using System.Collections.Generic;
using UnityEngine;

namespace Assets.ThoMagic.Renderer
{
    public class DrawGroup
    {
        private List<DrawCall> _drawCalls = new List<DrawCall>();

        public void Add(DrawCall drawCall) => _drawCalls.Add(drawCall);

        private int lodNr;

        public DrawGroup(int lodNr)
        {
            this.lodNr = lodNr;
        }

        public uint Add(
              Mesh mesh,
              Material[] materials,
              Matrix4x4 matrix,
              uint indirectArgsCount,
              List<GraphicsBuffer.IndirectDrawIndexedArgs> indirectDrawIndexedArgs,
              in RenderParams renderParams)
        {
            var drawCall = new DrawCall(lodNr, mesh, materials, matrix, indirectArgsCount, indirectDrawIndexedArgs, in renderParams);
            _drawCalls.Add(drawCall);
            return (uint)drawCall.Mesh.subMeshCount;
        }

        public uint Add(
             BillboardAsset mesh,
             Material material,
             Matrix4x4 matrix,
             uint indirectArgsCount,
             List<GraphicsBuffer.IndirectDrawIndexedArgs> indirectDrawIndexedArgs,
             in RenderParams renderParams)
        {
            var drawCall = new BillboardDrawCall(lodNr, mesh, material, matrix, indirectArgsCount, indirectDrawIndexedArgs, in renderParams);
            _drawCalls.Add(drawCall);
            return (uint)drawCall.Mesh.subMeshCount;
        }

        public void Draw(Camera camera, ObjectData obj, GraphicsBuffer indirectDrawIndexedArgs)
        {
            foreach (var drawCall in _drawCalls)
                drawCall?.Draw(camera, obj, indirectDrawIndexedArgs);
        }

        public virtual void SetInstances(ComputeBuffer instances, ComputeBuffer visibleIndexBuffer, ComputeBuffer metaBuffer)
        {
            foreach (var drawCall in _drawCalls)
                drawCall?.SetInstances(instances, visibleIndexBuffer, metaBuffer);
        }

        internal void Dispose()
        {
            foreach (var drawCall in _drawCalls)
                drawCall?.Dispose();

            _drawCalls.Clear();
        }
    }
}