using System;
using System.Collections.Generic;
using System.Text;
using Server.Gumps;
using Server.Items;
using Server.Network;
using Server.Prompts;

namespace Server.Mobiles
{
    public interface ITownCrierEntryList
    {
        List<TownCrierEntry> Entries { get; }
        TownCrierEntry GetRandomEntry();
        TownCrierEntry AddEntry(string[] lines, TimeSpan duration);
        void RemoveEntry(TownCrierEntry entry);
    }

    public class GlobalTownCrierEntryList : ITownCrierEntryList
    {
        private static GlobalTownCrierEntryList m_Instance;

        public static GlobalTownCrierEntryList Instance => m_Instance ??= new GlobalTownCrierEntryList();

        public bool IsEmpty => Entries == null || Entries.Count == 0;

        public List<TownCrierEntry> Entries { get; private set; }

        public TownCrierEntry GetRandomEntry()
        {
            if (Entries == null || Entries.Count == 0)
            {
                return null;
            }

            for (var i = Entries.Count - 1; Entries != null && i >= 0; --i)
            {
                if (i >= Entries.Count)
                {
                    continue;
                }

                var tce = Entries[i];

                if (tce.Expired)
                {
                    RemoveEntry(tce);
                }
            }

            return Entries?.RandomElement();
        }

        public TownCrierEntry AddEntry(string[] lines, TimeSpan duration)
        {
            Entries ??= new List<TownCrierEntry>();

            var tce = new TownCrierEntry(lines, duration);

            Entries.Add(tce);

            var instances = TownCrier.Instances;

            for (var i = 0; i < instances.Count; ++i)
            {
                instances[i].ForceBeginAutoShout();
            }

            return tce;
        }

        public void RemoveEntry(TownCrierEntry tce)
        {
            if (Entries == null)
            {
                return;
            }

            Entries.Remove(tce);

            if (Entries.Count == 0)
            {
                Entries = null;
            }
        }

        public static void Initialize()
        {
            CommandSystem.Register("TownCriers", AccessLevel.GameMaster, TownCriers_OnCommand);
        }

        [Usage("TownCriers"), Description("Manages the global town crier list.")]
        public static void TownCriers_OnCommand(CommandEventArgs e)
        {
            e.Mobile.SendGump(new TownCrierGump(e.Mobile, Instance));
        }
    }

    public class TownCrierEntry
    {
        public TownCrierEntry(string[] lines, TimeSpan duration)
        {
            Lines = lines;

            ExpireTime = Core.Now + duration.Clamp(TimeSpan.Zero, TimeSpan.FromDays(365));
        }

        public string[] Lines { get; }

        public DateTime ExpireTime { get; }

        public bool Expired => Core.Now >= ExpireTime;
    }

    public class TownCrierDurationPrompt : Prompt
    {
        private readonly ITownCrierEntryList m_Owner;

        public TownCrierDurationPrompt(ITownCrierEntryList owner) => m_Owner = owner;

        public override void OnResponse(Mobile from, string text)
        {
            if (!TimeSpan.TryParse(text, out var ts))
            {
                from.SendMessage("Value was not properly formatted. Use: <hours:minutes:seconds>");
                from.SendGump(new TownCrierGump(from, m_Owner));
                return;
            }

            if (ts < TimeSpan.Zero)
            {
                ts = TimeSpan.Zero;
            }

            from.SendMessage("Duration set to: {0}", ts);
            from.SendMessage("Enter the first line to shout:");

            from.Prompt = new TownCrierLinesPrompt(m_Owner, null, new List<string>(), ts);
        }

        public override void OnCancel(Mobile from)
        {
            from.SendLocalizedMessage(502980); // Message entry cancelled.
            from.SendGump(new TownCrierGump(from, m_Owner));
        }
    }

    public class TownCrierLinesPrompt : Prompt
    {
        private readonly TimeSpan m_Duration;
        private readonly TownCrierEntry m_Entry;
        private readonly List<string> m_Lines;
        private readonly ITownCrierEntryList m_Owner;

        public TownCrierLinesPrompt(ITownCrierEntryList owner, TownCrierEntry entry, List<string> lines, TimeSpan duration)
        {
            m_Owner = owner;
            m_Entry = entry;
            m_Lines = lines;
            m_Duration = duration;
        }

        public override void OnResponse(Mobile from, string text)
        {
            m_Lines.Add(text);

            from.SendMessage("Enter the next line to shout, or press <ESC> if the message is finished.");
            from.Prompt = new TownCrierLinesPrompt(m_Owner, m_Entry, m_Lines, m_Duration);
        }

        public override void OnCancel(Mobile from)
        {
            if (m_Entry != null)
            {
                m_Owner.RemoveEntry(m_Entry);
            }

            if (m_Lines.Count > 0)
            {
                m_Owner.AddEntry(m_Lines.ToArray(), m_Duration);
                from.SendMessage("Message has been set.");
            }
            else
            {
                if (m_Entry != null)
                {
                    from.SendMessage("Message deleted.");
                }
                else
                {
                    from.SendLocalizedMessage(502980); // Message entry cancelled.
                }
            }

            from.SendGump(new TownCrierGump(from, m_Owner));
        }
    }

    public class TownCrierGump : Gump
    {
        private readonly Mobile m_From;
        private readonly ITownCrierEntryList m_Owner;

        public TownCrierGump(Mobile from, ITownCrierEntryList owner) : base(50, 50)
        {
            m_From = from;
            m_Owner = owner;

            from.CloseGump<TownCrierGump>();

            AddPage(0);

            var entries = owner.Entries;

            owner.GetRandomEntry(); // force expiration checks

            var count = entries?.Count ?? 0;

            AddImageTiled(0, 0, 300, 38 + (count == 0 ? 20 : count * 85), 0xA40);
            AddAlphaRegion(1, 1, 298, 36 + (count == 0 ? 20 : count * 85));

            AddHtml(8, 8, 300 - 8 - 30, 20, "<basefont color=#FFFFFF><center>TOWN CRIER MESSAGES</center></basefont>");

            AddButton(300 - 8 - 30, 8, 0xFAB, 0xFAD, 1);

            if (count == 0)
            {
                AddHtml(8, 30, 284, 20, "<basefont color=#FFFFFF>The crier has no news.</basefont>");
            }
            else
            {
                for (var i = 0; i < entries!.Count; ++i)
                {
                    var tce = entries[i];

                    var toExpire = Utility.Max(tce.ExpireTime - Core.Now, TimeSpan.Zero);

                    var sb = new StringBuilder();

                    sb.Append("[Expires: ");

                    if (toExpire.TotalHours >= 1)
                    {
                        sb.Append((int)toExpire.TotalHours);
                        sb.Append(':');
                        sb.Append(toExpire.Minutes.ToString("D2"));
                    }
                    else
                    {
                        sb.Append(toExpire.Minutes);
                    }

                    sb.Append(':');
                    sb.Append(toExpire.Seconds.ToString("D2"));

                    sb.Append("] ");

                    for (var j = 0; j < tce.Lines.Length; ++j)
                    {
                        if (j > 0)
                        {
                            sb.Append("<br>");
                        }

                        sb.Append(tce.Lines[j]);
                    }

                    AddHtml(8, 35 + i * 85, 254, 80, sb.ToString(), true, true);

                    AddButton(300 - 8 - 26, 35 + i * 85, 0x15E1, 0x15E5, 2 + i);
                }
            }
        }

        public override void OnResponse(NetState sender, RelayInfo info)
        {
            if (info.ButtonID == 1)
            {
                m_From.SendMessage("Enter the duration for the new message. Format: <hours:minutes:seconds>");
                m_From.Prompt = new TownCrierDurationPrompt(m_Owner);
            }
            else if (info.ButtonID > 1)
            {
                var entries = m_Owner.Entries;
                var index = info.ButtonID - 2;

                if (index < entries?.Count)
                {
                    var tce = entries[index];
                    var ts = Utility.Max(tce.ExpireTime - Core.Now, TimeSpan.Zero);

                    m_From.SendMessage("Editing entry #{0}.", index + 1);
                    m_From.SendMessage("Enter the first line to shout:");
                    m_From.Prompt = new TownCrierLinesPrompt(m_Owner, tce, new List<string>(), ts);
                }
            }
        }
    }

    public class TownCrier : Mobile, ITownCrierEntryList
    {
        private Timer _autoShoutTimer;
        private Timer _newsTimer;

        [Constructible]
        public TownCrier()
        {
            Instances.Add(this);

            InitStats(100, 100, 25);

            Title = "the town crier";
            Hue = Race.Human.RandomSkinHue();

            if (!Core.AOS)
            {
                NameHue = 0x35;
            }

            if (Female = Utility.RandomBool())
            {
                Body = 0x191;
                Name = NameList.RandomName("female");
            }
            else
            {
                Body = 0x190;
                Name = NameList.RandomName("male");
            }

            AddItem(new FancyShirt(Utility.RandomBlueHue()));

            var skirt = Utility.Random(2) switch
            {
                0 => (Item)new Skirt(),
                1 => new Kilt(),
                _ => new Kilt()
            };

            skirt.Hue = Utility.RandomGreenHue();

            AddItem(skirt);

            AddItem(new FeatheredHat(Utility.RandomGreenHue()));

            var boots = Utility.Random(2) switch
            {
                0 => (Item)new Boots(),
                1 => new ThighBoots(),
                _ => new ThighBoots()
            };

            AddItem(boots);

            Utility.AssignRandomHair(this);
        }

        public TownCrier(Serial serial) : base(serial)
        {
            Instances.Add(this);
        }

        public static List<TownCrier> Instances { get; } = new();

        public List<TownCrierEntry> Entries { get; private set; }

        public TownCrierEntry GetRandomEntry()
        {
            if (Entries == null || Entries.Count == 0)
            {
                return GlobalTownCrierEntryList.Instance.GetRandomEntry();
            }

            for (var i = Entries.Count - 1; Entries != null && i >= 0; --i)
            {
                if (i >= Entries.Count)
                {
                    continue;
                }

                var tce = Entries[i];

                if (tce.Expired)
                {
                    RemoveEntry(tce);
                }
            }

            var entry = GlobalTownCrierEntryList.Instance.GetRandomEntry();

            return entry ?? (Entries?.Count > 0 && Utility.RandomBool() ? Entries.RandomElement() : null);
        }

        public TownCrierEntry AddEntry(string[] lines, TimeSpan duration)
        {
            Entries ??= new List<TownCrierEntry>();

            var tce = new TownCrierEntry(lines, duration);

            Entries.Add(tce);

            ForceBeginAutoShout();

            return tce;
        }

        public void RemoveEntry(TownCrierEntry tce)
        {
            if (Entries == null)
            {
                return;
            }

            Entries.Remove(tce);

            if (Entries.Count == 0)
            {
                Entries = null;
            }

            if (Entries == null && GlobalTownCrierEntryList.Instance.IsEmpty)
            {
                _autoShoutTimer.Stop();
                _autoShoutTimer = null;
            }
        }

        public void ForceBeginAutoShout()
        {
            _autoShoutTimer ??= Timer.DelayCall(TimeSpan.FromSeconds(5.0), TimeSpan.FromMinutes(1.0), AutoShout_Callback);
        }

        private void AutoShout_Callback()
        {
            var tce = GetRandomEntry();

            if (tce == null)
            {
                _autoShoutTimer.Stop();
                _autoShoutTimer = null;
            }
            else if (_newsTimer == null)
            {
                _newsTimer = Timer.DelayCall(
                    TimeSpan.FromSeconds(1.0),
                    TimeSpan.FromSeconds(3.0),
                    tce.Lines.Length,
                    () => ShoutNews_Callback(tce)
                );

                PublicOverheadMessage(MessageType.Regular, 0x3B2, 502976); // Hear ye! Hear ye!
            }
        }

        private void ShoutNews_Callback(TownCrierEntry tce)
        {
            var index = _newsTimer.Index;
            if (index >= tce.Lines.Length)
            {
                _newsTimer.Stop();
                _newsTimer = null;
            }
            else
            {
                PublicOverheadMessage(MessageType.Regular, 0x3B2, false, tce.Lines[index]);
            }
        }

        public override void OnDoubleClick(Mobile from)
        {
            if (from.AccessLevel >= AccessLevel.GameMaster)
            {
                from.SendGump(new TownCrierGump(from, this));
            }
            else
            {
                base.OnDoubleClick(from);
            }
        }

        public override bool HandlesOnSpeech(Mobile from) => _newsTimer == null && from.Alive && InRange(from, 12);

        public override void OnSpeech(SpeechEventArgs e)
        {
            if (_newsTimer == null && e.HasKeyword(0x30) && e.Mobile.Alive && InRange(e.Mobile, 12)) // *news*
            {
                Direction = GetDirectionTo(e.Mobile);

                var tce = GetRandomEntry();

                if (tce == null)
                {
                    PublicOverheadMessage(MessageType.Regular, 0x3B2, 1005643); // I have no news at this time.
                }
                else
                {
                    _newsTimer = Timer.DelayCall(
                        TimeSpan.FromSeconds(1.0),
                        TimeSpan.FromSeconds(3.0),
                        tce.Lines.Length,
                        () => ShoutNews_Callback(tce)
                    );

                    PublicOverheadMessage(MessageType.Regular, 0x3B2, 502978); // Some of the latest news!
                }
            }
        }

        public override bool CanBeDamaged() => false;

        public override void OnDelete()
        {
            Instances.Remove(this);
            base.OnDelete();
        }

        public override void Serialize(IGenericWriter writer)
        {
            base.Serialize(writer);

            writer.Write(0); // version
        }

        public override void Deserialize(IGenericReader reader)
        {
            base.Deserialize(reader);

            var version = reader.ReadInt();

            if (Core.AOS && NameHue == 0x35)
            {
                NameHue = -1;
            }
        }
    }
}