using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using MessagePack;
using Newtonsoft.Json;
using Unity.Mathematics;
using static Unity.Mathematics.math;

[MessagePackObject, JsonObject(MemberSerialization.OptIn), EntityTypeRestriction(HullType.Ship), Order(-100)]
public class HaulingControllerData : ControllerData
{
    [InspectableField, JsonProperty("targetDistance"), Key(6)]  
    public float DockTime = 2;
    public override IBehavior CreateInstance(ItemManager context, Entity entity, EquippedItem item)
    {
        return new HaulingController(context, this, entity, item);
    }
}

public class HaulingController : ControllerBase<HaulingTask>, IBehavior, IPersistentBehavior
{
    public BehaviorData Data => _data;
    private HaulingControllerData _data;
    
    private ItemManager ItemManager { get; }
    private Entity Entity { get; }
    private EquippedItem Item { get; }
    
    private bool _taskStarted;
    private int _itemsDelivered;
    private int _itemsCarried;
    private SimpleCommodity _simpleCommodityDelivery;
    private List<CraftedItemInstance> _craftedItemDelivery = new List<CraftedItemInstance>();
    
    public HaulingController(ItemManager itemManager, HaulingControllerData data, Entity entity, EquippedItem item) : base(itemManager, data, entity)
    {
        ItemManager = itemManager;
        _data = data;
        Entity = entity;
        Item = item;
    }

    public new bool Update(float delta)
    {
        if (Task != null)
        {
            if (!_taskStarted)
            {
                MoveTo(Task.Origin, true, OnPickup);
                //MoveTo(haulingTask.Zone, OnOriginZoneArrival);
                _taskStarted = true;
            }
        }
        return base.Update(delta);
    }
    
    // void OnOriginZoneArrival()
    // {
    //     var haulingTask = _context.ItemData.Get<HaulingTask>(Task);
    //     
    //     _entity.SetMessage("Entering pickup phase.");
    //     
    //     MoveTo(_context.ItemData.Get<Entity>(haulingTask.Origin), true, OnPickup);
    // }
    
    void OnPickup()
    {
        Entity.SetParent(Task.Origin);

        _itemsCarried = Task.Origin.TryTransferItems(Entity, Task.ItemType, Task.Quantity - _itemsDelivered);

        if (_itemsCarried == 0)
        {
            FinishTask();
            return;
        }
        
        Wait(_data.DockTime, OnItemObtained);
    }

    void OnItemObtained()
    {
        Entity.SetMessage("Entering delivery phase.");

        MoveTo(Task.Target, true, OnDelivery);
        //MoveTo(target.Zone.Data.ID, OnTargetZoneArrival);
    }
    
    // void OnTargetZoneArrival()
    // {
    //     var haulingTask = _context.ItemData.Get<HaulingTask>(Task);
    //     
    //     MoveTo(_context.ItemData.Get<Entity>(haulingTask.Target), true, OnDelivery);
    // }
    
    void OnDelivery()
    {
        Entity.SetParent(Task.Target);

        var itemsDelivered = Entity.TryTransferItems(Task.Target, Task.ItemType, _itemsCarried);
        _itemsCarried -= itemsDelivered;
        _itemsDelivered += itemsDelivered;

        Wait(_data.DockTime, () =>
        {
            // We were unable to transfer all onboard items to target entity, cargo is probably full. Bring back the surplus and end the mission
            if(_itemsCarried > 0)
                MoveTo(Task.Origin, true, ReturnSurplusToOrigin);
            // We have delivered the target quantity of items, end the mission
            else if(_itemsDelivered >= Task.Quantity)
                FinishTask();
            // We aren't done yet. Resetting the task will make us go for another delivery run
            else
                _taskStarted = false;
        });
    }

    void ReturnSurplusToOrigin()
    {
        Entity.SetParent(Task.Origin);

        Entity.TryTransferItems(Task.Origin, Task.ItemType, _itemsCarried);
        
        Wait(_data.DockTime, OnItemObtained);
        
        FinishTask();
    }

    public PersistentBehaviorData Store()
    {
        return new HaulingControllerPersistence
        {
            Task = Task
        };
    }

    public void Restore(PersistentBehaviorData data)
    {
        var towingControllerPersistence = data as HaulingControllerPersistence;
        Task = towingControllerPersistence.Task;
    }
}

public class HaulingControllerPersistence : PersistentBehaviorData
{
    [JsonProperty("task"), Key(0)]
    public HaulingTask Task;
}