speech.rake

namespace :speech do
  desc "Merge WAV files and encode to FLAC"
  task :encode do |t|
    wav  = "podcast-ep#{ENV['EP']}.wav"
    flac = "podcast-ep#{ENV['EP']}.flac"

    channels = []
    wavs = Dir["#{ENV['HOME']}/Music/GarageBand/Podcast ep#{ENV['EP']}-*.wav"]
    wavs.each_with_index do |w, i|
      mono = "podcast-ep#{ENV['EP']}-ch#{i+1}.wav"
      system 'sox', w, mono, 'remix', '1'
      channels << mono
    end

    system 'sox', '-M', *channels, wav
    channels.each do |file|
      File.unlink file
    end

    system 'flac', '-0', wav, '-f', '-o', flac

    File.unlink wav
  end

  desc "Upload FLAC to GCS"
  task :upload do |t|
    flac = "podcast-ep#{ENV['EP']}.flac"
    system 'gsutil', 'cp', flac, 'gs://rebuild-audio/'
    system 'gsutil', 'acl', 'ch', '-u', 'AllUsers:R', "gs://rebuild-audio/#{flac}"
  end
  
  desc "Request Search transcribe API and logs the operation ID"
  task :request do |t|
    flac = "podcast-ep#{ENV['EP']}.flac"

    channel = `soxi -c #{flac}`.chomp.to_i
    rate = `soxi -r #{flac}`.chomp.to_i

    data = api_request(channel: channel, rate: rate)

    open('_speech/operations.txt', 'a') do |f|
      f.puts "#{ENV['EP']} #{data['name']}"
    end

    File.unlink flac
  end

  def api_request(channel: 2, rate: 48000)
    require 'net/http'
    require 'json'

    phrases = File.readlines('_words.txt').map(&:chomp)

    uri = URI.parse "https://speech.googleapis.com/v1/speech:longrunningrecognize?key=#{ENV['GCLOUD_API_KEY']}"
    body = {
      config: {
        encoding: "FLAC",
        sampleRateHertz: rate,
        languageCode: "ja-JP",
        enableWordTimeOffsets: true,
        audioChannelCount: channel,
        enableSeparateRecognitionPerChannel: true,
        speechContexts: [
          { phrases: phrases }
        ]
      },
      audio: {
        uri: "gs://rebuild-audio/podcast-ep#{ENV['EP']}.flac",
      },
    }

    http = Net::HTTP.new(uri.host, uri.port)
    http.use_ssl = true

    req = Net::HTTP::Post.new uri.request_uri
    req['Content-Type'] = 'application/json'
    req.body = JSON.dump body

    resp = http.request req

    warn resp.body

    JSON.parse resp.body
  end
end