// Copyright Epic Games, Inc. All Rights Reserved.

using System;
using System.Buffers;
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Text;
using EpicGames.Core;
using EpicGames.Serialization;
using EpicGames.BuildGraph.Expressions;

namespace EpicGames.BuildGraph
{
	/// <summary>
	/// Helper class for writing BuildGraph bytecode to a buffer.
	/// </summary>
	public abstract class BgBytecodeWriter
	{
		/// <summary>
		/// Writes an opcode to the output
		/// </summary>
		/// <param name="opcode"></param>
		public abstract void WriteOpcode(BgOpcode opcode);

		/// <summary>
		/// Writes a string to the output
		/// </summary>
		/// <param name="str"></param>
		public abstract void WriteString(string str);

		/// <summary>
		/// Writes a signed integer value to the output
		/// </summary>
		/// <param name="value"></param>
		public abstract void WriteSignedInteger(long value);

		/// <summary>
		/// Writes an unsigned integer to the output
		/// </summary>
		/// <param name="value"></param>
		public void WriteUnsignedInteger(int value) => WriteUnsignedInteger((ulong)value);

		/// <summary>
		/// Writes an unsigned integer to the output
		/// </summary>
		/// <param name="value"></param>
		public abstract void WriteUnsignedInteger(ulong value);

		/// <summary>
		/// Writes an expression to the output buffer
		/// </summary>
		/// <param name="expr"></param>
		public abstract void WriteExpr(BgExpr expr);

		/// <summary>
		/// Writes an expression as a standalone fragment, encoding just the fragment index into the output stream
		/// </summary>
		/// <param name="expr"></param>
		public abstract void WriteExprAsFragment(BgExpr expr);

		/// <summary>
		/// Writes the method to be called for a particular node
		/// </summary>
		/// <param name="method">Method to be called</param>
		public abstract void WriteMethod(BgMethod method);
	}
}