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

  before_execute :require_dependencies
  autoload_quandl_client
  authenticated_users_only!
  
  description "Schedule a script to be run in the quandl cloud."
  syntax %{quandl schedule command [file]

  COMMANDS:
  
    schedule list
    schedule add       file
    schedule show      file
    schedule delete    file
    schedule replace   file
    
  EXAMPLES:
  
    $ quandl schedule add scraper.rb
    You have successfully scheduled scraper.rb.

    $ quandl schedule add scraper.rb --name weekly_scraper.rb --at "7pm Monday"
    You have successfully scheduled weekly-scraper.rb.
  
    $ quandl schedule replace scraper.rb --at "13:00"
    You have successfully replaced scraper.rb}
    
  options({
    String => {
      name:            "The name used to reference your scraper in the quandl cloud.",
      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)

  def list
    scrapers.each { |x| script_info x}
  end
  
  def show
    script_info scraper
  end
  
  def add
    result=Quandl::Client::Scraper.create( name: name, scraper: args.first, schedule_at: cron_at)
    if result.valid?
      info("You have successfully scheduled '#{scraper.name}'.")
      info("#{schedule_message}")
    else
      raise "#{Quandl::Command::Presenter.pretty_errors(result.errors.messages).to_s.gsub("\n", ' ')}"
    end
  end
  
  def download
    begin
      require 'open-uri'
      open( scraper.name, 'wb') do |file|
        $stdout << open(scraper.scraper_url, {ssl_verify_mode: OpenSSL::SSL::VERIFY_NONE}).read
      end
    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
      raise "#{Quandl::Command::Presenter.pretty_errors(result.errors.messages).to_s.gsub("\n", ' ')}"
    end

  end


  def replace
    (info("'#{name}' does not exist "); return;) if scraper.blank?
    cron_at   #validate if cron format is valid before deleting scraper
    info("You are about to replace '#{scraper.name}'")
    return unless confirmed?
    scraper.scraper = args.first
    scraper.schedule_at = cron_at
    scraper.save
    if scraper.valid?
      info("You have successfully replaced '#{scraper.name}'.")
      info("#{schedule_message}")
    else
      raise "#{Quandl::Command::Presenter.pretty_errors(scraper.errors.messages).to_s.gsub("\n", ' ')}"
      
    end
  end
  
  private

  def require_dependencies
    require 'chronic'
    require 'whedon'
  end

  def script_info(script)
    unless script.schedule_at.empty?
      info("#{(script.name+'.').ljust(20)} Scheduled: #{script_run_time(script.schedule_at)}")
    else
      info("#{(script.name+'.').ljust(20)} Scheduled: 3 times a day")
    end
  end

  
  def script_run_time(cron_time)
    "every #{cron_time.ends_with?('*') ? 'day' : DAYS_OF_THE_WEEK[cron_time[-1].to_i]} at #{script_next_run(cron_time).strftime("%H:%M (UTC)")}"
  end

  def script_next_run(cron_time)
    Whedon::Schedule.new(cron_time).next
  end


  def schedule_message
    if options.at
      "Your script first run will happen #{script_next_run(cron_at).strftime("on %d %B at %H:%M (UTC)")}. It will continue to run #{script_run_time(cron_at)}
Check your scrapers run status at #{quandl_url.gsub(/\/api\/?/,'')}/scrapers"
    else
      "It will run 3 times a day starting immediately.\n Check your scrapers run status at #{quandl_url.gsub(/\/api\/?/,'')}/scrapers"
    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_value=Chronic.parse(options.at)
    raise "#{options.at} is invalid time" if time_value.nil?
    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 options.name if options.name.present?
    return File.basename(args.first) if args.first.present?
  end
  
end