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//      Magicbane Emulator Project © 2013 - 2026
//                https://www.magicbane.com

package engine.parsers.wpak;

import engine.gameManager.ConfigManager;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.List;

// Reads the client's wpak cfg files (an mbEditorPro export of Config.wpak) into
// tokenized lines and XxxBEGIN/XxxEND blocks. Each parser maps the tokens itself.

public class WpakFileReader {

    public static final String wpakPath = ConfigManager.DEFAULT_DATA_DIR + "wpak/";

    // Lines starting with '#' or '*' are comments (PowerActions_LoadCfg 0x578EC0).
    // A '#' outside quotes ends the line, as in PowActionCostInfo.cfg.

    public static ArrayList<WpakLine> readLines(String fileName) throws IOException {

        ArrayList<WpakLine> lines = new ArrayList<>();
        List<String> fileLines = Files.readAllLines(Paths.get(wpakPath + fileName), StandardCharsets.ISO_8859_1);
        String text;
        String trimmed;
        ArrayList<String> tokens;

        for (int i = 0; i < fileLines.size(); i++) {
            text = fileLines.get(i);
            trimmed = text.trim();

            if (trimmed.isEmpty() || trimmed.charAt(0) == '#' || trimmed.charAt(0) == '*')
                continue;

            tokens = tokenize(fileName, i + 1, text);

            if (!tokens.isEmpty())
                lines.add(new WpakLine(fileName, i + 1, text, tokens));
        }

        return lines;
    }

    // A one-token line XxxBEGIN opens block "Xxx"; XxxEND closes the innermost one.

    public static WpakBlock readBlocks(String fileName) throws IOException {

        WpakBlock root = new WpakBlock(fileName, null);
        ArrayDeque<WpakBlock> openBlocks = new ArrayDeque<>();
        WpakBlock block;
        String token;

        openBlocks.push(root);

        for (WpakLine line : readLines(fileName)) {
            token = line.token(0);

            if (line.size() == 1 && token.length() > 5 && token.endsWith("BEGIN")) {
                block = new WpakBlock(token.substring(0, token.length() - 5), line);
                openBlocks.peek().children.add(block);
                openBlocks.push(block);
                continue;
            }

            if (line.size() == 1 && token.equals(openBlocks.peek().name + "END")) {
                openBlocks.pop();
                continue;
            }

            if (line.size() == 1 && closesOuterBlock(openBlocks, token))
                throw line.error(token + " before " + openBlocks.peek().name + "END (opened at " + openBlocks.peek().location() + ")");

            openBlocks.peek().children.add(line);
        }

        if (openBlocks.size() > 1)
            throw new WpakFormatException(openBlocks.peek().location() + ": " + openBlocks.peek().name + "BEGIN is never closed");

        return root;
    }

    private static boolean closesOuterBlock(ArrayDeque<WpakBlock> openBlocks, String token) {

        for (WpakBlock block : openBlocks)
            if (block.beginLine != null && token.equals(block.name + "END"))
                return true;

        return false;
    }

    // Whitespace separates tokens; double quotes group one token (quotes removed, no escapes).

    private static ArrayList<String> tokenize(String fileName, int lineNumber, String text) {

        ArrayList<String> tokens = new ArrayList<>();
        StringBuilder token = new StringBuilder();
        boolean inToken = false;
        boolean inQuotes = false;
        char c;

        for (int i = 0; i < text.length(); i++) {
            c = text.charAt(i);

            if (inQuotes) {
                if (c == '"') {
                    inQuotes = false;
                    tokens.add(token.toString());
                    token.setLength(0);
                } else
                    token.append(c);
                continue;
            }

            if (c == '"' || c == '#' || Character.isWhitespace(c)) {
                if (inToken) {
                    tokens.add(token.toString());
                    token.setLength(0);
                    inToken = false;
                }

                if (c == '#')
                    break;

                if (c == '"')
                    inQuotes = true;
                continue;
            }

            token.append(c);
            inToken = true;
        }

        if (inQuotes)
            throw new WpakFormatException(fileName + ":" + lineNumber + ": unclosed quote");

        if (inToken)
            tokens.add(token.toString());

        return tokens;
    }
}