TIOFormatter.java

package com.gmail.socraticphoenix.bill;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.zip.Deflater;

public class TioFormatter {
    public static final Deflater DEFLATER = new Deflater();
    private URL url;

    public TioFormatter() {
        try {
            this.url = new URL("https://tio.run/cgi-bin/run/api/");
        } catch (MalformedURLException e) {
            throw new IllegalStateException(e);
        }
    }

    private String lang;
    private String code;
    private String input;

    private String[] compFlags;
    private String[] cmdOpts;
    private String[] args;

    public TioFormatter setLang(String lang) {
        this.lang = lang;
        return this;
    }

    public TioFormatter setCode(String code) {
        this.code = code;
        return this;
    }

    public TioFormatter setInput(String input) {
        this.input = input;
        return this;
    }

    public TioFormatter setCompFlags(String... compFlags) {
        this.compFlags = compFlags;
        return this;
    }

    public TioFormatter setCmdOpts(String... cmdOpts) {
        this.cmdOpts = cmdOpts;
        return this;
    }

    public TioFormatter setArgs(String... args) {
        this.args = args;
        return this;
    }

    public byte[] format() {
        ByteArrayOutputStream cache = new ByteArrayOutputStream();
        try {
            writeVariable(cache, "lang", this.lang);
            writeVariable(cache, "args", this.args);
            writeVariable(cache, "TIO_CFLAGS", this.compFlags);
            writeVariable(cache, "TIO_OPTIONS", this.cmdOpts);

            writeFile(cache, ".code.tio", this.code.getBytes(StandardCharsets.UTF_8));
            writeFile(cache, ".input.tio", this.code.getBytes(StandardCharsets.UTF_8));

            return cache.toByteArray();
        } catch (IOException e) {
            throw new IllegalStateException("ByteArrayOutputStream threw IOException", e);
        }
    }

    private void writeVariable(ByteArrayOutputStream cache, String name, String... values) throws IOException {
        if (values.length > 0) {
            cache.write(("V" + name).getBytes(StandardCharsets.UTF_8));
            cache.write(0);
            cache.write(values.length);
            for (String v : values) {
                cache.write(v.getBytes(StandardCharsets.UTF_8));
                cache.write(0);
            }
        }
    }

    private void writeFile(ByteArrayOutputStream cache, String name, byte[] file) throws IOException {
        cache.write(("F" + name).getBytes(StandardCharsets.UTF_8));
        cache.write(0);
        cache.write(file.length);
        cache.write(file);
    }

}