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

namespace MUnique.OpenMU.GameLogic.PlugIns.ChatCommands;

using System.Globalization;
using System.Linq;
using System.Runtime.InteropServices;
using MUnique.OpenMU.GameLogic.CastleSiege;
using MUnique.OpenMU.GameLogic.PlugIns.PeriodicTasks;
using MUnique.OpenMU.GameLogic.Views;
using MUnique.OpenMU.Interfaces;
using MUnique.OpenMU.PlugIns;

/// <summary>
/// Sets the Castle Siege weekly auto-schedule. GM only. Times are UTC.
/// Usage: <c>/csschedule</c> (show) | <c>/csschedule Sunday 20:00</c> | <c>/csschedule Sunday,Wednesday 20:00</c> | <c>/csschedule clear</c>.
/// </summary>
[Guid("A1B2C3D4-0006-4E5F-9A0B-CA5710000006")]
[PlugIn]
[Display(Name = "Castle Siege Schedule", Description = "GM command: /csschedule [<days> <HH:mm UTC> | clear]")]
[ChatCommandHelp(Command, CharacterStatus.GameMaster)]
public class CastleSiegeScheduleChatCommandPlugIn : IChatCommandPlugIn
{
    private const string Command = "/csschedule";

    /// <inheritdoc />
    public string Key => Command;

    /// <inheritdoc/>
    public CharacterStatus MinCharacterStatusRequirement => CharacterStatus.GameMaster;

    /// <inheritdoc />
    public async ValueTask HandleCommandAsync(Player player, string command)
    {
        var context = CastleSiegeEventPlugIn.TryGetContext(player.GameContext);
        if (context is null)
        {
            await ShowAsync(player, "Castle Siege plugin not active.").ConfigureAwait(false);
            return;
        }

        var parts = command.Split(' ', StringSplitOptions.RemoveEmptyEntries);

        // "/csschedule" -> show current schedule.
        if (parts.Length == 1)
        {
            await ShowAsync(player, Describe(context)).ConfigureAwait(false);
            return;
        }

        // "/csschedule clear" -> disable auto-start.
        if (parts.Length == 2 && string.Equals(parts[1], "clear", StringComparison.OrdinalIgnoreCase))
        {
            context.SetSchedule(Array.Empty<DayOfWeek>(), null);
            await ShowAsync(player, "Castle Siege auto-schedule cleared (manual start only).").ConfigureAwait(false);
            return;
        }

        if (parts.Length < 3)
        {
            await ShowAsync(player, "Usage: /csschedule <day[,day...]> <HH:mm UTC>  |  /csschedule clear").ConfigureAwait(false);
            return;
        }

        var days = new List<DayOfWeek>();
        foreach (var token in parts[1].Split(',', StringSplitOptions.RemoveEmptyEntries))
        {
            if (!Enum.TryParse<DayOfWeek>(token, true, out var day))
            {
                await ShowAsync(player, $"Unknown day '{token}'. Use e.g. Sunday, Monday, Tuesday...").ConfigureAwait(false);
                return;
            }

            days.Add(day);
        }

        if (!TimeOnly.TryParse(parts[2], CultureInfo.InvariantCulture, out var time))
        {
            await ShowAsync(player, $"Invalid time '{parts[2]}'. Use 24h HH:mm (UTC).").ConfigureAwait(false);
            return;
        }

        context.SetSchedule(days, time);
        await ShowAsync(player, $"{Describe(context)} Server UTC now: {DateTime.UtcNow:ddd HH:mm}.").ConfigureAwait(false);
    }

    private static string Describe(CastleSiegeContext context)
    {
        var config = context.Configuration;
        if (config.RegistrationOpenTimes.Count == 0)
        {
            return "Castle Siege auto-schedule: (none). Set with /csschedule <days> <HH:mm UTC>.";
        }

        var days = config.RegistrationOpenDays.Count > 0 ? string.Join(",", config.RegistrationOpenDays) : "every day";
        var times = string.Join(",", config.RegistrationOpenTimes.Select(t => t.ToString("HH\\:mm")));
        return $"Castle Siege auto-schedule: {days} at {times} UTC (reg {config.RegistrationDuration:g} -> prep {config.PreparationDuration:g} -> war {config.SiegeDuration:g}).";
    }

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