using Barotrauma.Extensions;
using Barotrauma.Items.Components;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;

namespace Barotrauma
{
    [Flags]
    public enum InvSlotType
    {
        None = 0, Any = 1, RightHand = 2, LeftHand = 4, Head = 8, InnerClothes = 16, OuterClothes = 32, Headset = 64, Card = 128, Bag = 256, HealthInterface = 512
    };

    partial class CharacterInventory : Inventory
    {
        /// <summary>
        /// How much access other characters have to the inventory?
        /// <see cref="Restricted"/> = Only accessible when character is knocked down or handcuffed.
        /// <see cref="Limited"/> = Can also access inventories of bots on the same team and friendly pets.
        /// <see cref="Allowed"/> = Can also access other players in the same team (used for drag and drop give).
        /// </summary>
        public enum AccessLevel
        {
            Restricted,
            Limited,
            Allowed
        }
        
        private readonly Character character;

        public InvSlotType[] SlotTypes
        {
            get;
            private set;
        }
        
        public static readonly List<InvSlotType> AnySlot = new List<InvSlotType>() { InvSlotType.Any };

        public static bool IsHandSlotType(InvSlotType s) => s.HasFlag(InvSlotType.LeftHand) || s.HasFlag(InvSlotType.RightHand);

        protected bool[] IsEquipped;

        /// <summary>
        /// Can the inventory be accessed when the character is still alive
        /// </summary>
        public bool AccessibleWhenAlive
        {
            get;
            private set;
        }

        /// <summary>
        /// Can the inventory be accessed by the character itself when the character is still alive (only has an effect if AccessibleWhenAlive false)
        /// </summary>
        public bool AccessibleByOwner
        {
            get;
            private set;
        }

        private static string[] ParseSlotTypes(ContentXElement element)
        {
            string slotString = element.GetAttributeString("slots", null);
            return slotString == null ? Array.Empty<string>() : slotString.Split(',');
        }

        public CharacterInventory(ContentXElement element, Character character, bool spawnInitialItems)
            : base(character, ParseSlotTypes(element).Length)
        {
            this.character = character;
            IsEquipped = new bool[capacity];
            SlotTypes = new InvSlotType[capacity];

            AccessibleWhenAlive = element.GetAttributeBool("accessiblewhenalive", character.Info != null);
            AccessibleByOwner = element.GetAttributeBool("accessiblebyowner", AccessibleWhenAlive);

            string[] slotTypeNames = ParseSlotTypes(element);
            System.Diagnostics.Debug.Assert(slotTypeNames.Length == capacity);

            for (int i = 0; i < capacity; i++)
            {
                InvSlotType parsedSlotType = InvSlotType.Any;
                slotTypeNames[i] = slotTypeNames[i].Trim();
                if (!Enum.TryParse(slotTypeNames[i], out parsedSlotType))
                {
                    DebugConsole.ThrowError("Error in the inventory config of \"" + character.SpeciesName + "\" - " + slotTypeNames[i] + " is not a valid inventory slot type.", 
                        contentPackage: element.ContentPackage);
                }
                SlotTypes[i] = parsedSlotType;
                switch (SlotTypes[i])
                {
                    case InvSlotType.LeftHand:
                    case InvSlotType.RightHand:
                        slots[i].HideIfEmpty = true;
                        break;
                }               
            }
            
            InitProjSpecific(element);

            var itemElements = element.Elements().Where(e => e.Name.ToString().Equals("item", StringComparison.OrdinalIgnoreCase));
            int itemCount = itemElements.Count();
            if (itemCount > capacity)
            {
                DebugConsole.ThrowError($"Character \"{character.SpeciesName}\" is configured to spawn with more items than it has inventory capacity for.");
            }
#if DEBUG
            else if (itemCount > capacity - 2 && !character.IsPet && capacity > 0)
            {
                DebugConsole.ThrowError(
                    $"Character \"{character.SpeciesName}\" is configured to spawn with so many items it will have less than 2 free inventory slots. " +
                    "This can cause issues with talents that spawn extra loot in monsters' inventories."
                    + " Consider increasing the inventory size.",
                    contentPackage: element.ContentPackage);
            }
#endif

            if (!spawnInitialItems) { return; }

#if CLIENT
            //clients don't create items until the server says so
            if (GameMain.Client != null) { return; }
#endif

            foreach (var subElement in itemElements)
            {                
                string itemIdentifier = subElement.GetAttributeString("identifier", "");
                if (!ItemPrefab.Prefabs.TryGet(itemIdentifier, out var itemPrefab))
                {
                    DebugConsole.ThrowError("Error in character inventory \"" + character.SpeciesName + "\" - item \"" + itemIdentifier + "\" not found.",
                        contentPackage: element.ContentPackage);
                    continue;
                }

                string slotString = subElement.GetAttributeString("slot", "None");
                InvSlotType slot = Enum.TryParse(slotString, ignoreCase: true, out InvSlotType s) ? s : InvSlotType.None;

                bool forceToSlot = subElement.GetAttributeBool("forcetoslot", false);
                int amount = subElement.GetAttributeInt("amount", 1);
                for (int i = 0; i < amount; i++)
                {
                    Entity.Spawner?.AddItemToSpawnQueue(itemPrefab, this, ignoreLimbSlots: forceToSlot, slot: slot, onSpawned: (Item item) =>
                    {
                        if (item != null && item.ParentInventory != this)
                        {
                            string errorMsg = $"Failed to spawn the initial item \"{item.Prefab.Identifier}\" in the inventory of \"{character.SpeciesName}\".";
                            DebugConsole.ThrowError(errorMsg, contentPackage: element.ContentPackage);
                            GameAnalyticsManager.AddErrorEventOnce("CharacterInventory:FailedToSpawnInitialItem", GameAnalyticsManager.ErrorSeverity.Error, errorMsg);
                        }
                        else if (!character.Enabled)
                        {
                            foreach (var heldItem in character.HeldItems)
                            {
                                if (item.body != null) { item.body.Enabled = false; }
                            }
                        }
                    });
                }
            }
        }

        partial void InitProjSpecific(XElement element);

        public Item FindEquippedItemByTag(Identifier tag)
        {
            if (tag.IsEmpty) { return null; }
            for (int i = 0; i < slots.Length; i++)
            {
                if (SlotTypes[i] == InvSlotType.Any) { continue; }

                var item = slots[i].FirstOrDefault();
                if (item != null && item.HasTag(tag)) { return item; }
            }
            return null;
        }

        public int FindLimbSlot(InvSlotType limbSlot)
        {
            for (int i = 0; i < slots.Length; i++)
            {
                if (SlotTypes[i] == limbSlot) { return i; }
            }
            return -1;
        }

        public Item GetItemInLimbSlot(InvSlotType limbSlot)
        {
            for (int i = 0; i < slots.Length; i++)
            {
                if (SlotTypes[i] == limbSlot) { return slots[i].FirstOrDefault(); }
            }
            return null;
        }


        public bool IsInLimbSlot(Item item, InvSlotType limbSlot)
        {
            if (limbSlot == (InvSlotType.LeftHand | InvSlotType.RightHand))
            {
                int rightHandSlot = FindLimbSlot(InvSlotType.RightHand);
                int leftHandSlot = FindLimbSlot(InvSlotType.LeftHand);
                if (rightHandSlot > -1 && slots[rightHandSlot].Contains(item) &&
                    leftHandSlot > -1 && slots[leftHandSlot].Contains(item))
                {
                    return true;
                }
            }

            for (int i = 0; i < slots.Length; i++)
            {
                if (SlotTypes[i] == limbSlot && slots[i].Contains(item)) { return true; }
            }
            return false;
        }

        public override bool CanBePutInSlot(Item item, int i, bool ignoreCondition = false)
        {
            return 
                base.CanBePutInSlot(item, i, ignoreCondition) && item.AllowedSlots.Any(s => s.HasFlag(SlotTypes[i])) && 
                (SlotTypes[i] == InvSlotType.Any || slots[i].Items.Count < 1);
        }

        public override bool CanBePutInSlot(ItemPrefab itemPrefab, int i, float? condition, int? quality = null)
        {
            return 
                base.CanBePutInSlot(itemPrefab, i, condition, quality) &&
                (SlotTypes[i] == InvSlotType.Any || slots[i].Items.Count < 1);
        }

        public override void RemoveItem(Item item)
        {
            RemoveItem(item, tryEquipFromSameStack: false);
        }

        public void RemoveItem(Item item, bool tryEquipFromSameStack)
        {
            if (!Contains(item)) { return; }

            bool wasEquipped = character.HasEquippedItem(item);
            var indices = FindIndices(item);

            base.RemoveItem(item);
#if CLIENT
            CreateSlots();
            if (character == Character.Controlled)
            {
                character.SelectedItem?.GetComponent<CircuitBox>()?.OnViewUpdateProjSpecific();
            }
#endif
            CharacterHUD.RecreateHudTextsIfControlling(character);
            //if the item was equipped and there are more items in the same stack, equip one of those items
            if (tryEquipFromSameStack && wasEquipped)
            {
                int limbSlot = indices.Find(j => SlotTypes[j] != InvSlotType.Any);
                foreach (int i in indices)
                {
                    var itemInSameSlot = GetItemAt(i);
                    if (itemInSameSlot != null)
                    {
                        if (TryPutItem(itemInSameSlot, limbSlot, allowSwapping: false, allowCombine: false, character))
                        {
#if CLIENT
                            visualSlots[i].ShowBorderHighlight(GUIStyle.Green, 0.1f, 0.412f);
#endif
                        }
                        break;
                    }
                }
            }
        }


        /// <summary>
        /// If there is no room in the generic inventory (InvSlotType.Any), check if the item can be auto-equipped into its respective limbslot
        /// </summary>
        public bool TryPutItemWithAutoEquipCheck(Item item, Character user, IEnumerable<InvSlotType> allowedSlots = null, bool createNetworkEvent = true)
        {
            // Does not auto-equip the item if specified and no suitable any slot found (for example handcuffs are not auto-equipped)
            if (item.AllowedSlots.Contains(InvSlotType.Any))
            {
                var wearable = item.GetComponent<Wearable>();
                if (wearable != null && !wearable.AutoEquipWhenFull && !IsAnySlotAvailable(item))
                {
                    return false;
                }
            }

            if (allowedSlots != null && allowedSlots.Any() && !allowedSlots.Contains(InvSlotType.Any))
            {
                bool allSlotsTaken = true;
                foreach (var allowedSlot in allowedSlots)
                {
                    if (allowedSlot == (InvSlotType.RightHand | InvSlotType.LeftHand))
                    {
                        int rightHandSlot = FindLimbSlot(InvSlotType.RightHand);
                        int leftHandSlot = FindLimbSlot(InvSlotType.LeftHand);
                        if (rightHandSlot > -1 && slots[rightHandSlot].CanBePut(item) &&
                            leftHandSlot > -1 && slots[leftHandSlot].CanBePut(item))
                        {
                            allSlotsTaken = false;
                            break;
                        }
                    }
                    else
                    {
                        int slot = FindLimbSlot(allowedSlot);
                        if (slot > -1 && slots[slot].CanBePut(item))
                        {
                            allSlotsTaken = false;
                            break;
                        }
                    }

                }
                if (allSlotsTaken)
                {
                    int slot = FindLimbSlot(allowedSlots.First());
                    if (slot > -1 && slots[slot].Items.Any(it => it != item) && slots[slot].First().AllowDroppingOnSwapWith(item))
                    {
                        foreach (Item existingItem in slots[slot].Items.ToList())
                        {
                            existingItem.Drop(user);
                            if (existingItem.ParentInventory != null) { existingItem.ParentInventory.RemoveItem(existingItem); }
                        }
                    }
                }
            }

            return TryPutItem(item, user, allowedSlots, createNetworkEvent);
        }

        /// <summary>
        /// If there is room, puts the item in the inventory and returns true, otherwise returns false
        /// </summary>
        public override bool TryPutItem(Item item, Character user, IEnumerable<InvSlotType> allowedSlots = null, bool createNetworkEvent = true, bool ignoreCondition = false)
        {
            if (allowedSlots == null || !allowedSlots.Any()) { return false; }
            if (item == null)
            {
#if DEBUG
                throw new Exception("item null");
#else
                return false;
#endif
            }
            if (item.Removed)
            {
#if DEBUG
                throw new Exception("Tried to put a removed item (" + item.Name + ") in an inventory");
#else
                DebugConsole.ThrowError("Tried to put a removed item (" + item.Name + ") in an inventory.\n" + Environment.StackTrace.CleanupStackTrace());
                return false;
#endif
            }

            if (item.GetComponent<Pickable>() == null || item.AllowedSlots.None()) { return false; }

            bool inSuitableSlot = false;
            bool inWrongSlot = false;
            int currentSlot = -1;
            for (int i = 0; i < capacity; i++)
            {
                if (slots[i].Contains(item))
                {
                    currentSlot = i;
                    if (allowedSlots.Any(a => a.HasFlag(SlotTypes[i])))
                    {
                        if ((SlotTypes[i] == InvSlotType.RightHand || SlotTypes[i] == InvSlotType.LeftHand) && !allowedSlots.Contains(SlotTypes[i]))
                        {
                            //allowed slot = InvSlotType.RightHand | InvSlotType.LeftHand
                            // -> make sure the item is in both hand slots
                            inSuitableSlot = IsInLimbSlot(item, InvSlotType.RightHand) && IsInLimbSlot(item, InvSlotType.LeftHand);
                        }
                        else
                        {
                            inSuitableSlot = true;
                        }
                    }
                    else if (!allowedSlots.Any(a => a.HasFlag(SlotTypes[i])))
                    {
                        inWrongSlot = true;
                    }
                }
            }

            //all good
            if (inSuitableSlot && !inWrongSlot) { return true; }

            //try to place the item in a LimbSlot.Any slot if that's allowed
            if (allowedSlots.Contains(InvSlotType.Any) && item.AllowedSlots.Contains(InvSlotType.Any))
            {
                int freeIndex = GetFreeAnySlot(item, inWrongSlot);
                if (freeIndex > -1)
                {
                    PutItem(item, freeIndex, user, true, createNetworkEvent);
                    item.Unequip(character);
                    return true;
                }
            }

            int placedInSlot = -1;
            foreach (InvSlotType allowedSlot in allowedSlots)
            {
                if (allowedSlot.HasFlag(InvSlotType.RightHand) && character.AnimController.GetLimb(LimbType.RightHand) == null) { continue; }
                if (allowedSlot.HasFlag(InvSlotType.LeftHand) && character.AnimController.GetLimb(LimbType.LeftHand) == null) { continue; }

                //check if all the required slots are free
                bool free = true;
                for (int i = 0; i < capacity; i++)
                {
                    if (allowedSlot.HasFlag(SlotTypes[i]) && item.AllowedSlots.Any(s => s.HasFlag(SlotTypes[i])) && slots[i].Items.Any(it => it != item))
                    {
                        if (!slots[i].First().AllowedSlots.Contains(InvSlotType.Any) || !TryPutItem(slots[i].FirstOrDefault(), character, new List<InvSlotType> { InvSlotType.Any }, true, ignoreCondition))
                        {
                            free = false;
#if CLIENT
                            for (int j = 0; j < capacity; j++)
                            {
                                if (visualSlots != null && slots[j] == slots[i]) { visualSlots[j].ShowBorderHighlight(GUIStyle.Red, 0.1f, 0.9f); }
                            }
#endif
                        }
                    }
                }

                if (!free) { continue; }

                for (int i = 0; i < capacity; i++)
                {
                    if (allowedSlot.HasFlag(SlotTypes[i]) && item.GetComponents<Pickable>().Any(p => p.AllowedSlots.Any(s => s.HasFlag(SlotTypes[i]))) && slots[i].Empty())
                    {
                        bool removeFromOtherSlots = item.ParentInventory != this;
                        if (placedInSlot == -1 && inWrongSlot)
                        {
                            if (!slots[i].HideIfEmpty || SlotTypes[currentSlot] != InvSlotType.Any) { removeFromOtherSlots = true; }
                        }

                        PutItem(item, i, user, removeFromOtherSlots, createNetworkEvent);
                        item.Equip(character);
                        placedInSlot = i;
                    }
                }
                if (placedInSlot > -1) { break; }
            }

            return placedInSlot > -1;
        }

        public bool IsAnySlotAvailable(Item item) => GetFreeAnySlot(item, inWrongSlot: false) > -1;

        private int GetFreeAnySlot(Item item, bool inWrongSlot)
        {
            //attempt to stack first
            for (int i = 0; i < capacity; i++)
            {
                if (SlotTypes[i] != InvSlotType.Any) { continue; }
                if (!slots[i].Empty() && CanBePutInSlot(item, i))
                {
                    return i;
                }
            }
            for (int i = 0; i < capacity; i++)
            {
                if (SlotTypes[i] != InvSlotType.Any) { continue; }
                if (slots[i].Contains(item))
                {
                    return i;
                }
            }
            for (int i = 0; i < capacity; i++)
            {
                if (SlotTypes[i] != InvSlotType.Any) { continue; }
                if (CanBePutInSlot(item, i))
                {
                    return i;
                }
            }
            for (int i = 0; i < capacity; i++)
            {
                if (SlotTypes[i] != InvSlotType.Any) { continue; }
                if (inWrongSlot)
                {
                    //another item already in the slot
                    if (slots[i].Any() && slots[i].Items.Any(it => it != item)) { continue; }
                }
                else
                {
                    if (!CanBePutInSlot(item, i)) { continue; }
                }
                return i;
            }
            return -1;
        }

        public override bool TryPutItem(Item item, int index, bool allowSwapping, bool allowCombine, Character user, bool createNetworkEvent = true, bool ignoreCondition = false)
        {
            if (index < 0 || index >= slots.Length)
            {
                string errorMsg = "CharacterInventory.TryPutItem failed: index was out of range(" + index + ").\n" + Environment.StackTrace.CleanupStackTrace();
                GameAnalyticsManager.AddErrorEventOnce("CharacterInventory.TryPutItem:IndexOutOfRange", GameAnalyticsManager.ErrorSeverity.Error, errorMsg);
                return false;
            }
            //there's already an item in the slot
            if (slots[index].Any())
            {
                if (slots[index].Contains(item)) { return false; }
                return base.TryPutItem(item, index, allowSwapping, allowCombine, user, createNetworkEvent, ignoreCondition);
            }

            if (SlotTypes[index] == InvSlotType.Any)
            {
                if (!item.GetComponents<Pickable>().Any(p => p.AllowedSlots.Contains(InvSlotType.Any))) { return false; }
                if (slots[index].Any()) { return slots[index].Contains(item); }
                PutItem(item, index, user, true, createNetworkEvent);
                return true;
            }

            InvSlotType placeToSlots = InvSlotType.None;

            bool slotsFree = true;
            foreach (Pickable pickable in item.GetComponents<Pickable>())
            {
                foreach (InvSlotType allowedSlot in pickable.AllowedSlots)
                {
                    if (!allowedSlot.HasFlag(SlotTypes[index])) { continue; }
                    for (int i = 0; i < capacity; i++)
                    {
                        if (allowedSlot.HasFlag(SlotTypes[i]) && slots[i].Any() && !slots[i].Contains(item))
                        {
                            slotsFree = false;
                            break;
                        }
                        placeToSlots = allowedSlot;
                    }
                }
            }

            if (!slotsFree) { return false; }

            return TryPutItem(item, user, new List<InvSlotType>() { placeToSlots }, createNetworkEvent, ignoreCondition);
        }

        protected override void PutItem(Item item, int i, Character user, bool removeItem = true, bool createNetworkEvent = true)
        {
            base.PutItem(item, i, user, removeItem, createNetworkEvent);
#if CLIENT
            CreateSlots();
            if (character == Character.Controlled)
            {
                HintManager.OnObtainedItem(character, item);
                character.SelectedItem?.GetComponent<CircuitBox>()?.OnViewUpdateProjSpecific();
            }
#endif
            CharacterHUD.RecreateHudTextsIfControlling(character);
            if (item.CampaignInteractionType == CampaignMode.InteractionType.Cargo)
            {
                item.AssignCampaignInteractionType(CampaignMode.InteractionType.None);
            }
            item.Equipper = user;            
        }

        protected override void CreateNetworkEvent(Range slotRange)
        {
            GameMain.NetworkMember?.CreateEntityEvent(character, new Character.InventoryStateEventData(slotRange));
        }

    }
}