// This file is part of Cait <https://github.com/Fuwn/cait>.
// Copyright (C) 2022-2022 Fuwn <contact@fuwn.me>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 3.
//
// 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
// Copyright (C) 2022-2022 Fuwn <contact@fuwn.me>
// SPDX-License-Identifier: GPL-3.0-only

#include <iostream>

#include "parser.hh"
#include "utility.hh"

namespace cait {

parser_exception::parser_exception(const std::string &message)
    : std::runtime_error(message) {}

auto parser_exception::x() -> void {}

token_bundle::token_bundle(std::size_t &_j, token_t &bundle_token,
                           std::vector<token_t> &_parsed_token_line,
                           std::vector<token_t> &_token_line)
    : j(_j), token(bundle_token), parsed_token_line(_parsed_token_line),
      token_line(_token_line) {}

template <typename T>
range_t<T>::range_t(T begin, T end) : _begin(begin), _end(end) {}

template <typename T> auto range_t<T>::begin() -> T { return this->_begin; }

template <typename T> auto range_t<T>::end() -> T { return this->_end; }

template <typename T> auto range(T b, T e) -> range_t<T> {
  return range_t<T>(b, e);
}

parser::parser(token_tree &token_tree) {
  this->fix_tree(token_tree);
  this->prune_empty_token_lines();
}

[[nodiscard]] auto parser::tree() const noexcept -> const token_tree & {
  return this->_tree;
}

[[nodiscard]] auto parser::nodes() const noexcept -> const node_tree & {
  return this->_nodes;
}

auto parser::token_parse_assignment_operator(token_bundle bundle) -> void {
  auto &local = bundle.token_line[bundle.j - 1];

  if (local.type != token_type::pool_depth) {
    local = local.with_type(token_type::variable_declaration);
  }

  bundle.parsed_token_line.push_back(local);
  bundle.parsed_token_line.push_back(bundle.token);

  for (auto &token_line_item :
       range(bundle.token_line.begin() + 2, bundle.token_line.end())) {
    token_line_item.type = token_type::variable_value;
  }

  bundle.parsed_token_line.insert(bundle.parsed_token_line.end(),
                                  bundle.token_line.begin() + 2,
                                  bundle.token_line.end());

  bundle.j += bundle.token_line.size() - 1;
}

auto parser::token_parse_rule_pool_declaration(token_bundle bundle) -> void {
  bundle.parsed_token_line.push_back(bundle.token);
  bundle.parsed_token_line.push_back(
      bundle.token_line[bundle.j + 1].with_type(token_type::identifier));

  bundle.j += bundle.token_line.size();
}

auto parser::token_parse_default_declaration(token_bundle bundle) -> void {
  bundle.parsed_token_line.push_back(bundle.token);

  for (auto &token_line_item :
       range(bundle.token_line.begin() + 1, bundle.token_line.end())) {
    token_line_item.type = token_type::default_target;
  }

  bundle.parsed_token_line.insert(bundle.parsed_token_line.end(),
                                  bundle.token_line.begin() + 1,
                                  bundle.token_line.end());

  bundle.j += bundle.token_line.size();
}

auto parser::token_parse_include_subninja_declaration(token_bundle bundle)
    -> void {
  bundle.parsed_token_line.push_back(bundle.token);
  bundle.parsed_token_line.push_back(
      bundle.token_line[bundle.j + 1].with_type(token_type::string_literal));

  bundle.j += bundle.token_line.size();
}

auto parser::token_parse_rule_variable(token_bundle bundle) -> void {
  bundle.parsed_token_line.push_back(bundle.token);

  for (auto &token_line_item :
       range(bundle.token_line.begin() + 2, bundle.token_line.end())) {
    token_line_item.type = token_type::variable_value;
  }

  bundle.parsed_token_line.insert(bundle.parsed_token_line.end(),
                                  bundle.token_line.begin() + 1,
                                  bundle.token_line.end());

  bundle.j += bundle.token_line.size() - 1;
}

auto parser::token_parse_build_declaration(token_bundle bundle) -> void {
  bundle.parsed_token_line.push_back(bundle.token);

  {
    auto &output_file_token = bundle.token_line[bundle.j + 1];

    output_file_token.word =
        output_file_token.word.substr(0, output_file_token.word.size() - 1);

    bundle.parsed_token_line.push_back(
        output_file_token.with_type(token_type::build_output));

    // We can actually just throw away the colon...
    // parsed_token_line.push_back(
    //     cait::token(output_file_token.line, output_file_token.begin +
    //     1,
    //                 output_file_token.end + 1, ":")
    //         .with_type(token_type::colon));
  }

  bundle.token_line[2].type = token_type::build_rule;

  for (auto &token_line_item :
       range(bundle.token_line.begin() + 3, bundle.token_line.end())) {
    token_line_item.type = token_type::build_input;
  }

  bundle.parsed_token_line.insert(bundle.parsed_token_line.end(),
                                  bundle.token_line.begin() + 2,
                                  bundle.token_line.end());

  bundle.j += bundle.token_line.size();
}

auto parser::fix_tree(token_tree &token_tree) -> void {
  for (auto &token_line : token_tree) {
    std::vector<token> parsed_token_line;

    for (std::size_t j = 0; j < token_line.size(); ++j) {
      auto &token = token_line[j];

      switch (token.type) {
      case token_type::assignment_operator: {
        this->token_parse_assignment_operator(
            token_bundle(j, token, parsed_token_line, token_line));
      } break;
      case token_type::rule_declaration:
      case token_type::pool_declaration: {
        this->token_parse_rule_pool_declaration(
            token_bundle(j, token, parsed_token_line, token_line));
      } break;
      case token_type::default_declaration: {
        this->token_parse_default_declaration(
            token_bundle(j, token, parsed_token_line, token_line));
      } break;
      case token_type::include_declaration:
      case token_type::subninja_declaration: {
        this->token_parse_include_subninja_declaration(
            token_bundle(j, token, parsed_token_line, token_line));
      } break;
      case token_type::rule_command:
      case token_type::rule_depfile:
      case token_type::rule_deps:
      case token_type::rule_msvc_deps_prefix:
      case token_type::rule_description:
      case token_type::rule_dyndep:
      case token_type::rule_generator:
      case token_type::rule_in:
      case token_type::rule_in_newline:
      case token_type::rule_out:
      case token_type::rule_restat:
      case token_type::rule_rspfile:
      case token_type::rule_rspfile_content: {
        this->token_parse_rule_variable(
            token_bundle(j, token, parsed_token_line, token_line));
      } break;
      case token_type::build_declaration: {
        this->token_parse_build_declaration(
            token_bundle(j, token, parsed_token_line, token_line));
      } break;
      case token_type::string_literal:
      case token_type::variable_declaration:
      case token_type::identifier:
      case token_type::build_output:
      case token_type::build_input:
      case token_type::build_rule:
      case token_type::default_target:
      case token_type::variable_value:
      case token_type::pool_depth:
        break;
      }

      this->_tree.push_back(parsed_token_line);
    }
  }
}

auto parser::generate_nodes(const std::string &file_name,
                            const std::vector<std::string> &lines) -> void {
  for (std::size_t i = 0; i < this->_tree.size(); ++i) {
    auto &token_line = this->_tree[i];

    for (std::size_t j = 0; j < token_line.size(); ++j) {
      auto &token = token_line[j];

      switch (token.type) {
      case token_type::variable_declaration: {
        this->_nodes.push_back(
            node::variable(token_line[0], std::vector(token_line.begin() + 2,
                                                      token_line.end())));

        j += token_line.size();
      } break;
      case token_type::default_declaration: {
        this->_nodes.push_back(node::default_(
            std::vector(token_line.begin() + 1, token_line.end())));
      } break;
      case token_type::include_declaration: {
        this->_nodes.push_back(node::include(token_line[1]));
      } break;
      case token_type::subninja_declaration: {
        this->_nodes.push_back(node::subninja(token_line[1]));
      } break;
      case token_type::build_declaration: {
        this->_nodes.push_back(
            node::build(token_line[1], token_line[2],
                        std::vector(token_line.begin() + 3, token_line.end())));
      } break;
      case token_type::rule_declaration: {
        auto command_line_index = i + 1;
        auto &command_line = this->_tree[command_line_index];
        node::item_map_type item_map;

        while (command_line[0].type == token_type::rule_command ||
               command_line[0].type == token_type::rule_description ||
               command_line[0].type == token_type::rule_depfile ||
               command_line[0].type == token_type::rule_deps ||
               command_line[0].type == token_type::rule_msvc_deps_prefix ||
               command_line[0].type == token_type::rule_dyndep ||
               command_line[0].type == token_type::rule_generator ||
               command_line[0].type == token_type::rule_in ||
               command_line[0].type == token_type::rule_in_newline ||
               command_line[0].type == token_type::rule_out ||
               command_line[0].type == token_type::rule_restat ||
               command_line[0].type == token_type::rule_rspfile ||
               command_line[0].type == token_type::rule_rspfile_content) {
          item_map.insert(std::make_pair(
              command_line[0].word,
              std::vector(command_line.begin() + 2, command_line.end())));

          command_line_index += 1;
          command_line = this->_tree[command_line_index];
        }

        // Handle unknown rule variable error
        if (command_line[1].type == token_type::assignment_operator) {
          std::ostringstream error;

          error << "cait: error: " << file_name << ":" << command_line[0].line
                << ": unexpected variable '" << command_line[0].word << "'\n"
                << lines[command_line[0].line - 1] << "\n";

          for (auto &word : command_line) {
            error << std::string(word.word.size(), ' ');
          }

          auto leading_spaces = [](const std::string &string) -> std::size_t {
            std::size_t count = 0;

            while (string[count] == ' ') {
              count += 1;
            }

            return count;
          };

          error << std::string(leading_spaces(lines[command_line[0].line - 1]),
                               ' ')
                << "  ^ near here\n";

          throw parser_exception(error.str());
        }

        // Handle no command line error
        if (item_map.count("command") == 0) {
          std::ostringstream error;

          error << "cait: error: " << file_name << ":" << command_line[0].line
                << ": expected 'command =' line\n";

          throw parser_exception(error.str());
        }

        this->_nodes.push_back(node::rule(token_line[1], item_map));

        i += 1;
      } break;
      case token_type::pool_declaration: {
        this->_nodes.push_back(
            node::pool(token_line[1], this->_tree[i + 1][2]));

        i += 1;
      } break;
      case token_type::string_literal:
        std::cout << "string: " << token.word << "\n";
        break;
      case token_type::rule_command:
      case token_type::assignment_operator:
      case token_type::identifier:
      case token_type::build_output:
      case token_type::rule_depfile:
      case token_type::rule_deps:
      case token_type::rule_msvc_deps_prefix:
      case token_type::rule_description:
      case token_type::rule_dyndep:
      case token_type::rule_generator:
      case token_type::rule_in:
      case token_type::rule_in_newline:
      case token_type::rule_out:
      case token_type::rule_restat:
      case token_type::rule_rspfile:
      case token_type::rule_rspfile_content:
      case token_type::build_input:
      case token_type::build_rule:
      case token_type::default_target:
      case token_type::variable_value:
      case token_type::pool_depth:
        break;
      }
    }
  }
}

auto parser::prune_empty_token_lines() -> void {
  for (int j = 0; static_cast<size_t>(j) < this->_tree.size(); ++j) {
    if (this->_tree[static_cast<size_t>(j)].empty()) {
      this->_tree.erase(this->_tree.begin() + j);
    }
  }
}

} // namespace cait