// Copyright (C) 2012 Jeffrey B. Arnold
//
// 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 prettify.parser.Prettify;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.regex.Pattern;

/**
 * This is similar to the lang-r.js in JavaScript Prettify.
 * <p/>
 * To use, include prettify.js and this file in your HTML page.
 * Then put your code in an HTML tag like
 * <pre class="prettyprint lang-r"> code </pre>
 * <p/>
 * Language definition from
 * http://cran.r-project.org/doc/manuals/R-lang.html.
 * Many of the regexes are shared  with the pygments SLexer,
 * http://pygments.org/.
 * <p/>
 * Original: https://raw.github.com/jrnold/prettify-lang-r-bugs/master/lang-r.js
 *
 * @author jeffrey.arnold@gmail.com
 */
public class LangR extends Lang {

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

        _shortcutStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_PLAIN, Pattern.compile("^[\\t\\n\\r \\xA0]+"), null, "\t\n\r " + Character.toString((char) 0xA0)}));
        _shortcutStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_STRING, Pattern.compile("^\\\"(?:[^\\\"\\\\]|\\\\[\\s\\S])*(?:\\\"|$)"), null, "\""}));
        _shortcutStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_STRING, Pattern.compile("^\\'(?:[^\\'\\\\]|\\\\[\\s\\S])*(?:\\'|$)"), null, "'"}));

        _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_COMMENT, Pattern.compile("^#.*")}));
        _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_KEYWORD, Pattern.compile("^(?:if|else|for|while|repeat|in|next|break|return|switch|function)(?![A-Za-z0-9_.])")}));
        // hex numbes
        _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_LITERAL, Pattern.compile("^0[xX][a-fA-F0-9]+([pP][0-9]+)?[Li]?")}));
        // Decimal numbers
        _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_LITERAL, Pattern.compile("^[+-]?([0-9]+(\\.[0-9]+)?|\\.[0-9]+)([eE][+-]?[0-9]+)?[Li]?")}));
        // builtin symbols
        _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_LITERAL, Pattern.compile("^(?:NULL|NA(?:_(?:integer|real|complex|character)_)?|Inf|TRUE|FALSE|NaN|\\.\\.(?:\\.|[0-9]+))(?![A-Za-z0-9_.])")}));
        // assignment, operators, and parens, etc.
        _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_PUNCTUATION, Pattern.compile("^(?:<<?-|->>?|-|==|<=|>=|<|>|&&?|!=|\\|\\|?|\\*|\\+|\\^|\\/|!|%.*?%|=|~|\\$|@|:{1,3}|[\\[\\](){};,?])")}));
        // valid variable names
        _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_PLAIN, Pattern.compile("^(?:[A-Za-z]+[A-Za-z0-9_.]*|\\.[a-zA-Z_][0-9a-zA-Z\\._]*)(?![A-Za-z0-9_.])")}));
        // string backtick
        _fallthroughStylePatterns.add(Arrays.asList(new Object[]{Prettify.PR_STRING, Pattern.compile("^`.+`")}));

        setShortcutStylePatterns(_shortcutStylePatterns);
        setFallthroughStylePatterns(_fallthroughStylePatterns);
    }

    public static List<String> getFileExtensions() {
        return Arrays.asList(new String[]{"r", "s", "R", "S", "Splus"});
    }
}