#!/usr/bin/env ruby
# frozen_string_literal: false

require 'pwn'
require 'optparse'

opts = {}
OptionParser.new do |options|
  options.banner = "USAGE:
    #{$PROGRAM_NAME} [opts]
  "

  options.on('-tFREQ', '--target-freq=FREQ', '<Required - Frequency to Conclude Scanning (e.g. 900000000 == 900 mHz>') do |s|
    opts[:start_freq] = s
  end

  options.on('-dMODE', '--demodulator-mode=MODE', '<Optional - Set Demodulator ModeOFF | RAW | AM | FM | WFM | WFM_ST | WFM_ST_OIRT | LSB |USB | CW | CWL | CWU (Defaults to AM)>') do |d|
    opts[:demodulator_mode] = d
  end

  options.on('-sFREQ', '--start-freq=FREQ', '<Optional - Frequency to Set when Scanning Begins (Defaults to last known frequency)>') do |s|
    opts[:start_freq] = s
  end

  options.on('-hHOST', '--host=HOST', '<Optional - GQRX Host (Defaults to 127.0.0.1)>') do |h|
    opts[:host] = h
  end

  options.on('-pPORT', '--port=PORT', '<Optional - GQRX Port (Defaults to 7356)>') do |p|
    opts[:port] = p
  end
end.parse!

if opts.empty?
  puts `#{$PROGRAM_NAME} --help`
  exit 1
end

def gqrx_cmd(opts = {})
  # f - Get frequency [Hz]
  # F - Set frequency [Hz]
  # m - Get demodulator mode
  # M - Set demodulator mode (OFF, RAW, AM, FM, WFM, WFM_ST,
  #     WFM_ST_OIRT, LSB, USB, CW, CWL, CWU)
  # l STRENGTH - Get signal strength [dBFS]
  # l SQL - Get squelch threshold [dBFS]
  # L SQL <sql> - Set squelch threshold to <sql> [dBFS]
  # u RECORD - Get status of audio recorder
  # U RECORD <status> - Set status of audio recorder to <status>
  # c - Close connection
  # AOS - Acquisition of signal (AOS) event, start audio recording
  # LOS - Loss of signal (LOS) event, stop audio recording
  # \dump_state - Dump state (only usable for compatibility)
  gqrx_sock = opts[:gqrx_sock]
  cmd = opts[:cmd]

  gqrx_sock.write("#{cmd}\n")
  does_respond = gqrx_sock.wait_readable
  gqrx_sock.readline.chomp if does_respond
end

begin
  pwn_provider = 'ruby-gem'
  pwn_provider = ENV.fetch('PWN_PROVIDER') if ENV.keys.any? { |s| s == 'PWN_PROVIDER' }

  demodulator_mode = opts[:demodulator_mode] ||= 'AM'
  raise "ERROR: Invalid demodulator mode: #{demodulator_mode}" unless %w[OFF RAW AM FM WFM WFM_ST WFM_ST_OIRT LSB USB CW CWL CWU].include?(demodulator_mode)

  puts "Setting demodulator mode to #{demodulator_mode}..."
  demod_resp = gqrx_cmd(gqrx_sock: gqrx_sock, cmd: "M #{demodulator_mode}")
  puts demod_resp

  start_freq = opts[:start_freq].to_i
  start_freq = gqrx_cmd(gqrx_sock: gqrx_sock, cmd: 'f').to_i if start_freq.zero?

  end_freq = opts[:end_freq].to_i
  raise 'ERROR: Invalid end frequency' if end_freq.zero?

  puts "Scanning from #{start_freq} to #{end_freq}..."

  host = opts[:host] ||= '127.0.0.1'
  port = opts[:port] ||= 7356
  puts "Connecting to GQRX at #{host}:#{port}..."

  gqrx_sock = PWN::Plugins::Sock.connect(target: host, port: port)
  # If start value is greater than end value, go in reverse
  if start_freq > end_freq
    end_freq.downto(start_freq) do |freq|
      gqrx_cmd(gqrx_sock: gqrx_sock, cmd: "F #{freq}")
      resp = gqrx_cmd(gqrx_sock: gqrx_sock, cmd: 'f')
      puts "Reached #{resp}..."
    end
  else
    (start_freq..end_freq).each do |freq|
      puts "Scanning #{freq}..."
      gqrx_cmd(gqrx_sock: gqrx_sock, cmd: "F #{freq}")
      resp = gqrx_cmd(gqrx_sock: gqrx_sock, cmd: 'f')
      puts "Reached #{resp}..."
    end
  end
rescue SystemExit, Interrupt
  puts "\nGoodbye."
ensure
  resp = gqrx_cmd(gqrx_sock: gqrx_sock, cmd: 'c')
  gqrx_sock = PWN::Plugins::Sock.disconnect(sock_obj: gqrx_sock)
end