using System;
using Server.Mobiles;
using Server.Spells.Ninjitsu;

namespace Server.Misc
{
  public enum DFAlgorithm
  {
    Standard,
    PainSpike
  }

  public class WeightOverloading
  {
    public const int OverloadAllowance = 4; // We can be four stones overweight without getting fatigued

    public static DFAlgorithm DFA{ get; set; }

    public static void Initialize()
    {
      EventSink.Movement += EventSink_Movement;
    }

    public static void FatigueOnDamage(Mobile m, int damage)
    {
      double fatigue = 0.0;

      switch (DFA)
      {
        case DFAlgorithm.Standard:
        {
          fatigue = damage * (100.0 / m.Hits) * ((double)m.Stam / 100) - 5.0;
          break;
        }
        case DFAlgorithm.PainSpike:
        {
          fatigue = damage * (100.0 / m.Hits + (50.0 + m.Stam) / 100 - 1.0) - 5.0;
          break;
        }
      }

      if (fatigue > 0)
        m.Stam -= (int)fatigue;
    }

    public static int GetMaxWeight(Mobile m) => m.MaxWeight;

    public static void EventSink_Movement(MovementEventArgs e)
    {
      Mobile from = e.Mobile;

      if (!from.Alive || from.AccessLevel > AccessLevel.Player)
        return;

      if (!from.Player)
      {
        // Else it won't work on monsters.
        DeathStrike.AddStep(from);
        return;
      }

      int maxWeight = GetMaxWeight(from) + OverloadAllowance;
      int overWeight = Mobile.BodyWeight + from.TotalWeight - maxWeight;

      if (overWeight > 0)
      {
        from.Stam -= GetStamLoss(from, overWeight, (e.Direction & Direction.Running) != 0);

        if (from.Stam == 0)
        {
          from.SendLocalizedMessage(
            500109); // You are too fatigued to move, because you are carrying too much weight!
          e.Blocked = true;
          return;
        }
      }

      if (from.Stam * 100 / Math.Max(from.StamMax, 1) < 10)
        --from.Stam;

      if (from.Stam == 0)
      {
        from.SendLocalizedMessage(500110); // You are too fatigued to move.
        e.Blocked = true;
        return;
      }

      if (from is PlayerMobile pm)
      {
        int amt = pm.Mounted ? 48 : 16;

        if (++pm.StepsTaken % amt == 0)
          --pm.Stam;
      }

      DeathStrike.AddStep(from);
    }

    public static int GetStamLoss(Mobile from, int overWeight, bool running)
    {
      int loss = 5 + overWeight / 25;

      if (from.Mounted)
        loss /= 3;

      if (running)
        loss *= 2;

      return loss;
    }

    public static bool IsOverloaded(Mobile m)
    {
      if (!m.Player || !m.Alive || m.AccessLevel > AccessLevel.Player)
        return false;

      return Mobile.BodyWeight + m.TotalWeight > GetMaxWeight(m) + OverloadAllowance;
    }
  }
}