/**
 * @file SRF (Simple Record Format) grammar for tree-sitter
 * @author Emil Lerch
 * @license MIT
 */

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

module.exports = grammar({
  name: 'srf',

  extras: _ => [],

  rules: {
    document: $ => repeat($._line),

    _line: $ => choice(
      $.magic,
      $.directive,
      $.comment,
      $.field,
      $.blank_line,
    ),

    magic: $ => seq(
      '#!srfv1',
      optional($.inline_comment),
      '\n',
    ),

    inline_comment: _ => /[ \t]+#[^\n]*/,

    directive: $ => choice(
      $.directive_long,
      $.directive_compact,
      $.directive_requireeof,
      $.directive_eof,
      $.directive_expires,
      $.directive_created,
      $.directive_modified,
      $.directive_unknown,
    ),

    directive_long: $ => seq('#!long', optional($.inline_comment), '\n'),
    directive_compact: $ => seq('#!compact', optional($.inline_comment), '\n'),
    directive_requireeof: $ => seq('#!requireeof', optional($.inline_comment), '\n'),
    directive_eof: $ => seq('#!eof', optional($.inline_comment), '\n'),
    directive_expires: $ => seq(
      '#!expires=',
      field('value', $.timestamp),
      optional($.inline_comment),
      '\n',
    ),
    directive_created: $ => seq(
      '#!created=',
      field('value', $.timestamp),
      optional($.inline_comment),
      '\n',
    ),
    directive_modified: $ => seq(
      '#!modified=',
      field('value', $.timestamp),
      optional($.inline_comment),
      '\n',
    ),
    directive_unknown: _ => seq(
      /#!/,
      /[a-zA-Z][a-zA-Z0-9_]*/,
      optional(seq('=', /[^\n]*/)),
      '\n',
    ),

    timestamp: _ => /[0-9-]+/,

    comment: _ => token(seq('#', optional(seq(/[^!\n]/, /[^\n]*/)), '\n')),

    blank_line: _ => token(/[ \t]*\n/),

    field: $ => choice(
      $.typed_field,
      $.untyped_field,
    ),

    typed_field: $ => seq(
      $.key,
      ':',
      $.type_hint,
      ':',
      optional($.value),
      /[,\n]/,
    ),

    untyped_field: $ => seq(
      $.key,
      '::',
      optional($.value),
      /[,\n]/,
    ),

    key: _ => /[^#\n:, \t][^:,]*/,

    type_hint: _ => choice(
      'string',
      'num',
      'bool',
      'null',
      'binary',
      /[0-9]+/,
    ),

    value: _ => /[^\n,]+/,
  },
});