#pragma once

#include <vector>
#include <string>

// Foward declarations of STD classes to minimise includes //
namespace std
{
	template<typename T1 = char>
	struct char_traits;

	template<typename T1, typename T2>
	class basic_ifstream;

	template<typename T1, typename T2>
	class basic_ofstream;

	using ifstream = basic_ifstream<char, char_traits<char>>;
	using ofstream = basic_ofstream<char, char_traits<char>>;
}

// This file contains everything that is exported from Lexer.lib
// The rest of the items within the Lexer project are internal only

namespace LX
{
	struct InvalidCharInSource
	{
		std::streamsize index;
		char invalid;
	};

	// Data type to store a more computer readable version of files
	struct __declspec(novtable) Token final
	{
		// Enum to hold the type of the token
		enum TokenType : short
		{
			// General tokens //

			STRING_LITERAL,
			NUMBER_LITERAL,
			IDENTIFIER,
			RETURN,

			// Operators //

			ADD, SUB, MUL, DIV,

			// Keywords //

			FOR, WHILE,
			IF, ELSE, ELIF,

			FUNCTION,

			// You made a mistake somehow //

			UNDEFINED = -1
		};

		// Constructor of the tokens to set their info
		Token(const TokenType _type, std::string _contents);

		// Contents of the token (may be empty if not needed)
		// Const to avoid external changes
		const std::string contents;

		// Type of the token
		// Const to avoid external changes
		const TokenType type;
	};

	// Lexer function to take in a file and output a vector of tokens
	const std::vector<Token> LexicalAnalyze(std::ifstream& src, std::ofstream* log);
}