=begin
  Copyright (c) 2020 Marek Küthe
  This program is free software. It comes without any warranty, to
  the extent permitted by applicable law. You can redistribute it
  and/or modify it under the terms of the Do What The Fuck You Want
  To Public License, Version 2, as published by Sam Hocevar. See
  http://www.wtfpl.net/ for more details.
=end

require "socket"

def samcmd fircmd, seccmd, args = {}
  cmd = "#{fircmd} #{seccmd}"
  args.each_pair { |arg, value|
    cmd << " #{arg}=\"#{value.to_s}\""
  }
  return cmd
end

def parsesamcmd ans
  ans.chomp!
  ans += " "
  f = ans.index " "
  s = ans.index " ", f + 1
  w = ans[f+1...s]
  
  args = Hash.new
  loop do
    g1 = ans.index "=", s+1
    break if g1 == nil
    g2 = nil
    if ans[g1+1] == "\""
      g2 = ans.index "\"", g1+2
      args[ans[s+1..g1-1]] = ans[g1+2..g2-1]
    else
      g2 = ans.index " ", g1+1
      args[ans[s+1..g1-1]] = ans[g1+1..g2-1]
    end
    s = g2
  end
  
  return [ans[0...f], w, args]
end

def ping dest
  pinger = TCPSocket.new "127.0.0.1", 7656
  pinger.puts samcmd "HELLO", "VERSION"
  pinger.gets
  sta = Time.now
  pinger.puts samcmd "STREAM", "CONNECT", {
    "ID" => $samid,
    "DESTINATION" => dest
  }
  res = parsesamcmd pinger.gets
  fin = Time.now
  pinger.close
  return res, fin-sta
end

def randomcode len=5
  symbols = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"
  res = ""
  rnd = Random.new
  for i in 0...len
    res += symbols[rnd.rand(0...symbols.length)]
  end
  return res
end

if ARGV.length == 0
  puts <<~ENDOFUSAGE
  Usage: ruby #{__FILE__} <b64|b32|eepsite> [-v] [-l length] [-q quantity] [-c count]
  Options:
    -v\tverbose
    -l\tLength of the tunnels
    -q\tNumber of tunnels
    -c\tNumber of ping attempts
  ENDOFUSAGE
  exit
end

$eepsite = ARGV[0]
$verbose = false
$samnickname = "i2p-pinger"
$samid = "i2p-pinger-#{randomcode}"
$tunlen = 1
$tunq = 1
$tunb = 1
$count = 4

if ARGV.include? "-l"
  $tunlen = ARGV[ARGV.index("-l") + 1]
end

if ARGV.include? "-q"
  $tunq = ARGV[ARGV.index("-q") + 1]
end

if ARGV.include? "-c"
  $count = ARGV[ARGV.index("-c") + 1].to_i
end

if ARGV.include? "-b"
  $tunb = ARGV[ARGV.index("-b") + 1].to_i
end

if ARGV.include? "-v"
  $verbose = true
end

control = TCPSocket.new "127.0.0.1", 7656

control.puts samcmd "HELLO", "VERSION"
res = parsesamcmd control.gets
if res[2]["RESULT"] != "OK"
  $stderr.puts "Error [4] #{res.inspect}"
  exit
end
puts "--- Create sam session ---" if $verbose
control.puts samcmd "SESSION", "CREATE", {
  "STYLE" => "STREAM",
  "ID" => $samid,
  "DESTINATION" => "TRANSIENT",
  "SIGNATURE_TYPE" => "ECDSA_SHA512_P521",
  "i2cp.leaseSetEncType" => "4,0",
  "i2cp.destination.sigType" => "EdDSA_SHA512_EdNAM25519",
  "inbound.length" => $tunlen.to_s,
  "outbound.length" => $tunlen.to_s,
  "inbound.nickname" => $samnickname,
  "outbound.nickname" => $samnickname,
  "outbound.priority" => "20",
  "inbound.priority" => "20",
  "inbound.quantity" => $tunq.to_s,
  "outbound.quantity" => $tunq.to_s,
  "outbound.backupQuantity" => $tunb.to_s,
  "inbound.backupQuantity" => $tunb.to_s
}
res = parsesamcmd control.gets
if res[2]["RESULT"] != "OK"
  $stderr.puts "Error [1] #{res.inspect}"
  exit
end
$mydest = res[2]["DESTINATION"]

puts "--- Naming lookup ---" if $verbose
dest = nil
if ARGV[0].include? ".i2p"
  control.puts samcmd "NAMING", "LOOKUP", {
    "NAME" => $eepsite
  }
  res = parsesamcmd control.gets
  if res[2]["RESULT"] != "OK"
    $stderr.puts "Error [2] #{res.inspect}"
    exit
  end
  dest = res[2]["VALUE"]
else
  dest = ARGV[0]
end

controlping = Thread.new {
  res = parsesamcmd control.gets.chomp
  if res[0] == "PING"
    control.puts "PONG #{res[1]}"
  end
}

puts "--- Start pinging ---" if $verbose
strhop = "hops"
strhop = "hop" if $tunlen == 1
strtun = "tunnels"
strtun = "tunnel" if $tunq == 1
print "The connection to the destination is established via #{$tunlen} #{strhop} with #{$tunq} #{strtun}.\n\n"
times = Array.new
status = Array.new  # success = true; failed = false
for i in 0...$count
  res, t = ping dest
  times << t
  if res[2]["RESULT"] == "OK"
    puts "Ping successful: #{t}s"
    status << true
  elsif res[2]["RESULT"] == "INVALID_KEY" 
    $stderr.puts "The specified destination is not valid. No further ping attempts are made."
    break
  else
    puts "Ping failed - #{res[2].values.join " "}: #{t}s"
    status << false
    sleep 3
  end
  sleep 1
end

puts "\nPing evaluation: A total of "
puts "\t#{$count} (100.0%) pings were sent."
puts "\t#{status.count true} (#{(status.count(true).to_f / $count * 100).round 2}%) of them were successful and"
puts "\t#{status.count false} (#{(status.count(false).to_f / $count * 100).round 2}%) failed."
puts "\tThe average response time was #{times.inject(0.0) { |sum, x| sum + x} / times.length} seconds."

controlping.exit
control.puts "QUIT"
control.close