class Quandl::Command::Tasks::Schedule < Quandl::Command::Task

  depends 'chronic', 'whedon', 'open-uri', 'zlib', 'archive/tar/minitar'
  
  autoload_quandl_client
  authenticated_users_only!
  
  description "Schedule a script to be run in the quandl cloud."
  syntax %{quandl schedule command [file(s)]

  COMMANDS:
  
    schedule list      [FILE]
    schedule add       RUN_FILE [DEPENDENT_FILE1] [DEPENDENT_FILE2] [--at TIME]
    schedule delete    SCRIPT
    schedule run       SCRIPT

  EXAMPLES:
  
    $ quandl schedule add scraper.rb
    You have successfully scheduled scraper.rb.

    $ quandl schedule add scraper.rb helper.txt helper2.txt --at "7pm Monday"
    You have successfully scheduled scraper.rb to run alongside helper.txt, helper2.txt. [weekly scraper]

    $ quandl schedule deleted scraper.rb
    You have successfully deleted scraper.rb.

    $ quandl schedule run scraper.rb
    Your scraper.rb will run immediately.
  }

  options({
    String => {
      at:              "Time to run your script in UTC timezone. e.g. '14:30','7pm Monday', 'friday 13:00'"
    }
  })
  
  DAYS_OF_THE_WEEK = %w(Sunday Monday Tuesday Wednesday Thursday Friday Saturday)
  
  validate :cron_at_should_be_valid!
  
  def execute
    # fire a subcommand if specified
    return self.send(args.shift) if args.first.present? && self.respond_to?(args.first)
    # otherwise fire add
    return add if args.first.present? && args.first.downcase != "help"
    # otherwise display syntax
    info(syntax)
  end
  
  def list
    if args.first
      (info("'#{name}' does not exist "); return;) if scraper.blank?
      script_info scraper
    else
      # create new blank scope and iterate over all pages
      Quandl::Client::Scraper.scope.new.each_in_page{|x| script_info(x) }
    end
  end

  def add
    upload_file = Tempfile.new('temp')
    begin
      result=Quandl::Client::Scraper.create( name: name, scraper: file_to_send(args, upload_file), schedule_at: cron_at_utc)
      if result.valid?
        info("You have successfully scheduled '#{scraper.name}'.")
        info("#{schedule_message}")
      else
        error "#{Quandl::Command::Presenter.pretty_errors(result.errors.messages).to_s.gsub("\n", ' ')}"
      end
    ensure
      upload_file.close!
    end
  end
  
  def download
    begin
      $stdout.binmode
      $stdout << open(scraper.scraper_url, "rb", {ssl_verify_mode: OpenSSL::SSL::VERIFY_NONE}).read
    rescue => err
      present err
    end
  end
  
  def delete
    (info("'#{name}' does not exist "); return;) if scraper.blank?
    info("You are about to delete '#{scraper.name}'")
    return unless confirmed?
    result=scraper.destroy if scraper.respond_to?(:destroy)
    if result.valid?
      info("You have successfully deleted '#{scraper.name}'")
    else
      error "#{Quandl::Command::Presenter.pretty_errors(result.errors.messages).to_s.gsub("\n", ' ')}"
    end

  end

  def run
    (info("'#{name}' does not exist "); return;) if scraper.blank?
    info("You are about to run '#{scraper.name}'")
    return unless confirmed?
    result=scraper.run_now if scraper.respond_to?(:run_now)
    if result.valid?
      info("Your '#{scraper.name}' will run immediately.")
    else
      if result.status == 429
        info("You have exceeded your daily run limit.")
      else
        error "#{Quandl::Command::Presenter.pretty_errors(result.errors.messages).to_s.gsub("\n", ' ')}"
      end
    end

  end

  #not supported for now
=begin
  def replace
    upload_file = Tempfile.new('temp')
    begin
      (info("'#{name}' does not exist "); return;) if scraper.blank?
      info("You are about to replace '#{scraper.name}'")
      return unless confirmed?
      scraper.scraper = file_to_send(args, upload_file)
      scraper.schedule_at = cron_at_utc
      scraper.save
      if scraper.valid?
        info("You have successfully replaced '#{scraper.name}'.")
        info("#{schedule_message}") if cron_at
      else
        error "#{Quandl::Command::Presenter.pretty_errors(scraper.errors.messages).to_s.gsub("\n", ' ')}"
      end
    ensure
      upload_file.close!
    end
  end
=end
  
  private

  def script_info(script)
    message = script.name.to_s.ljust(20)
    message += " Scheduled: #{script.schedule_run_time.to_s.ljust(30)}"
    message += " Next: in #{script.schedule_next}" if script.schedule_next.present?
    info message
  end

  def schedule_message
    if options.at
      "Your script first run will happen in #{scraper.schedule_next}. It will continue to run #{scraper.schedule_run_time}
Check your script run status at #{quandl_url.gsub(/\/api\/?/,'')}/schedule/#{scraper.id}"
    else
      "It will run 3 times a day starting immediately.\nCheck your script run status at #{quandl_url.gsub(/\/api\/?/,'')}/schedule/#{scraper.id}"
    end
  end

  def scrapers
    @scrapers ||= Quandl::Client::Scraper.where( page: page ).fetch
  end
  
  def scraper
    defined?(@scraper) ? @scraper : ( @scraper = find_scraper )
  end
  
  def find_scraper
    return nil unless args.first.present?
    # if the arg is numeric lookup the id. otherwise search for a scraper by name and grab the id
    id = args.first.numeric? ? args.first : Quandl::Client::Scraper.where( name: name ).try(:first).try(:id)
    # find the scraper with the id
    Quandl::Client::Scraper.find(id) unless id.nil?
  end

  def cron_at
    return nil unless options.at
    time_to_cron Chronic.parse(options.at)
  end

  def cron_at_utc
    return nil unless options.at
    time_to_cron Chronic.parse(options.at).utc
  end

  def time_to_cron(time_value)
    day_of_the_week = options.at =~ (/Mon|Tue|Wed|Thu|Fri|Sat|Sun/i) ? time_value.wday : '*'
    "* #{time_value.min} #{time_value.hour} * * #{day_of_the_week}"
  end

  def name
    return File.basename(args.first) if args.first.present?
  end

  def cron_at_should_be_valid!
    if options.at.present? && !Chronic.parse(options.at)
      self.errors.add(:base,"#{options.at} is invalid time format" )
      return false
    end
    true
  end

  def file_to_send(values, upload_file)
    if [*values].count > 1
      file = upload_file
      Archive::Tar::Minitar.pack( values, Zlib::GzipWriter.new( File.new( file, 'wb' ) ) )
    else
      file = [*values].first
    end
    file
  end


end