
                }
            else
                {
                return buildHTML4ImageTag( imageRelativeFilename,
                        alt,
                        align,
                        cssClassForImage,
                        width,
                        height,
                        fileBeingDistributed );
                }
            }
        else
            {
            // some html or some custom <img rather than filename
            return imageRelativeFilename;
            }
        }

    /**
     * Ensure an image is a reasonable size.  Throws an exception if criteria are not met or image does not exist.
     *
     * @param projectImage name of the time in the image directory tree, .png, .jpg, .gif, .webp
     * @param lowWidth     lowest allowable width
     * @param lowHeight    lowest allowable height
     * @param highWidth    highest allowable width
     * @param highHeight   highest allowable height
     */
    public static void ensureProjectImageSize( String projectImage, int lowWidth, int lowHeight, int highWidth,
                                               int highHeight )
        {
        if ( ST.isEmpty( projectImage ) )
            {
            return;
            }
        int[] dimensions = getProjectImageDimensions( projectImage );
        int width = dimensions[ 0 ];
        int height = dimensions[ 1 ];
        final File absFile = Tools.toFileFromUPath( "image/" + projectImage );
        if ( width == 0 || height == 0 )
            {
            throw new IllegalArgumentException( "image " + absFile + " is missing or corrupt." );
            }
        if ( width < lowWidth || height < lowHeight )
            {
            throw new IllegalArgumentException( "image " + absFile + " [" + width + "x" + height + "] is smalller than [" + lowWidth + "x" + lowHeight + "]" );
            }
        if ( width > highWidth || height > highHeight )
            {
            throw new IllegalArgumentException( "image " + absFile + " [" + width + "x" + height + "] is bigger than [" + highWidth + "x" + highHeight + "]" );
            }
        }

    /**
     * Find out width and height of an image in the /image/* tree. Do not confuse with the more general
     * ImageInfo.getImageDimensions.
     *
     * @param projectImage name of image file in the image tree, e.g. navigate/home.png
     *
     * @return array[2] [0[=width [1]=height   0 0 means invalid.  Does not throw exception.
     */
    public static int[] getProjectImageDimensions( String projectImage )
        {
        // see if we have done this one before
        Integer wxh = doneBefore.get( projectImage );
        final int width;
        final int height;
        if ( wxh != null )
            {
            // use previous dimensions, saving time to look up image.
            // packed width in msw and height in lsw
            width = wxh >>> 16;
            height = wxh & 0xffff;
            return new int[] { width, height };
            }
        else
            {
            int[] dimensions = ImageInfo.getImageDimensions( Tools.toFileFromUPath( "image/" + projectImage
            ).getAbsolutePath() );
            width = dimensions[ 0 ];
            height = dimensions[ 1 ];
            if ( width == 0 || height == 0 )
                {
                return new int[] { 0, 0 };
                }
            // new good one
            // pack width in msw and height in lsw
            doneBefore.put( projectImage, width << 16 | height );
            return dimensions;
            }
        }
    }