import java.io.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Logger;

public class Merge {

    private static final Logger log = Logger.getLogger(Merge.class.getName());
    private static final File ROOT_FOLDER = new File(System.getProperty("user.home") + (System.getProperty("os.name").contains("Windows") ? "/AppData/Roaming/X-Chat 2/xchatlogs" : "/.xchat2/xchatlogs"));
    private static final HashMap<String, File[]> files = new HashMap<String, File[]>();
    private static final HashMap<File, File[]> filesToWrite = new HashMap<File, File[]>();

    public static void main(String... args) {
        long startTime = System.currentTimeMillis();
        if (ROOT_FOLDER.exists()) {
            for (final File f : ROOT_FOLDER.listFiles()) {
                if (f.isDirectory() && f.getName().contains("System")) { //mandatory check
                    for (final File sub : f.listFiles()) {
                        String channelName = (!sub.getName().contains("#") ? "privmsg-" : "") + sub.getName().split("-")[1].replaceAll(".log", "");
                        if (files.containsKey(channelName)) {
                            ArrayList<File> tempFiles = new ArrayList<File>();
                            for (File t : files.get(channelName)) {
                                tempFiles.add(t);
                            }
                            tempFiles.add(sub);
                            File[] array = new File[tempFiles.size()];
                            array = tempFiles.toArray(array);
                            files.put(channelName, array);
                        } else {
                            files.put(channelName, new File[]{sub});
                        }
                    }
                }
            }
        } else {
            log.info("No log folder detected.");
        }
        String channel;
        File f;
        for (Map.Entry<String, File[]> es : files.entrySet()) {
            channel = es.getKey();
            f = new File(ROOT_FOLDER.getAbsolutePath() + "/merged-" + channel + ".log");
            try {
                if (f.exists()) {
                    if (f.delete()) {
                        f.createNewFile();
                    }
                }
            } catch (IOException ioe) {
                ioe.printStackTrace();
            }
            filesToWrite.put(f, es.getValue());
        }
        try {
            BufferedWriter bw;
            for (Map.Entry<File, File[]> entry : filesToWrite.entrySet()) {
                bw = new BufferedWriter(new FileWriter(entry.getKey()));
                for (File read : entry.getValue()) {
                    bw.write(readFile(read.getAbsolutePath()));
                }
                bw.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        System.out.println("That took " + (System.currentTimeMillis() - startTime) + " ms.");
    }

    private static String readFile(String path) throws IOException {
        FileInputStream fstream = new FileInputStream(path);
        DataInputStream in = new DataInputStream(fstream);
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        String strLine;
        StringBuilder sb = new StringBuilder();
        while ((strLine = br.readLine()) != null) {
            if (!strLine.contains("**** LOGGEN") && !strLine.contains("**** LOGGING") && !strLine.equals("")) {
                sb.append(strLine).append("\n");
            }
        }
        br.close();
        in.close();
        fstream.close();
        return sb.toString();
    }
}