using System;
using System.Text;
using Vintagestory.API.Client;
using Vintagestory.API.Common;
using Vintagestory.API.Datastructures;
using Vintagestory.API.MathTools;
using Vintagestory.GameContent;

namespace ButterflyPins.BlockEntities;

public class BlockEntityButterflyPinBoard : BlockEntityDisplay
{
    private const int MaxBoardSlots = 9;
    private const float BoardMargin = 1f / 16f;
    private const float BoardSurface = 1f / 16f;
    private const string ButterflyPinPrefix = "clothes-butterflypin-";

    private readonly InventoryGeneric inventory;

    public override InventoryBase Inventory => inventory;

    public override string InventoryClassName => "butterflypinboard";

    public override int DisplayedItems => ActiveSlotCount;

    private int Rows => Math.Max(1, Block?.Attributes?["rows"].AsInt(2) ?? 2);

    private int Columns => Math.Max(1, Block?.Attributes?["columns"].AsInt(2) ?? 2);

    private float RenderScale => Block?.Attributes?["renderScale"].AsFloat(0.18f) ?? 0.18f;

    private float DisplayOriginX => GetDisplayFloat("displayOriginX", 0.31666666f);

    private float DisplayOriginY => GetDisplayFloat("displayOriginY", 0.01333332f);

    private float DisplayOriginZ => GetDisplayFloat("displayOriginZ", 0.47916666f);

    private float DisplayStepX => GetDisplayFloat("displayStepX", -0.25f);

    private float DisplayStepY => GetDisplayFloat("displayStepY", -0.25f);

    private int ActiveSlotCount => Rows * Columns;

    public BlockEntityButterflyPinBoard()
    {
        inventory = new InventoryGeneric(MaxBoardSlots, null, null);
    }

    public override void FromTreeAttributes(ITreeAttribute tree, IWorldAccessor worldForResolving)
    {
        base.FromTreeAttributes(tree, worldForResolving);
        RedrawAfterReceivingTreeAttributes(worldForResolving);
    }

    public bool TryInsert(IPlayer byPlayer, int slotIndex, ItemSlot activeSlot)
    {
        if (!IsValidSlot(slotIndex) || activeSlot.Empty || !CanInsert(slotIndex, activeSlot.Itemstack))
            return false;

        ItemStack sourceStack = activeSlot.Itemstack;
        ItemStack placedStack = sourceStack.Clone();
        placedStack.StackSize = 1;
        inventory[slotIndex].Itemstack = placedStack;

        activeSlot.TakeOut(1);
        activeSlot.MarkDirty();
        inventory[slotIndex].MarkDirty();
        MarkChanged();
        return true;
    }

    public bool TryTake(IPlayer byPlayer, int slotIndex)
    {
        if (!CanTake(slotIndex))
            return false;

        ItemSlot slot = inventory[slotIndex];
        ItemStack stack = slot.Itemstack!;
        slot.Itemstack = null;
        slot.MarkDirty();

        if (!byPlayer.InventoryManager.TryGiveItemstack(stack, true))
            Api.World.SpawnItemEntity(stack, Pos.ToVec3d().Add(0.5, 0.5, 0.5));

        MarkChanged();
        return true;
    }

    public bool CanInsert(int slotIndex, ItemStack stack)
    {
        return IsValidSlot(slotIndex) && inventory[slotIndex].Empty && IsButterflyPin(stack);
    }

    public bool CanTake(int slotIndex)
    {
        return IsValidSlot(slotIndex) && !inventory[slotIndex].Empty;
    }

    public void DropContents()
    {
        for (int slotIndex = 0; slotIndex < ActiveSlotCount; slotIndex++)
        {
            ItemSlot slot = inventory[slotIndex];
            ItemStack? stack = slot.Itemstack;
            if (stack == null)
                continue;

            Api.World.SpawnItemEntity(stack, Pos.ToVec3d().Add(0.5, 0.5, 0.5));
            slot.Itemstack = null;
            slot.MarkDirty();
        }
    }

    public override void GetBlockInfo(IPlayer forPlayer, StringBuilder dsc)
    {
        int highlightedSlot = -1;
        BlockSelection? selection = forPlayer?.CurrentBlockSelection;
        if (selection?.Position != null && selection.Position.Equals(Pos))
            highlightedSlot = GetSlotIndex(selection.HitPosition);

        AppendContentsBlockInfo(dsc, highlightedSlot);
    }

    public bool AppendContentsBlockInfo(StringBuilder builder, int highlightedSlot)
    {
        int initialLength = builder.Length;

        for (int slotIndex = 0; slotIndex < ActiveSlotCount; slotIndex++)
        {
            ItemStack? stack = inventory[slotIndex].Itemstack;
            if (stack == null)
                continue;

            if (builder.Length > initialLength)
                builder.AppendLine();
            else if (initialLength > 0)
                builder.AppendLine();

            string itemName = stack.GetName();
            if (slotIndex == highlightedSlot)
            {
                builder.Append("<font color=\"#00ffff\">");
                builder.Append(itemName);
                builder.Append("</font>");
                continue;
            }

            builder.Append(itemName);
        }

        return builder.Length > initialLength;
    }

    public int GetSlotIndex(Vec3d hitPosition)
    {
        Vec3d local = ToBaseOrientation(hitPosition);
        if (local.X < BoardMargin || local.X > 1 - BoardMargin || local.Y < BoardMargin || local.Y > 1 - BoardMargin)
            return -1;

        double width = (1 - (BoardMargin * 2)) / Columns;
        double height = (1 - (BoardMargin * 2)) / Rows;

        int column = GameMath.Clamp((int)((local.X - BoardMargin) / width), 0, Columns - 1);
        if (IsNorthSouthVariant())
            column = (Columns - 1) - column;

        int rowFromBottom = GameMath.Clamp((int)((local.Y - BoardMargin) / height), 0, Rows - 1);
        int rowFromTop = Rows - 1 - rowFromBottom;

        return (rowFromTop * Columns) + column;
    }

    private bool IsValidSlot(int slotIndex)
    {
        return slotIndex >= 0 && slotIndex < ActiveSlotCount;
    }

    private bool IsButterflyPin(ItemStack stack)
    {
        AssetLocation? code = stack.Collectible?.Code;
        return code != null && code.Path.StartsWith(ButterflyPinPrefix, StringComparison.Ordinal);
    }

    private void MarkChanged()
    {
        RedrawAfterReceivingTreeAttributes(Api.World);
        base.MarkDirty(true);
        Api.World.BlockAccessor.MarkBlockDirty(Pos);
    }

    private Vec3d ToBaseOrientation(Vec3d hitPosition)
    {
        Vec3d centered = new(hitPosition.X - 0.5, hitPosition.Y, hitPosition.Z - 0.5);
        float angle = -GetRotationY();
        float sin = GameMath.Sin(angle);
        float cos = GameMath.Cos(angle);

        return new Vec3d(
            (centered.X * cos) - (centered.Z * sin) + 0.5,
            hitPosition.Y,
            (centered.X * sin) + (centered.Z * cos) + 0.5
        );
    }

    private float GetDisplayFloat(string key, float defaultValue)
    {
        return Block?.Attributes?[key].AsFloat(defaultValue) ?? defaultValue;
    }

    protected override float[][] genTransformationMatrices()
    {
        float[][] matrices = new float[DisplayedItems][];
        float boardRotationY = GetRotationY();
        float itemRotationY = boardRotationY - GameMath.PIHALF;

        for (int slotIndex = 0; slotIndex < DisplayedItems; slotIndex++)
        {
            int row = slotIndex / Columns;
            int column = slotIndex % Columns;

            Vec3f off = new(
                DisplayOriginX + (column * DisplayStepX),
                DisplayOriginY + (row * DisplayStepY),
                DisplayOriginZ
            );
            off = new Matrixf().RotateY(boardRotationY).TransformVector(off.ToVec4f(0)).XYZ;

            matrices[slotIndex] = new Matrixf()
                .Translate(off.X, off.Y, off.Z)
                .Translate(0.5f, 0.5f, 0.5f)
                .RotateY(itemRotationY)
                .Scale(RenderScale, RenderScale, RenderScale)
                .Translate(-0.5f, -0.5f, -0.5f)
                .Values;
        }

        return matrices;
    }

    public float GetRotationY()
    {
        string side = Block?.Variant?["side"] ?? "south";
        return side switch
        {
            "north" => GameMath.PI,
            "east" => GameMath.PIHALF,
            "west" => GameMath.PI + GameMath.PIHALF,
            _ => 0f,
        };
    }

    private bool IsNorthSouthVariant()
    {
        string side = Block?.Variant?["side"] ?? "south";
        return side is "north" or "south";
    }

    public float GetRenderScale()
    {
        return RenderScale;
    }
}