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

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

  rules: {
    document: ($) => repeat($._statement),
    _statement: ($) =>
      choice(
        $.type_declaration,
        $.define_declaration,
        $.import_declaration,
        $.service_declaration,
        $.enum_declaration,
      ),
    type_declaration: ($) => seq("type", $.identifier, optional($.attributes)),
    attributes: ($) =>
      seq("{", optional(seq($.attribute, repeat($.attribute))), "}"),
    attribute: ($) => seq($.pair, ";"),

    enum_declaration: ($) => seq("enum", $.identifier, $.enum_values),
    enum_values: ($) =>
      seq(
        "{",
        optional(seq($._enum_value, repeat(seq(",", $._enum_value)))),
        "}",
      ),
    _enum_value: ($) =>
      choice($.enum_value_declaration, $.enum_value_assignment),
    enum_value_assignment: ($) => seq($.identifier, "=", $.number),
    enum_value_declaration: ($) => seq($.identifier),

    define_declaration: ($) =>
      seq("define", $.identifier, choice($.string, $.identifier), ";"),

    import_declaration: ($) => seq("import", $.string, ";"),

    service_declaration: ($) =>
      seq("service", $.identifier, $.service_functions),

    service_functions: ($) =>
      seq(
        "{",
        optional(
          repeat(
            seq(
              repeat($.function_decorator),
              choice($.service_function, $.service_notification),
            ),
          ),
        ),
        "}",
      ),

    function_decorator: ($) => seq("@", $.identifier, $.decorator_arguments),
    decorator_arguments: ($) =>
      seq(
        "(",
        optional(seq($.string, optional(repeat(seq(",", $.string))))),
        ")",
      ),
    service_notification: ($) =>
      seq(
        "notification",
        field("name", $.identifier),
        field("parameters", $.function_arguments),
        ";",
      ),
    service_function: ($) =>
      seq(
        field("name", $.identifier),
        field("parameters", $.function_arguments),
        ":",
        field("return_type", $.type),
        ";",
      ),
    function_arguments: ($) =>
      seq(
        "(",
        optional(
          seq($.function_argument, repeat(seq(",", $.function_argument))),
        ),
        ")",
      ),
    function_argument: ($) =>
      seq(
        field("argument_identifier", $.identifier),
        ":",
        field("argument_type", $.type),
      ),

    pair: ($) =>
      seq(
        field("key", $.identifier),
        optional("?"),
        ":",
        field("value", $.type),
      ),

    type: ($) =>
      choice($.map_type, $.array_type, $.primitive_type, $.identifier),
    primitive_type: ($) => choice("int", "string", "float", "boolean", "void"),
    array_type: ($) => seq(choice($.primitive_type, $.identifier), "[]"),
    map_type: ($) => seq("{", $.map_key_type, ",", $.type, "}"),
    map_key_type: ($) => choice("int", "string"),

    identifier: ($) => /[a-zA-Z_][a-zA-Z_0-9]*/,

    string: ($) => choice(seq('"', '"'), seq('"', $._string_content, '"')),
    _string_content: ($) =>
      repeat1(choice($.string_content, $.escape_sequence)),
    string_content: (_) => token.immediate(prec(1, /[^\\"\n]+/)),
    escape_sequence: (_) =>
      token.immediate(seq("\\", /(\"|\\|\/|b|f|n|r|t|u)/)),

    number: ($) => /[0-9]+/,
  },
});