module ExportPayments

  def self.initiate_export(npo_id, params, user_id)

    ParamValidation.new({ npo_id: npo_id, params: params, user_id: user_id },
                        npo_id: { required: true, is_integer: true },
                        params: { required: true, is_hash: true },
                        user_id: { required: true, is_integer: true })
    npo = Nonprofit.where('id = ?', npo_id).first
    unless npo
      raise ParamValidation::ValidationError.new("Nonprofit #{npo_id} doesn't exist!", key: :npo_id)
    end
    user = User.where('id = ?', user_id).first
    unless user
      raise ParamValidation::ValidationError.new("User #{user_id} doesn't exist!", key: :user_id)
    end

    e = Export.create(nonprofit: npo, user: user, status: :queued, export_type: 'ExportPayments', parameters: params.to_json)

    DelayedJobHelper.enqueue_job(ExportPayments, :run_export, [npo_id, params.to_json, user_id, e.id])
  end

  def self.run_export(npo_id, params, user_id, export_id)
    # need to check that
    ParamValidation.new({ npo_id: npo_id, params: params, user_id: user_id, export_id: export_id },
                        npo_id: { required: true, is_integer: true },
                        params: { required: true, is_json: true },
                        user_id: { required: true, is_integer: true },
                        export_id: { required: true, is_integer: true })

    params = JSON.parse(params, :object_class=> HashWithIndifferentAccess)
    # verify that it's also a hash since we can't do that at once
    ParamValidation.new({ params: params },
                        params: { is_hash: true })
    begin
      export = Export.find(export_id)
    rescue ActiveRecord::RecordNotFound
      raise ParamValidation::ValidationError.new("Export #{export_id} doesn't exist!", key: :export_id)
    end
    export.status = :started
    export.save!

    unless Nonprofit.exists?(npo_id)
      raise ParamValidation::ValidationError.new("Nonprofit #{npo_id} doesn't exist!", key: :npo_id)
    end
    user = User.where('id = ?', user_id).first
    unless user
      raise ParamValidation::ValidationError.new("User #{user_id} doesn't exist!", key: :user_id)
    end

    file_date = Time.now.getutc().strftime('%m-%d-%Y--%H-%M-%S')
    filename = "tmp/csv-exports/payments-#{file_date}.csv"

    url = CHUNKED_UPLOADER.upload(filename, QueryPayments.for_export_enumerable(npo_id, params, 30000).map{|i| i.to_csv}, :content_type => 'text/csv')
    export.url = url
    export.status = :completed
    export.ended = Time.now
    export.save!

    ExportMailer.delay.export_payments_completed_notification(export)
  rescue => e
    if export
      export.status = :failed
      export.exception = e.to_s
      export.ended = Time.now
      export.save!
      if user
        ExportMailer.delay.export_payments_failed_notification(export)
      end
      raise e
    end
    raise e
  end
end