require 'json'
require 'resque'
require 'resque-retry'
require 'net/http'
require 'digest/md5'

module JamRuby
  class JamTrackMixdownPackager
    extend JamRuby::ResqueStats

    include JamRuby::S3ManagerMixin

    TAP_IN_PADDING = 2

    MAX_PAN = 90
    MIN_PAN = -90
    KNOCK_SECONDS = 0.035

    attr_accessor :mixdown_package_id, :settings, :mixdown_package, :mixdown, :step
    @queue = :jam_track_mixdown_packager

    def log
      @log || Logging.logger[JamTrackMixdownPackager]
    end

    def self.perform(mixdown_package_id, bitrate=48)
      jam_track_builder = JamTrackMixdownPackager.new()
      jam_track_builder.mixdown_package_id = mixdown_package_id
      jam_track_builder.run
    end

    def compute_steps
      @step = 0
      number_downloads = @track_settings.length
      number_volume_adjustments = (@track_settings.select { |track| should_alter_volume? track }).length

      pitch_shift_steps = @mixdown.will_pitch_shift? ? 1 : 0
      mix_steps = 1
      package_steps = 1

      number_downloads + number_volume_adjustments + pitch_shift_steps + mix_steps + package_steps
    end

    def run
      begin
        log.info("Mixdown job starting. mixdown_packager_id #{mixdown_package_id}")
        begin
          @mixdown_package = JamTrackMixdownPackage.find(mixdown_package_id)


          # bailout check
          if @mixdown_package.signed?
            log.debug("package is already signed. bailing")
            return
          end

          @mixdown = @mixdown_package.jam_track_mixdown
          @settings = @mixdown.settings

          process_jmep

          track_settings

          # compute the step count
          total_steps = compute_steps

          # track that it's started ( and avoid db validations )
          signing_started_at = Time.now
          last_step_at = Time.now
          #JamTrackMixdownPackage.where(:id => @mixdown_package.id).update_all(:signing_started_at => signing_started_at, :should_retry => false, packaging_steps: total_steps, current_packaging_step: 0, last_step_at: last_step_at, :signing => true)

          # because we are skipping 'after_save', we have to keep the model current for the notification.  A bit ugly...

          @mixdown_package.current_packaging_step = 0
          @mixdown_package.packaging_steps = total_steps
          @mixdown_package.signing_started_at = signing_started_at
          @mixdown_package.signing = true
          @mixdown_package.should_retry = false
          @mixdown_package.last_step_at = last_step_at
          @mixdown_package.queued = false
          @mixdown_package.save

          SubscriptionMessage.mixdown_signing_job_change(@mixdown_package)

          package

          log.info "Signed mixdown package to #{@mixdown_package[:url]}"

        rescue Exception => e
          # record the error in the database
          post_error(e)

          #SubscriptionMessage.mixdown_signing_job_change(@mixdown_package)
          # and let the job fail, alerting ops too
          raise
        end
      end
    end

    def should_alter_volume? track

      # short cut is possible if vol = 1.0 and pan = 0
      vol = track[:vol]
      pan = track[:pan]

      vol != 1.0 || pan != 0
    end

    def process_jmep
      @start_points = []
      @initial_padding = 0.0
      @tap_in_initial_silence = 0

      speed = @settings['speed'] || 0

      @speed_factor = 1.0 + (-speed.to_f / 100.0)
      @inverse_speed_factor = 1 - (-speed.to_f / 100)

      log.info("speed factor #{@speed_factor}")

      jmep = @mixdown.jam_track.jmep_json

      if jmep.nil?
        log.debug("no jmep")
        return
      end

      events = jmep["Events"]

      return if events.nil? || events.length == 0

      metronome = nil
      events.each do |event|
        if event.has_key?("metronome")
          metronome = event["metronome"]
          break
        end
      end

      if metronome.nil? || metronome.length == 0
        log.debug("no metronome events for jmep", jmep)
        return
      end

      @start_points = metronome.select { |x| puts x.inspect; x["action"] == "start" }

      log.debug("found #{@start_points.length} metronome start points")

      start_point = @start_points[0]

      if start_point
        start_time = parse_time(start_point["ts"])

        if start_time < 2.0
          padding = start_time - 2.0
          @initial_padding = padding.abs
          @initial_tap_in = start_time
        end
      end

      if @speed_factor != 1.0
        metronome.length.times do |count|

          # we expect to find metronome start/stop grouped
          if count % 2 == 0

            start = metronome[count]
            stop = metronome[count + 1]

            if start["action"] != "start" || stop["action"] != "stop"
              # bail out
              log.error("found de-coupled metronome events #{start.to_json} | #{stop.to_json}")
              next
            end

            bpm = start["bpm"].to_f
            stop_time = parse_time(stop['ts'])
            ticks = stop['ticks'].to_i


            new_bpm = bpm * @inverse_speed_factor
            new_stop_time = stop_time * @speed_factor
            new_start_time = new_stop_time - (60.0/new_bpm * ticks)

            log.info("original bpm:#{bpm} start: #{parse_time(start["ts"])} stop: #{stop_time}")
            log.info("updated  bpm:#{new_bpm} start: #{new_start_time} stop: #{new_stop_time}")

            stop["ts"] = new_stop_time
            start["ts"] = new_start_time
            start["bpm"] = new_bpm
            stop["bpm"] = new_bpm

            @tap_in_initial_silence = (@initial_tap_in + @initial_padding) * @speed_factor

          end

        end
      end

      @start_points = metronome.select { |x| puts x.inspect; x["action"] == "start" }

    end

    # format like: "-0:00:02:820"
    def parse_time(ts)

      if ts.is_a?(Float)
        return ts
      end

      time = 0.0
      negative = false

      if ts.start_with?('-')
        negative = true
      end

      # parse time_format
      bits = ts.split(':').reverse

      bit_position = 0
      bits.each do |bit|
        if bit_position == 0
          # milliseconds
          milliseconds = bit.to_f
          time += milliseconds/1000
        elsif bit_position == 1
          # seconds
          time += bit.to_f
        elsif bit_position == 2
          # minutes
          time += 60 * bit.to_f
        elsif bit_position == 3
          # hours
          # not bothering
        end

        bit_position += 1
      end

      if negative
        time = 0.0 - time
      end

      time
    end

    def path_to_resources
      File.join(File.dirname(File.expand_path(__FILE__)), '../../../lib/jam_ruby/app/assets/sounds')
    end

    def knock_file
      if long_sample_rate == 44100
        knock = File.join(path_to_resources, 'knock44.wav')
      else
        knock = File.join(path_to_resources, 'knock48.wav')
      end
      knock
    end

    def create_silence(tmp_dir, segment_count, duration)
      file = File.join(tmp_dir, "#{segment_count}.wav")

      # -c 2 means stereo
      cmd("sox -n -r #{long_sample_rate} -c 2 #{file} trim 0.0 #{duration}", "silence")

      file
    end

    def create_tapin_track(tmp_dir)

      return nil if @start_points.length == 0

      segment_count = 0


      #initial_silence = @initial_tap_in + @initial_padding

      initial_silence = @tap_in_initial_silence

      #log.info("tapin data: initial_tap_in: #{@initial_tap_in}, initial_padding: #{@initial_padding}, initial_silence: #{initial_silence}")

      time_points = []
      files = []
      if initial_silence > 0

        files << create_silence(tmp_dir, segment_count, initial_silence)

        time_points << {type: :silence, ts: initial_silence}
        segment_count += 1
      end


      time_cursor = nil
      @start_points.each do |start_point|
        tap_time = parse_time(start_point["ts"])
        if !time_cursor.nil?
          between_silence = tap_time - time_cursor
          files << create_silence(tmp_dir, segment_count, between_silence)
          time_points << {type: :silence, ts: between_silence}
        end
        time_cursor = tap_time
        bpm = start_point["bpm"].to_f

        tick_silence = 60.0/bpm - KNOCK_SECONDS

        ticks = start_point["ticks"].to_i

        ticks.times do |tick|
          files << knock_file
          files << create_silence(tmp_dir, segment_count, tick_silence)
          time_points << {type: :knock, ts: KNOCK_SECONDS}
          time_points << {type: :silence, ts: tick_silence}
          time_cursor + 60.0/bpm
          segment_count += 1
        end
      end

      log.info("time points for tap-in: #{time_points.inspect}")
      # do we need to pad with time? not sure

      sequence_cmd = "sox "
      files.each do |file|
        sequence_cmd << "\"#{file}\" "
      end

      count_in = File.join(tmp_dir, "count-in.wav")
      sequence_cmd << "\"#{count_in}\""

      cmd(sequence_cmd, "count_in")
      @count_in_file = count_in
      count_in
    end

    # creates a list of tracks to actually mix
    def track_settings
      altered_tracks = @settings["tracks"] || []

      @track_settings = []

      #void slider2Pan(int i, float *f);

      stems = @mixdown.jam_track.stem_tracks
      @track_count = stems.length

      @include_count_in = @settings["count-in"] && @start_points.length > 0 && @mixdown_package.encrypt_type.nil?

      # temp
      # @include_count_in = true

      if @include_count_in
        @track_count += 1
      end

      stems.each do |stem|

        vol = 1.0
        pan = 0
        match = false
        skipped = false
        # is this stem in the altered_tracks list?
        altered_tracks.each do |alteration|

          if alteration["id"] == stem.id
            if alteration["mute"] || alteration["vol"] == 0
              log.debug("leaving out track because muted or 0 volume #{alteration.inspect}")
              skipped = true
              next
            else
              vol = alteration["vol"] || vol
              pan = alteration["pan"] || pan
            end
            @track_settings << {stem: stem, vol: vol, pan: pan}
            match = true
            break
          end
        end

        # if we didn't deliberately skip this one, and if there was no 'match' (meaning user did not specify), then we leave this in unchanged
        if !skipped && !match
          @track_settings << {stem: stem, vol: vol, pan: pan}
        end
      end

      if @include_count_in
        @track_settings << {count_in: true, vol: 1.0, pan: 0}
      end

      @track_settings
    end

    def slider_to_pan(pan)
      # transpose MIN_PAN to MAX_PAN to
      # 0-1.0 range
      #assumes abs(MIN_PAN) == abs(MAX_PAN)
      #  k = f(i) = (i)/(2*MAX_PAN) + 0.5
      # so f(MIN_PAN) = -0.5 + 0.5 = 0

      k = ((pan * (1.0))/ (2.0 * MAX_PAN)) + 0.5
      l, r = 0

      if k == 0
        l = 0.0
        r = 1.0
      else
        l = Math.sqrt(k)
        r = Math.sqrt(1-k)
      end

      [l, r]
    end

    def package

      log.info("Settings: #{@settings.to_json}")

      Dir.mktmpdir do |tmp_dir|

        # download all files
        @track_settings.each do |track|

          if track[:count_in]
            file = create_tapin_track(tmp_dir)
            bump_step(@mixdown_package)
          else
            jam_track_track = track[:stem]

            file = File.join(tmp_dir, jam_track_track.id + '.ogg')

            bump_step(@mixdown_package)

            # download each track needed
            s3_manager.download(jam_track_track.url_by_sample_rate(@mixdown_package.sample_rate), file)
          end

          track[:file] = file
        end

        audio_process tmp_dir
      end
    end

    def audio_process(tmp_dir)
      # use sox remix to apply mute, volume, pan settings


      # step 1: apply pan and volume per track.  mute and vol of 0 has already been handled, by virtue of those tracks not being present in @track_settings
      # step 2: mix all tracks into single track, dividing by constant number of  jam tracks, which is same as done by client backend
      # step 3: apply pitch and speed (if applicable)
      # step 4: encrypt with jkz (if applicable)

      apply_vol_and_pan tmp_dir

      create_silence_padding tmp_dir

      mix tmp_dir

      pitch_speed tmp_dir

      final_packaging tmp_dir
    end

    # output is :volumed_file in each track in @track_settings
    def apply_vol_and_pan(tmp_dir)
      @track_settings.each do |track|

        jam_track_track = track[:stem]
        count_in = track[:count_in]
        file = track[:file]

        unless should_alter_volume? track
          track[:volumed_file] = file
        else
          pan_l, pan_r = slider_to_pan(track[:pan])

          vol = track[:vol]

          # short
          channel_l = pan_l * vol
          channel_r = pan_r * vol

          bump_step(@mixdown_package)

          # sox claps.wav claps-remixed.wav remix 1v1.0 2v1.0

          if count_in
            volumed_file = File.join(tmp_dir, 'count-in' + '-volumed.ogg')
          else
            volumed_file = File.join(tmp_dir, jam_track_track.id + '-volumed.ogg')
          end

          cmd("sox \"#{file}\" \"#{volumed_file}\" remix 1v#{channel_r} 2v#{channel_l}", 'vol_pan')

          track[:volumed_file] = volumed_file
        end
      end
    end

    def create_silence_padding(tmp_dir)
      if @initial_padding > 0 && @include_count_in

        @padding_file = File.join(tmp_dir, "initial_padding.ogg")

        # -c 2 means stereo
        cmd("sox -n -r #{long_sample_rate} -c 2 #{@padding_file} trim 0.0 #{@initial_padding}", "initial_padding")

        @track_settings.each do |track|

          next  if track[:count_in]

          input = track[:volumed_file]
          output = input[0..-5] + '-padded.ogg'

          padd_cmd = "sox '#{@padding_file}' '#{input}' '#{output}'"

          cmd(padd_cmd, "pad_track_with_silence")
          track[:volumed_file] = output
        end
      end
    end

    # output is @mix_file
    def mix(tmp_dir)

      bump_step(@mixdown_package)

      @mix_file = File.join(tmp_dir, "mix.ogg")


      pitch = @settings['pitch'] || 0
      speed = @settings['speed'] || 0


      real_count = @track_settings.count
      real_count -= 1 if @include_count_in

      # if there is only one track to mix, we need to skip mixing (sox will barf if you try to mix one file), but still divide by number of tracks
      if real_count <= 1
        mix_divide = 1.0/@track_count
        cmd = "sox -v #{mix_divide} \"#{@track_settings[0][:volumed_file]}\" \"#{@mix_file}\""
        cmd(cmd, 'volume_adjust')
      else
        # sox -m will divide by number of inputs by default.  But we purposefully leave out tracks that are mute/no volume (to save downloading/processing time in this job)
        # so we need to tell sox to divide by how many tracks there are as a constant, because this is how the client works today
        #sox -m -v 1/n file1 -v 1/n file2 out
        cmd = "sox -m"
        mix_divide = 1.0/@track_count
        @track_settings.each do |track|

          # if pitch/shifted, we lay the tap-in after pitch/speed shift
          # next if (pitch != 0 || speed != 0) && track[:count_in]
          next if track[:count_in]

          volumed_file = track[:volumed_file]
          cmd << " -v #{mix_divide} \"#{volumed_file}\""
        end


        cmd << " \"#{@mix_file}\""
        cmd(cmd, 'mix_adjust')
      end


    end

    def long_sample_rate
      sample_rate = 48000
      if @mixdown_package.sample_rate != 48
        sample_rate = 44100
      end
      sample_rate
    end

    # output is @speed_mix_file
    def pitch_speed tmp_dir

      # # usage
      # This app will take an ogg, wav, or mp3 file (for the uploads) as its input and output an ogg file.
      # Usage:
      # sbsms path-to-input.ogg path-to-output.ogg TimeStrech PitchShift

      # input is @mix_file, created by mix()
      # output is @speed_mix_file

      pitch = @settings['pitch'] || 0
      speed = @settings['speed'] || 0

      # if pitch and speed are 0, we do nothing here
      if pitch == 0 && speed == 0
        @speed_mix_file = @mix_file
      else
        bump_step(@mixdown_package)

        @speed_mix_file = File.join(tmp_dir, "speed_mix_file.ogg")

        # usage: sbsms infile<.wav|.aif|.mp3|.ogg> outfile<.ogg> rate[0.01:100] halfsteps[-48:48] outSampleRateInHz

        sample_rate = long_sample_rate

        # rate comes in as a percent (like 5, -5 for 5%, -5%).  We need to change that to 1.05/
        sbsms_speed = speed/100.0
        sbsms_speed = 1.0 + sbsms_speed

        sbsms_pitch = pitch
        cmd("sbsms \"#{@mix_file}\" \"#{@speed_mix_file}\" #{sbsms_speed} #{sbsms_pitch} #{sample_rate}", 'speed_pitch_shift')
      end

      if @include_count_in
        # lay the tap-ins over the recording
        layered = File.join(tmp_dir, "layered_speed_mix.ogg")
        cmd("sox -m '#{@count_in_file}' '#{@speed_mix_file}' '#{layered}'", "layer_tap_in")
        @speed_mix_file = layered
      end
    end

    def final_packaging tmp_dir

      bump_step(@mixdown_package)

      url = nil
      private_key = nil
      md5 = nil
      length = 0
      output = nil

      if @mixdown_package.encrypt_type
        output, private_key = encrypt_jkz tmp_dir
      else
        # create output file to correct output format
        output = convert tmp_dir
      end

      # upload output to S3
      s3_url = "#{@mixdown_package.store_dir}/#{@mixdown_package.filename}"
      s3_manager.upload(s3_url, output)

      length = File.size(output)
      computed_md5 = Digest::MD5.new
      File.open(output, 'rb').each { |line| computed_md5.update(line) }
      md5 = computed_md5.to_s

      @mixdown_package.finish_sign(s3_url, private_key, length, md5.to_s)
    end

    # returns output destination, converting if necessary
    def convert(tmp_dir)
      # if the file already ends with the desired file type, call it a win
      if @speed_mix_file.end_with?(@mixdown_package.file_type)
        @speed_mix_file
      else
        # otherwise we need to convert from lastly created file to correct
        output = File.join(tmp_dir, "output.#{@mixdown_package.file_type}")

        cmd("#{APP_CONFIG.normalize_ogg_path} --bitrate 192 \"#{@speed_mix_file}\"", 'normalize')

        if @mixdown_package.file_type == JamTrackMixdownPackage::FILE_TYPE_AAC
          cmd("ffmpeg -i \"#{@speed_mix_file}\" -c:a libfdk_aac -b:a 128k \"#{output}\"", 'convert_aac')
        elsif @mixdown_package.file_type == JamTrackMixdownPackage::FILE_TYPE_MP3
          cmd("ffmpeg -i \"#{@speed_mix_file}\" -ab 192k \"#{output}\"", 'convert_mp3')
        else
          raise 'unknown file_type'
        end


        output
      end
    end

    def encrypt_jkz(tmp_dir)
      py_root = APP_CONFIG.jamtracks_dir
      step = 0

      private_key = nil
      # we need to make the id of the custom mix be the name of the file (ID.ogg)
      custom_mix_name = File.join(tmp_dir, "#{@mixdown.id}.ogg")
      FileUtils.mv(@speed_mix_file, custom_mix_name)
      jam_file_opts = ""
      jam_file_opts << " -i #{Shellwords.escape("#{custom_mix_name}+mixdown")}"

      sku = @mixdown_package.id
      title = @mixdown.name
      output = File.join(tmp_dir, "#{title.parameterize}.jkz")
      py_file = File.join(py_root, "jkcreate.py")
      version = @mixdown_package.version

      right = @mixdown.jam_track.right_for_user(@mixdown.user)

      if @mixdown_package.sample_rate == 48
        private_key = right.private_key_48
      else
        private_key = right.private_key_44
      end

      unless private_key
        @error_reason = 'no_private_key'
        @error_detail = 'user needs to generate JamTrack for given sample rate'
        raise @error_reason
      end

      private_key_file = File.join(tmp_dir, 'skey.pem')
      File.open(private_key_file, 'w') { |f| f.write(private_key) }

      log.debug("PRIVATE KEY")
      log.debug(private_key)
      log.info "Executing python source in #{py_file}, outputting to #{tmp_dir} (#{output})"

      cli = "python #{py_file} -D -k #{sku} -p #{Shellwords.escape(tmp_dir)}/pkey.pem -s #{Shellwords.escape(tmp_dir)}/skey.pem #{jam_file_opts} -o #{Shellwords.escape(output)} -t #{Shellwords.escape(title)} -V #{Shellwords.escape(version)}"

      Open3.popen3(cli) do |stdin, stdout, stderr, wait_thr|
        pid = wait_thr.pid
        exit_status = wait_thr.value
        err = stderr.read(1000)
        out = stdout.read(1000)
        #puts "stdout: #{out}, stderr: #{err}"
        raise ArgumentError, "Error calling python script: #{err}" if err.present?
        raise ArgumentError, "Error calling python script: #{out}" if out && (out.index("No track files specified") || out.index("Cannot find file"))

        private_key = File.read(private_key_file)
      end
      return output, private_key
    end

    def cmd(cmd, type)

      log.debug("executing #{cmd}")

      output = `#{cmd}`

      result_code = $?.to_i

      if result_code == 0
        output
      else
        @error_reason = type + "_fail"
        @error_detail = "#{cmd}, #{output}"
        raise "command `#{cmd}` failed."
      end
    end

    # increment the step, which causes a notification to be sent to the client so it can keep the UI fresh as the packaging step goes on
    def bump_step(mixdown_package)
      step = @step
      last_step_at = Time.now
      mixdown_package.current_packaging_step = step
      mixdown_package.last_step_at = last_step_at
      JamTrackMixdownPackage.where(:id => mixdown_package.id).update_all(last_step_at: last_step_at, current_packaging_step: step)
      SubscriptionMessage.mixdown_signing_job_change(mixdown_package)

      @step = step + 1
    end

    # set @error_reason before you raise an exception, and it will be sent back as the error reason
    # otherwise, the error_reason will be unhandled-job-exception
    def post_error(e)
      begin
        # if error_reason is null, assume this is an unhandled error
        unless @error_reason
          @error_reason = "unhandled-job-exception"
          @error_detail = e.to_s
        end
        @mixdown_package.finish_errored(@error_reason, @error_detail)

        log.error "mixdown  package failed. reason=#{@error_reason}\n#detail=#{@error_detail}"
      rescue Exception => e
        log.error "unable to post back to the database the error #{e}"
      end
    end
  end
end