require "mail"

class ReadingsMailer
    
  SSL_OPTS = {
                :openssl_verify_mode => OpenSSL::SSL::VERIFY_NONE,
  }  
  
  # IMAP_OPTS = { :address    => "mail.van-halteren.net",
                                # :port       => 993,
                                # :user_name  => 'aart@van-halteren.net',
                                # :password   => 'XXXXX',
                                # :openssl_verify_mode => OpenSSL::SSL::VERIFY_NONE,
                                # :enable_ssl => true
  # }
                              
  #
  # Class methods
  #
  class << self
    def deliver(date)     
    # Read SMTP options from smtp.yml
    smtp_opts = YAML::load(File.open('config/smtp.yml')).symbolize_keys
    smtp_opts.merge!(SSL_OPTS) if smtp_opts[:ssl] && smtp_opts[:ssl_verify_mode].eql?("none")
    
    # Fetch today's usage
    usage_today = Reading.diff_on(date)
    consumption_today, production_today = Reading.consumed_and_produced_for_diff(usage_today)
    net_consumption_high, net_consumption_low = Reading.net_consumed_high_and_low_for_diff(usage_today)

    # Calculate costs for oxxio and easy energy
    c = Cost.new
    oxxio_normaal_cost, oxxio_dal_cost = c.oxxio_energy_cost(date.to_s,net_consumption_high,net_consumption_low)
    oxxio_cost = oxxio_normaal_cost+oxxio_dal_cost
    easy_cost = c.easy_energy_cost_barplot(date) # side effect: generates a PNG
    # rounding
    oxxio_cost = oxxio_cost.round(2)
    easy_cost = easy_cost.round(2)
    
    mail = Mail.new do
        delivery_method :smtp, smtp_opts
        to      'a.t.van.halteren@vu.nl'
        from    'SmartMeter <aart@van-halteren.net>'
        subject "SmartMeter report for #{date}"

        text_part do
          body "Summary for #{date}\n
                -------------------------------\n\n
                Total kWH electricity consumed: #{consumption_today}\n
                Total kWH electricity produced:  #{production_today}\n
                Total m3 gas consumed: #{usage_today[:total_m3_gas_consumed]}\n\n
                kWH cost (Oxxio): EUR #{ oxxio_cost }\n
                kWH cost (EasyEnergy): EUR #{ easy_cost }\n
               "
        end
      
        html_part do
          content_type 'text/html; charset=UTF-8'
          body "<h1>Summary for #{date}</h1>" +
               "<p>Total kWH electricity consumed: #{consumption_today}</p>" +
               "<p>Total kWH electricity produced:  #{production_today}</p>" +
               "<p>Total m3 gas consumed: #{usage_today[:total_m3_gas_consumed]}</p>" +
               "</br>" +
               "<p>kWH cost (Oxxio): <b>EUR #{ oxxio_cost} </b></p>" +
               "<p>kWH cost (EasyEnergy): <b>EUR #{ easy_cost} </b></p>"
        end 
        
        # add attachment
        filename = "easy_cost_%s.png" % date.strftime("%F")
        add_file :filename => filename, :content => File.read("plots/%s" % filename) 
      end
      
      mail.deliver!
    end

    # default is current year
    def deliver_for_month(month, year=nil)
      return if (month <1 || month >12)

      year = Date.today.year unless year
      date = Date.parse("%s%.2d01" % [year,month])
      date_str = date.strftime("%B %Y")
      
      # Read SMTP options from smtp.yml
      smtp_opts = YAML::load(File.open('config/smtp.yml')).symbolize_keys
      smtp_opts.merge!(SSL_OPTS) if smtp_opts[:ssl] && smtp_opts[:ssl_verify_mode].eql?("none")
    
      # Fetch today's usage
      usage_month = Reading.diff_in_month(date)
      consumption_month, production_month = Reading.consumed_and_produced_for_diff(usage_month)
      net_consumption_normaal, net_consumption_dal = Reading.net_consumed_high_and_low_for_diff(usage_month)


      # Calculate costs for oxxio and easy energy
      c = Cost.new
      vat = 1 + c.vat_at(date)

      # cost with VAT, but without energiebelasting.
      oxxio_raw_cost = c.oxxio_energy_cost(date.to_s,net_consumption_normaal, net_consumption_dal, false).sum.round(2)
      easy_energy_raw_cost = c.easy_energy_raw_cost_in_month(date).compact.sum.round(2)

      # cost with VAT and with energiebelasting
      oxxio_cost = c.oxxio_energy_cost(date.to_s,net_consumption_normaal, net_consumption_dal).sum.round(2)
      easy_energy_cost = c.easy_energy_cost_in_month(date).compact.sum.round(2)

      # opslag Easy Energy
      easy_energy_opslag = (c.easy_energy_rate(date.to_s)*vat*(net_consumption_normaal + net_consumption_dal)).round(2)

      mail = Mail.new do
        delivery_method :smtp, smtp_opts
        to      'a.t.van.halteren@vu.nl'
        from    'SmartMeter <aart@van-halteren.net>'
        subject "SmartMeter Month report for #{date_str}"

        text_part do
          body "Summary for #{date_str}\n
                -------------------------------\n\n
                Total kWH electricity consumed: #{consumption_month}\n
                Total kWH electricity produced:  #{production_month}\n
                Total m3 gas consumed: #{usage_month[:total_m3_gas_consumed]}\n\n
                Levering kWH cost (Oxxio) : EUR #{ oxxio_raw_cost }\n
                Levering kWH cost (EasyEnergy): EUR #{ easy_energy_raw_cost }\n
                Total kWH cost (Oxxio) : EUR #{ oxxio_cost }\n
                Total kWH cost (EasyEnergy): EUR #{ easy_energy_cost }, inclusief opslag van EUR #{ easy_energy_opslag }\n
               "
        end
      
        html_part do
          content_type 'text/html; charset=UTF-8'
          body "<h1>Summary for #{date_str}</h1>" +
               "<p>Total kWH electricity consumed: #{consumption_month}</p>" +
               "<p>Total kWH electricity produced:  #{production_month}</p>" +
               "<p>Total m3 gas consumed: #{usage_month[:total_m3_gas_consumed]}</p>" +
               "</br>" +
               "<p>Levering kWH cost (Oxxio): <b>EUR #{ oxxio_raw_cost} </b></p>" +
               "<p>Levering kWH cost (EasyEnergy): <b>EUR #{ easy_energy_raw_cost} </b></p>" +
               "<p>Total kWH cost (Oxxio): <b>EUR #{ oxxio_cost} </b></p>" +
               "<p>Total kWH cost (EasyEnergy): <b>EUR #{ easy_energy_cost} </b>, inclusief opslag van <b>EUR #{ easy_energy_opslag }</b></p>"
        end 
        
      end
      
      mail.deliver!
    end
  end   
end