using System;
using Server.Gumps;
using Server.Mobiles;

namespace Server.Engines.MLQuests.Objectives
{
  public abstract class BaseObjective
  {
    public virtual bool IsTimed => false;
    public virtual TimeSpan Duration => TimeSpan.Zero;

    public virtual bool CanOffer(IQuestGiver quester, PlayerMobile pm, bool message)
    {
      return true;
    }

    public abstract void WriteToGump(Gump g, ref int y);

    public virtual BaseObjectiveInstance CreateInstance(MLQuestInstance instance)
    {
      return null;
    }
  }

  public abstract class BaseObjectiveInstance
  {
    public enum DataType : byte
    {
      None,
      EscortObjective,
      KillObjective,
      DeliverObjective
    }

    public BaseObjectiveInstance(MLQuestInstance instance, BaseObjective obj)
    {
      Instance = instance;

      if (obj.IsTimed)
        EndTime = DateTime.UtcNow + obj.Duration;
    }

    public MLQuestInstance Instance{ get; }

    public bool IsTimed => EndTime != DateTime.MinValue;

    public DateTime EndTime{ get; set; }

    public bool Expired{ get; set; }

    public virtual DataType ExtraDataType => DataType.None;

    public virtual void WriteToGump(Gump g, ref int y)
    {
      if (IsTimed)
        WriteTimeRemaining(g, ref y, EndTime > DateTime.UtcNow ? EndTime - DateTime.UtcNow : TimeSpan.Zero);
    }

    public static void WriteTimeRemaining(Gump g, ref int y, TimeSpan timeRemaining)
    {
      g.AddHtmlLocalized(103, y, 120, 16, 1062379, 0x15F90, false, false); // Est. time remaining:
      g.AddLabel(223, y, 0x481, timeRemaining.TotalSeconds.ToString("F0"));
      y += 16;
    }

    public virtual bool AllowsQuestItem(Item item, Type type)
    {
      return false;
    }

    public virtual bool IsCompleted()
    {
      return false;
    }

    public virtual void CheckComplete()
    {
      if (IsCompleted())
      {
        Instance.Player.PlaySound(0x5B6); // public sound
        Instance.CheckComplete();
      }
    }

    public virtual void OnQuestAccepted()
    {
    }

    public virtual void OnQuestCancelled()
    {
    }

    public virtual void OnQuestCompleted()
    {
    }

    public virtual bool OnBeforeClaimReward()
    {
      return true;
    }

    public virtual void OnClaimReward()
    {
    }

    public virtual void OnAfterClaimReward()
    {
    }

    public virtual void OnRewardClaimed()
    {
    }

    public virtual void OnQuesterDeleted()
    {
    }

    public virtual void OnPlayerDeath()
    {
    }

    public virtual void OnExpire()
    {
    }

    public virtual void Serialize(GenericWriter writer)
    {
      // Version info is written in MLQuestPersistence.Serialize

      if (IsTimed)
      {
        writer.Write(true);
        writer.WriteDeltaTime(EndTime);
      }
      else
      {
        writer.Write(false);
      }

      // For type checks on deserialization
      // (This way quest objectives can be changed without breaking serialization)
      writer.Write((byte)ExtraDataType);
    }

    public static void Deserialize(GenericReader reader, int version, BaseObjectiveInstance objInstance)
    {
      if (reader.ReadBool())
      {
        DateTime endTime = reader.ReadDeltaTime();

        if (objInstance != null)
          objInstance.EndTime = endTime;
      }

      DataType extraDataType = (DataType)reader.ReadByte();

      switch (extraDataType)
      {
        case DataType.EscortObjective:
        {
          bool completed = reader.ReadBool();

          if (objInstance is EscortObjectiveInstance instance)
            instance.HasCompleted = completed;

          break;
        }
        case DataType.KillObjective:
        {
          int slain = reader.ReadInt();

          if (objInstance is KillObjectiveInstance instance)
            instance.Slain = slain;

          break;
        }
        case DataType.DeliverObjective:
        {
          bool completed = reader.ReadBool();

          if (objInstance is DeliverObjectiveInstance instance)
            instance.HasCompleted = completed;

          break;
        }
      }
    }
  }
}