//============================================================================//
//                                                                            //
//                       artichoke programming language                       //
//                                                                            //
//      Copyright (C) 2025 Erick Saul Guzman Ramos, whoami.artichoke.dev      //
//                                                                            //
//                                                                            //
//  This program is free software: you can redistribute it and/or modify      //
//  it under the terms of the GNU Affero General Public License as published  //
//  by the Free Software Foundation, either version 3 of the License, or      //
//  (at your option) any later version.                                       //
//                                                                            //
//  This program is distributed in the hope that it will be useful,           //
//  but WITHOUT ANY WARRANTY; without even the implied warranty of            //
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the             //
//  GNU Affero General Public License for more details.                       //
//                                                                            //
//  You should have received a copy of the GNU Affero General Public License  //
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.    //
//                                                                            //
//============================================================================//

#pragma once

#include <deque>

#include <artichoke/Util/Expected.hpp>
#include <artichoke/Coroutine/Generator.hpp>

#include <artichoke/Tokenizer/Token.hpp>
#include <artichoke/Tokenizer/TokenizerRange.hpp>

namespace arti::lang {

  struct [[nodiscard]] Tokenizer {
    Tokenizer() noexcept = delete;

    Tokenizer(std::string source) noexcept;

    ~Tokenizer() noexcept = default;

    Tokenizer(Tokenizer &&rhs) noexcept;
    Tokenizer &operator=(Tokenizer &&rhs) noexcept;

    Tokenizer(const Tokenizer &rhs) = delete;
    Tokenizer &operator=(const Tokenizer &rhs) = delete;

    Expected<void> consume(std::size_t n = 1) noexcept;
    Expected<Token> peek(std::size_t n = 0) noexcept;
    Expected<Token> peekExpect(
      TokenV tokenType,
      std::string_view message = "",
      std::size_t n = 0
    ) noexcept;

    bool finished() const noexcept;

    void swap(Tokenizer &other) noexcept;

    TokenizerRange range() noexcept;

   private:
    Generator<Expected<Token>> tokenize();

    void skip_whitespace();
    Expected<void> skip_comment();

    Expected<Token> readNumber();
    Expected<Token> readString();
    Expected<Token> readCharacter();
    Expected<Token> readIdentifier();
    Expected<Token> readOperator();

    size_t line;
    size_t column;
    std::string::iterator iter;

    Generator<Expected<Token>> tokensGenerator;

    std::deque<Token> tokensBuffer;

    std::string source;
  };

} // namespace arti::lang