# frozen_string_literal: true

require 'bbs'
require 'time'
require_relative 'oracle'

module Sermo
  # An MS-DOS-flavoured machine for SERMO-BBS: pretend you sat down at an old
  # PC, watched it POST and boot, and landed at a C:\> prompt. Built-in DOS
  # commands behave; anything else is treated as a question and handed to
  # Sermo::Oracle (the conversational core).
  #
  # This whole OS is data: to add another character-mode OS later, write a new
  # BBS::FakeOS.define block in its own file — no engine changes needed.
  DOS = BBS::FakeOS.define do
    name   'SERMO-DOS'
    prompt 'C:\\>'

    # Classic light-grey-on-black console palette.
    colors text:   "\e[0;37m",
           bright: "\e[1;37m",
           accent: "\e[1;32m",
           error:  "\e[1;31m",
           dim:    "\e[1;30m"

    # ── Power-on self test → boot ──────────────────────────────────────────────
    boot do
      cls
      print 'Award Modular BIOS v4.51PG, An Energy Star Ally',           delay: 0.3
      print 'Copyright (C) 1984-98, Award Software, Inc.',  newline: 2,  delay: 0.3
      print 'Main Processor   : Intel 80486DX2 @ 66 MHz',                delay: 0.2
      memtest 16_384, step: 4096, delay: 0.05
      print '',                                                          delay: 0.2
      print 'Detecting IDE Primary Master  ... SERMO HDD 504MB',         delay: 0.3
      print 'Detecting IDE Primary Slave   ... None',                    delay: 0.2
      print 'Detecting Floppy Drive A:     ... 1.44M, 3.5 in.', newline: 2, delay: 0.3
      print 'Verifying DMI Pool Data ...........',                       delay: 0.5
      print 'Starting MS-DOS...',                              newline: 2, delay: 0.8

      print 'HIMEM   is testing extended memory...done.',                delay: 0.3
      print 'C:\\> LOADHIGH SMARTDRV.EXE',                               delay: 0.3
      print 'C:\\> MSCDEX.EXE   /D:SERMO0',                   newline: 2, delay: 0.4

      cls
      big_banner 'SERMO DOS', font: 'standard'
      print 'SERMO-DOS  Version 6.22   (c) 1994-2026 Teletype Games',    delay: 0.1
      print ''
    end

    # Shown once, after boot, before the first prompt.
    ready do
      puts 'Type HELP for a list of commands — or just type a question and ask.'
      puts ''
    end

    # ── Built-in commands ───────────────────────────────────────────────────────
    command 'ver', help: 'Display the SERMO-DOS version' do |_args, io|
      io.puts 'SERMO-DOS Version 6.22'
    end

    command 'cls', help: 'Clear the screen' do |_args, io|
      io.cls
    end

    command 'date', help: 'Display the current date' do |_args, io|
      io.puts Time.now.strftime('Current date is %a %m-%d-%Y')
    end

    command 'time', help: 'Display the current time' do |_args, io|
      io.puts Time.now.strftime('Current time is %H:%M:%S')
    end

    command 'echo', help: 'Display a message' do |args, io|
      io.puts(args.empty? ? 'ECHO is on.' : args)
    end

    command 'mem', help: 'Display memory usage' do |_args, io|
      io.puts '    655360 bytes total conventional memory'
      io.puts '    655360 bytes available to MS-DOS'
      io.puts '    643072 largest executable program size'
      io.puts ' 15728640 bytes total contiguous extended memory'
    end

    command 'dir', help: 'List the directory' do |_args, io|
      io.puts ' Volume in drive C is SERMO'
      io.puts ' Directory of C:\\'
      io.puts ''
      io.puts 'COMMAND  COM        54 645  06-05-26   6:22a'
      io.puts 'SERMO    SYS        12 080  06-05-26   6:22a'
      io.puts 'AUTOEXEC BAT           128  06-05-26   6:22a'
      io.puts 'CONFIG   SYS           256  06-05-26   6:22a'
      io.puts '        4 file(s)        67 109 bytes'
      io.puts '                    503 312 384 bytes free'
    end

    command 'help', '?', help: 'Show this help' do |_args, io|
      io.puts 'Supported commands:'
      io.puts ''
      io.puts '  VER    DATE   TIME   ECHO   MEM'
      io.puts '  DIR    CLS    HELP   EXIT'
      io.puts ''
      io.puts 'Anything else you type is treated as a question and answered.'
    end

    command 'exit', 'quit', 'logoff', help: 'Disconnect' do |_args, io|
      io.puts 'Goodbye.'
      io.halt
    end

    # ── Everything else is a conversation ────────────────────────────────────────
    on_unknown do |input, io|
      io.newline
      Sermo::Oracle.answer(input, io.ctx).each_line do |line|
        io.puts "  #{line.chomp}", style: :bright
      end
      io.newline
    end
  end
end