package nl.sbdeveloper.themeparkplus.util;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;
import org.bukkit.plugin.java.JavaPlugin;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * License class for SBDevelopment
 *
 * v1.6 - Changed on 06-08-2020
 *
 * @author Stijn [SBDeveloper]
 * @since 23-12-2019
 */
public class License implements Listener {
    /*
     This file is part of ThemeParkRidecountAddon.
     Copyright (c) 2018-2020 SBDevelopment - All Rights Reserved
     Unauthorized copying of this file, via any medium is strictly prohibited
     Proprietary and confidential
     Written by Stijn Bannink <stijnbannink23@gmail.com>, January 2020
    */

    private JavaPlugin plugin; // The plugin instance
    private String license; // The license code
    private String prefix; // The correct prefix for this plugin
    @Nullable private String invalidReason; // The reason the license is invalid, if null it's not invalid!
    @Nullable private static Boolean valid; // If true, it's valid, if false, it's not valid, if null it's not checked!

    /**
     * Construct a new license
     *  @param plugin The Main class [Javaplugin]
     * @param prefix The prefix, like TPP or AF
     * @param license The license from the config
     */
    public License(JavaPlugin plugin, String prefix, String license) {
        this.prefix = prefix;
        this.plugin = plugin;
        this.license = license;

        Bukkit.getPluginManager().registerEvents(this, plugin);

        validateLicense();
    }

    @EventHandler
    public void onJoin(PlayerJoinEvent e) {
        if (this.invalidReason == null) return;

        Player p = e.getPlayer();
        if (p.isOp() || p.hasPermission("sbd.licensemessages")) {
            Bukkit.getScheduler().runTaskLater(this.plugin, () -> p.sendMessage(ChatColor.GOLD + "[" + ChatColor.RED + this.plugin.getName() + ChatColor.GOLD + "] " + ChatColor.RED + "The license is incorrect! Reason: " + ChatColor.GOLD + this.invalidReason), 3 * 20L /* 3 sec */);
        }
    }

    /**
     * Check a license
     *
     */
    private void validateLicense() {
        //STEP 1: Check prefix
        if (!this.license.split("-")[0].contains(this.prefix)) {
            disable("You used the wrong license for this product.");
            return;
        }

        //STEP 2: Send license request
        String url = "https://sbdplugins.nl/wp-json/lmfwc/v2/licenses/" + this.license;
        @Nullable JsonObject response;
        try {
            response = sendGETRequestJSON(url);
        } catch (IOException e) {
            disable("Couldn't send the request.");
            return;
        }

        if (response == null) {
            disable("Couldn't send the request.");
            return;
        }

        JsonObject dataObject = response.get("data").getAsJsonObject();

        //STEP 3: Check status
        switch(dataObject.get("status").getAsString()) {
            case "2":
                //Delivered -> Try to activate (double check timesActivated)
                break;
            case "3":
                //Activated!
                break;
            default:
                disable("Your license has a wrong status.");
                return;
        }

        //STEP 4: Check times activated, and if not activated, activate.
        if (dataObject.get("timesActivated").isJsonNull() || dataObject.get("timesActivated").getAsString().equalsIgnoreCase("0")) {
            activate();
            return;
        }

        //STEP 5: Check expire date
        if (dataObject.get("expiresAt").isJsonNull()) {
            disable("Your license has no expire date.");
            return;
        }

        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date date;
        try {
            date = format.parse(dataObject.get("expiresAt").getAsString());
        } catch (ParseException e) {
            e.printStackTrace();
            disable("Your license has a wrong expire date.");
            return;
        }

        if (date == null) {
            disable("Your license has a wrong expire date.");
            return;
        }

        if (!(date.after(new Date()))) {
            disable("Your license has expired.");
            return;
        }

        //STEP 6: Check IP and port.
        if (!dataObject.get("ipcheck").getAsBoolean()) {
            disable("Your license has been used with another IP. Update it in our Discord.");
            return;
        }

        if (dataObject.get("port").isJsonNull()) {
            disable("Your license has no port.");
            return;
        }

        String por = dataObject.get("port").getAsString();
        if (!checkPortValue(Bukkit.getServer().getPort(), por)) {
            disable("Your license has been used with another Port. Update it in our Discord.");
            return;
        }

        valid = true;
    }

    /**
     * Activate the license
     *
     */
    private void activate() {
        //STEP 1: Send license activate request
        String url = "https://sbdplugins.nl/wp-json/lmfwc/v2/licenses/activate/" + this.license + "?port=" + Bukkit.getServer().getPort();
        @Nullable JsonObject response;
        try {
            response = sendGETRequestJSON(url);
        } catch (IOException e) {
            disable("Couldn't send the activate request.");
            return;
        }

        if (response == null) {
            disable("Couldn't send the activate request.");
            return;
        }

        JsonObject dataObject = response.get("data").getAsJsonObject();

        //STEP 2: Check status
        switch(dataObject.get("status").getAsString()) {
            case "2":
                //Delivered -> STILL NOT ACTIVATED?! -> Double check
                break;
            case "3":
                //Activated!
                break;
            default:
                disable("Your license has a wrong status.");
                return;
        }

        //STEP 3: Check times activated, and if still not activated, disable.
        if (dataObject.get("timesActivated").isJsonNull() || dataObject.get("timesActivated").getAsString().equalsIgnoreCase("0")) {
            disable("Couldn't activate the license.");
        }
    }

    /**
     * Disable the plugin (private)
     *
     * @param reason The disabling reason
     */
    private void disable(String reason) {
        this.invalidReason = reason;

        Bukkit.getScheduler().runTask(this.plugin, () -> {
            valid = false;

            Bukkit.getLogger().severe("[" + this.plugin.getName() + "] Stopping plugin because licensing system check failed.");
            Bukkit.getLogger().severe("[" + this.plugin.getName() + "] Reason: " + reason);
            Bukkit.getLogger().severe("[" + this.plugin.getName() + "] Contact the developer if you believe something is wrong on their side.");
            Bukkit.getPluginManager().disablePlugin(this.plugin);
        });
    }

    /**
     * Send an GET request with JSONObject response
     *
     * @param uri The URL
     *
     * @return The JSONObject
     * @throws IOException URL errors
     */
    @Nullable
    private JsonObject sendGETRequestJSON(String uri) throws IOException {
        URL url = new URL(uri);
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.setRequestMethod("GET");
        con.setRequestProperty("User-Agent", "Mozilla/5.0");
        String authStringEnc = "Y2tfMGEzNWEzMWE2NzExNmM3NDg2MGEwYTJhNjUxNGVjZjM4NTBmM2JmMDpjc185NmYxZGNlYjI4MWRkZDExOTBjMzQ3ZjJjYzMwMGNjZTIzYWNhODI1";
        con.setRequestProperty("Authorization", "Basic " + authStringEnc);
        int code = con.getResponseCode();
        if (code == 404) {
            disable("404_error");
            return null;
        }
        BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuilder response = new StringBuilder();
        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();

        JsonParser parser = new JsonParser();
        return parser.parse(response.toString()).getAsJsonObject();
    }

    private boolean checkPortValue(int input, @NotNull String dataValue) {
        //STEP 1: Check wildcard
        if (dataValue.equals("*")) return true;

        //STEP 2: Check if equals
        try {
            int dataVal = Integer.parseInt(dataValue);

            return input == dataVal;
        } catch (NumberFormatException ignored) {}

        //STEP 3: Check if range
        if (dataValue.contains("-")) {
            String[] dataSplit = dataValue.split("-");

            //STEP 3.1: Check if min or max is wildcard
            if (dataSplit[0].equals("*") && !dataSplit[1].equals("*")) {
                int max = Integer.parseInt(dataSplit[1]);
                return input <= max;
            } else if (dataSplit[1].equals("*") && !dataSplit[0].equals("*")) {
                int min = Integer.parseInt(dataSplit[0]);
                return min <= input;
            } else {
                try {
                    int min = Integer.parseInt(dataSplit[0]);
                    int max = Integer.parseInt(dataSplit[1]);

                    return (min <= input) && (input <= max);
                } catch (NumberFormatException ex) {
                    return false;
                }
            }
        }

        //Else, invalid value
        return false;
    }

    /**
     * Check if the license is valid
     *
     * @return true -> VALID, false -> INVALID, null -> UNCHECKED
     */
    @Nullable
    public static Boolean isValid() {
        return valid;
    }
}