using System;
using System.IO;
using System.Diagnostics;

partial class Program
{
	public static int Main(string[] args)
	{
		if (args.Length < 2)
		{
			Console.WriteLine("Usage: refreshc <path-to-glsl> <output-directory>");
			return 1;
		}

		string glslPath = args[0];
		string outputDir = args[1];

		if (!ValidateArgs(glslPath, outputDir))
		{
			return 1;
		}

		string shaderName = Path.GetFileNameWithoutExtension(glslPath);
		string shaderType = Path.GetExtension(glslPath);
		string spirvPath = Path.Combine(outputDir, $"{shaderName}.spv");

		if (CompileGlslToSpirv(glslPath, shaderName, spirvPath) != 0)
		{
			return 1;
		}

		string hlslPath = Path.Combine(outputDir, $"{shaderName}.hlsl");
		if (TranslateSpirvToHlsl(spirvPath, hlslPath) != 0)
		{
			return 1;
		}

		// FIXME: Is there a cross-platform way to compile HLSL to DXBC?

#if PS5
		if (TranslateHlslToPS5(hlslPath, shaderName, shaderType, outputDir) != 0)
		{
			return 1;
		}
#endif

		return 0;
	}

	static bool ValidateArgs(string glslPath, string outputDir)
	{
		if (!File.Exists(glslPath))
		{
			Console.WriteLine($"refreshc: glsl source file ({glslPath}) does not exist");
			return false;
		}

		string ext = Path.GetExtension(glslPath);
		if (ext != ".vert" && ext != ".frag" && ext != ".comp")
		{
			Console.WriteLine("refreshc: Expected glsl source file with extension '.vert', '.frag', or '.comp'");
			return false;
		}

		if (!Directory.Exists(outputDir))
		{
			Console.WriteLine($"refreshc: Output directory ({outputDir}) does not exist");
			return false;
		}

		return true;
	}

	static int CompileGlslToSpirv(string glslPath, string shaderName, string outputPath)
	{
		Process glslc = Process.Start(
			"glslc",
			$"{glslPath} -o {outputPath}"
		);
		glslc.WaitForExit();
		if (glslc.ExitCode != 0)
		{
			Console.WriteLine($"refreshc: Could not compile GLSL code");
			return 1;
		}

		return 0;
	}

	static int TranslateSpirvToHlsl(string spirvPath, string outputPath)
	{
		Process spirvcross = Process.Start(
			"spirv-cross",
			$"{spirvPath} --hlsl --shader-model 50 --output {outputPath}"
		);
		spirvcross.WaitForExit();
		if (spirvcross.ExitCode != 0)
		{
			Console.WriteLine($"refreshc: Could not translate SPIR-V to HLSL");
			return 1;
		}

		return 0;
	}
}