package cc.fascinated.bat.service;

import cc.fascinated.bat.common.TimerUtils;
import cc.fascinated.bat.event.EventListener;
import cc.fascinated.bat.model.BatGuild;
import cc.fascinated.bat.premium.PremiumProfile;
import com.mongodb.client.model.Filters;
import lombok.Getter;
import lombok.NonNull;
import lombok.extern.log4j.Log4j2;
import net.dv8tion.jda.api.events.guild.GuildJoinEvent;
import net.dv8tion.jda.api.events.guild.GuildLeaveEvent;
import net.dv8tion.jda.api.hooks.ListenerAdapter;
import org.bson.Document;
import org.jetbrains.annotations.NotNull;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.DependsOn;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;

/**
 * @author Fascinated (fascinated7)
 */
@Service
@Log4j2(topic = "Guild Service")
@Getter
@DependsOn({"discordService", "mongoService"})
public class GuildService extends ListenerAdapter implements EventListener {
    private static final long SAVE_INTERVAL = TimeUnit.MINUTES.toMillis(5);

    /**
     * The cached guilds
     */
    private final Map<String, BatGuild> guilds = new HashMap<>();

    @Autowired
    public GuildService() {
        TimerUtils.scheduleRepeating(() -> {
            long before = System.currentTimeMillis();
            for (BatGuild guild : guilds.values()) {
                guild.save();
            }
            log.info("Saved {} guilds in {}ms", guilds.size(), System.currentTimeMillis() - before);
        }, SAVE_INTERVAL, SAVE_INTERVAL);

        DiscordService.JDA.addEventListener(this);
    }

    /**
     * Validates the premium status of all guilds
     * <p>
     * This method is scheduled to run every day at midnight
     * </p>
     */
    @Scheduled(cron = "0 0 0 * * *")
    private void validatePremiumStatus() {
        for (BatGuild guild : guilds.values()) {
            PremiumProfile premium = guild.getPremiumProfile();
            if (!premium.hasExpired()) {
                return;
            }
            premium.removePremium();
            log.info("Removed premium status from guild \"{}\"", guild.getName());
        }
    }

    /**
     * Gets a guild by its ID
     *
     * @param id The ID of the guild
     * @return The guild
     */
    public BatGuild getGuild(@NonNull String id) {
        long before = System.currentTimeMillis();
        // Guild is cached
        if (guilds.containsKey(id)) {
            return guilds.get(id);
        }
        if (DiscordService.JDA.getGuildById(id) == null) {
            log.warn("Attempted to get guild with ID \"{}\" but it does not exist", id);
            return null;
        }
        // Guild is not cached
        Document document = MongoService.INSTANCE.getGuildsCollection().find(Filters.eq("_id", id)).first();
        if (document != null) {
            BatGuild guild = new BatGuild(id, document);
            guilds.put(id, guild);
            log.info("Loaded guild \"{}\" in {}ms", guild.getName(), System.currentTimeMillis() - before);
            return guild;
        }
        // New guild
        BatGuild guild = new BatGuild(id, new Document());
        guilds.put(id, guild);
        log.info("Created guild \"{}\" - \"{}\"", guild.getName(), guild.getId());
        return guild;
    }

    @Override
    public final void onGuildJoin(GuildJoinEvent event) {
        BatGuild guild = getGuild(event.getGuild().getId());
        log.info("Joined guild \"{}\"", guild.getName());
    }

    @Override
    public void onGuildLeave(@NotNull GuildLeaveEvent event) {
        BatGuild guild = getGuild(event.getGuild().getId());
        log.info("Left guild \"{}\"", guild.getName());
        guild.save();
        guilds.remove(guild.getId());
    }

    @Override
    public void onSpringShutdown() {
        log.info("Saving all guilds before shutdown...");
        for (BatGuild guild : guilds.values()) {
            guild.save();
        }
        log.info("Saved all guilds.");
    }
}