#!/usr/bin/env ruby
require "lignite"
require "thor"
require "fileutils"
include Lignite::Bytes

# The VM current working directory is /home/root/lms2012/sys
# which is not very useful. A better default is /home/root/lms2012/prjs
# which is displayed on the 2nd tab of the brick UI.
EV3TOOL_HOME = "../prjs".freeze

def phandles
  handles = sc.list_open_handles
  puts "OPEN HANDLES: ", hexdump(handles)
end

class Ev3Tool < Thor
  desc "upload LOCAL_FILENAME [BRICK_FILENAME]", "upload a program or a file"
  map "ul" => "upload"
  def upload(local_filename, brick_filename = nil)
    data = File.read(local_filename, encoding: Encoding::BINARY)
    unless brick_filename
      prj = File.basename(local_filename, ".rbf")
      brick_filename = "#{EV3TOOL_HOME}/#{prj}/#{prj}.rbf"
    end
    handle = sc.begin_download(data.bytesize, brick_filename)
    sc.continue_download(handle, data)
  end

  desc "download BRICK_FILENAME [LOCAL_FILENAME]", "download a file"
  map "dl" => "download"
  def download(brick_filename, local_filename = nil)
    local_filename ||= File.basename(brick_filename)
    fsize, handle, data = sc.begin_upload(4096, brick_filename)
    File.open(local_filename, "w") do |f|
      loop do
        f.write(data)
        fsize -= data.bytesize
        break if fsize.zero?
        handle, data = sc.continue_upload(handle, 4096)
      end
    end
  end

  desc "list-files DIRNAME", "list DIRNAME in a long format"
  map "ls-l" => "list-files"
  def list_files(name)
    name ||= EV3TOOL_HOME
    name = "#{EV3TOOL_HOME}/#{name}" unless name.start_with?("/")

    result = ""
    fsize, handle, data = sc.list_files(4096, name)
    loop do
      result += data
      fsize -= data.bytesize
      break if fsize.zero?
      handle, data = sc.continue_list_files(handle, 4096)
    end
    result
  rescue Lignite::VMError
    nil
  end

  desc "ls DIRNAME", "list DIRNAME in a short format"
  def ls(name)
    raw = list_files(name)
    return nil if raw.nil?

    raw.lines.map do |l|
      l = l.chomp
      next nil if ["./", "../"].include?(l)
      next l if l.end_with?("/")
      # skip checksum + space + size + space
      l[32 + 1 + 8 + 1..-1]
    end.compact
  end

  desc "start NAME", "start a program"
  def start(name)
    if name.include?("/")
      name = "#{EV3TOOL_HOME}/#{name}" unless name.start_with?("/")
    else
      name = "#{EV3TOOL_HOME}/#{name}/#{name}.rbf"
    end

    unless file_exist?(name)
      $stderr.puts "File #{name.inspect} not found"
      exit 1
    end

    slot = Lignite::USER_SLOT
    no_debug = 0
    dc.block do
      # these are local variables
      data32 :size
      data32 :ip
      file_load_image(slot, name, :size, :ip)
      program_start(slot, :size, :ip, no_debug)
    end
  end

  desc "stop", "stop a running program"
  def stop
    dc.program_stop(Lignite::USER_SLOT)
  end

  no_commands do
    def file_exist?(name)
      dirname = File.dirname(name)
      filename = File.basename(name)
      files = ls(dirname) || []
      files.include?(filename)
    end

    def assisted_connection
      Lignite::Connection.create
    rescue => e
      fn = Lignite::Connection::Bluetooth.config_filename
      $stderr.puts <<MSG
Could not connect to EV3.
Use a USB cable or configure a Bluetooth address in #{fn.inspect}.
Details:
  #{e.message}
MSG

      template = Lignite::Connection::Bluetooth.template_config_filename
      if !File.exist?(fn) && File.exist?(template)
        FileUtils.mkdir_p(File.dirname(fn))
        FileUtils.install(template, fn)
        $stderr.puts "(A template config file has been copied for your convenience)"
      end
      exit 1
    end

    def sc
      return @sc if @sc
      @sc = Lignite::SystemCommands.new(conn)
    end

    def dc
      return @dc if @dc
      @dc = Lignite::DirectCommands.new(conn)
    end

    def conn
      @conn ||= assisted_connection
    end
  end
end

Ev3Tool.start(ARGV)