package cc.fascinated.bat.service;

import cc.fascinated.bat.command.BatCommand;
import cc.fascinated.bat.command.BatSubCommand;
import cc.fascinated.bat.command.impl.global.beatsaber.scoresaber.LinkSubCommand;
import cc.fascinated.bat.command.impl.global.beatsaber.scoresaber.ScoreSaberCommand;
import cc.fascinated.bat.command.impl.global.beatsaber.scoresaber.UserSubCommand;
import cc.fascinated.bat.common.EmbedUtils;
import cc.fascinated.bat.model.BatGuild;
import cc.fascinated.bat.model.user.BatUser;
import lombok.NonNull;
import lombok.extern.log4j.Log4j2;
import net.dv8tion.jda.api.JDA;
import net.dv8tion.jda.api.entities.Guild;
import net.dv8tion.jda.api.events.interaction.command.SlashCommandInteractionEvent;
import net.dv8tion.jda.api.hooks.ListenerAdapter;
import net.dv8tion.jda.api.interactions.commands.OptionMapping;
import org.jetbrains.annotations.NotNull;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.DependsOn;
import org.springframework.stereotype.Service;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author Fascinated (fascinated7)
 */
@Service @Log4j2
@DependsOn("discordService")
public class CommandService extends ListenerAdapter {
    /**
     * The registered commands
     */
    private final Map<String, BatCommand> commands = new HashMap<>();

    /**
     * The guild service to use
     */
    private final GuildService guildService;

    /**
     * The user service to use
     */
    private final UserService userService;

    /**
     * The application context to use
     */
    private final ApplicationContext context;

    @Autowired
    public CommandService(@NonNull GuildService guildService, @NonNull UserService userService, @NonNull ApplicationContext context) {
        this.guildService = guildService;
        this.userService = userService;
        this.context = context;
        DiscordService.JDA.addEventListener(this);

        // Guild commands
        // todo: add some, duh

        // Global commands
        registerCommand(context.getBean(ScoreSaberCommand.class)
                .addSubCommand("link", context.getBean(LinkSubCommand.class))
                .addSubCommand("user", context.getBean(UserSubCommand.class)
        ));

        registerSlashCommands(); // Register all slash commands
    }

    /**
     * Registers a command
     *
     * @param command The command to register
     */
    public void registerCommand(@NonNull BatCommand command) {
        commands.put(command.getName().toLowerCase(), command);
    }

    /**
     * Registers all slash commands
     */
    public void registerSlashCommands() {
        log.info("Registering all slash commands");
        JDA jda = DiscordService.JDA;
        long before = System.currentTimeMillis();

        // Unregister all commands that Discord has but we don't
        jda.retrieveCommands().complete().forEach(command -> {
            if (commands.containsKey(command.getName())) {
                return;
            }

            jda.deleteCommandById(command.getId()).complete(); // Unregister the command on Discord
            log.info("Unregistered unknown command \"{}\" from Discord", command.getName());
        });

        // Register all commands
        for (BatCommand command : commands.values()) {
            if (command.getCommandData() == null) {
                continue;
            }

            jda.upsertCommand(command.getCommandData()).complete(); // Register the command on Discord
        }
        log.info("Registered all slash commands in {}ms", System.currentTimeMillis() - before);
    }

    @Override
    public void onSlashCommandInteraction(@NotNull SlashCommandInteractionEvent event) {
        Guild discordGuild = event.getGuild();
        if (discordGuild == null) {
            return;
        }
        if (event.getUser().isBot()) {
            return;
        }
        if (event.getMember() == null) {
            return;
        }

        String commandName = event.getName();
        BatCommand command = commands.get(commandName);
        if (command == null) {
            return;
        }

        BatGuild guild = guildService.getGuild(discordGuild.getId());
        BatUser user = userService.getUser(event.getUser().getId());

        // No args provided, use the main command executor
        List<OptionMapping> options = event.getInteraction().getOptions();

        try {
            if (options.isEmpty()) {
                command.execute(guild, user, event.getChannel().asTextChannel(), event.getMember(), event.getInteraction(), null);
            }

            // Check if the sub command exists
            for (Map.Entry<String, BatSubCommand> subCommand : command.getSubCommands().entrySet()) {
                for (OptionMapping option : options) {
                    if (subCommand.getKey().equalsIgnoreCase(option.getName())) {
                        subCommand.getValue().execute(guild, user, event.getChannel().asTextChannel(), event.getMember(), event.getInteraction(), option);
                        break;
                    }
                }
            }
        } catch (Exception ex) {
            log.error("An error occurred while executing command \"{}\"", commandName, ex);
            event.replyEmbeds(EmbedUtils.buildErrorEmbed("An error occurred while executing the command\n\n" +
                    ex.getLocalizedMessage()).build()).queue();
        }
    }
}