/**
 * @file Ground VM textual representation highlighter
 * @author Maxwell Jeffress <maxwelljeffress@proton.me>
 * @license MIT
 */

/// <reference types="tree-sitter-cli/dsl" />
// @ts-check

module.exports = grammar({
  name: "ground",

  extras: $ => [
    /\s/,
    $.comment,
  ],

  rules: {
    source_file: $ => repeat($._statement),

    _statement: $ => choice(
      $.label_definition,
      $.function_definition,
      $.struct_definition,
      $.instruction,
    ),

    comment: $ => token(seq('#', /.*/)),

    label_definition: $ => seq('@', $.identifier),

    function_definition: $ => seq(
      'fun',
      field('name', $.function_reference),
      field('return_type', $.type_reference),
      repeat(seq(field('arg_type', $.type_reference), field('arg_name', $.direct_reference))),
      repeat($._statement),
      'endfun'
    ),

    struct_definition: $ => seq(
      'struct',
      field('name', $.type_reference),
      repeat($._statement),
      'endstruct'
    ),

    instruction: $ => seq(
      field('keyword', $.keyword),
      repeat($._argument)
    ),

    keyword: $ => choice(
      'if', 'jump', 'end', 'input', 'print', 'println',
      'set', 'init', 'gettype', 'exists', 'setlist', 'setlistat',
      'getlistat', 'getlistsize', 'listappend', 'getstrsize', 'getstrcharat',
      'add', 'subtract', 'multiply', 'divide', 'equal', 'inequal', 'not',
      'greater', 'lesser', 'stoi', 'stod', 'tostring', 'return', 'call',
      'use', 'extern', 'getfield', 'setfield'
    ),

    _argument: $ => choice(
      $.value_reference,
      $.direct_reference,
      $.line_reference,
      $.function_reference,
      $.type_reference,
      $.string,
      $.int,
      $.double,
      $.char,
      $.bool
    ),

    value_reference: $ => seq('$', $.identifier),
    direct_reference: $ => seq('&', $.identifier),
    line_reference: $ => seq('%', $.identifier),
    function_reference: $ => seq('!', $.identifier),
    type_reference: $ => seq('-', $.identifier),

    identifier: $ => /[a-zA-Z_][a-zA-Z0-9_]*/,

    string: $ => /"[^"]*"/,
    int: $ => /-?\d+/,
    double: $ => /-?\d+\.\d+/,
    char: $ => /'[^']'/,
    bool: $ => choice('true', 'false'),
  }
});