module MtaSettings

# File lib/mta_settings.rb, line 64
def self.from_env(env = ENV)
  domain = env['MTA_DOMAIN'] || LOCALHOST
  if url = env[env['MTA_PROVIDER'].presence || 'MTA_URL'].presence
    method, settings = from_url(url)
    if method == :smtp && settings[:domain] == LOCALHOST
      settings[:domain] = domain
    end
    [method, settings]
  elsif env['SENDGRID_USERNAME'].present?
    [:smtp, {
      :address              => "smtp.sendgrid.net",
      :port                 => 587,
      :authentication       => :plain,
      :enable_starttls_auto => true,
      :user_name            => env['SENDGRID_USERNAME'],
      :password             => env['SENDGRID_PASSWORD'],
      :domain               => domain,
    }]
  elsif env['MANDRILL_APIKEY'].present?
    [:smtp, {
      :address              => "smtp.mandrillapp.com",
      :port                 => 587,
      :authentication       => :plain,
      :enable_starttls_auto => true,
      :user_name            => env['MANDRILL_USERNAME'],
      :password             => env['MANDRILL_APIKEY'],
      :domain               => domain,
    }]
  elsif env['POSTMARK_API_TOKEN'].present?
    [:smtp, {
      :address              => env['POSTMARK_SMTP_SERVER'] || 'smtp.postmarkapp.com',
      :port                 => 25,
      :authentication       => :cram_md5,
      :enable_starttls_auto => true,
      :user_name            => env['POSTMARK_API_TOKEN'],
      :password             => env['POSTMARK_API_TOKEN'],
      :domain               => domain,
    }]
  elsif env['MAILGUN_SMTP_LOGIN'].present?
    [:smtp, {
      :address              => env['MAILGUN_SMTP_SERVER'] || 'smtp.mailgun.org',
      :port                 => env['MAILGUN_SMTP_PORT'] || '25',
      :authentication       => :plain,
      :enable_starttls_auto => true,
      :user_name            => env['MAILGUN_SMTP_LOGIN'],
      :password             => env['MAILGUN_SMTP_PASSWORD'],
      :domain               => domain,
    }]
  elsif env['MAILTRAP_API_TOKEN'].present?
    response = Net::HTTP.get(URI.parse("https://mailtrap.io/api/v1/inboxes.json?api_token=#{env['MAILTRAP_API_TOKEN']}"))
    first_inbox = JSON.parse(response)[0]
    [:smtp, {
      :address              => first_inbox['domain'],
      :port                 => first_inbox['smtp_ports'][0],
      :authentication       => :plain,
      :user_name            => first_inbox['username'],
      :password             => first_inbox['password'],
      :domain               => first_inbox['domain']
    }]
  end
end

# File lib/mta_settings.rb, line 11
def self.from_url(url)
  return if url.blank?
  # Use MTA_URL=: to short circuit configuration
  return [nil, nil] if url == ':'
  # Use MTA_URL=test: to use the test method without changing settings
  return [$1.tr('+-.', '___').to_sym, nil] if url =~ /\A^([\w+-.]+):\z/
  uri = URI.parse(url.to_s)

  settings = {
    :user_name => (CGI.unescape(uri.user) if uri.user),
    :password => (CGI.unescape(uri.password) if uri.password),
    :address => uri.host,
    :port => uri.port,
    :location => (uri.path if uri.path != '/'),
  }.reject do |k, v|
    v.nil?
  end

  if !settings[:location] && uri.opaque =~ /^[^?]/
    settings[:location] = CGI.unescape(uri.opaque.split('?').first)
  end

  CGI.parse(uri.query || uri.opaque.to_s.split('?')[1].to_s).each do |k, v|
    settings[k.to_sym] = v.join("\n")[/.+/m]
  end

  adapter = uri.scheme.downcase.tr('+-.', '___').to_sym
  case adapter
  when :sendmail, :exim
    settings[:location] ||= "/usr/sbin/#{adapter}"
    settings[:arguments] ||= '-i -t'

  when :file
    settings[:location] ||=
      if defined?(Rails.root)
        "#{Rails.root}/tmp/mails"
      else
        "#{Dir.tmpdir}/mails"
      end

  when :smtp, :smtps
    settings[:ssl] = (adapter == :smtps)
    adapter = :smtp
    settings[:enable_starttls_auto] = true
    settings[:authentication] ||= :plain if settings[:user_name]
    settings[:domain] ||=
      (settings.delete(:location) || LOCALHOST).sub(/^\//, '')

  end

  [adapter, settings]
end