/*
 * 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.
 */
package org.apache.maven.doxia.sink;

import javax.swing.text.MutableAttributeSet;

import java.util.Map;
import java.util.Set;

/**
 * A set of attributes for a sink event.
 * <p>
 * All sink methods that produce some presentation-level output should have at least
 * one form that allows to pass in a Set of SinkEventAttributes. For instance in
 * </p>
 * <pre>void text(String text, SinkEventAttributes attributes);</pre>
 * <p>
 * the <code>attributes</code> parameter can be used to specify some text styling
 * options, or other optional parameters.
 * </p>
 * <p>
 * What kind of attributes are supported depends on the event and the sink
 * implementation. The sink API just specifies a list of suggested attribute
 * names, that sinks are expected to recognize, and parsers are expected to use
 * preferably when emitting events.
 * </p>
 * <p>
 * It is recommended that for simple attributes, both keys and values should be
 * lower-case Strings, but this is not mandatory. One example of an exception is
 * the {@link #STYLE} attribute, whose value may itself be an AttributeSet again.
 * </p>
 * <p>
 * The <b>base attributes</b> that are supported by almost all events are
 * {@link #CLASS}, {@link #ID}, {@link #LANG}, {@link #STYLE} and {@link #TITLE}.
 * </p>
 *
 * @author ltheussl
 * @since 1.1
 */
@SuppressWarnings("checkstyle:interfaceistype")
public interface SinkEventAttributes extends MutableAttributeSet {
    // base

    /**
     * The class of the event element.
     */
    String CLASS = "class";

    /**
     * A unique id for the event element.
     */
    String ID = "id";

    /**
     * The language code for the event element.
     */
    String LANG = "lang";

    /**
     * An inline style definition.
     *
     * <p>
     *   Generally supported values are "italic", "bold", "monospaced" and AttributeSets.
     * </p>
     * <p>
     *   If the value of this Attribute is itself an AttributeSet, it is interpreted as a
     *   sequence of CSS properties. For instance, the HTML paragraph opening
     * </p>
     * <pre>
     *   &lt;p style="color: red; margin-left: 20px"&gt;
     * </pre>
     * <p>
     *   can be produced by an HTML Sink via the event
     *   <code>{@link Sink#paragraph(SinkEventAttributes)}</code>, where the value of the
     *   SinkEventAttribute is an AttributeSet with two Attributes ("<code>color</code>" and
     *   "<code>margin-left</code>" with values "<code>red</code>" and "<code>20px</code>",
     *   respectively).
     * </p>
     */
    String STYLE = "style";

    /**
     * A text to display in a tool tip.
     */
    String TITLE = "title";

    // head

    /**
     * A space separated list of URL's that contains meta data information about the document.
     */
    String PROFILE = "profile";

    /**
     * An electronic mail address.
     */
    String EMAIL = "email";

    /**
     * The value of a meta element, used together with {@link #NAME}.
     *
     * @since 2.2.0
     */
    String CONTENT = "content";

    // img

    /**
     * Specifies the alignment of the event element within its parent element.
     *
     * <p>
     *   Generally supported values are "left", "right", "center", "justify".
     * </p>
     */
    String ALIGN = "align";

    /**
     * Defines a short description of the event element.
     */
    String ALT = "alt";

    /**
     * Defines a border around an event element.
     */
    String BORDER = "border";

    /**
     * Defines the height of an event element.
     */
    String HEIGHT = "height";

    /**
     * Defines white space on the left and right side of an event element.
     */
    String HSPACE = "hspace";

    /**
     * Defines an image as a server-side image map. Only used by the figureGraphics Sink event.
     */
    String ISMAP = "ismap";

    /**
     * The URL of an external resource, eg an image.
     */
    String SRC = "src";

    /**
     * Defines an image as a client-side image map.
     */
    String USEMAP = "usemap";

    /**
     * Defines white space on the top and bottom of the event element.
     */
    String VSPACE = "vspace";

    /**
     * Sets the width of  an event element.
     */
    String WIDTH = "width";

    // hr

    /**
     * Used to indicate that an element comes with a shadow.
     */
    String NOSHADE = "noshade";

    /**
     * Specifies the size, or thickness, or height of an event element.
     */
    String SIZE = "size";

    // anchor

    /**
     * Specifies the name of an anchor.
     */
    String NAME = "name";

    // link

    /**
     * Specifies the character encoding of text associated with an event element.
     */
    String CHARSET = "charset";

    /**
     * May be used in conjunction with {@link #SHAPE}.
     *
     * <p>
     *   Valid values are the same as for the corresponding HTML attributes.
     * </p>
     */
    String COORDS = "coords";

    /**
     * The target URL of an event element, eg a link.
     */
    String HREF = "href";

    /**
     * Specifies the base language of the target URL.
     *
     * <p>
     *   Used in conjunction with {@link #HREF}.
     * </p>
     */
    String HREFLANG = "hreflang";

    /**
     * For references to external resourcs, specifies the relationship between
     * the current document and the target URL.
     *
     * <p>
     *   Valid values are the same as for the corresponding HTML attribute.
     * </p>
     */
    String REL = "rel";

    /**
     * For references to external resourcs, specifies the relationship between
     * the target URL and the current document.
     *
     * <p>
     *   Valid values are the same as for the corresponding HTML attribute.
     * </p>
     */
    String REV = "rev";

    /**
     * Defines the type of region to be defined for a mapping.
     *
     * <p>
     *   Used with the {@link #COORDS} attribute.
     * </p>
     */
    String SHAPE = "shape";

    /**
     * Where to open the target URL.
     *
     * <p>
     *   Valid values are the same as for the corresponding HTML attribute.
     * </p>
     */
    String TARGET = "target";

    /**
     * Specifies the MIME (Multipurpose Internet Mail Extensions) type of an
     * external resource URL, eg a link.
     */
    String TYPE = "type";

    // table

    /**
     * Specifies the background color of an event element.
     */
    String BGCOLOR = "bgcolor";

    /**
     * Specifies the space between cell walls and contents.
     */
    String CELLPADDING = "cellpadding";

    /**
     * Specifies the space between cells.
     */
    String CELLSPACING = "cellspacing";

    /**
     * Specifies which sides of a border surrounding an element should be visible.
     *
     * <p>
     *   Valid values are the same as for the corresponding HTML attribute.
     * </p>
     */
    String FRAME = "frame";

    /**
     * Specifies horizontal/vertical divider lines between certain elements, eg table cells.
     */
    String RULES = "rules";

    /**
     * Specifies a summary of an event attribute for speech-synthesizing/non-visual target output.
     */
    String SUMMARY = "summary";

    // table cell

    /**
     * Specifies an abbreviated version of the content in an element.
     */
    String ABBRV = "abbrv";

    /**
     * Defines a name for a cell.
     */
    String AXIS = "axis";

    /**
     * Indicates the number of columns a cell should span. Used in tables.
     */
    String COLSPAN = "colspan";

    /**
     * A space-separated list of cell IDs that supply header information for the cell.
     */
    String HEADERS = "headers";

    /**
     * Whether to disable or enable automatic text wrapping for an element.
     */
    String NOWRAP = "nowrap";

    /**
     * Indicates the number of rows a cell should span. Used in tables.
     */
    String ROWSPAN = "rowspan";

    /**
     * A general scope parameter. In Particular, for table cells this
     * specifies if the cell provides header information for the rest of the
     * row that contains it ("row"), or for the rest of the column ("col"),
     * or for the rest of the row group that contains it ("rowgroup"),
     * or for the rest of the column group that contains it ("colgroup").
     */
    String SCOPE = "scope";

    /**
     * Specifies the vertical alignment of an element.
     *
     * <p>
     *   Generally accepted values are "top", "baseline", "middle", "bottom", "sup", "sub".
     * </p>
     */
    String VALIGN = "valign";

    // text

    /**
     * Specifies a decoration for an element.
     *
     * <p>
     *   Generally accepted values are "underline", "overline", "line-through", "source".
     * </p>
     */
    String DECORATION = "decoration";

    /**
     * Specifies the semantics of an element.
     *
     * <p>
     *   Generally accepted values are "emphasis", "strong",
     *   "small", "line-through", "citation", "quote", "definition", "abbreviation",
     *   "italic", "bold", "monospaced", "code, "variable", "sample", "keyboard",
     *   "superscript", "subscript", "annotation", "highlight", "ruby", "rubyBase",
     *   "rubyText", "rubyTextContainer", "rubyParentheses", "bidirectionalIsolation",
     *   "bidirectionalOverride", "phrase", "insert", "delete".
     * </p>
     */
    String SEMANTICS = "semantics";

    /**
     * Specifies the semantics of an element.
     *
     * <p>
     *   Generally accepted values are "article", "section",
     *   "navigation", "sidebar".
     * </p>
     */
    String SECTIONS = "sections";

    /**
     * Specifies a value for the data element.
     */
    String VALUE = "value";

    /**
     * Specifies a machine readable date/time for the time element.
     */
    String DATETIME = "datetime";

    /**
     * Returns a {@link Set} view of the attributes in form  of {@link Map.Entry} items.
     * The set is backed by the underlying map, so changes to the map are
     * reflected in the set, and vice-versa.  If the map is modified
     * while an iteration over the set is in progress (except through
     * the iterator's own {@code remove} operation, or through the
     * {@code setValue} operation on a map entry returned by the
     * iterator) the results of the iteration are undefined.  The set
     * supports element removal, which removes the corresponding
     * mapping from the map, via the {@code Iterator.remove},
     * {@code Set.remove}, {@code removeAll}, {@code retainAll} and
     * {@code clear} operations.  It does not support the
     * {@code add} or {@code addAll} operations.
     *
     * @return a set view of the attributes
     * @since 2.1.0
     */
    Set<Map.Entry<String, Object>> entrySet();
}