class Net::SMTP
  def mailfrom(from_addr)
    from_addr = from_addr[/<([^>]+)>/, 1] if from_addr.include?('<')

    if $SAFE > 0
      raise SecurityError, 'tainted from_addr' if from_addr.tainted?
    end
    getok("MAIL FROM:<#{from_addr}>")
  end
end

class Service::Email < Service
  string     :address
  password   :secret
  boolean    :send_from_author
  white_list :address

  def receive_push
    extend PushEmail
    deliver_to_addresses
  end

  def receive_public
    extend PublicEmail
    deliver_to_addresses
  end

  def deliver_to_addresses
    if addresses.size.zero?
      raise_config_error "Invalid addresses: #{data['address'].inspect}"
    end

    configure_mail_defaults unless mail_configured?

    addresses.each do |address|
      send_message_to address
    end
  end

  def send_message_to(address)
    send_mail mail_message(address)
  end

  def send_mail(mail)
    mail.deliver!
  end

  def configure_mail_defaults
    my = self

    Mail.defaults do
      delivery_method :smtp,
        :address              => my.smtp_address,
        :port                 => my.smtp_port,
        :domain               => my.smtp_domain,
        :user_name            => my.smtp_user_name,
        :password             => my.smtp_password,
        :authentication       => my.smtp_authentication,
        :enable_starttls_auto => my.smtp_enable_starttls_auto?,
        :openssl_verify_mode  => my.smtp_openssl_verify_mode
    end

    mail_configured!
  end

  def mail_configured?
    defined?(@@mail_configured) && @@mail_configured
  end

  def mail_configured!
    @@mail_configured = true
  end

  def addresses
    @addresses ||= data['address'].to_s.split(' ').slice(0, 2)
  end

  def mail_message(address)
    my = self

    Mail.new do
      to       address
      from     my.mail_from
      reply_to my.mail_from
      subject  my.mail_subject
      headers  my.secret_header

      text_part do
        content_type 'text/plain; charset=UTF-8'
        body         my.mail_body
      end
    end
  end

  def secret_header
    secret ? {'Approved' => secret} : {}
  end

  def secret
    data['secret'] if data['secret'].to_s.size > 0
  end

  def shorten(text, limit)
    text.slice(0, limit) << '...'
  end

  def align(text, indent = '  ')
    margin = text[/\A\s+/].size

    text.gsub(/^\s{#{margin}}/, indent)
  end

  def send_from_author?
    config_boolean_true?('send_from_author')
  end

  def smtp_address
    @smtp_address ||= email_config['address']
  end

  def smtp_port
    @smtp_port ||= (email_config['port'] || 25).to_i
  end

  def smtp_domain
    @smtp_domain ||= email_config['domain'] || 'localhost.localdomain'
  end

  def smtp_authentication
    @smtp_authentication ||= email_config['authentication']
  end

  def smtp_user_name
    @smtp_user_name ||= email_config['user_name']
  end

  def smtp_password
    @smtp_password ||= email_config['password']
  end

  def smtp_enable_starttls_auto?
    @smtp_enable_starttls_auto ||= (email_config['enable_starttls_auto'] != 'false' && true)
  end

  def smtp_openssl_verify_mode
    @smtp_openssl_verify_mode ||= email_config['openssl_verify_mode']
  end

  def smtp_logging?
    @smtp_logging ||= email_config['enable_logging']
  end

  def noreply_address
    @noreply_address ||= email_config['noreply_address'] || "GitHub <noreply@github.com>"
  end

  module RepositoryEmailHelpers
    def name_with_owner
      File.join(owner_name, repository_name)
    end

    def owner_name
      payload['repository']['owner']['login']
    end

    def repository_name
      payload['repository']['name']
    end

    def repo_url
      payload['repository']['url']
    end
  end

  module PushEmail
    include RepositoryEmailHelpers

    # Public
    def mail_subject
      if first_commit
        "[#{name_with_owner}] #{first_commit_sha.slice(0, 6)}: #{first_commit_title}"
      else
        "[#{name_with_owner}]"
      end
    end

    # Public
    def mail_body
      body = commits.inject(repository_text) do |text, commit|
        text << commit_text(commit)
      end

      body << compare_text unless single_commit?

      body << <<-NOTE

      **NOTE:** GitHub Services has been marked for deprecation: https://developer.github.com/changes/2018-04-25-github-services-deprecation/

      We will provide an alternative path for the email notifications by January 31st, 2019.
      NOTE
    end

    # Public
    def mail_from
      send_from_author? ? author_address : noreply_address
    end

    def repository_text
      align(<<-EOH)
        Branch: #{branch_ref}
        Home:   #{repo_url}
      EOH
    end

    def commit_text(commit)
      gitsha   = commit['id']
      added    = commit['added'].map    { |f| ['A', f] }
      removed  = commit['removed'].map  { |f| ['R', f] }
      modified = commit['modified'].map { |f| ['M', f] }

      changed_paths = (added + removed + modified).sort_by { |(char, file)| file }
      changed_paths = changed_paths.collect { |entry| entry * ' ' }.join("\n    ")

      timestamp = Date.parse(commit['timestamp'])

      commit_author = "#{commit['author']['name']} <#{commit['author']['email']}>"

      text = align(<<-EOH)
        Commit: #{gitsha}
            #{commit['url']}
        Author: #{commit_author}
        Date:   #{timestamp} (#{timestamp.strftime('%a, %d %b %Y')})

      EOH

      if changed_paths.size > 0
        text << align(<<-EOH)
          Changed paths:
            #{changed_paths}

        EOH
      end

      text << align(<<-EOH)
        Log Message:
        -----------
        #{commit['message']}


      EOH

      text
    end

    def compare_text
      "Compare: #{payload['compare']}"
    end

    def single_commit?
      first_commit == last_commit
    end

    def branch_ref
      payload['ref']
    end

    def author_address
      "#{author_name} <#{author_email}>"
    end

    def author
      commit = last_commit || {}
      commit['author'] || commit['committer'] || payload['pusher']
    end

    def author_name
      author['name']
    end

    def author_email
      author['email']
    end

    def last_commit
      payload['commits'].last # assume that the last committer is also the pusher
    end

    def first_commit_sha
      first_commit['id']
    end

    def first_commit_title(limit = 50)
      title_line = first_commit['message'][/\A[^\n]+/] || ''

      title_line.length > limit ? shorten(title_line, limit) : title_line
    end

    def first_commit
      payload['commits'].first
    end

    # must be a difference with push payloads
    def owner_name
      payload['repository']['owner']['name']
    end
  end

  module PublicEmail
    include RepositoryEmailHelpers

    # Public
    def mail_subject
      "#{name_with_owner} has changed from Private to Public"
    end

    # Public
    def mail_body
      "#{name_with_owner} has changed from Private to Public\n\n#{repo_url}"
    end

    # Public
    def mail_from
      noreply_address
    end
  end
end
