module Raddar
  class OmniauthCompletion
    def self.complete(auth_data, current_user = nil)
      user = User.new(password: Devise.friendly_token[0,20])

      provider = auth_data[:provider]

      account = ExternalAccount.find_by(provider: provider, uid: auth_data[:uid])

      if current_user.present?
        if account.present?
          if account.user != current_user
            raise 'Another user already owns this account.'
          end
        else
          create_account_for(current_user, auth_data)
        end

        user = current_user
      elsif account.present?
        user = account.user
      elsif auth_data[:info][:email].present?
        user_with_the_given_email = User.find_by(email: auth_data[:info][:email])

        if user_with_the_given_email.present?
          create_account_for(user_with_the_given_email, auth_data)

          user = user_with_the_given_email
        end
      end

      populate(user, auth_data)

      if user.valid?
        if user.new_record?
          user.confirm!

          user.save

          create_account_for(user, auth_data)
        else
          user.save
        end
      end

      user
    end

    private

    def self.create_account_for(user, auth_data)
      account = user.external_accounts.new

      account.provider = auth_data[:provider]
      account.token    = auth_data[:credentials][:token]
      account.secret   = auth_data[:credentials][:secret]
      account.verified = auth_data[:info][:verified]
      account.name     = auth_data[:info][:nickname]
      account.uid      = auth_data[:uid]
      account.email    = auth_data[:info][:email]
      account.url      = auth_data[:info][:urls][account.provider.titleize.to_sym]

      account.save!
    end

    def self.populate(user, auth_data)
      user.email    = user.email.presence || auth_data[:info][:email]

      user.name     ||= auth_data[:info][:nickname]
      user.bio      ||= auth_data[:info][:description]
      user.location ||= auth_data[:info][:location]

      user.remote_avatar_url = auth_data[:info][:image] if user.avatar.blank?

      if auth_data[:provider] == 'facebook'
        fb_birthday = auth_data[:extra][:raw_info][:birthday]

        user.birthday ||= Date.strptime(fb_birthday, '%m/%d/%Y') if fb_birthday
        user.gender   ||= auth_data[:extra][:raw_info][:gender]
      end
    end
  end
end