/*
 * [ProviderBase.java]
 *
 * Summary: Base class for all poster providers.
 *
 * 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:
 *  1.1 2008-09-27
 */
package com.mindprod.poster;

import com.mindprod.common18.ST;
import com.mindprod.fastcat.FastCat;
import com.mindprod.htmlmacros.support.BuildImage;
import com.mindprod.hunkio.HunkIO;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Base class for all poster providers.
 *
 * @author Roedy Green, Canadian Mind Products
 * @version 1.1 2008-09-27
 * @since 2008
 */
abstract class ProviderBase
    {
    /**
     * true if should check if already done
     */
    static final boolean CHECK_IF_ALREADY_DONE = true;

    /**
     * true if debugging, display extra output
     */
    static final boolean DEBUGGING = false;

    /**
     * true if testing, don't actually change any files or check if done before
     */
    static final boolean TESTING = false;

    /**
     * find place to patch image background colour
     */
    private static final Pattern BACKGROUND_FOR_PATCH_COLOR = Pattern.compile(
            "div.titlehome\\s*\\{\\s*+background\\-color:\\s*(#\\p{XDigit}{6});" );

    /**
     * find place to patch image foreground colour
     */
    private static final Pattern PATCH_FOREGROUND_COLOR = Pattern.compile(
            "div.titlehome\\s+h1\\s*\\{\\s*color:\\s*(#\\p{XDigit}{6});" );

    /**
     * a description of the image
     */
    final String extraDescription/*  "Ren&eacute; Magritte&rsquo;s <cite>The Last Cry</cite>" */;

    /**
     * name of local large jpg with .jpg or .png extension or directory
     */
    final String bareImageName/* "maldives.jpg" */;

    /**
     * a few words to title the poster thumbnail
     */
    final String title;

    /**
     * used to ensure a colour has the format #rrggbb
     */
    @SuppressWarnings( { "FieldCanBeLocal" } )
    private final Pattern LEGAL_COLOUR_PATTERN = Pattern.compile( "#[\\p{XDigit}]{6}" );

    /**
     * background colour to match the image, #rrggbb with lead #
     */
    private final String background;

    /**
     * foreground colour to match the image,  #rrggbb with lead #
     */
    private final String foreground;

    /**
     * text of index.html
     */
    String homePage;

    /**
     * height of the local image in px
     */
    int localImageHeight/* 266 px */;

    /**
     * width of the local image in px
     */
    int localImageWidth/* 400 px */;

    /**
     * home.css, the aux style sheet to let us control home page colours.
     */
    private File homeCssFile;

    /**
     * index.htm
     */
    private File indexHtmlFile;

    /**
     * text of home.css
     */
    private String stylesheet;

    /**
     * abstract constructor to describe a new Poster.
     *
     * @param bareImageName    name of local image ending in .jpg .png or gif
     * @param title            short title of the picture
     * @param extraDescription what is in the picture, a longer description of the picture.
     * @param background       #rrggbb hex background
     * @param foreground       #rrggbb hex foreground
     */
    ProviderBase( String bareImageName, final String title, final String extraDescription, String background,
                  String foreground )
        {
        // forgive extra lead #. Work internally with lead #
        background = '#' + ST.trimLeading( background, '#' );
        if ( LEGAL_COLOUR_PATTERN.matcher( background ).matches() )
            {
            this.background = background;
            }
        else
            {
            throw new IllegalArgumentException( "Invalid background colour " + background );
            }
        foreground = '#' + ST.trimLeading( foreground, '#' );
        if ( LEGAL_COLOUR_PATTERN.matcher( foreground ).matches() )
            {
            this.foreground = foreground;
            }
        else
            {
            throw new IllegalArgumentException( "Invalid foreground colour " + foreground );
            }
        this.title = title;
        if ( !( bareImageName.endsWith( ".jpg" ) || bareImageName.endsWith( ".png" ) || bareImageName.endsWith( ".gif" ) ) )
            {
            bareImageName += ".jpg";
            }
        this.bareImageName = bareImageName;
        this.extraDescription = extraDescription;
        }

    /**
     * save data to a file in one big chunk with safety temp rename to avoid data corruption if we fail to complete
     * the write..
     *
     * @param fileBeingProcessed file to save data to
     * @param contents           contents of file.
     *
     * @throws IOException if problem saving the file
     */
    static void saveOneFile( File fileBeingProcessed, String contents )
            throws IOException
        {
        final File tempFile = HunkIO.createTempFile( "temp_", ".tmp", fileBeingProcessed );
        final FileWriter emit = new FileWriter( tempFile );
        emit.write( contents );
        emit.close();
        HunkIO.deleteAndRename( tempFile, fileBeingProcessed );
        }

    /**
     * get rid of any old local images, keep current one.
     */
    @SuppressWarnings( { "ResultOfMethodCallIgnored" } )
    void deleteOldLocalImages()
        {
        // look in E:\mindprod\image\home
        File dir = new File( "E:/mindprod/image", providerName() );
        String[] files = dir.list();
        for ( String file : files )
            {
            File old = new File( dir, file );
            if ( !old.getName().startsWith( bareImageName ) )
                {
                old.delete();
                }
            }
        }

    /**
     * get the local image size. Stores results in localImageWidth and localImageSize.
     */
    void getLocalImageSize()
        {
        final int[] dimensions = BuildImage.getProjectImageDimensions( providerName() + "/" + bareImageName );
        localImageWidth = dimensions[ 0 ];
        localImageHeight = dimensions[ 1 ];
        if ( localImageWidth == 0 )
            {
            throw new IllegalArgumentException( "missing Image file "
                                                + bareImageName + " or malformed size " + localImageWidth + " x " +
                                                localImageHeight );
            }
        }

    /**
     * internal provider name, also dir where the local image is stored on hard disk,  without lead E:/mindprod/image
     *
     * @return e.g. artcom or allposterscom
     */
    abstract String providerName();

    /**
     * read all poster files files into RAM
     *
     * @throws java.io.IOException if can't access one of the poster html files.
     */
    void read() throws IOException
        {
        indexHtmlFile = new File( "E:/mindprod/index.html" );
        homeCssFile = new File( "E:/mindprod/home.css" );
        homePage = HunkIO.readEntireFile( indexHtmlFile );
        stylesheet = HunkIO.readEntireFile( homeCssFile );
        }

    /**
     * replace background and foreground colours on titlehome style.
     */
    void replaceColoursOnStylesheet()
        {
        // patch background colour
        // div.titlehome{
        // background-color: #a0bcd4
        final Matcher mb = BACKGROUND_FOR_PATCH_COLOR.matcher( stylesheet );
        final int backgroundOffset;
        if ( mb.find() )
            {
            backgroundOffset = mb.start( 1 );
            }
        else
            {
            throw new IllegalArgumentException( "can't find background-color: in home.css" );
            }
        // patch foreground colour
        // div.titlehome h1{
        // color: #f1f4ed;
        final Matcher mf = PATCH_FOREGROUND_COLOR.matcher( stylesheet.substring( backgroundOffset ) );
        final int foregroundOffset;
        if ( mf.find() )
            {
            // get absolute offset inside stylesheet
            foregroundOffset = mf.start( 1 ) + backgroundOffset;
            }
        else
            {
            throw new IllegalArgumentException( "can't find foreground color, div.titlehome h1 { color:, in home.css" );
            }
        /// should stay exactly the same length.
        final int repLen = "#rrggbb".length();
        final FastCat sb = new FastCat( 5 );
        sb.append( stylesheet.substring( 0, backgroundOffset ) );
        sb.append( background );
        sb.append( stylesheet.substring( backgroundOffset + repLen, foregroundOffset ) );
        sb.append( foreground );
        sb.append( stylesheet.substring( foregroundOffset + repLen ) );
        stylesheet = sb.toString();
        }

    /**
     * replace the reference to the local image on the home page
     */
    abstract void replaceLocalImageOnHomePage();

    /**
     * save all changes in RAM to data files.
     *
     * @throws IOException if problem writing files.
     */
    void save() throws IOException
        {
        saveOneFile( indexHtmlFile, homePage );
        saveOneFile( homeCssFile, stylesheet );
        }
    }