using AssetRipper.Export.Modules.Shaders.ShaderBlob;
using AssetRipper.Export.Modules.Shaders.ShaderBlob.Parameters;
using AssetRipper.Export.Modules.Shaders.UltraShaderConverter.UShader.Function;
using AssetRipper.Import.Logging;

namespace AssetRipper.Export.Modules.Shaders.UltraShaderConverter.USIL.Metadders;

public class USILSamplerMetadder : IUSILOptimizer
{
	public bool Run(UShaderProgram shader, ShaderSubProgram shaderData)
	{
		List<USILInstruction> instructions = shader.instructions;
		foreach (USILInstruction instruction in instructions)
		{
			foreach (USILOperand operand in instruction.srcOperands)
			{
				if (operand.operandType == USILOperandType.SamplerRegister)
				{
					TextureParameter? texParam = shaderData.TextureParameters.FirstOrDefault(
						p => p.SamplerIndex == operand.registerIndex
					);

					if (texParam == null)
					{
						operand.operandType = USILOperandType.Sampler2D;
						Logger.Warning($"Could not find texture parameter for sampler {operand}");
						continue;
					}

					int dimension = texParam.Dim;
					switch (dimension)
					{
						case 2:
							operand.operandType = USILOperandType.Sampler2D;
							break;
						case 3:
							operand.operandType = USILOperandType.Sampler3D;
							break;
						case 4:
							operand.operandType = USILOperandType.SamplerCube;
							break;
						case 5:
							operand.operandType = USILOperandType.Sampler2DArray;
							break;
						case 6:
							operand.operandType = USILOperandType.SamplerCubeArray;
							break;
					}

					if (texParam != null)
					{
						operand.metadataName = texParam.Name;
						operand.metadataNameAssigned = true;
					}
				}
				else if (operand.operandType == USILOperandType.ResourceRegister)
				{
					TextureParameter? texParam = shaderData.TextureParameters.FirstOrDefault(
						p => p.Index == operand.registerIndex
					);

					if (texParam == null)
					{
						Logger.Warning($"Could not find texture parameter for resource {operand}");
						continue;
					}

					if (texParam != null)
					{
						operand.metadataName = texParam.Name;
						operand.metadataNameAssigned = true;
					}
				}
			}
		}
		return true; // any changes made?
	}
}