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

namespace Server.Items
{
  public abstract class BaseExplosionPotion : BasePotion
  {
    private const int ExplosionRange = 2; // How long is the blast radius?

    private static bool LeveledExplosion = false; // Should explosion potions explode other nearby potions?
    private static bool InstantExplosion = false; // Should explosion potions explode on impact?
    private static bool RelativeLocation = false; // Is the explosion target location relative for mobiles?

    private Timer m_Timer;

    public BaseExplosionPotion(PotionEffect effect) : base(0xF0D, effect)
    {
    }

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

    public abstract int MinDamage{ get; }
    public abstract int MaxDamage{ get; }

    public override bool RequireFreeHand => false;

    public List<Mobile> Users{ get; private set; }

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

      writer.Write(0); // version
    }

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

      int version = reader.ReadInt();
    }

    public virtual IEntity FindParent(Mobile from)
    {
      if (HeldBy?.Holding == this)
        return HeldBy;

      if (RootParent != null)
        return RootParent;

      if (Map == Map.Internal)
        return from;

      return this;
    }

    public override void Drink(Mobile from)
    {
      if (Core.AOS && (from.Paralyzed || from.Frozen || from.Spell != null && from.Spell.IsCasting))
      {
        from.SendLocalizedMessage(1062725); // You can not use a purple potion while paralyzed.
        return;
      }

      ThrowTarget targ = from.Target as ThrowTarget;
      Stackable = false; // Scavenged explosion potions won't stack with those ones in backpack, and still will explode.

      if (targ?.Potion == this)
        return;

      from.RevealingAction();

      if (Users == null)
        Users = new List<Mobile>();

      if (!Users.Contains(from))
        Users.Add(from);

      from.Target = new ThrowTarget(this);

      if (m_Timer == null)
      {
        from.SendLocalizedMessage(500236); // You should throw it now!

        int timer = 3;

        if (Core.ML)
          m_Timer = Timer.DelayCall(TimeSpan.FromSeconds(1.0), TimeSpan.FromSeconds(1.25), 5,
            () => Detonate_OnTick(from, timer--)); // 3.6 seconds explosion delay
        else
          m_Timer = Timer.DelayCall(TimeSpan.FromSeconds(0.75), TimeSpan.FromSeconds(1.0), 4,
            () => Detonate_OnTick(from, timer--)); // 2.6 seconds explosion delay
      }
    }

    private void Detonate_OnTick(Mobile from, int timer)
    {
      if (Deleted)
        return;

      IEntity parent = FindParent(from);

      if (timer == 0)
      {
        Point3D loc;
        Map map;

        if (parent is Item item)
        {
          loc = item.GetWorldLocation();
          map = item.Map;
        }
        else if (parent is Mobile m)
        {
          loc = m.Location;
          map = m.Map;
        }
        else
        {
          return;
        }

        Explode(from, true, loc, map);
        m_Timer = null;
      }
      else
      {
        if (parent is Item item)
          item.PublicOverheadMessage(MessageType.Regular, 0x22, false, timer.ToString());
        else if (parent is Mobile mobile)
          mobile.PublicOverheadMessage(MessageType.Regular, 0x22, false, timer.ToString());
      }
    }

    private void Reposition_OnTick(Mobile from, Point3D loc, Map map)
    {
      if (Deleted)
        return;

      if (InstantExplosion)
        Explode(from, true, loc, map);
      else
        MoveToWorld(loc, map);
    }

    public void Explode(Mobile from, bool direct, Point3D loc, Map map)
    {
      if (Deleted)
        return;

      Consume();

      for (int i = 0; Users != null && i < Users.Count; ++i)
      {
        Mobile m = Users[i];

        if (m.Target is ThrowTarget targ && targ.Potion == this)
          Target.Cancel(m);
      }

      if (map == null)
        return;

      Effects.PlaySound(loc, map, 0x307);

      Effects.SendLocationEffect(loc, map, 0x36B0, 9, 10, 0, 0);
      int alchemyBonus = 0;

      if (direct)
        alchemyBonus = (int)(from.Skills.Alchemy.Value / (Core.AOS ? 5 : 10));

      IPooledEnumerable<IEntity> eable = map.GetObjectsInRange(loc, ExplosionRange, LeveledExplosion);
      int toDamage = 0;

      List<IEntity> toExplode = eable.Where(o =>
      {
        if (!(o is Mobile mobile) || from != null &&
            (!SpellHelper.ValidIndirectTarget(from, mobile) || !from.CanBeHarmful(mobile, false)))
          return o is BaseExplosionPotion && o != this;

        ++toDamage;
        return true;
      }).ToList();

      eable.Free();

      int min = Scale(from, MinDamage);
      int max = Scale(from, MaxDamage);

      for (int i = 0; i < toExplode.Count; ++i)
      {
        IEntity o = toExplode[i];

        if (o is Mobile m)
        {
          from?.DoHarmful(m);

          int damage = Utility.RandomMinMax(min, max);

          damage += alchemyBonus;

          if (!Core.AOS && damage > 40)
            damage = 40;
          else if (Core.AOS && toDamage > 2)
            damage /= toDamage - 1;

          AOS.Damage(m, from, damage, 0, 100, 0, 0, 0);
        }
        else if (o is BaseExplosionPotion pot)
        {
          pot.Explode(from, false, pot.GetWorldLocation(), pot.Map);
        }
      }
    }

    private class ThrowTarget : Target
    {
      public ThrowTarget(BaseExplosionPotion potion) : base(12, true, TargetFlags.None)
      {
        Potion = potion;
      }

      public BaseExplosionPotion Potion{ get; }

      protected override void OnTarget(Mobile from, object targeted)
      {
        if (Potion.Deleted || Potion.Map == Map.Internal)
          return;

        if (!(targeted is IPoint3D p))
          return;

        Map map = from.Map;

        if (map == null)
          return;

        SpellHelper.GetSurfaceTop(ref p);

        from.RevealingAction();

        IEntity to = new Entity(Serial.Zero, new Point3D(p), map);

        if (p is Mobile m)
        {
          if (!RelativeLocation) // explosion location = current mob location.
            p = m.Location;
          else
            to = m;
        }

        Effects.SendMovingEffect(from, to, Potion.ItemID, 7, 0, false, false, Potion.Hue);

        if (Potion.Amount > 1) Mobile.LiftItemDupe(Potion, 1);

        Potion.Internalize();
        Timer.DelayCall(TimeSpan.FromSeconds(1.0), () => Potion.Reposition_OnTick(from, new Point3D(p), map));
      }
    }
  }
}