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 | path-to-input-directory> <output-directory>");
			return 1;
		}

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

		if (!Directory.Exists(outputDir))
		{
			Console.WriteLine($"refreshc: Output directory ({outputDir}) does not exist");
			return 1;
		}

		if (Directory.Exists(inputPath))
		{
			// Loop over and compile each file in the directory
			string[] files = Directory.GetFiles(inputPath);
			foreach (string file in files)
			{
				Console.WriteLine($"Compiling {file}");
				int res = CompileShader(file, outputDir);
				if (res != 0)
				{
					return res;
				}
			}
		}
		else
		{
			if (!File.Exists(inputPath))
			{
				Console.WriteLine($"refreshc: glsl source file or directory ({inputPath}) does not exist");
				return 1;
			}

			int res = CompileShader(inputPath, outputDir);
			if (res != 0)
			{
				return res;
			}
		}

		return 0;
	}

	static int CompileShader(string glslPath, string outputDir)
	{
		int res = 0;
		string shaderName = Path.GetFileNameWithoutExtension(glslPath);
		string shaderType = Path.GetExtension(glslPath);

		if (shaderType != ".vert" && shaderType != ".frag" && shaderType != ".comp")
		{
			Console.WriteLine("refreshc: Expected glsl source file with extension '.vert', '.frag', or '.comp'");
			return 1;
		}

		string spirvPath = Path.Combine(outputDir, $"{shaderName}.spv");
		res = CompileGlslToSpirv(glslPath, shaderName, spirvPath);
		if (res != 0)
		{
			return res;
		}

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

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

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

		return res;
	}

	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;
	}
}