#!/usr/bin/env ruby

require 'sinatra'
require 'sinatra/cross_origin'
require "sinatra/reloader"
require 'nanomsg'
require 'zipf'
require 'json'
require 'haml'
require_relative './derivation_to_json/derivation_to_json'

# #############################################################################
# Load configuration file and setup global variables
# #############################################################################
require_relative "#{ARGV[0]}" # load configuration for this session
$lock             = false     # lock if currently learning/translating
$last_reply       = nil       # cache last reply
$confirmed        = true      # client received translation?
$additional_rules = []        # corrected OOVs
if !FileTest.exist? LOCK_FILE # locked?
  $db  = {}                   # data file (JSON format)
  $env = {}                   # environment variables (socket connections to daemons)
end

# #############################################################################
# Daemons
# #############################################################################
DIR="/fast_scratch/simianer/lfpe"
$daemons = {
  :tokenizer        => "#{DIR}/lfpe/util/wrapper.rb -a tokenize   -S '__ADDR__' -e #{EXTERNAL} -l #{TARGET_LANG}",
  :detokenizer      => "#{DIR}/lfpe/util/wrapper.rb -a detokenize -S '__ADDR__' -e #{EXTERNAL} -l #{TARGET_LANG}",
  :detokenizer_src  => "#{DIR}/lfpe/util/wrapper.rb -a detokenize -S '__ADDR__' -e #{EXTERNAL} -l #{SOURCE_LANG}",
  :truecaser        => "#{DIR}/lfpe/util/wrapper.rb -a truecase   -S '__ADDR__' -e #{EXTERNAL} -t #{SESSION_DIR}/truecase.model",
  #:lowercaser   => "#{DIR}/lfpe/util/wrapper.rb -a lowercase  -S '__ADDR__' -e #{EXTERNAL}",
  :dtrain           => "#{CDEC}/training/dtrain/dtrain_net_interface -c #{SESSION_DIR}/dtrain.ini -d #{WORK_DIR}/dtrain.debug.json -o #{WORK_DIR}/weights -a '__ADDR__' -E -R",
  :extractor        => "python -m cdec.sa.extract -c #{SESSION_DIR}/sa.ini --online -u -S '__ADDR__'",
  :aligner_fwd      => "#{CDEC}/word-aligner/net_fa -f #{SESSION_DIR}/forward.params  -m #{FWD_MEAN_SRCLEN_MULT}  -T #{FWD_TENSION}  --sock_url '__ADDR__'",
  :aligner_back     => "#{CDEC}/word-aligner/net_fa -f #{SESSION_DIR}/backward.params -m #{BACK_MEAN_SRCLEN_MULT} -T #{BACK_TENSION} --sock_url '__ADDR__'",
  :atools           => "#{CDEC}/utils/atools_net -c grow-diag-final-and -S '__ADDR__'"
}

# #############################################################################
# Set-up Sinatra
# #############################################################################
set :bind,              SERVER_IP
set :port,              WEB_PORT
set :allow_origin,      :any
set :allow_methods,     [:get, :post, :options]
set :allow_credentials, true
set :max_age,           "1728000"
set :expose_headers,    ['Content-Type']
set :public_folder,     File.dirname(__FILE__) + '/static'

# #############################################################################
# Helper functions
# #############################################################################
def logmsg name, msg
  STDERR.write "[#{name}] #{msg}\n"
end

def start_daemon cmd, name, addr
  logmsg :server, "starting #{name} daemon"
  cmd.gsub! '__ADDR__', addr
  pid = fork do
    exec cmd
  end
  sock = NanoMsg::PairSocket.new
  sock.connect addr
  logmsg :server, "< got #{sock.recv} from #{name}"

  return sock, pid
end

def stop_all_daemons
  logmsg :server, "shutting down all daemons"
  $env.each { |name,p|
    p[:socket].send "shutdown" # every daemon shuts down after receiving this keyword
    logmsg :server, "< #{name} is #{p[:socket].recv}"
  }
end

def update_database
  $db['progress'] += 1
  j = JSON.generate $db
  f = WriteFile.new DB_FILE
  f.write j.to_s
  f.close
end

def init
  # database connection
  $db = JSON.parse ReadFile.read DB_FILE
  # working directory
  `mkdir -p #{WORK_DIR}/g`
  # setup environment, start daemons
  port = BEGIN_PORT_RANGE
  $daemons.each { |name,cmd|
    sock, pid = start_daemon cmd, name, "tcp://127.0.0.1:#{port}"
    $env[name] = { :socket => sock, :pid => pid }
    port += 1
  }
  # lock
  `touch #{LOCK_FILE}`
end

def send_recv daemon, msg                            # simple pair communcation
  socket = $env[daemon][:socket]                     # query -> answer
  logmsg daemon, "> sending message: '#{msg}'"
  socket.send msg
  logmsg daemon, "waiting ..."
  ans = socket.recv.force_encoding("UTF-8").strip
  logmsg daemon, "< received answer: '#{ans}'"

  return ans
end

def cleanstr s
  s.gsub! "[", " "
  s.gsub! "]", " "
  s.gsub! "|", " "

  return s
end

# #############################################################################
# Run init() [just once]
# #############################################################################
init if !FileTest.exist?(LOCK_FILE)

# #############################################################################
# Routes
# #############################################################################
get '/' do
  cross_origin

  return ""                                                            # return
end

get '/next' do      # (receive post-edit, update models), send next translation
  cross_origin
  # already processing request?
  return "locked" if $lock                                             # return
  $lock = true
  key = params[:key]            # TODO: do something with it, e.g. simple auth?
  if params[:correct]
    logmsg :server, "correct: #{params[:correct]}"
    grammar = "#{WORK_DIR}/g/#{$db['progress']}.grammar"
    src, tgt = splitpipe(params[:correct])
    tgt = cleanstr(tgt)
    src = src.split("\t").map { |i| i.strip }
    tgt = tgt.split("\t").map { |i| i.strip }
    src.each_with_index { |s,i|
      next if s==''||tgt[i]==''
      a = ""
      tgt[i].split.each_index { |k|
        a += " 0-#{k}"
      }
      a.strip!
      rule = "[X] ||| #{s} ||| #{tgt[i]} ||| ForceRule=1 ||| #{a}"
      $additional_rules << rule
    }
    $confirmed = true
  end
  # received post-edit -> update models
  # 0. save raw post-edit
  # 1. tokenize
  # 2. truecase
  # 3. save processed post-edit
  # 4. update weights
  # 5. update grammar extractor
  # 5a. forward alignment
  # 5b. backward alignment
  # 5c. symmetrize alignment
  # 5d. actual update
  # 6. update database
  if params[:example]
    logmsg :server, params[:example]
    rcv_obj = JSON.parse params[:example]
    # 0. save raw post-edit
    #source, reference = params[:example].strip.split(" ||| ")
    source = rcv_obj["source_value"]
    reference = rcv_obj["target"].join " "
    reference = cleanstr(reference)
    $db['feedback'] << params[:example]
    $db['post_edits_raw'] << reference.strip
    $db['durations'] << rcv_obj['duration'].to_i
    # 1. tokenize
      reference = send_recv :tokenizer, reference
    # 2. truecase
      reference = send_recv :truecaser, reference
    # 3. save processed post-edits
      logmsg :db, "saving processed post-edit"
      $db['post_edits'] << reference.strip
    nochange = false
    if rcv_obj[:nochange]
      logmsg :server, "no change -> no updates!"
      nochange = true
    end
    if !NOLEARN && !NOMT && !nochange
      logmsg :server, "updating ..."
    # 4. update weights
      grammar = "#{WORK_DIR}/g/#{$db['progress']}.grammar"
      annotated_source = "<seg grammar=\"#{grammar}\"> #{source} </seg>"
      send_recv :dtrain, "#{annotated_source} ||| #{reference}"
    # 5. update grammar extractor
    # 5a. get forward alignment
      source_lc = source.downcase
      reference_lc = reference.downcase
      a_fwd = send_recv :aligner_fwd, "#{source_lc} ||| #{reference_lc}"
    # 5b. get backward alignment
      a_back = send_recv :aligner_back, "#{source_lc} ||| #{reference_lc}"
    # 5c. symmetrize alignment
      a = send_recv :atools, "#{a_fwd} ||| #{a_back}"
    # 5d actual extractor
      send_recv :extractor, "default_context ||| #{source} ||| #{reference} ||| #{a}"
    # 6. update database
      logmsg :db, "updating database"
      $db['updated'] << true
    else
      $db['updated'] << false
    end
    update_database
  end
  source     = $db['source_segments'][$db['progress']]
  raw_source = $db['raw_source_segments'][$db['progress']]
  if !source # input is done -> displays thank you
    logmsg :server, "end of input, sending 'fin'"
    $lock = false
    return {'fin'=>true}.to_json                                       # return
  elsif !$confirmed \
    || ($confirmed && $last_reply && $last_reply!="" \
        && !params[:example] && !$last_reply.to_json["oovs"]) # send last reply
    logmsg :server, "locked, re-sending last reply"
    logmsg :server, "last_reply: '#{$last_reply}'"
    $lock = false
    return $last_reply                                                 # return
  else
    # translate next sentence
    # 0. no mt?
    # 1. generate grammar
    # - additional rules
    # 2. check for OOV
    # 3. translate
    # 4. detokenize
    # 5. reply
    source.strip!
    # 0. no mt?
    if NOMT
      $lock = false
      logmsg :server, "no mt"
      obj = Hash.new
      obj["progress"] = $db["progress"]
      obj["source"] = source
      obj["raw_source"] = raw_source
      return obj.to_json                                               # return
    end
    # 1. generate grammar for current sentence
    grammar = "#{WORK_DIR}/g/#{$db['progress']}.grammar"
    send_recv :extractor, "default_context ||| #{source} ||| #{grammar}"
    # - additional rules
    $additional_rules.each { |rule|
     logmsg :server, "adding rule '#{rule}' to grammar '#{grammar}'"
     `echo "#{rule}" >> #{grammar}`
    }
    # 2. check for OOVs
    src_r = ReadFile.readlines(grammar).map {
      |l| splitpipe(l)[1].strip.split
    }.flatten.uniq
    oovs = []
    source.split.each { |token|
      if !src_r.include? token
        oovs << token
        logmsg :server, "OOV token: '#{token}'"
      end
    }
    oovs.uniq!
    logmsg :server, "OOVs: #{oovs.to_s}"
    if oovs.size > 0                                                     # OOVs
      obj = Hash.new
      obj["oovs"] = oovs
      obj["progress"] = $db['progress']
      raw_source_annot = "#{raw_source}"
      oovs.each { |o|
        raw_source_annot.gsub! "#{o}", "***#{o}###"
      }
      obj["raw_source"] = raw_source_annot
      $last_reply = obj.to_json
      logmsg :server, "OOV reply: '#{$last_reply}'"
      $lock = false
      $confirmed = false
      return $last_reply                                               # return
    end
    # 3. translation
    msg = "act:translate ||| <seg grammar=\"#{grammar}\"> #{source} </seg>"
    deriv_s = send_recv(:dtrain, msg)
    obj_str = proc_deriv(deriv_s)
    obj = JSON.parse obj_str
    obj["transl"] = obj["target_groups"].join " "
    # 4. detokenizer
    obj["transl_detok"] = send_recv(:detokenizer, obj["transl"]).strip
    obj["target_groups"].each_index { |j|
      prev = obj["target_groups"][j][0]
      obj["target_groups"][j] = send_recv(:detokenizer, obj["target_groups"][j]).strip
      obj["target_groups"][j][0]=prev if j > 0
    }
    obj["source"] = source
    obj["progress"]= $db['progress']
    obj["raw_source"] = raw_source
    w_idx = 0
    obj["source_groups"][0][0] = obj["source_groups"][0][0].upcase
    obj["source_groups"].each_with_index { |i,j|
      prev = obj["source_groups"][j][0]
      obj["source_groups"][j] = send_recv(:detokenizer_src, obj["source_groups"][j]).strip
      obj["source_groups"][j][0]=prev if j > 0
    }
    # save
    $db["derivations"] << deriv_s
    $db["derivations_proc"] << obj_str
    $db["mt_raw"] << obj["transl"]
    $db["mt"] << obj["transl_detok"]
    # 5. reply
    $last_reply = obj.to_json
    $lock = false
    $confirmed = false
    logmsg :server, "response: '#{$last_reply}'"
    return $last_reply                                                 # return
  end

  return "{}"                                                  # return [ERROR]
end

get '/debug' do                                                    # debug view
  fn = "#{WORK_DIR}/dtrain.debug.json"                      # TODO: other tools
  data = {}
  # make debug.haml work
  data["kbest"] = []
  data["weights_before"] = {}
  data["weights_after"] = {}
  if File.exist? fn
    data = JSON.parse ReadFile.read(fn).force_encoding("UTF-8")
  end
  data2 = {}
  data2 = JSON.parse ReadFile.read(DB_FILE).force_encoding("UTF-8")
  if data2["durations"].size == 0
    data2["durations"] << -1
  end


  haml :debug, :locals => { :data => data, :data2 => data2, :additional_rules => $additional_rules, :session_key => SESSION_KEY }
end

get '/confirm' do                        # client confirms received translation
  cross_origin
  $confirmed = true
  logmsg :server, "confirmed = #{$confirmed}"

  return "#{$confirmed}"
end

get '/set_learning_rate/:rate' do
  logmsg :server, "set learning rate, #{params[:rate]}"
  return "locked" if $lock
  send_recv :dtrain, "set_learning_rate #{params[:rate].to_f}"

  return "done"
end

get '/set_sparse_learning_rate/:rate' do
  logmsg :server, "set sparse learning rate, #{params[:rate]}"
  return "locked" if $lock
  send_recv :dtrain, "set_sparse_learning_rate #{params[:rate].to_f}"

  return "done"
end

get '/reset_progress' do                                # reset current session
  return "locked" if $lock
  $db = JSON.parse ReadFile.read DB_FILE
  $db['post_edits'].clear
  $db['post_edits_raw'].clear
  $db['mt'].clear
  $db['mt_raw'].clear
  $db['updated'].clear
  $db['durations'].clear
  $db['derivations'].clear
  $db['derivations_proc'].clear
  $db['feedback'].clear
  $db['progress'] = -1
  update_database
  $confirmed = true
  $last_reply = nil

  return "reset done"
end

get '/reset_weights' do
  logmsg :server, "reset weights"
  return "locked" if $lock
  send_recv :dtrain, "reset_weights"

  return "reset weights done"
end

get '/reset_extractor' do
  logmsg :server, "reset extractor"
  return "locked" if $lock
  send_recv :extractor, "default_context ||| drop"

  return "reset extractor done"
end

get '/reset_add_rules' do
  $additional_rules.clear

  return "reset add. rules done"
end

get '/shutdown' do                          # stop daemons and shut down server
  logmsg :server, "shutting down daemons"
  stop_all_daemons

  return "stopped all daemons, ready to shutdown"
end