using System;
using System.Collections.Generic;
using Server.Network;
using Server.Targeting;

namespace Server.Items
{
    public abstract class BaseDoor : Item, ILockable, ITelekinesisable
    {
        private static readonly Point3D[] m_Offsets =
        {
            new(-1, 1, 0),
            new(1, 1, 0),
            new(-1, 0, 0),
            new(1, -1, 0),
            new(1, 1, 0),
            new(1, -1, 0),
            new(0, 0, 0),
            new(0, -1, 0),

            new(0, 0, 0),
            new(0, 0, 0),
            new(0, 0, 0),
            new(0, 0, 0)
        };

        private BaseDoor m_Link;
        private bool m_Open;

        private Timer m_Timer;

        public BaseDoor(int closedID, int openedID, int openedSound, int closedSound, Point3D offset) : base(closedID)
        {
            OpenedID = openedID;
            ClosedID = closedID;
            OpenedSound = openedSound;
            ClosedSound = closedSound;
            Offset = offset;

            m_Timer = new InternalTimer(this);

            Movable = false;
        }

        public BaseDoor(Serial serial) : base(serial)
        {
        }

        [CommandProperty(AccessLevel.GameMaster)]
        public bool Open
        {
            get => m_Open;
            set
            {
                if (m_Open != value)
                {
                    m_Open = value;

                    ItemID = m_Open ? OpenedID : ClosedID;

                    if (m_Open)
                    {
                        Location = new Point3D(X + Offset.X, Y + Offset.Y, Z + Offset.Z);
                    }
                    else
                    {
                        Location = new Point3D(X - Offset.X, Y - Offset.Y, Z - Offset.Z);
                    }

                    Effects.PlaySound(this, m_Open ? OpenedSound : ClosedSound);

                    if (m_Open)
                    {
                        m_Timer.Start();
                    }
                    else
                    {
                        m_Timer.Stop();
                    }
                }
            }
        }

        [CommandProperty(AccessLevel.GameMaster)]
        public int OpenedID { get; set; }

        [CommandProperty(AccessLevel.GameMaster)]
        public int ClosedID { get; set; }

        [CommandProperty(AccessLevel.GameMaster)]
        public int OpenedSound { get; set; }

        [CommandProperty(AccessLevel.GameMaster)]
        public int ClosedSound { get; set; }

        [CommandProperty(AccessLevel.GameMaster)]
        public Point3D Offset { get; set; }

        [CommandProperty(AccessLevel.GameMaster)]
        public BaseDoor Link
        {
            get
            {
                if (m_Link?.Deleted == true)
                {
                    m_Link = null;
                }

                return m_Link;
            }
            set => m_Link = value;
        }

        public virtual bool UseChainedFunctionality => false;

        [CommandProperty(AccessLevel.GameMaster)]
        public bool Locked { get; set; }

        [CommandProperty(AccessLevel.GameMaster)]
        public uint KeyValue { get; set; }

        public void OnTelekinesis(Mobile from)
        {
            Effects.SendLocationParticles(EffectItem.Create(Location, Map, EffectItem.DefaultDuration), 0x376A, 9, 32, 5022);
            Effects.PlaySound(Location, Map, 0x1F5);

            Use(from);
        }

        public static void Initialize()
        {
            EventSink.OpenDoorMacroUsed += EventSink_OpenDoorMacroUsed;

            CommandSystem.Register("Link", AccessLevel.GameMaster, Link_OnCommand);
            CommandSystem.Register("ChainLink", AccessLevel.GameMaster, ChainLink_OnCommand);
        }

        [Usage("Link"), Description("Links two targeted doors together.")]
        private static void Link_OnCommand(CommandEventArgs e)
        {
            e.Mobile.BeginTarget(-1, false, TargetFlags.None, Link_OnFirstTarget);
            e.Mobile.SendMessage("Target the first door to link.");
        }

        private static void Link_OnFirstTarget(Mobile from, object targeted)
        {
            if (!(targeted is BaseDoor door))
            {
                from.BeginTarget(-1, false, TargetFlags.None, Link_OnFirstTarget);
                from.SendMessage("That is not a door. Try again.");
            }
            else
            {
                from.BeginTarget(-1, false, TargetFlags.None, Link_OnSecondTarget, door);
                from.SendMessage("Target the second door to link.");
            }
        }

        private static void Link_OnSecondTarget(Mobile from, object targeted, BaseDoor first)
        {
            if (!(targeted is BaseDoor second))
            {
                from.BeginTarget(-1, false, TargetFlags.None, Link_OnSecondTarget, first);
                from.SendMessage("That is not a door. Try again.");
            }
            else
            {
                first.Link = second;
                second.Link = first;
                from.SendMessage("The doors have been linked.");
            }
        }

        [Usage("ChainLink"), Description("Chain-links two or more targeted doors together.")]
        private static void ChainLink_OnCommand(CommandEventArgs e)
        {
            e.Mobile.BeginTarget(-1, false, TargetFlags.None, ChainLink_OnTarget, new List<BaseDoor>());
            e.Mobile.SendMessage("Target the first of a sequence of doors to link.");
        }

        private static void ChainLink_OnTarget(Mobile from, object targeted, List<BaseDoor> list)
        {
            if (!(targeted is BaseDoor door))
            {
                from.BeginTarget(-1, false, TargetFlags.None, ChainLink_OnTarget, list);
                from.SendMessage("That is not a door. Try again.");
            }
            else
            {
                if (list.Count > 0 && list[0] == door)
                {
                    if (list.Count >= 2)
                    {
                        for (var i = 0; i < list.Count; ++i)
                        {
                            list[i].Link = list[(i + 1) % list.Count];
                        }

                        from.SendMessage("The chain of doors have been linked.");
                    }
                    else
                    {
                        from.BeginTarget(-1, false, TargetFlags.None, ChainLink_OnTarget, list);
                        from.SendMessage("You have not yet targeted two unique doors. Target the second door to link.");
                    }
                }
                else if (list.Contains(door))
                {
                    from.BeginTarget(-1, false, TargetFlags.None, ChainLink_OnTarget, list);
                    from.SendMessage(
                        "You have already targeted that door. Target another door, or retarget the first door to complete the chain."
                    );
                }
                else
                {
                    list.Add(door);

                    from.BeginTarget(-1, false, TargetFlags.None, ChainLink_OnTarget, list);

                    if (list.Count == 1)
                    {
                        from.SendMessage("Target the second door to link.");
                    }
                    else
                    {
                        from.SendMessage("Target another door to link. To complete the chain, retarget the first door.");
                    }
                }
            }
        }

        private static void EventSink_OpenDoorMacroUsed(Mobile m)
        {
            if (m.Map == null)
            {
                return;
            }

            int x = m.X, y = m.Y;

            switch (m.Direction & Direction.Mask)
            {
                case Direction.North:
                    --y;
                    break;
                case Direction.Right:
                    ++x;
                    --y;
                    break;
                case Direction.East:
                    ++x;
                    break;
                case Direction.Down:
                    ++x;
                    ++y;
                    break;
                case Direction.South:
                    ++y;
                    break;
                case Direction.Left:
                    --x;
                    ++y;
                    break;
                case Direction.West:
                    --x;
                    break;
                case Direction.Up:
                    --x;
                    --y;
                    break;
            }

            var sector = m.Map.GetSector(x, y);

            foreach (var item in sector.Items)
            {
                if (item.Location.X == x && item.Location.Y == y && item.Z + item.ItemData.Height > m.Z &&
                    m.Z + 16 > item.Z && item is BaseDoor && m.CanSee(item) && m.InLOS(item))
                {
                    if (m.CheckAlive())
                    {
                        m.SendLocalizedMessage(500024); // Opening door...
                        item.OnDoubleClick(m);
                    }

                    break;
                }
            }
        }

        public static Point3D GetOffset(DoorFacing facing) => m_Offsets[(int)facing];

        public bool CanClose()
        {
            if (!m_Open)
            {
                return true;
            }

            var map = Map;

            if (map == null)
            {
                return false;
            }

            var p = new Point3D(X - Offset.X, Y - Offset.Y, Z - Offset.Z);

            return CheckFit(map, p, 16);
        }

        private bool CheckFit(Map map, Point3D p, int height)
        {
            if (map == Map.Internal)
            {
                return false;
            }

            var x = p.X;
            var y = p.Y;
            var z = p.Z;

            var sector = map.GetSector(x, y);
            var items = sector.Items;
            var mobs = sector.Mobiles;

            for (var i = 0; i < items.Count; ++i)
            {
                var item = items[i];

                if (!(item is BaseMulti) && item.ItemID <= TileData.MaxItemValue && item.AtWorldPoint(x, y) &&
                    !(item is BaseDoor))
                {
                    var id = item.ItemData;
                    var surface = id.Surface;
                    var impassable = id.Impassable;

                    if ((surface || impassable) && item.Z + id.CalcHeight > z && z + height > item.Z)
                    {
                        return false;
                    }
                }
            }

            for (var i = 0; i < mobs.Count; ++i)
            {
                var m = mobs[i];

                if (m.Location.X == x && m.Location.Y == y)
                {
                    if (m.Hidden && m.AccessLevel > AccessLevel.Player)
                    {
                        continue;
                    }

                    if (!m.Alive)
                    {
                        continue;
                    }

                    if (m.Z + 16 > z && z + height > m.Z)
                    {
                        return false;
                    }
                }
            }

            return true;
        }

        public List<BaseDoor> GetChain()
        {
            var list = new List<BaseDoor>();
            var c = this;

            do
            {
                list.Add(c);
                c = c.Link;
            } while (c != null && !list.Contains(c));

            return list;
        }

        public bool IsFreeToClose()
        {
            if (!UseChainedFunctionality)
            {
                return CanClose();
            }

            var list = GetChain();

            var freeToClose = true;

            for (var i = 0; freeToClose && i < list.Count; ++i)
            {
                freeToClose = list[i].CanClose();
            }

            return freeToClose;
        }

        public virtual bool IsInside(Mobile from) => false;

        public virtual bool UseLocks() => true;

        public virtual void Use(Mobile from)
        {
            if (Locked && !m_Open && UseLocks())
            {
                if (from.AccessLevel >= AccessLevel.GameMaster)
                {
                    from.LocalOverheadMessage(
                        MessageType.Regular,
                        0x3B2,
                        502502
                    ); // That is locked, but you open it with your godly powers.
                    // from.Send( new MessageLocalized( Serial, ItemID, MessageType.Regular, 0x3B2, 3, 502502, "", "" ) ); // That is locked, but you open it with your godly powers.
                }
                else if (Key.ContainsKey(from.Backpack, KeyValue))
                {
                    from.LocalOverheadMessage(
                        MessageType.Regular,
                        0x3B2,
                        501282
                    ); // You quickly unlock, open, and relock the door
                }
                else if (IsInside(from))
                {
                    from.LocalOverheadMessage(
                        MessageType.Regular,
                        0x3B2,
                        501280
                    ); // That is locked, but is usable from the inside.
                }
                else
                {
                    if (Hue == 0x44E && Map == Map.Malas)      // doom door into healer room in doom
                    {
                        SendLocalizedMessageTo(from, 1060014); // Only the dead may pass.
                    }
                    else
                    {
                        from.LocalOverheadMessage(MessageType.Regular, 0x3B2, 502503); // That is locked.
                    }

                    return;
                }
            }

            if (m_Open && !IsFreeToClose())
            {
                return;
            }

            if (m_Open)
            {
                OnClosed(from);
            }
            else
            {
                OnOpened(from);
            }

            if (UseChainedFunctionality)
            {
                var open = !m_Open;

                var list = GetChain();

                for (var i = 0; i < list.Count; ++i)
                {
                    list[i].Open = open;
                }
            }
            else
            {
                Open = !m_Open;

                var link = Link;

                if (m_Open && link?.Open == false)
                {
                    link.Open = true;
                }
            }
        }

        public virtual void OnOpened(Mobile from)
        {
        }

        public virtual void OnClosed(Mobile from)
        {
        }

        public override void OnDoubleClick(Mobile from)
        {
            if (from.AccessLevel == AccessLevel.Player && !from.InRange(GetWorldLocation(), 2))
            {
                from.LocalOverheadMessage(MessageType.Regular, 0x3B2, 1019045); // I can't reach that.
            }
            else
            {
                Use(from);
            }
        }

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

            writer.Write(0); // version

            writer.Write(KeyValue);

            writer.Write(m_Open);
            writer.Write(Locked);
            writer.Write(OpenedID);
            writer.Write(ClosedID);
            writer.Write(OpenedSound);
            writer.Write(ClosedSound);
            writer.Write(Offset);
            writer.Write(m_Link);
        }

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

            var version = reader.ReadInt();

            switch (version)
            {
                case 0:
                    {
                        KeyValue = reader.ReadUInt();
                        m_Open = reader.ReadBool();
                        Locked = reader.ReadBool();
                        OpenedID = reader.ReadInt();
                        ClosedID = reader.ReadInt();
                        OpenedSound = reader.ReadInt();
                        ClosedSound = reader.ReadInt();
                        Offset = reader.ReadPoint3D();
                        m_Link = reader.ReadEntity<BaseDoor>();

                        m_Timer = new InternalTimer(this);

                        if (m_Open)
                        {
                            m_Timer.Start();
                        }

                        break;
                    }
            }
        }

        private class InternalTimer : Timer
        {
            private readonly BaseDoor m_Door;

            public InternalTimer(BaseDoor door) : base(TimeSpan.FromSeconds(20.0), TimeSpan.FromSeconds(10.0))
            {
                m_Door = door;
            }

            protected override void OnTick()
            {
                if (m_Door.Open && m_Door.IsFreeToClose())
                {
                    m_Door.Open = false;
                }
            }
        }
    }
}