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

using Cpp2Beef;
using LibClang;

namespace KTX.Setup;

class ExampleGenerator : Cpp2BeefGenerator, this(Span<char8*> args)
{
	protected override Span<char8*> Args => args;
	protected override Flags Flags => .None;

	StreamWriter ktxWriter = new .()..Create("../src/KTX.bf")..Write("""
		// This file was generated by Cpp2Beef

		using System;
		using System.Interop;

		namespace KTX;


		""") ~ delete _;
	StreamWriter ktxVulkanWriter = new .()..Create("../src/KTXVulkan.bf")..Write("""
		// This file was generated by Cpp2Beef

		using System;
		using System.Interop;

		namespace KTX;


		""") ~ delete _;
	StreamWriter khrDfWriter = new .()..Create("../src/KHR_df.bf")..Write("""
		// This file was generated by Cpp2Beef

		using System;
		using System.Interop;

		namespace KTX;


		""") ~ delete _;

	protected override StreamWriter GetWriterForHeader(StringView header)
	{
		if (header.EndsWith("ktx.h"))
			return ktxWriter;
		if (header.EndsWith("ktxvulkan.h"))
			return ktxVulkanWriter;
		if (header.EndsWith("khr_df.h"))
			return khrDfWriter;
		return null;
	}

	Dictionary<String, CXType> vtblPfns = new .(24) ~ DeleteDictionaryAndKeys!(_);

	protected override void HandleCursor(CXCursor cursor)
	{
		switch (cursor.kind)
		{
		case .TypedefDecl:
			let spelling = GetCursorSpelling!(cursor);
			if (spelling == "ktxHashList" || spelling == "ktxHashListEntry" || spelling == "ktxStream")
				return;
		case .MacroDefinition:
			let spelling = GetCursorSpelling!(cursor);
			if (spelling == "KTXTEXTURECLASSDEFN" || spelling == "KTX_APIENTRYP" || spelling == "KTX_API" ||
				spelling == "KTX_APIENTRY" || spelling == "KTX_error_code")
				return;

			if (Clang.Cursor_IsMacroFunctionLike(cursor) == 0 || !spelling.StartsWith("ktx")) break;
			BeginCursor(cursor);
			AccessSpecifier(cursor);
			str.Append("static ");
			let nameInBindings = spelling[(spelling.IndexOf('_')+1)...];
			Runtime.Assert(vtblPfns.TryGetAlt(nameInBindings, ?, let pfnType));
			Type(Clang.GetResultType(pfnType));
			str.Append(' ');
			str.Append(nameInBindings);
			Flush();
			let tokens = ScopeTokenize!(cursor, unit);
			WriteTokens(tokens[1...], Clang.GetRangeEnd(Clang.Cursor_GetSpellingNameRange(cursor, 0, 0)), .Identifier);
			String buffer = scope .(256)..Append(str);
			uint32 argI = 0;
			insert: for (int i = 0; i < buffer.Length; i++)
			{
				switch (buffer[i])
				{
				case '(', ',':
					str.Clear();
					Type(Clang.GetArgType(pfnType, argI++));
					str.Append(' ');
					int idx = i+1 + (_ == ',' ? 1 : 0);
					buffer.Insert(idx, str);
				case ')':
					buffer.Insert(i+1, " =>");
					break insert;
				}
			}
			buffer.Replace("->", ".");
			str.Set(buffer);
			str.Append(';');
			return;
		case .StructDecl:
			if (Clang.Cursor_IsAnonymous(cursor) != 0)
				return;
			if (Clang.GetCursorLexicalParent(cursor).kind == .StructDecl)
				return;
			let spelling = GetCursorSpelling!(cursor);
			if (spelling == "ktxKVListEntry" || (spelling == "ktxStream" && Clang.EqualCursors(cursor, Clang.GetTypeDeclaration(Clang.GetCursorType(cursor))) != 0))
				return;
			BeginCursor(cursor);
			Record(cursor);
			return;
		case .FieldDecl:
			if (GetCursorSpelling!(Clang.GetCursorSemanticParent(cursor)) == "ktxTexture_vtbl")
				vtblPfns.Add(new .(GetCursorSpelling!(cursor)),
					Clang.GetPointeeType(Clang.GetTypedefDeclUnderlyingType(Clang.GetTypeDeclaration(Clang.GetCursorType(cursor))))
				);
		default:
		}
		base.HandleCursor(cursor);
		if (fileInfo.prevEnd == default)
			fileInfo.prevEnd = GetCursorAnchor(cursor);
	}

	append String blockBuffer;
	protected override Block GetCursorBlock(CXCursor cursor)
	{
		if (cursor.kind == .FunctionDecl || cursor.kind == .MacroDefinition) do
		{
			let spelling = GetCursorSpelling!(cursor);
			if (!spelling.StartsWith("ktx")) break;
			int index = spelling.IndexOf('_');
			if (index < 0) break;
			blockBuffer.Set(spelling[..<index]);
			return .CustomBlock(blockBuffer);
		}
		return base.GetCursorBlock(cursor);
	}

	protected override void WriteCustomAttributes(CXCursor cursor)
	{
		if (cursor.kind == .FunctionDecl || (cursor.kind == .TypedefDecl &&
			{
				let type = Clang.GetTypedefDeclUnderlyingType(cursor);
				let pointee = Clang.GetPointeeType(type).kind;
				type.kind == .Pointer && (pointee == .FunctionNoProto || pointee == .FunctionProto)
			}))
		{
			str.Append("[CallingConvention(KTX_APIENTRYP)] ");
		}
		base.WriteCustomAttributes(cursor);
	}

	protected override void WriteTokensAfterEquals(CXCursor cursor)
	{
		if (cursor.kind == .ParmDecl)
			return; // avoid clang compiler bug
		base.WriteTokensAfterEquals(cursor);
	}

	protected override void WriteToken(CXToken token)
	{
		if (currentCursor.kind == .MacroDefinition)
		{
			let cursorSpelling = GetCursorSpelling!(currentCursor);
			if (Clang.GetTokenKind(token) == .Punctuation && cursorSpelling == "KTX_IDENTIFIER_REF")
				switch (GetTokenSpelling!(token))
				{
				case "{": str.Append("uint8[?]("); return;
				case "}": str.Append(')'); return;
				}
			else if (cursorSpelling == "KTX_TRUE" || cursorSpelling == "KTX_FALSE")
			{
				str.Append(GetTokenSpelling!(token));
				return;
			}
			else if (cursorSpelling == "KTX_FACESLICE_WHOLE_LEVEL")
			{
				str.Append("uint32.MaxValue");
				return;
			}
		}
		base.WriteToken(token);
	}

	protected override void Type(CXType type, TypeParamMode paramMode = .None)
	{
		if (currentCursor.kind == .TypedefDecl && Clang.EqualTypes(Clang.GetCursorType(currentCursor), type) != 0 && GetTypeSpelling!(type) == "ktx_uint32_t")
		{
			let cursorSpelling = GetCursorSpelling!(currentCursor);
			str.Append(cursorSpelling);
			if (cursorSpelling.EndsWith("_flags"))
			{
				str.Length--;
				str.Append("_bits");
			}
			str.Append("_e");
			return;
		}
		base.Type(type, paramMode);
	}

	protected override void GetNameInBindings(CXCursor cursor, String outString)
	{
		switch (cursor.kind)
		{
		case .EnumDecl:
			var spelling = GetCursorSpelling!(cursor);
			if (spelling.StartsWith("_khr"))
				spelling.RemoveFromStart(1);
			outString.Append(spelling);
			return;
		case .EnumConstantDecl:
			var parent = GetCursorSpelling!(Clang.GetCursorSemanticParent(cursor));
			if (parent == "ktx_error_code_e") break;
			if (parent == "_khr_word_e")
				parent = "khr_df_word_e";
			var spelling = GetCursorSpelling!(cursor);
			if (parent == "_khr_df_model_channels_e")
			{
				spelling.RemoveFromStart("KHR_DF_CHANNEL_".Length);
				outString.Append(spelling);
				return;
			}
			if (parent == "ktxSupercmpScheme")
			{
				spelling.RemoveFromStart("KTX_SS_".Length);
				UpperSnakeCase2PascalCase(spelling, outString);
				return;
			}
			if (parent == "ktxTextureCreateStorageEnum")
			{
				spelling.RemoveFromStart("KTX_TEXTURE_CREATE_".Length);
				UpperSnakeCase2PascalCase(spelling, outString);
				return;
			}
			if (parent == "ktxTextureCreateFlagBits")
			{
				spelling.RemoveFromStart("KTX_TEXTURE_CREATE_".Length);
				if (spelling.EndsWith("_BIT"))
					spelling.RemoveFromEnd(4);
				UpperSnakeCase2PascalCase(spelling, outString);
				return;
			}
			for (var part in parent.Split('_', .RemoveEmptyEntries))
			{
				if (part == "e") break;
				part.Length++;
				if (!spelling.StartsWith(part, .OrdinalIgnoreCase))
				{
					if (part.EndsWith("s_") && spelling.StartsWith(part[..<^2], .OrdinalIgnoreCase))
						part.Length--;
					else
						break;
				}
				spelling.RemoveFromStart(part.Length);
			}
			if (spelling[0].IsDigit)
				outString.Append('_');
			UpperSnakeCase2PascalCase(spelling, outString);
			return;
		case .FunctionDecl:
			let spelling = GetCursorSpelling!(cursor);
			int index = spelling.IndexOf('_');
			if (index < 0) break;
			outString.Append(spelling[(index+1)...]);
			return;
		default:
		}
        base.GetNameInBindings(cursor, outString);
	}
}

class Program
{
	[CLink] static extern int32 system(char8*);

	public static int Main(String[] args)
	{
		if (system("git -C .. submodule init") != 0)
			Runtime.FatalError("Failed to fetch KTX-Software");
		/*if (system(scope $"wget -O include/KHR/khr_df.h https://registry.khronos.org/DataFormat/api/1.3/khr_df.h") != 0)
			Runtime.FatalError("Failed to download khr_df.h");
		if (system(scope $"wget -O include/vulkan_core.h https://raw.githubusercontent.com/KhronosGroup/Vulkan-Headers/refs/heads/main/include/vulkan/vulkan_core.h") != 0)
			Runtime.FatalError("Failed to download vulkan_core.h");
		if (system(scope $"wget -O include/vk_platform.h https://raw.githubusercontent.com/KhronosGroup/Vulkan-Headers/refs/heads/main/include/vulkan/vk_platform.h") != 0)
			Runtime.FatalError("Failed to download vk_platform.h");*/

		scope ExampleGenerator(char8*[?]("--language=c", "-I../KTX-Software/lib/include", "-I../KTX-Software/external/dfdutils", "-DKTX_DOXYGEN_SKIP")).Generate("include/all.h");
		return 0;
	}
}