require 'common/plugin'
require 'common/filesystem'

module DovecotPlugin
  # Code that all Dovecot plugins (Prune, Rm, Mv...) will
  # share.  That is, we implement the Plugin interface.
  include Plugin

  def initialize(cfg)
    @domain_root = cfg.mail_root
  end

  def describe_domain(domain)
    begin
      domain_path = get_domain_path(domain)
      return domain_path
    rescue NonexistentDomainError => e
      return "Doesn't exist: #{e.to_s}"
    end
  end

  def describe_user(user)
    begin
      user_path = get_user_path(user)
      return user_path
    rescue NonexistentUserError => e
      return "Doesn't exist: #{e.to_s}"
    end
  end


  protected;

  def get_domain_path(domain)
    # Return the filesystem path for the given domain.
    # That is, the directory where its mail is stored.
    # Only works if the domain directory exists!
    domain_path = File.join(@domain_root, domain)

    if File.directory?(domain_path)
      return domain_path
    else
      raise NonexistentDomainError.new(domain)
    end
  end


  def get_user_path(user)
    # Return the filesystem path of this user's mailbox.
    # Only works if the user exists!
    if not user.include?('@')
      msg = "#{user}: Users must contain an '@' symbol."
      raise InvalidUserError.new(msg)
    end

    user_parts = user.split('@')
    local_part = user_parts[0]
    domain_part = user_parts[1]

    begin
      domain_path = get_domain_path(domain_part)
    rescue NonexistentDomainError
      raise NonexistentUserError.new(user)
    end

    user_path = File.join(domain_path, local_part)

    if File.directory?(user_path)
      return user_path
    else
      raise NonexistentUserError.new(user)
    end
  end


  def list_domains()
    return Filesystem.get_subdirs(@domain_root)
  end

  def list_domains_users(domains)
    users = []

    domains.each do |domain|
      begin
        # Throws a NonexistentDomainError if the domain's path
        # doesn't exist on the filesystem. In this case, we want
        # to report zero users.
        domain_path = get_domain_path(domain)
        usernames = Filesystem.get_subdirs(domain_path)

        usernames.each do |username|
          users << "#{username}@#{domain}"
        end
      rescue NonexistentDomainError
        # Party hard.
      end
    end

    return users
  end


  def list_users()
    domains = list_domains()
    users = list_domains_users(domains)
    return users
  end

end