class Autobackup

# File lib/Autobackup.rb, line 12
def self.call
  new.call
end

# File lib/Autobackup.rb, line 17
def initialize(attrs={})
  Heroku::Command.load
  Heroku::Auth.credentials = [ ENV['HEROKU_USERNAME'], ENV['HEROKU_API_KEY'] ]


end

# File lib/Autobackup.rb, line 24
def call
  # initialize the heroku client interface
  ENV['APPNAME'].split(",").each do |app|
    execute_backup(app)
  end
end

# File lib/Autobackup.rb, line 57
def download_file(dbname)
  puts "Downloading file in local system"
  # download the file from heroku and save it into a temp file
  File.open(temp_file, "wb") do |output|
    streamer = lambda do |chunk, remaining_bytes, total_bytes|
      output.write chunk
    end

    # https://github.com/excon/excon/issues/475
    Excon.get backup_url,
      :response_block    => streamer,
      :omit_default_port => true
  end
  # initiate upload to S3
  puts "Download complete..."
  upload_file(temp_file,dbname)
end

# File lib/Autobackup.rb, line 31
def execute_backup(appname)
  puts "================================="
  puts "Starting back up for "+appname

  @client = Heroku::Command::Pg.new([], :app =>appname)
  # database is standard database_url but is configurable in case the app has multiple DBs
  begin
    attachment = client.send(:generate_resolver).resolve(database)

    # Actual backup interface to heroku
    backup = client.send(:hpg_client, attachment).backups_capture
    client.send(:poll_transfer, "backup", backup[:uuid])
    puts "Backup complete ..."
    # get the public url of the backup file for uploading to S3
    self.backup_url = Heroku::Client::HerokuPostgresqlApp
    .new(appname).transfers_public_url(backup[:num])[:url]
    download_file(appname)

    puts "Back up for "+ appname + " complete"
    puts "================================="
  rescue
    puts "The application "+ appname + "is not accessible to you"
  end

end

# File lib/Autobackup.rb, line 76
def upload_file(filepath,dbname)
  # code for actual s3 upload
  puts "Uploading file in S3..."
  Aws.config.update({
                      region: 'ap-southeast-1',
                      credentials: Aws::Credentials.new(ENV['S3_ACCESS_ID'],ENV['S3_ACCESS_SECRET'])

  })
  s3 = Aws::S3::Resource.new(region:ENV['S3_REGION'])
  obj = s3.bucket(ENV['S3_BUCKET']).object(generate_file_name(dbname))
  obj.upload_file(filepath)
  puts "Upload Complete"
end

# File lib/Autobackup.rb, line 103
def current_time
  Time.now.getutc.to_s
end

# File lib/Autobackup.rb, line 100
def current_timestamp
  Time.now.getutc.to_i
end

# File lib/Autobackup.rb, line 93
def database
  "DATABASE_URL"
end

# File lib/Autobackup.rb, line 107
def generate_file_name(dbname)
  'backup_for_'+dbname+"_"+current_timestamp.to_s+"("+current_time+")"

end

# File lib/Autobackup.rb, line 97
def temp_file
  "#{Dir.tmpdir}/pgbackup"
end