// <copyright file="CastleSiegeGuardsmanTalkPlugIn.cs" company="MUnique">
// Licensed under the MIT License. See LICENSE file in the project root for full license information.
// </copyright>

namespace MUnique.OpenMU.GameLogic.CastleSiege;

using System.Runtime.InteropServices;
using MUnique.OpenMU.GameLogic.NPC;
using MUnique.OpenMU.GameLogic.PlugIns;
using MUnique.OpenMU.GameLogic.PlugIns.PeriodicTasks;
using MUnique.OpenMU.GameLogic.Views;
using MUnique.OpenMU.Interfaces;
using MUnique.OpenMU.PlugIns;

/// <summary>
/// Handles talking to the Castle Siege 'Guardsman' NPC (number 224): registers the talking
/// player's guild for the current siege while the state machine is in the registration phase.
/// P2 first increment — guild marks, entrance fee and minimum-guild requirements come later.
/// </summary>
[Guid("CA5710A0-7A1B-4C2D-8E3F-000000000224")]
[PlugIn]
[Display(Name = "Castle Siege Guardsman", Description = "Registers a guild for the Castle Siege when talking to the Guardsman (NPC 224).")]
public class CastleSiegeGuardsmanTalkPlugIn : IPlayerTalkToNpcPlugIn
{
    /// <summary>Gets the NPC number of the Castle Siege 'Guardsman'.</summary>
    public static short GuardsmanNpcNumber => 224;

    /// <inheritdoc />
    public async ValueTask PlayerTalksToNpcAsync(Player player, NonPlayerCharacter npc, NpcTalkEventArgs eventArgs)
    {
        if (npc.Definition.Number != GuardsmanNpcNumber)
        {
            return;
        }

        // We handle the dialog ourselves (no client-side window), so suppress the default "not implemented" message.
        eventArgs.HasBeenHandled = true;

        var context = CastleSiegeEventPlugIn.TryGetContext(player.GameContext);
        if (context is null)
        {
            await ShowAsync(player, "Castle Siege is not active on this server.").ConfigureAwait(false);
            return;
        }

        if (!CastleSiegeEventPlugIn.IsCastleSiegeServer(player.GameContext))
        {
            await ShowAsync(player, $"The Castle Siege runs on server {context.Configuration.CastleSiegeServerId}. Switch to that server to register and fight.").ConfigureAwait(false);
            return;
        }

        if (context.State != CastleSiegeState.RegisterGuild)
        {
            await ShowAsync(player, "Castle Siege registration is not open right now.").ConfigureAwait(false);
            return;
        }

        if (player.GuildStatus is not { } guildStatus || guildStatus.Position != GuildPosition.GuildMaster)
        {
            await ShowAsync(player, "Only a guild master can register for the Castle Siege.").ConfigureAwait(false);
            return;
        }

        // Registrations are keyed on the guild's persistent id, so a later rename cannot detach them.
        if (await CastleSiegeEventPlugIn.GetPersistentGuildAsync(player).ConfigureAwait(false) is not { } guild)
        {
            await ShowAsync(player, "Your guild could not be resolved. Please try again in a moment.").ConfigureAwait(false);
            return;
        }

        var guildName = guild.Name;
        if (context.IsRegistered(guild.Id))
        {
            await ShowAsync(player, $"Your guild '{guildName}' is already registered for the Castle Siege.").ConfigureAwait(false);
            return;
        }

        var fee = context.Configuration.RegistrationFee;
        if (fee > 0 && !player.TryRemoveMoney(fee))
        {
            await ShowAsync(player, $"You need {fee} zen to register your guild for the Castle Siege.").ConfigureAwait(false);
            return;
        }

        context.RegisterGuild(guild.Id, guildName);
        await ShowAsync(player, fee > 0
            ? $"Your guild '{guildName}' is registered for the Castle Siege. ({fee} zen paid)"
            : $"Your guild '{guildName}' is registered for the Castle Siege.").ConfigureAwait(false);
    }

    private static ValueTask ShowAsync(Player player, string text)
        => player.InvokeViewPlugInAsync<IShowMessagePlugIn>(p => p.ShowMessageAsync(text, MessageType.BlueNormal));
}