using Content.Server.Interfaces.GameObjects;
using SS14.Shared.GameObjects;
using SS14.Shared.Interfaces.GameObjects;
using SS14.Shared.Utility;
using System.Collections.Generic;
using System;
using System.Linq;
using YamlDotNet.RepresentationModel;

namespace Content.Server.GameObjects
{
    public class HandsComponent : Component, IHandsComponent
    {
        public override string Name => "Hands";

        private string activeIndex;
        public string ActiveIndex
        {
            get => activeIndex;
            set
            {
                if (!hands.ContainsKey(value))
                {
                    throw new ArgumentException($"No hand '{value}'");
                }

                activeIndex = value;
            }
        }

        private Dictionary<string, IInventorySlot> hands = new Dictionary<string, IInventorySlot>();
        private IInventoryComponent inventory;

        public override void Initialize()
        {
            inventory = Owner.GetComponent<IInventoryComponent>();
            base.Initialize();
        }

        public override void OnRemove()
        {
            inventory = null;
            base.OnRemove();
        }

        public override void LoadParameters(YamlMappingNode mapping)
        {
            foreach (var node in mapping.GetNode<YamlSequenceNode>("hands"))
            {
                AddHand(node.AsString());
            }
            base.LoadParameters(mapping);
        }

        public IEnumerable<IItemComponent> GetAllHeldItems()
        {
            throw new NotImplementedException();
            /*
            foreach (var slot in hands.Values)
            {
                if (slot.Item != null)
                {
                    yield return slot.Item;
                }
            }
            */
        }

        public IItemComponent GetHand(string index)
        {
            var slot = hands[index];
            return slot.Item;
        }

        /// <summary>
        ///     Enumerates over the hand keys, returning the active hand first.
        /// </summary>
        private IEnumerable<string> ActivePriorityEnumerable()
        {
            throw new NotImplementedException();
            /*
            yield return ActiveIndex;
            foreach (var hand in hands.Keys)
            {
                if (hand == ActiveIndex)
                {
                    continue;
                }

                yield return hand;
            }
            */
        }

        public bool PutInHand(IItemComponent item)
        {
            foreach (var hand in ActivePriorityEnumerable())
            {
                if (PutInHand(item, hand, fallback: false))
                {
                    return true;
                }
            }

            return false;
        }

        public bool PutInHand(IItemComponent item, string index, bool fallback = true)
        {
            if (!CanPutInHand(item, index))
            {
                return fallback && PutInHand(item);
            }

            var slot = hands[index];
            return slot.Owner.Insert(slot.Name, item);
        }

        public bool CanPutInHand(IItemComponent item)
        {
            foreach (var hand in ActivePriorityEnumerable())
            {
                if (CanPutInHand(item, hand))
                {
                    return true;
                }
            }

            return false;
        }

        public bool CanPutInHand(IItemComponent item, string index)
        {
            var slot = hands[index];
            return slot.Owner.CanInsert(slot.Name, item);
        }

        public bool Drop(string index)
        {
            if (!CanDrop(index))
            {
                return false;
            }

            var slot = hands[index];
            return slot.Owner.Drop(slot.Name);
        }

        public bool CanDrop(string index)
        {
            var slot = hands[index];
            return slot.Item != null && slot.Owner.CanDrop(slot.Name);
        }

        public void AddHand(string index)
        {
            if (HasHand(index))
            {
                throw new InvalidOperationException($"Hand '{index}' already exists.");
            }

            var slot = inventory.AddSlot(HandSlotName(index));
            hands[index] = slot;
        }

        public void RemoveHand(string index)
        {
            if (!HasHand(index))
            {
                throw new InvalidOperationException($"Hand '{index}' does not exist.");
            }

            inventory.RemoveSlot(HandSlotName(index));
            hands.Remove(index);
        }

        public bool HasHand(string index)
        {
            return hands.ContainsKey(index);
        }

        /// <summary>
        ///     Get the name of the slot passed to the inventory component.
        /// </summary>
        private string HandSlotName(string index) => $"_hand_{index}";
    }
}