using Barotrauma.Networking;
using FarseerPhysics;
using Lidgren.Network;
using Microsoft.Xna.Framework;
using System.Collections.Generic;
using System.Xml.Linq;

namespace Barotrauma.Items.Components
{
    class Holdable : Pickable, IServerSerializable
    {
        //the position(s) in the item that the Character grabs
        protected Vector2[] handlePos;
        private Vector2[] scaledHandlePos;

        private InputType prevPickKey;
        private string prevMsg;
        private Dictionary<RelatedItem.RelationType, List<RelatedItem>> prevRequiredItems;

        //the distance from the holding characters elbow to center of the physics body of the item
        protected Vector2 holdPos;

        protected Vector2 aimPos;

        private float swingState;

        private bool attachable, attached, attachedByDefault;
        private PhysicsBody body;
        public PhysicsBody Pusher
        {
            get;
            private set;
        }

        //the angle in which the Character holds the item
        protected float holdAngle;

        public PhysicsBody Body
        {
            get { return item.body ?? body; }
        }

        [Serialize(false, true)]
        public bool Attached
        {
            get { return attached && item.ParentInventory == null; }
            set { attached = value; }
        }

        [Serialize(true, true)]
        public bool Aimable
        {
            get;
            set;
        }

        [Serialize(false, false)]
        public bool ControlPose
        {
            get;
            set;
        }

        [Serialize(false, false)]
        public bool Attachable
        {
            get { return attachable; }
            set { attachable = value; }
        }

        [Serialize(true, false)]
        public bool Reattachable
        {
            get;
            set;
        }

        [Serialize(false, false)]
        public bool AttachedByDefault
        {
            get { return attachedByDefault; }
            set { attachedByDefault = value; }
        }

        [Serialize("0.0,0.0", false),Editable]
        public Vector2 HoldPos
        {
            get { return ConvertUnits.ToDisplayUnits(holdPos); }
            set { holdPos = ConvertUnits.ToSimUnits(value); }
        }

        [Serialize("0.0,0.0", false)]
        public Vector2 AimPos
        {
            get { return ConvertUnits.ToDisplayUnits(aimPos); }
            set { aimPos = ConvertUnits.ToSimUnits(value); }
        }

        [Serialize(0.0f, false), Editable]
        public float HoldAngle
        {
            get { return MathHelper.ToDegrees(holdAngle); }
            set { holdAngle = MathHelper.ToRadians(value); }
        }

        private Vector2 swingAmount;
        [Serialize("0.0,0.0", false), Editable]
        public Vector2 SwingAmount
        {
            get { return ConvertUnits.ToDisplayUnits(swingAmount); }
            set { swingAmount = ConvertUnits.ToSimUnits(value); }
        }
        
        [Serialize(0.0f, false), Editable]
        public float SwingSpeed { get; set; }

        [Serialize(false, false), Editable]
        public bool SwingWhenHolding { get; set; }
        [Serialize(false, false), Editable]
        public bool SwingWhenAiming { get; set; }
        [Serialize(false, false), Editable]
        public bool SwingWhenUsing { get; set; }
        
        public Holdable(Item item, XElement element)
            : base(item, element)
        {
            body = item.body;

            Pusher = null;
            if (element.GetAttributeBool("blocksplayers", false))
            {
                Pusher = new PhysicsBody(item.body.width, item.body.height, item.body.radius, item.body.Density)
                {
                    BodyType = FarseerPhysics.Dynamics.BodyType.Dynamic,
                    CollidesWith = Physics.CollisionCharacter,
                    CollisionCategories = Physics.CollisionItemBlocking,
                    Enabled = false
                };
                Pusher.FarseerBody.FixedRotation = false;
                Pusher.FarseerBody.GravityScale = 0.0f;
            }

            handlePos = new Vector2[2];
            scaledHandlePos = new Vector2[2];
            Vector2 previousValue = Vector2.Zero;
            for (int i = 1; i < 3; i++)
            {
                int index = i - 1;
                string attributeName = "handle" + i;
                var attribute = element.Attribute(attributeName);
                // If no value is defind for handle2, use the value of handle1.
                var value = attribute != null ? ConvertUnits.ToSimUnits(XMLExtensions.ParseVector2(attribute.Value)) : previousValue;
                handlePos[index] = value;
                previousValue = value;
            }

            canBePicked = true;
            
            if (attachable)
            {
                prevMsg = DisplayMsg;
                prevPickKey = PickKey;
                prevRequiredItems = new Dictionary<RelatedItem.RelationType, List<RelatedItem>>(requiredItems);
                                
                if (item.Submarine != null)
                {
                    if (item.Submarine.Loading)
                    {
                        AttachToWall();
                        attached = false;
                    }
                    else //the submarine is not being loaded, which means we're either in the sub editor or the item has been spawned mid-round
                    {
                        if (Screen.Selected == GameMain.SubEditorScreen)
                        {
                            //in the sub editor, attach
                            AttachToWall();
                        }
                        else
                        {
                            //spawned mid-round, deattach
                            DeattachFromWall();
                        }
                    }
                }
            }    
        }

        public override void Load(XElement componentElement)
        {
            base.Load(componentElement);
            if (attachable)
            {
                prevMsg = DisplayMsg;
                prevPickKey = PickKey;
                prevRequiredItems = new Dictionary<RelatedItem.RelationType, List<RelatedItem>>(requiredItems);
            }
        }

        public override void Drop(Character dropper)
        {
            Drop(true, dropper);
        }

        private void Drop(bool dropConnectedWires, Character dropper)
        {
            if (dropConnectedWires)
            {
                DropConnectedWires(dropper);
            }

            if (attachable)
            {
                DeattachFromWall();

                if (body != null)
                {
                    item.body = body;
                }
            }
            
            if (Pusher != null) Pusher.Enabled = false;
            if (item.body != null) item.body.Enabled = true;
            IsActive = false;

            if (picker == null)
            {
                if (dropper == null) return;
                picker = dropper;
            }
            if (picker.Inventory == null) return;

            item.Submarine = picker.Submarine;
            if (item.body != null)
            {
                item.body.ResetDynamics();
                Limb heldHand;
                Limb arm;
                if (picker.Inventory.IsInLimbSlot(item, InvSlotType.LeftHand))
                {
                    heldHand = picker.AnimController.GetLimb(LimbType.LeftHand);
                    arm = picker.AnimController.GetLimb(LimbType.LeftArm);
                }
                else
                {
                    heldHand = picker.AnimController.GetLimb(LimbType.RightHand);
                    arm = picker.AnimController.GetLimb(LimbType.RightArm);
                }

                float xDif = (heldHand.SimPosition.X - arm.SimPosition.X) / 2f;
                float yDif = (heldHand.SimPosition.Y - arm.SimPosition.Y) / 2.5f;
                //hand simPosition is actually in the wrist so need to move the item out from it slightly
                item.SetTransform(heldHand.SimPosition + new Vector2(xDif, yDif), 0.0f);
            }

            picker.DeselectItem(item);
            picker.Inventory.RemoveItem(item);
            picker = null;
        }

        public override void Equip(Character character)
        {
            picker = character;

            if (character != null) item.Submarine = character.Submarine;

            if (item.body == null)
            {
                if (body != null)
                {
                    item.body = body;
                }
                else
                {
                    return;
                }
            }

            if (!item.body.Enabled)
            {
                Limb rightHand = picker.AnimController.GetLimb(LimbType.RightHand);
                item.SetTransform(rightHand.SimPosition, 0.0f);
            }

            bool alreadySelected = character.HasEquippedItem(item);
            if (picker.TrySelectItem(item) || picker.HasEquippedItem(item))
            {
                item.body.Enabled = true;
                IsActive = true;

#if SERVER
                if (!alreadySelected) GameServer.Log(character.LogName + " equipped " + item.Name, ServerLog.MessageType.ItemInteraction);
#endif
            }
        }

        public override void Unequip(Character character)
        {
            if (picker == null) return;

            picker.DeselectItem(item);
#if SERVER
            GameServer.Log(character.LogName + " unequipped " + item.Name, ServerLog.MessageType.ItemInteraction);
#endif

            item.body.Enabled = false;
            IsActive = false;
        }

        public bool CanBeAttached()
        {
            if (!attachable || !Reattachable) return false;

            //can be attached anywhere in sub editor
            if (Screen.Selected == GameMain.SubEditorScreen) return true;

            //can be attached anywhere inside hulls
            if (item.CurrentHull != null) return true;

            return Structure.GetAttachTarget(item.WorldPosition) != null;
        }
        
        public bool CanBeDeattached()
        {
            if (!attachable || !attached) return true;

            //allow deattaching everywhere in sub editor
            if (Screen.Selected == GameMain.SubEditorScreen) return true;

            //don't allow deattaching if part of a sub and outside hulls
            return item.Submarine == null || item.CurrentHull != null;
        }

        public override bool Pick(Character picker)
        {
            if (!attachable)
            {
                return base.Pick(picker);
            }

            if (!CanBeDeattached()) return false;

            if (Attached)
            {
                return base.Pick(picker);
            }
            else
            {
                //not attached -> pick the item instantly, ignoring picking time
                return OnPicked(picker);
            }
        }

        public override bool OnPicked(Character picker)
        {
            if (base.OnPicked(picker))
            {
                DeattachFromWall();

#if SERVER
                if (GameMain.Server != null && attachable)
                {
                    item.CreateServerEvent(this);
                    if (picker != null)
                    {
                        GameServer.Log(picker.LogName + " detached " + item.Name + " from a wall", ServerLog.MessageType.ItemInteraction);
                    }
                }
#endif
                return true;
            }

            return false;
        }

        public void AttachToWall()
        {
            if (!attachable) return;

            //outside hulls/subs -> we need to check if the item is being attached on a structure outside the sub
            if (item.CurrentHull == null && item.Submarine == null)
            {
                Structure attachTarget = Structure.GetAttachTarget(item.WorldPosition);
                if (attachTarget != null)
                {
                    if (attachTarget.Submarine != null)
                    {
                        //set to submarine-relative position
                        item.SetTransform(ConvertUnits.ToSimUnits(item.WorldPosition - attachTarget.Submarine.Position), 0.0f, false);
                    }
                    item.Submarine = attachTarget.Submarine;
                }
            }

            var containedItems = item.ContainedItems;
            if (containedItems != null)
            {
                foreach (Item contained in containedItems)
                {
                    if (contained.body == null) continue;
                    contained.SetTransform(item.SimPosition, contained.body.Rotation);
                }
            }

            body.Enabled = false;
            item.body = null;

            DisplayMsg = prevMsg;
            PickKey = prevPickKey;
            requiredItems = new Dictionary<RelatedItem.RelationType, List<RelatedItem>>(prevRequiredItems);

            attached = true;
        }

        public void DeattachFromWall()
        {
            if (!attachable) return;

            attached = false;

            //make the item pickable with the default pick key and with no specific tools/items when it's deattached
            requiredItems.Clear();
            DisplayMsg = "";
            PickKey = InputType.Select;
        }

        public override bool Use(float deltaTime, Character character = null)
        {
            if (!attachable || item.body == null) { return character == null || character.IsKeyDown(InputType.Aim); }
            if (character != null)
            {
                if (!character.IsKeyDown(InputType.Aim)) { return false; }
                if (!CanBeAttached()) { return false; }
#if SERVER
                if (GameMain.Server != null)
                {
                    item.CreateServerEvent(this);
                    GameServer.Log(character.LogName + " attached " + item.Name + " to a wall", ServerLog.MessageType.ItemInteraction);
                }
#endif
            }

            if (GameMain.NetworkMember == null || GameMain.NetworkMember.IsServer)
            {
                if (character != null) { item.Drop(character); }
                AttachToWall();
            }

            return true;
        }

        public override void UpdateBroken(float deltaTime, Camera cam)
        {
            Update(deltaTime, cam);
        }

        public override void Update(float deltaTime, Camera cam)
        {
            if (item.body == null || !item.body.Enabled) return;
            if (picker == null || !picker.HasEquippedItem(item))
            {
                if (Pusher != null) Pusher.Enabled = false;
                IsActive = false;
                return;
            }

            Vector2 swing = Vector2.Zero;
            if (swingAmount != Vector2.Zero)
            {
                swingState += deltaTime;
                swingState %= 1.0f;
                if (SwingWhenHolding ||
                    (SwingWhenAiming && picker.IsKeyDown(InputType.Aim)) ||
                    (SwingWhenUsing && picker.IsKeyDown(InputType.Aim) && picker.IsKeyDown(InputType.Use)))
                {
                    swing = swingAmount * new Vector2(
                        PerlinNoise.GetPerlin(swingState * SwingSpeed * 0.1f, swingState * SwingSpeed * 0.1f) - 0.5f,
                        PerlinNoise.GetPerlin(swingState * SwingSpeed * 0.1f + 0.5f, swingState * SwingSpeed * 0.1f + 0.5f) - 0.5f);
                }
            }
            
            ApplyStatusEffects(ActionType.OnActive, deltaTime, picker);

            if (item.body.Dir != picker.AnimController.Dir) Flip();

            item.Submarine = picker.Submarine;
            
            if (picker.HasSelectedItem(item))
            {
                scaledHandlePos[0] = handlePos[0] * item.Scale;
                scaledHandlePos[1] = handlePos[1] * item.Scale;
                picker.AnimController.HoldItem(deltaTime, item, scaledHandlePos, holdPos + swing, aimPos + swing, picker.IsKeyDown(InputType.Aim) && aimPos != Vector2.Zero, holdAngle);
            }
            else
            {
                Limb equipLimb = null;
                if (picker.Inventory.IsInLimbSlot(item, InvSlotType.Headset) || picker.Inventory.IsInLimbSlot(item, InvSlotType.Head))
                {
                    equipLimb = picker.AnimController.GetLimb(LimbType.Head);
                }
                else if (picker.Inventory.IsInLimbSlot(item, InvSlotType.InnerClothes) || 
                    picker.Inventory.IsInLimbSlot(item, InvSlotType.OuterClothes))
                {
                    equipLimb = picker.AnimController.GetLimb(LimbType.Torso);
                }

                if (equipLimb != null)
                {
                    float itemAngle = (equipLimb.Rotation + holdAngle * picker.AnimController.Dir);

                    Matrix itemTransfrom = Matrix.CreateRotationZ(equipLimb.Rotation);
                    Vector2 transformedHandlePos = Vector2.Transform(handlePos[0] * item.Scale, itemTransfrom);

                    item.body.ResetDynamics();
                    item.SetTransform(equipLimb.SimPosition - transformedHandlePos, itemAngle);
                }
            }
        }

        public void Flip()
        {
            handlePos[0].X = -handlePos[0].X;
            handlePos[1].X = -handlePos[1].X;
            item.body.Dir = -item.body.Dir;
        }

        public override void OnItemLoaded()
        {
            if (item.Submarine != null && item.Submarine.Loading) return;
            OnMapLoaded();
        }

        public override void OnMapLoaded()
        {
            if (!attachable) return;
            
            if (Attached)
            {
                AttachToWall();
            }
            else
            {
                if (item.ParentInventory != null)
                {
                    if (body != null)
                    {
                        item.body = body;
                        body.Enabled = false;
                    }
                }
                DeattachFromWall();
            }
        }

        public override void ServerWrite(NetBuffer msg, Client c, object[] extraData = null)
        {
            base.ServerWrite(msg, c, extraData);
            if (!attachable || body == null) { return; }

            msg.Write(Attached);
            msg.Write(body.SimPosition.X);
            msg.Write(body.SimPosition.Y);
        }

        public override void ClientRead(ServerNetObject type, NetBuffer msg, float sendingTime)
        {
            base.ClientRead(type, msg, sendingTime);
            bool shouldBeAttached = msg.ReadBoolean();
            Vector2 simPosition = new Vector2(msg.ReadFloat(), msg.ReadFloat());

            if (!attachable)
            {
                DebugConsole.ThrowError("Received an attachment event for an item that's not attachable.");
                return;
            }

            if (shouldBeAttached)
            {
                if (!attached)
                {
                    Drop(false, null);
                    item.SetTransform(simPosition, 0.0f);
                    AttachToWall();
                }
            }
            else
            {
                if (attached)
                {
                    DropConnectedWires(null);

                    if (body != null)
                    {
                        item.body = body;
                        item.body.Enabled = true;
                    }
                    IsActive = false;

                    DeattachFromWall();
                }
            }
        }
    }
}