// Copyright (C) 2011 Martin S.
//
// 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 prettify.lang;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.regex.Pattern;
import prettify.parser.Prettify;

/**
 * This is similar to the lang-tex.js in JavaScript Prettify.
 * 
 * All comments are adapted from the JavaScript Prettify.
 * 
 * <p>
 * Support for tex highlighting as discussed on
 * <a href="http://meta.tex.stackexchange.com/questions/872/text-immediate-following-double-backslashes-is-highlighted-as-macro-inside-a-code/876#876">meta.tex.stackexchange.com</a>.
 *
 * @author Martin S.
 */
public class LangTex extends Lang {

  public LangTex() {
    List<List<Object>> _shortcutStylePatterns = new ArrayList<List<Object>>();
    List<List<Object>> _fallthroughStylePatterns = new ArrayList<List<Object>>();

    // whitespace
    _shortcutStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_PLAIN, Pattern.compile("^[\\t\\n\\r \\xA0]+"), null, "\t\n\r " + Character.toString((char) 0xA0)}));
    // all comments begin with '%'
    _shortcutStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_COMMENT, Pattern.compile("^%[^\\r\\n]*"), null, "%"}));
    //[PR['PR_DECLARATION'], /^\\([egx]?def|(new|renew|provide)(command|environment))\b/],
    // any command starting with a \ and contains
    // either only letters (a-z,A-Z), '@' (internal macros)
    _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_KEYWORD, Pattern.compile("^\\\\[a-zA-Z@]+")}));
    // or contains only one character
    _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_KEYWORD, Pattern.compile("^\\\\.")}));
    // Highlight dollar for math mode and ampersam for tabular
    _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_TYPE, Pattern.compile("^[$&]")}));
    // numeric measurement values with attached units
    _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_LITERAL, Pattern.compile("[+-]?(?:\\.\\d+|\\d+(?:\\.\\d*)?)(cm|em|ex|in|pc|pt|bp|mm)", Pattern.CASE_INSENSITIVE)}));
    // punctuation usually occurring within commands
    _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_PUNCTUATION, Pattern.compile("^[{}()\\[\\]=]+")}));

    setShortcutStylePatterns(_shortcutStylePatterns);
    setFallthroughStylePatterns(_fallthroughStylePatterns);
  }

  public static List<String> getFileExtensions() {
    return Arrays.asList(new String[]{"latex", "tex"});
  }
}