package Modules;

import Controll.GuildController;
import Controll.SuperModule;
import net.dv8tion.jda.api.EmbedBuilder;
import net.dv8tion.jda.api.entities.Message;
import net.dv8tion.jda.api.events.GenericEvent;
import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
import org.joda.time.DateTime;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.*;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Fold extends SuperModule{

    private final Logger logger = LoggerFactory.getLogger(Fold.class);
    public static final String COMMAND = "fold";

    private static final int BYTE_LIMIT = 16 * 1024;
    private static final int MAX_MESSAGE_LIMIT = 10;

    private static final String     teamSummary = "https://apps.foldingathome.org/daily_team_summary.txt",
                                    userSummary = "https://apps.foldingathome.org/daily_user_summary.txt";

    private String  teamFile = "/home/bots/MissingIdentifier/MissingIdent/team_summary.txt",
                    userFile = "/home/bots/MissingIdentifier/MissingIdent/user_summary.txt";

    public Fold(GuildController guildController){
        super(COMMAND, guildController, null);
    }

    @Override
    public String getCommand() {
        return Fold.COMMAND;
    }

    @Override
    public String getDescription() {
        return "Get statistics for a team that partakes in https://foldingathome.org\n`fold -t TEAMNAME` teamname to be filtered\n`fold -u update` update statistics";
    }

    @Override
    public void execute(GenericEvent genericEvent) {
        if (!(genericEvent instanceof GuildMessageReceivedEvent)) return;

        GuildMessageReceivedEvent event = (GuildMessageReceivedEvent) genericEvent;

        if (!isCommand(event.getMessage()))
            return;

        logger.debug("Fold command triggered");

        //VARS
        Pattern teamPattern, userPattern;
        Message msg = event.getChannel().sendMessage("Got it!").complete();
        String teamInfo = null;

        // Update Locale Files if parameter "u" is given
        if (getParameter(event.getMessage().getContentRaw(), "u") != null)
            msg = update(event, msg);

        // Generate Pattern to look for decide if looking for ID or Name of Team fall back is null and will cause an error
        if (getParameter(event.getMessage().getContentRaw(), "t") != null) {
            String input = getParameter(event.getMessage().getContentRaw(), "t");
            logger.info("looking for team: " + input);
            teamPattern = Pattern.compile("(?m)^[0-9]+\\t" + input + "\\t[0-9]+\\t[0-9]+$");
        } else if (getParameter(event.getMessage().getContentRaw(), "id") != null) {
            String input = getParameter(event.getMessage().getContentRaw(), "id");
            logger.info("looking for team: " + input);
            teamPattern = Pattern.compile("(?m)^" + input + "\\t[^\\t]*\\t[0-9]+\\t[0-9]+$");
        } else
            return; // TODO error handling


        //LOOK for Team
        try (BufferedReader teamReader = Files.newBufferedReader(Paths.get(teamFile))) {

            teamInfo = teamReader.readLine();
            while (teamInfo != null) {
                Matcher teamMatcher = teamPattern.matcher(teamInfo);
                if (teamMatcher.find()) {
                    // Send quick info
                    msg = msg.editMessage(teamMatcher.group()).complete();
                    break;
                }
                teamInfo = teamReader.readLine();
            }
        } catch (IOException e) {
            logger.error(e.toString());
        }

        if (teamInfo == null) {
            msg.editMessage("No team with this Identifier found!").queue();
            return;
        }

        // Look for users
        try (BufferedReader userReader = Files.newBufferedReader(Paths.get(userFile))) {

            // Like skringbuilder only for embeded messages
            EmbedBuilder eb = new EmbedBuilder();

            // Add Team info
            eb.setTitle(teamInfo.split("\t")[1] + " [ " + teamInfo.split("\t")[0] + " ]");       // Team Name
            eb.setDescription("Work Units done:\t" + teamInfo.split("\t")[3] + "\n" +
                    "Total Score:\t\t" + teamInfo.split("\t")[2]);              // WUs and Score
            eb.setTimestamp(new DateTime().toDate().toInstant());

            userPattern = Pattern.compile("(?m)^[0-9a-zA-Z_]+\\t[0-9]+\\t[0-9]+\\t" + teamInfo.split("\t")[0] + "$");
            String userInfo = userReader.readLine();

            long userPosition = 0;
            int messageCount = 0;
            msg = msg.editMessage(teamInfo + "\n\nread 0 lines").complete();

            while (userInfo != null) {
                userPosition++;
                Matcher userMatcher = userPattern.matcher(userInfo);
                if (userMatcher.find()) {
                    eb.addField(userInfo.split("\t")[0], "Work Units:\t" + userInfo.split("\t")[2] + "\n" +
                            "Score:\t\t" + userInfo.split("\t")[1], true);

                    //msg = msg.editMessage(teamInfo + "\n\nread " + userPosition + " lines").complete();
                    // IF mesage is to long, rmeove last entry and split output
                    if (!eb.isValidLength()){
                        eb.getFields().remove(eb.getFields().size()-1);
                        msg.getChannel().sendMessage(eb.build()).complete();

                        eb = new EmbedBuilder();
                        messageCount++;

                        if(messageCount > MAX_MESSAGE_LIMIT){
                            msg.getChannel().sendMessage("To many entries! aborted to prevent spam!").queue();
                            return;
                        }

                        eb.addField(userInfo.split("\t")[0], "Work Units:\t" + userInfo.split("\t")[2] + "\n" +
                                "Score:\t\t" + userInfo.split("\t")[1], true);

                    }
                }

                if (userPosition % 250000 == 0)
                    msg = msg.editMessage(teamInfo + "\n\nread " + userPosition + " lines").complete();

                userInfo = userReader.readLine();
            }

            //Send final result
            msg.getChannel().sendMessage(eb.build()).complete();
            msg.delete().queue();
        } catch (IOException e) {
            logger.error(e.toString());
        }
    }

    private Message update(GuildMessageReceivedEvent event, Message msg) {
        if(!checkForAdmin(event.getMember()))
        {
            // if the user that calls this function is not admin, here should be an interval check that interrupts if the files have recently been updated to mitigate abuse.
            // admins should of course be able to call this any time.
            // the date of the current files can be read from the first line of each file and needs to be parsed.
            return msg; // if it's not done by an admin, just cancel out
        }

        logger.debug("Get new Statistic from Server");

        TrustManager[] trustAllCerts = new TrustManager[]{
                new X509TrustManager() {
                    public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                        return null;
                    }
                    public void checkClientTrusted(
                            java.security.cert.X509Certificate[] certs, String authType) {
                    }
                    public void checkServerTrusted(
                            java.security.cert.X509Certificate[] certs, String authType) {
                    }
                }
        };

        // Activate the new trust manager
        try {
            SSLContext sc = SSLContext.getInstance("SSL");
            sc.init(null, trustAllCerts, new java.security.SecureRandom());
            HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
        } catch (Exception e) {
            logger.error(e.toString());
        }

        byte buffer[] = new byte[BYTE_LIMIT];
        int bytesRead;

        try(
            BufferedOutputStream teamOutput = new BufferedOutputStream(new FileOutputStream(teamFile, false));
            BufferedInputStream teamInput = new BufferedInputStream(new URL(teamSummary).openStream())
        ) {
            long i = 0;
            while((bytesRead = teamInput.read(buffer, 0, BYTE_LIMIT)) != -1){
                teamOutput.write(buffer, 0, bytesRead);

                i+=bytesRead;

                if (i % 50000 <= 200)
                    msg = msg.editMessage("Updating Teamstats, processed " + i + " Bytes").complete();

            }

            teamOutput.flush();
        } catch (IOException e) {
            logger.error(e.toString());
        }

        try(
            BufferedOutputStream userOutput = new BufferedOutputStream(new FileOutputStream(userFile, false));
            BufferedInputStream userInput = new BufferedInputStream(new URL(userSummary).openStream())
        ){
            long i = 0;
            while((bytesRead = userInput.read(buffer, 0, BYTE_LIMIT)) != -1){
                userOutput.write(buffer, 0, bytesRead);

                i+=bytesRead;

                if (i % 50000 <= 200)
                    msg = msg.editMessage("Updating Userstats, processed " + i + " Bytes").complete();
            }

            userOutput.flush();
        } catch (IOException e) {
            logger.error(e.toString());
        }

        return msg.editMessage("done!").complete();

    }

    @Override
    public String showSettings() {
        return null;
    }
}