/**************************************************************************/
/*  aethex_tokenizer.h                                                    */
/**************************************************************************/
/*                         This file is part of:                          */
/*                          AETHEX ENGINE                                 */
/*                     https://aethex.foundation                          */
/**************************************************************************/
/* Copyright (c) 2026-present AeThex Labs.                                */
/**************************************************************************/

#pragma once

#include "core/string/ustring.h"
#include "core/templates/vector.h"

class AeThexTokenizer {
public:
	enum TokenType {
		// Literals
		TK_IDENTIFIER,
		TK_NUMBER,
		TK_STRING,
		TK_TEMPLATE_STRING,
		
		// Keywords - Core constructs
		TK_REALITY,        // Module/namespace
		TK_JOURNEY,        // Cross-platform function
		TK_PORTAL,         // Import/export
		TK_BEACON,         // Event/signal
		TK_ARTIFACT,       // Class
		TK_ESSENCE,        // Interface
		TK_CHRONICLE,      // Enum
		
		// Keywords - Control flow
		TK_WHEN,           // If
		TK_OTHERWISE,      // Else
		TK_TRAVERSE,       // For
		TK_WHILE,
		TK_BREAK,
		TK_CONTINUE,
		TK_RETURN,
		TK_YIELD,
		
		// Keywords - Data
		TK_LET,
		TK_CONST,
		TK_MUT,
		TK_NEW,
		
		// Keywords - Platform
		TK_PLATFORM,
		TK_SYNC,
		TK_ASYNC,
		TK_AWAIT,
		TK_ACROSS,
		TK_ALL,
		
		// Keywords - Actions
		TK_NOTIFY,
		TK_REVEAL,
		TK_SUMMON,
		TK_BANISH,
		
		// Keywords - Literals
		TK_TRUE,
		TK_FALSE,
		TK_NULL,
		TK_SELF,
		TK_SUPER,
		
		// Operators
		TK_PLUS,           // +
		TK_MINUS,          // -
		TK_STAR,           // *
		TK_SLASH,          // /
		TK_PERCENT,        // %
		TK_CARET,          // ^
		TK_EQUAL,          // =
		TK_EQUAL_EQUAL,    // ==
		TK_NOT_EQUAL,      // !=
		TK_LESS,           // <
		TK_LESS_EQUAL,     // <=
		TK_GREATER,        // >
		TK_GREATER_EQUAL,  // >=
		TK_AND,            // and / &&
		TK_OR,             // or / ||
		TK_NOT,            // not / !
		TK_PLUS_EQUAL,     // +=
		TK_MINUS_EQUAL,    // -=
		TK_ARROW,          // ->
		TK_FAT_ARROW,      // =>
		
		// Punctuation
		TK_COLON,          // :
		TK_SEMICOLON,      // ;
		TK_COMMA,          // ,
		TK_DOT,            // .
		TK_PAREN_OPEN,     // (
		TK_PAREN_CLOSE,    // )
		TK_BRACKET_OPEN,   // [
		TK_BRACKET_CLOSE,  // ]
		TK_BRACE_OPEN,     // {
		TK_BRACE_CLOSE,    // }
		
		// Special
		TK_NEWLINE,
		TK_INDENT,
		TK_DEDENT,
		TK_EOF,
		TK_ERROR,
	};
	
	struct Token {
		TokenType type = TK_ERROR;
		String value;
		int line = 0;
		int column = 0;
	};
	
private:
	String source;
	int pos = 0;
	int line = 1;
	int column = 1;
	Vector<Token> tokens;
	int indent_stack_count = 0;
	
	char peek(int offset = 0) const;
	char advance();
	bool match(char expected);
	void skip_whitespace();
	void skip_comment();
	
	Token make_token(TokenType type, const String &value = "");
	Token scan_string(char quote);
	Token scan_number();
	Token scan_identifier();
	TokenType check_keyword(const String &identifier);
	
public:
	Error tokenize(const String &p_source);
	const Vector<Token> &get_tokens() const { return tokens; }
	
	static String token_type_to_string(TokenType type);
};