package cc.fascinated.bat.service;

import cc.fascinated.bat.command.BatCommand;
import cc.fascinated.bat.command.BatCommandExecutor;
import cc.fascinated.bat.command.BatSubCommand;
import cc.fascinated.bat.command.Category;
import cc.fascinated.bat.common.EmbedUtils;
import cc.fascinated.bat.model.BatGuild;
import cc.fascinated.bat.model.BatUser;
import lombok.Getter;
import lombok.NonNull;
import lombok.extern.log4j.Log4j2;
import net.dv8tion.jda.api.JDA;
import net.dv8tion.jda.api.Permission;
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.Command;
import org.jetbrains.annotations.NotNull;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.DependsOn;
import org.springframework.stereotype.Service;

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

/**
 * @author Fascinated (fascinated7)
 */
@Service
@Log4j2 @Getter
@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;

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

    /**
     * Registers a command
     *
     * @param command The command to register
     */
    public void registerCommand(@NonNull BatCommand command) {
        if (commands.get(command.getName().toLowerCase()) != null) {
            return;
        }
        log.info("Registered command \"{}\"", command.getName());
        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
        List<Command> discordCommands = jda.updateCommands().addCommands(commands.values().stream().map(BatCommand::getCommandData).toList()).complete();
        for (Command discordCommand : discordCommands) {
            commands.get(discordCommand.getName()).setCommandSnowflake(discordCommand.getIdLong());
            if (!discordCommand.getSubcommands().isEmpty()) {
                for (Command.Subcommand subCommand : discordCommand.getSubcommands()) {
                    commands.get(discordCommand.getName()).getSubCommands().get(subCommand.getName()).setCommandSnowflake(subCommand.getIdLong());
                }
            }
        }
        log.info("Registered all slash commands in {}ms", System.currentTimeMillis() - before);
    }

    /**
     * Gets commands that are in a specific category
     *
     * @param category The category
     * @return The commands
     */
    public List<BatCommand> getCommandsByCategory(Category category) {
        return commands.values().stream().filter(command -> command.getCategory() == category).toList();
    }

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

        String commandName = event.getName();
        BatCommand command = commands.get(commandName);
        if (command == null) {
            return;
        }
        boolean ranInsideGuild = discordGuild != null;
        BatGuild guild = ranInsideGuild ? guildService.getGuild(discordGuild.getId()) : null;
        BatUser user = userService.getUser(event.getUser().getId());

        try {
            BatCommandExecutor executor = null;
            List<Permission> requiredPermissions = new ArrayList<>();

            // No args provided, use the main command executor
            if (event.getInteraction().getSubcommandName() == null) {
                executor = command;
                requiredPermissions.addAll(command.getRequiredPermissions());
            } else {
                // Subcommand provided, use the subcommand executor
                for (Map.Entry<String, BatSubCommand> subCommand : command.getSubCommands().entrySet()) {
                    if (subCommand.getKey().equalsIgnoreCase(event.getInteraction().getSubcommandName())) {
                        executor = subCommand.getValue();
                        requiredPermissions.addAll(subCommand.getValue().getRequiredPermissions());
                        requiredPermissions.addAll(command.getRequiredPermissions()); // not sure if we'd want this, but it's here for now
                        break;
                    }
                }
            }

            if (executor == null) {
                event.replyEmbeds(EmbedUtils.errorEmbed()
                        .setDescription("Unable to find a command executor the command name ):")
                        .build()).queue();
                return;
            }

            // Check if the user has the required permissions
            if (ranInsideGuild && event.getMember() != null) {
                List<Permission> missingPermissions = new ArrayList<>();
                for (Permission permission : requiredPermissions) {
                    if (!event.getMember().hasPermission(permission)) {
                        missingPermissions.add(permission);
                    }
                }
                if (!missingPermissions.isEmpty()) {
                    event.replyEmbeds(EmbedUtils.errorEmbed()
                                    .setDescription("You are missing the following permissions to execute this command: " + missingPermissions)
                                    .build())
                            .setEphemeral(true)
                            .queue();
                    return;
                }
            }
            log.info("Executing command \"{}\" for user \"{}\"", commandName, user.getDiscordUser().getName());
            executor.execute(guild, user, ranInsideGuild ? event.getChannel().asTextChannel() : event.getChannel().asPrivateChannel(),
                    event.getMember(), event.getInteraction());
        } catch (Exception ex) {
            log.error("An error occurred while executing command \"{}\"", commandName, ex);

            event.replyEmbeds(EmbedUtils.successEmbed()
                            .setDescription("An error occurred while executing the command\n\n" + ex.getLocalizedMessage())
                            .build())
                    .queue();
        }
    }
}