AdvancedScripts/src/main/java/de/steamwar/advancedscripts/lexer/ScriptColorizer.java

/*
 *   This file is a part of the SteamWar software.
 *
 *   Copyright (C) 2023  SteamWar.de-Serverteam
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Affero General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *   GNU Affero General Public License for more details.
 *
 *   You should have received a copy of the GNU Affero General Public License
 *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package de.steamwar.advancedscripts.lexer;

import net.minecraft.util.Formatting;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

public class ScriptColorizer {

    private static final Set<String> KEYWORDS = Set.of(
            "and", "break", "do", "else", "elseif", "end", "for", "function", "goto", "if", "in", "local", "nil", "not", "or", "repeat", "return", "then", "until", "while"
    );

    private ScriptColorizer() {
        throw new IllegalStateException("Utility class██");
    }

    public static List<Token> colorize(String line) {
        List<Token> tokens = colorizeComment(line);
        if (tokens != null) return tokens;
        return colorizeLine(line);
    }

    private static List<Token> colorizeComment(String line) {
        if (!line.startsWith("--")) return null;
        return List.of(new Token(line, TokenTypeColors.COMMENT));
    }

    private static List<Token> colorizeLine(String line) {
        List<Token> tokens = new ArrayList<>();

        StringBuilder currentToken = new StringBuilder();

        boolean inString = false;
        boolean doubleQuoteString = false;

        for (char c : line.toCharArray()) {
            switch (c) {
                case '"' -> {
                    if (inString) {
                        if (doubleQuoteString) {
                            tokens.add(toStringToken(currentToken.toString()));
                            currentToken = new StringBuilder();
                            tokens.add(new Token(c + "", TokenTypeColors.STRING));
                            inString = false;
                            doubleQuoteString = false;
                        }
                    } else {
                        inString = true;
                        doubleQuoteString = true;
                        if (!currentToken.isEmpty()) {
                            tokens.add(toToken(currentToken.toString()));
                            currentToken = new StringBuilder();
                        }
                        tokens.add(new Token(c + "", TokenTypeColors.STRING));
                    }
                }
                case '\'' -> {
                    if (inString) {
                        if (!doubleQuoteString) {
                            tokens.add(toStringToken(currentToken.toString()));
                            currentToken = new StringBuilder();
                            tokens.add(new Token(c + "", TokenTypeColors.STRING));
                            inString = false;
                        }
                    } else {
                        inString = true;
                        doubleQuoteString = false;
                        if (!currentToken.isEmpty()) {
                            tokens.add(toToken(currentToken.toString()));
                            currentToken = new StringBuilder();
                        }
                        tokens.add(new Token(c + "", TokenTypeColors.STRING));
                    }
                }
                case '-', ';', '(', ')', ',', ' ', '{', '\t' -> {
                    if (inString) {
                        currentToken.append(c);
                    } else {
                        if (!currentToken.isEmpty()) {
                            tokens.add(toToken(currentToken.toString()));
                        }
                        tokens.add(new Token(String.valueOf(c), TokenTypeColors.OTHER));
                        currentToken = new StringBuilder();
                    }
                }
                default -> {
                    if (inString && c == '&') {
                        if (!currentToken.isEmpty()) {
                            tokens.add(toStringToken(currentToken.toString()));
                        }
                        currentToken = new StringBuilder();
                    }
                    currentToken.append(c);
                }
            }
        }

        if (currentToken.length() > 0) {
            tokens.add(toToken(currentToken.toString()));
        }

        return tokens;
    }

    private static Token toStringToken(String text) {
        if (text.length() > 1 && text.charAt(0) == '&') {
            Formatting formatting = Formatting.byCode(text.charAt(1));
            if (formatting == null || !formatting.isColor()) {
                return new Token(text, TokenTypeColors.STRING);
            }
            return new Token(text, formatting.getColorValue());
        }
        return new Token(text, TokenTypeColors.STRING);
    }

    private static Token toToken(String text) {
        if (text.length() > 0) {
            if (KEYWORDS.contains(text)) {
                return new Token(text, TokenTypeColors.CONSTANT);
            } else if ("true".contentEquals(text) || "false".contentEquals(text)) {
                return new Token(text, TokenTypeColors.BOOLEAN);
            } else if (text.matches("[0-9]+")) {
                return new Token(text, TokenTypeColors.NUMBER);
            } else {
                return new Token(text, TokenTypeColors.OTHER);
            }
        } else {
            return Token.SPACE;
        }
    }
}