// <copyright file="CastleSiegeThroneCaptureTalkPlugIn.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.Linq;
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 registering on the throne at the Sinior (223) / Crown (216) NPCs on Valley of Loren.
/// A registered guild takes the throne only when it has destroyed all castle defenses (gates + statues)
/// AND is holding both Crown Switches (a member standing on each). The guild on the throne when the siege
/// ends becomes the castle owner. Capturing broadcasts a server-wide golden message.
/// </summary>
[Guid("CA5710A0-7A1B-4C2D-8E3F-000000000223")]
[PlugIn]
[Display(Name = "Castle Siege Throne (Sinior/Crown)", Description = "Registers a guild on the throne (Sinior 223 / Crown 216) once defenses are down and both switches held.")]
public class CastleSiegeThroneCaptureTalkPlugIn : IPlayerTalkToNpcPlugIn
{
    private static readonly short[] ThroneNpcNumbers = { 223, 216 };

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

        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 (player.GuildStatus is not { } guildStatus)
        {
            await ShowAsync(player, "Only members of a registered guild can take the throne.").ConfigureAwait(false);
            return;
        }

        var guildName = guildStatus.GuildId.ToString();
        if (player.GameContext is IGameServerContext serverContext)
        {
            var guild = await serverContext.GuildServer.GetGuildAsync(guildStatus.GuildId).ConfigureAwait(false);
            if (guild?.Name is { Length: > 0 } name)
            {
                guildName = name;
            }
        }

        if (!context.RegisteredGuilds.Contains(guildName))
        {
            await ShowAsync(player, "Your guild is not registered for this Castle Siege.").ConfigureAwait(false);
            return;
        }

        // The throne is taken by holding the Crown, not by talking here — give guidance based on the state.
        await ShowAsync(player, DescribeThroneStep(context, guildName)).ConfigureAwait(false);
    }

    private static string DescribeThroneStep(CastleSiegeContext context, string guildName)
    {
        if (context.Phase != CastleSiegePhase.Siege)
        {
            return "The siege is not running yet.";
        }

        if (context.DefensesRemaining > 0)
        {
            return $"Destroy all castle gates first ({context.DefensesRemaining} remaining), then hold both Crown Switches.";
        }

        var eligible = context.GetShieldEligibleGuild();
        if (eligible is null)
        {
            return "All gates are down! Hold BOTH Crown Switches with your guild — the Crown's shield will drop.";
        }

        if (eligible == guildName)
        {
            return "Your guild holds both switches and the shield is down — send your GUILD MASTER to hold the Crown to take the throne!";
        }

        return $"Guild '{eligible}' is holding both switches. Take a switch back to raise their shield.";
    }

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