package uulm.teamname.marvelous.server;

import com.beust.jcommander.JCommander;
import com.beust.jcommander.ParameterException;
import org.tinylog.Logger;
import org.tinylog.configuration.Configuration;
import uulm.teamname.marvelous.gamelibrary.config.CharacterConfig;
import uulm.teamname.marvelous.gamelibrary.config.FieldType;
import uulm.teamname.marvelous.gamelibrary.config.PartyConfig;
import uulm.teamname.marvelous.gamelibrary.config.ScenarioConfig;
import uulm.teamname.marvelous.gamelibrary.json.JSON;
import uulm.teamname.marvelous.gamelibrary.json.ValidationUtility;
import uulm.teamname.marvelous.server.args.ServerArgs;
import uulm.teamname.marvelous.server.netconnector.MarvelousServer;

import java.io.*;
import java.net.InetSocketAddress;
import java.util.HashMap;
import java.util.Map;

/**
 * The MainClass of the Server application. The main responsibility of this class is to parse command line arguments,
 * set the log level, load the configuration files, and create and manage the threads that make up the server itself.
 * To run the server edit your IntelliJ run config, and enter
 * {@code -c .\configs\marvelheros.character.json -m .\configs\matchconfig_1.game.json
 * -s .\configs\asgard.scenario.json -v} into the arguments field.
 */
public class Server {
    private static PartyConfig partyConfig;
    private static ScenarioConfig scenarioConfig;
    private static CharacterConfig characterConfig;

    private static Integer maxLobbies;

    public static void main(String[] args) {
        ServerArgs serverArgs = new ServerArgs();
        JCommander jc = JCommander.newBuilder().addObject(serverArgs).build();

        try {
            jc.parse(args);
        } catch (ParameterException e) {
            Logger.error("Invalid parameters: {}", e.getMessage());
            System.exit(1);
            return;
        }

        if(serverArgs.isHelp()) {
            jc.usage();
            System.exit(0);
            return;
        }

        maxLobbies = serverArgs.getMaxLobbies();

        if (serverArgs.isVerbose() || serverArgs.isCheckConfig()) {
            // If checkConfig, the LogLevel is also set to max, because more information
            // is exactly what checking the requirements means
            setLogLevel(5);
        } else {
            setLogLevel(serverArgs.getLogLevel());
        }

        ScenarioConfig scenarioConfig = readScenarioConfig(serverArgs.getScenarioConfigFile());
        CharacterConfig characterConfig = readCharacterConfig(serverArgs.getCharacterConfigFile());
        PartyConfig partyConfig = readPartyConfig(serverArgs.getMatchConfigFile());

        // If only configurations should be checked, the server exits here
        if (serverArgs.isCheckConfig()) {
            Logger.info("Exiting as configuration file check is done");
            System.exit(0);
            return;
        }

        Logger.info("populating static Server variables with config objects");
        Server.scenarioConfig = scenarioConfig;
        Server.characterConfig = characterConfig;
        Server.partyConfig = partyConfig;

        InetSocketAddress address = new InetSocketAddress(serverArgs.getPort());
        Logger.trace("Inet address {} created", address);

        Logger.trace("Instantiating MarvelousServer...");
        MarvelousServer netConnector = new MarvelousServer(address);

        Logger.trace("Starting MarvelousServer...");
        netConnector.start();

        Logger.trace("End of Main reached. Exiting main thread.");
    }

    /** Function that sets the log level for {@link Logger Tinylog}.
     * It has to be executed <b>BEFORE ANY LOGGING OPERATIONS</b> .
     */
    private static void setLogLevel(int logLevel) {
        Map<String, String> map = new HashMap<>();

        Configuration.replace(map);

        String logLevelDescriptor = switch (logLevel) {
            case 0  -> "off";
            case 1  -> "error";
            case 2  -> "warn";
            case 3  -> "info";
            case 4  -> "debug";
            case 5  -> "trace";
            default -> "info";
        };

        // Add log writer 1, a console writer (which logs to the console)
        map.put("writer1", "console");
        map.put("writer1.level", logLevelDescriptor);
        map.put("writer1.format", "[{thread}] {level}: {message}");

        // Add log writer 2, a file writer logging to the file server.log
        map.put("writer2", "file");
        map.put("writer2.level", logLevelDescriptor);
        map.put("writer2.file", "./logs/server.log");

        Configuration.replace(map);

        Logger.info("Log level set to '{}'", logLevelDescriptor);
    }


    private static ScenarioConfig readScenarioConfig(File source) {

        if (!source.exists()) {
            Logger.error("Scenario Configuration file not found. Exiting...");
            System.exit(1);
        }
        var config = JSON.parseScenarioConfig(source);
        if (config.isEmpty()) {
            Logger.error("Scenario Configuration couldn't be parsed. Exiting...");
            System.exit(1);
        }

        Logger.trace("Validating configuration file...");

        var violations = ValidationUtility.validate(config.get());

        if (violations.isPresent()) {
            Logger.error("Scenario Configuration vas invalid: {}", violations.get());
            System.exit(1);
        }

        int grassFields = 0;

        for (FieldType[] row: config.get().scenario) {
            for (FieldType type: row) {
                if (type == FieldType.GRASS) grassFields++;
            }
            if (grassFields > 18) break;
        }

        if (grassFields <= 18) {
            Logger.error(
                    "Scenario Configuration vas invalid: Only {} grass fields found, which is less than 18"
                    , grassFields);
            System.exit(1);
        }

        Logger.info("Scenario Config file loaded");

        return config.get();
    }


    private static CharacterConfig readCharacterConfig(File source) {

        if (!source.exists()) {
            Logger.error("Character Configuration file not found. Exiting...");
            System.exit(1);
        }
        var config = JSON.parseCharacterConfig(source);
        if (config.isEmpty()) {
            Logger.error("Character Configuration couldn't be parsed. Exiting...");
            System.exit(1);
        }

        var violations = ValidationUtility.validate(config.get());

        if (violations.isPresent()) {
            Logger.error("Scenario Configuration vas invalid: {}", violations.get());
            System.exit(1);
        }

        Logger.info("Character Config file loaded");

        return config.get();
    }


    private static PartyConfig readPartyConfig(File source) {

        if (!source.exists()) {
            Logger.error("Party Configuration file not found. Exiting...");
            System.exit(1);
        }
        var config = JSON.parsePartyConfig(source);
        if (config.isEmpty()) {
            Logger.error("Party Configuration couldn't be parsed. Exiting...");
            System.exit(1);
        }


        var violations = ValidationUtility.validate(config.get());

        if (violations.isPresent()) {
            Logger.error("Party Configuration vas invalid: {}", violations.get());
            System.exit(1);
        }

        Logger.info("Party Config file loaded");

        return config.get();
    }


    /** Returns the party configuration the server was initialized with */
    public static PartyConfig getPartyConfig() {
        return partyConfig;
    }

    /** Returns the scenario configuration the server was initialized with */
    public static ScenarioConfig getScenarioConfig() {
        return scenarioConfig;
    }

    /** Returns the character configuration the server was initialized with */
    public static CharacterConfig getCharacterConfig() {
        return characterConfig;
    }

    /** Returns the maximum amount of lobbies the server should create */
    public static Integer getMaxLobbies() {
        return maxLobbies;
    }
}