/*
 *  Copyright 2010 Anyware Services
 *
 *  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.
 */
package org.ametys.web.skin;

import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.configuration.DefaultConfigurationBuilder;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.ametys.runtime.i18n.I18nizableText;


/**
 * A skin
 * Do not mistake with {@link SkinParametersModel}
 */
public class SkinModel
{
    private static Logger _logger = LoggerFactory.getLogger(SkinModel.class);
    
    /** The skin id (e.g. the directory name) */
    protected String _id;
    /** The skin directory */
    protected Path _file;
    /** The skin name */
    protected I18nizableText _label;
    /** The skin description */
    protected I18nizableText _description;
    /** The skin thumbnail 16x16 */
    protected String _smallImage;
    /** The skin thumbnail 32x32 */
    protected String _mediumImage;
    /** The skin thumbnail 48x48 */
    protected String _largeImage;
    
    /** The last time the file was loaded */
    protected long _lastConfUpdate;
    /** Is the skin modifiable */
    protected boolean _modifiable;
    
    private long _lastDefaultValuesUpdate;
    private Map<String, String> _defaultValues;
    private String _defaultColorTheme;
    
    private long _lastColorsUpdate;
    private Map<String, Theme> _themes = new HashMap<>();
    private List<String> _colors = new ArrayList<>();
    
    private long _lastCssStylesUpdate;
    private Map<String, List<CssMenuItem>> _cssStyles = new HashMap<>();
    
    /**
     * Creates a skin
     * @param id The id of the skin (e.g. the directory name)
     * @param file The skin file
     * @param modifiable Is this model modifiable?
     */
    public SkinModel(String id, Path file, boolean modifiable)
    {
        _id = id;
        _file = file;
        _modifiable = modifiable;
    }
    
    /**
     * The configuration default values (if configuration file does not exist or is unreadable)
     */
    protected void _defaultValues()
    {
        _lastConfUpdate = new Date().getTime();
        
        _label = new I18nizableText(_id);
        _description = new I18nizableText("");
        _smallImage = "/plugins/web/resources/img/skin/skin_16.png";
        _mediumImage = "/plugins/web/resources/img/skin/skin_32.png";
        _largeImage = "/plugins/web/resources/img/skin/skin_48.png";
    }
    
    /**
     * Is the model modifiable?
     * @return true if modifiable
     */
    public boolean isModifiable()
    {
        return _modifiable;
    }
    
    /**
     * Refresh the conf values
     */
    public void refreshValues()
    {
        Path configurationFile = _file.resolve(Skin.CONF_PATH);
        if (Files.exists(configurationFile))
        {
            try
            {
                long millis = Files.getLastModifiedTime(configurationFile).toMillis();
                if (_lastConfUpdate < millis)
                {
                    _lastConfUpdate = millis;
                    try (InputStream is = Files.newInputStream(configurationFile))
                    {
                        Configuration configuration = new DefaultConfigurationBuilder().build(is);
                        
                        this._label = _configureI18nizableText(configuration.getChild("label", false), new I18nizableText(this._id));
                        this._description = _configureI18nizableText(configuration.getChild("description", false), new I18nizableText(""));
                        this._smallImage = _configureThumbnail(configuration.getChild("thumbnail").getChild("small").getValue(null), "/plugins/web/resources/img/skin/skin_16.png");
                        this._mediumImage = _configureThumbnail(configuration.getChild("thumbnail").getChild("medium").getValue(null), "/plugins/web/resources/img/skin/skin_32.png");
                        this._largeImage = _configureThumbnail(configuration.getChild("thumbnail").getChild("large").getValue(null), "/plugins/web/resources/img/skin/skin_48.png");
                    }
                }
            }
            catch (Exception e)
            {
                _defaultValues();
                if (_logger.isWarnEnabled())
                {
                    _logger.warn("Cannot read the configuration file " + Skin.CONF_PATH + " for the model '" + this._id + "'. Continue as if file was not existing", e);
                }
            }
        }
        else
        {
            _defaultValues();
        }
    }
    
    /**
     * Get the default color theme
     * @return The default color theme or <code>null</code>
     */
    public String getDefaultColorTheme ()
    {
        _refreshDefaultValues ();
        return _defaultColorTheme;
    }
    
    /**
     * Get color themes of this model
     * @return color themes of this model
     */
    public Map<String, Theme> getThemes ()
    {
        _refreshColorsValues ();
        return _themes;
    }
    
    /**
     * Get a theme of this model
     * @param themeId the theme id
     * @return the theme
     */
    public Theme getTheme (String themeId)
    {
        _refreshColorsValues();
        return _themes.get(themeId);
    }
    
    /**
     * Get the default colors of this model
     * @return The default colors of this model
     */
    public List<String> getDefaultColors ()
    {
        _refreshColorsValues();
        return _colors;
    }
    
    /**
     * Get the default colors of this theme
     * @param themeId The theme id
     * @return the default colors of this theme
     */
    public List<String> getColors (String themeId)
    {
        _refreshColorsValues();
        if (_themes.containsKey(themeId))
        {
            return _themes.get(themeId).getColors();
        }
        return new ArrayList<>();
    }
    
    /**
     * Get all style items of this model
     * @return the list of items of css style
     */
    public Map<String, List<CssMenuItem>> getStyleItems ()
    {
        _refreshCssStyles();
        return _cssStyles;
    }
    
    /**
     * Get the items of this css style
     * @param styleId The css style id
     * @return the list of items of css style
     */
    public List<CssMenuItem> getStyleItems (String styleId)
    {
        _refreshCssStyles();
        return _cssStyles.get(styleId);
    }
    
    /**
     * Get model default values
     * @return The default values
     */
    public Map<String, String> getDefaultValues ()
    {
        _refreshDefaultValues ();
        return _defaultValues;
    }
    
    private void _refreshColorsValues ()
    {
        Path configurationFile = _file.resolve("model/colors.xml");
        if (Files.exists(configurationFile))
        {
            try
            {
                long millis = Files.getLastModifiedTime(configurationFile).toMillis();
                if (_lastColorsUpdate < millis)
                {
                    _lastColorsUpdate = millis;
                    _colors = new ArrayList<>();
                    _themes = new LinkedHashMap<>();
                    
                    try (InputStream is = Files.newInputStream(configurationFile))
                    {
                        Configuration configuration = new DefaultConfigurationBuilder().build(is);
                        Configuration[] themesConf = configuration.getChildren("theme");
                        
                        for (Configuration themeConf : themesConf)
                        {
                            String name = themeConf.getAttribute("id");
                            I18nizableText label = _configureI18nizableText (themeConf.getChild("label"), new I18nizableText(""));
                            I18nizableText description = _configureI18nizableText (themeConf.getChild("description"), new I18nizableText(""));
                            
                            Configuration[] colorsConf = themeConf.getChild("colors").getChildren("color");
                            
                            List<String> colors = new ArrayList<>();
                            for (Configuration colorConf : colorsConf)
                            {
                                colors.add(colorConf.getValue().toLowerCase());
                            }
                            
                            _themes.put(name, new Theme(name, label, description, colors));
                        }
                        
                        Configuration[] children = configuration.getChild("default", true).getChildren("color");
                        for (Configuration colorConf : children)
                        {
                            _colors.add(colorConf.getValue().toLowerCase());
                        }
                    }
                }
            }
            catch (Exception e)
            {
                if (_logger.isWarnEnabled())
                {
                    _logger.warn("Cannot read the configuration file model/colors.xml for the model '" + this._id + "'. Continue as if file was not existing", e);
                }
                
                _colors = new ArrayList<>();
                _themes = new HashMap<>();
            }
        }
        else
        {
            _colors = new ArrayList<>();
            _themes = new HashMap<>();
        }
    }
    
    private void _refreshCssStyles ()
    {
        Path configurationFile = _file.resolve("model/css-styles.xml");
        if (Files.exists(configurationFile))
        {
            try
            {
                long millis = Files.getLastModifiedTime(configurationFile).toMillis();
                if (_lastCssStylesUpdate < millis)
                {
                    _lastCssStylesUpdate = millis;
                    _cssStyles = new HashMap<>();
                    
                    try (InputStream is = Files.newInputStream(configurationFile))
                    {
                        Configuration configuration = new DefaultConfigurationBuilder().build(is);
                        Configuration[] children = configuration.getChildren();
                        for (Configuration styleConf : children)
                        {
                            String name = styleConf.getName();
                            List<CssMenuItem> items = _configureStyleItems (styleConf);
                            _cssStyles.put(name, items);
                        }
                    }
                }
            }
            catch (Exception e)
            {
                if (_logger.isWarnEnabled())
                {
                    _logger.warn("Cannot read the configuration file model/css-styles.xml for the model '" + this._id + "'. Continue as if file was not existing", e);
                }
                
                _cssStyles = new HashMap<>();
            }
        }
        else
        {
            _cssStyles = new HashMap<>();
        }
    }
    
    private List<CssMenuItem> _configureStyleItems (Configuration styleConfig) throws ConfigurationException
    {
        List<CssMenuItem> items = new ArrayList<>();
        
        Configuration[] children = styleConfig.getChildren();
        for (Configuration child : children)
        {
            if (child.getName().equals("separator"))
            {
                items.add(new Separator());
            }
            else
            {
                String value = child.getChild("value").getValue();
                I18nizableText label = _configureI18nizableText (child.getChild("label"), new I18nizableText(value));
                String iconCls = child.getChild("iconCls").getValue(null);
                String icon = _configureIcon (child.getChild("icon", false));
                String cssClass = child.getChild("cssclass", true).getValue(null);
                
                items.add(new CssStyleItem(value, label, iconCls, icon, cssClass));
            }
        }
        
        return items;
    }
    
    
    private void _refreshDefaultValues ()
    {
        Path configurationFile = _file.resolve("model/default-values.xml");
        if (Files.exists(configurationFile))
        {
            try
            {
                long millis = Files.getLastModifiedTime(configurationFile).toMillis();

                if (_lastDefaultValuesUpdate < millis)
                {
                    _defaultValues = new HashMap<>();
                    _lastDefaultValuesUpdate = millis;
                    
                    try (InputStream is = Files.newInputStream(configurationFile))
                    {
                        Configuration configuration = new DefaultConfigurationBuilder().build(is);
                        Configuration[] parametersConf = configuration.getChildren("parameter");
                        
                        for (Configuration paramConf : parametersConf)
                        {
                            String value = paramConf.getValue(null);
                            if (StringUtils.isNotEmpty(value))
                            {
                                _defaultValues.put(paramConf.getAttribute("id"), paramConf.getValue());
                            }
                        }
                        
                        _defaultColorTheme = configuration.getChild("color-theme", true).getValue(null);
                    }
                }
            }
            catch (Exception e)
            {
                _logger.error("Cannot read the configuration file model/default-values.xml for the model '" + this._id + "'. Continue as if file was not existing", e);
                
                _defaultValues = new HashMap<>();
                _defaultColorTheme = null;
            }
        }
        else
        {
            _defaultValues = new HashMap<>();
            _defaultColorTheme = null;
        }
    }
    
    private String _configureThumbnail(String value, String defaultImage)
    {
        if (value == null)
        {
            return defaultImage;
        }
        else
        {
            return "/models/" + this._id + "/resources/" + value;
        }
    }
    
    private I18nizableText _configureI18nizableText(Configuration configuration, I18nizableText defaultValue) throws ConfigurationException
    {
        if (configuration != null)
        {
            boolean i18nSupported = configuration.getAttributeAsBoolean("i18n", false);
            if (i18nSupported)
            {
                String catalogue = configuration.getAttribute("catalogue", null);
                if (catalogue == null)
                {
                    catalogue = "model." + this._id;
                }

                return new I18nizableText(catalogue, configuration.getValue());
            }
            else
            {
                return new I18nizableText(configuration.getValue(""));
            }
        }
        else
        {
            return defaultValue;
        }
        
    }
    
    private String _configureIcon (Configuration iconConf) throws ConfigurationException
    {
        if (iconConf != null)
        {
            String pluginName = iconConf.getAttribute("plugin");
            String path = iconConf.getValue();
            
            return "/plugins/" + pluginName + "/resources/" + path;
        }
        return null;
    }

    /**
     * The skin id
     * @return the id
     */
    public String getId()
    {
        return _id;
    }
    
    /**
     * The skin label
     * @return The label
     */
    public I18nizableText getLabel()
    {
        return _label;
    }
    /**
     * The skin description
     * @return The description. Can not be null but can be empty
     */
    public I18nizableText getDescription()
    {
        return _description;
    }
    
    /**
     * The small image file uri
     * @return The small image file uri
     */
    public String getSmallImage()
    {
        return _smallImage;
    }

    /**
     * The medium image file uri
     * @return The medium image file uri
     */
    public String getMediumImage()
    {
        return _mediumImage;
    }
    
    /**
     * The large image file uri
     * @return The large image file uri
     */
    public String getLargeImage()
    {
        return _largeImage;
    }

    /**
     * Get the skin's file directory
     * @return the skin's file directory
     */
    public Path getPath ()
    {
        return _file;
    }
    
    /*----------------------------------------------------*/
    /*                 Internal classes                   */
    /*----------------------------------------------------*/
    /**
     * Bean representing a theme
     *
     */
    public class Theme
    {
        private String _themeId;
        private I18nizableText _themeLabel;
        private I18nizableText _themeDescription;
        private List<String> _themeColors;

        /**
         * Constructor
         * @param id the theme id
         * @param label the theme's label
         * @param description the theme's description
         * @param colors the theme's colors
         */
        public Theme (String id, I18nizableText label, I18nizableText description, List<String> colors)
        {
            _themeId = id;
            _themeLabel = label;
            _themeDescription = description;
            _themeColors = colors;
        }
        
        /**
         * Get the id
         * @return the id
         */
        public String getId ()
        {
            return _themeId;
        }
        
        /**
         * Get the label
         * @return the label
         */
        public I18nizableText getLabel ()
        {
            return _themeLabel;
        }
        
        /**
         * Get the description
         * @return the description
         */
        public I18nizableText getDescription ()
        {
            return _themeDescription;
        }
        
        /**
         * Get the colors
         * @return the colors
         */
        public List<String> getColors ()
        {
            return _themeColors;
        }
        
        /**
         * Get the color to the given index
         * @param index The index of color
         * @return The color
         */
        public String getColor (int index)
        {
            try
            {
                return _themeColors.get(index);
            }
            catch (IndexOutOfBoundsException e)
            {
                // Returns the last color
                return _themeColors.get(_themeColors.size() - 1);
            }
        }
    }
    
    /**
     * Bean representing a item of css style
     *
     */
    public class CssStyleItem implements CssMenuItem
    {
        private String _cssValue;
        private I18nizableText _styleLabel;
        private String _styleIcon;
        private String _styleIconCls;
        private String _cssClass;

        /**
         * Constructor
         * @param value the value
         * @param label the item's label
         * @param iconCls the CSS class for icon. Can be null.
         * @param icon the icon. Can be null.
         * @param cssClass the css class. Can be null.
         */
        public CssStyleItem (String value, I18nizableText label, String iconCls, String icon, String cssClass)
        {
            _cssValue = value;
            _styleLabel = label;
            _styleIcon = icon;
            _styleIconCls = iconCls;
            _cssClass = cssClass;
        }
        
        /**
         * Get the value
         * @return the value
         */
        public String getValue ()
        {
            return _cssValue;
        }
        
        /**
         * Get the label
         * @return the label
         */
        public I18nizableText getLabel ()
        {
            return _styleLabel;
        }
        
        /**
         * Get the icon css class
         * @return the icon css class or <code>null</code>
         */
        public String getIconCls ()
        {
            return _styleIconCls;
        }
        
        /**
         * Get the icon
         * @return the icon or <code>null</code>
         */
        public String getIcon ()
        {
            return _styleIcon;
        }
        
        /**
         * Get the css class
         * @return The css class or <code>null</code>
         */
        public String getCssClass ()
        {
            return _cssClass;
        }
    }
    
    /**
     * Item representing a separator
     */
    public class Separator implements CssMenuItem
    {
        /**
         * Constructor
         */
        public Separator()
        {
            // Nothing to do
        }
        
    }
    
    /**
     * Abstract representation of a menu item
     */
    public interface CssMenuItem
    {
        // Empty
    }
}