#-- encoding: UTF-8
#-- copyright
# OpenProject is an open source project management software.
# Copyright (C) 2012-2020 the OpenProject GmbH
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
# Copyright (C) 2006-2017 Jean-Philippe Lang
# Copyright (C) 2010-2013 the ChiliProject Team
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# See docs/COPYRIGHT.rdoc for more details.
#++

namespace :ldap do

  def parse_args
    # Rake croaks when using commas in default args without properly escaping
    args = {}
    ARGV.drop(1).each do |arg|
      key, val = arg.split(/\s*=\s*/, 2)
      args[key.to_sym] = val
    end

    args
  end

  desc 'Synchronize users from the LDAP auth source with an optional filter' \
       'rake ldap:sync["name=<LdapAuthSource Name>", filter=<Optional RFC2254 filter string>]'
  task sync: :environment do
    args = parse_args
    ldap = LdapAuthSource.find_by!(name: args.fetch(:name))

    # Parse filter string if available
    filter = Net::LDAP::Filter.from_rfc2254 args.fetch(:filter, 'objectClass = *')

    # Open LDAP connection
    ldap_con = ldap.send(:initialize_ldap_con, ldap.account, ldap.account_password)

    User.transaction do
      ldap_con.search(base: ldap.base_dn, filter: filter) do |entry|

        user = User.find_or_initialize_by(login: entry[ldap.attr_login])
        user.attributes = {
          firstname: entry[ldap.attr_firstname],
          lastname: entry[ldap.attr_lastname],
          mail: entry[ldap.attr_mail],
          admin: entry[ldap.attr_admin],
          auth_source: ldap
        }

        if user.changed?
          prefix = user.new_record? ? 'Created' : 'Updated'
          Rails.logger.info "#{prefix} user #{user.login} from ldap synchronization"
          user.save
        end
      end
    end
  end

  desc 'Synchronize a list of user IDs with the LDAP auth source' \
       'rake ldap:sync_user_list LDAP=<LdapAuthSource Name>" USERLIST=<Path to file with newline separated USER ids>'
  task sync_user_list: :environment do
    file = ENV['USERLIST']
    ldap_name = ENV['LDAP']

    ldap = LdapAuthSource.find_by!(name: ldap_name)

    # Open connection
    puts "--> Opening LDAP connection"
    ldap_con = ldap.instance_eval { initialize_ldap_con(account, account_password) }
    base_dn = ldap.send :base_dn

    attr_login = ldap.send :attr_login
    object_filter = Net::LDAP::Filter.eq('objectClass', '*')
    attributes = ldap.instance_eval do
      ['dn', attr_login, attr_firstname, attr_lastname, attr_mail, attr_admin]
    end

    puts "--> Reading username file #{file}"
    File.read(file).lines.each do |username|
      # Trim and skip empty
      username.chomp!
      next unless username.present?

      login_filter = Net::LDAP::Filter.eq(attr_login, username)

      entries = ldap_con.search(base: base_dn, filter: object_filter & login_filter, attributes: attributes)


      if entries.count == 0
        warn "Did not find entry for #{username}"
        next
      end

      if entries.count > 1
        warn "Found multiple entries for #{username}: #{entries.map(&:dn)}. Skipping"
        next
      end

      entry = entries.first
      user = User.find_or_initialize_by(login: LdapAuthSource.get_attr(entry, ldap.attr_login))
      user.attributes = ldap.send(:get_user_attributes_from_ldap_entry, entry).except(:dn)

      if user.changed?
        prefix = user.new_record? ? 'Created' : 'Updated'

        if user.save
          puts "#{prefix} user #{user.login} from ldap synchronization"
        else
          puts "Failed to save #{user.login}: #{user.errors.full_messages.join(", ")}."
        end
      end
    end
  end

  desc 'Register a LDAP auth source for the given LDAP URL and attribute mapping: ' \
       'rake ldap:register["url=<URL> name=<Name> onthefly=<true,false>map_{login,firstname,lastname,mail,admin}=attribute"]'
  task register: :environment do
    args = parse_args

    url = URI.parse(args[:url])
    unless %w(ldap ldaps).include?(url.scheme)
      raise "Expected #{args[:url]} to be a valid ldap(s) URI."
    end


    source = LdapAuthSource.find_or_initialize_by(name: args[:name])

    unless source.new_record?
      puts "LDAP auth source #{args[:name]} already exists. Updating its attributes instead."
    end

    source.attributes = {
      host: url.host,
      port: url.port,
      tls_mode: url.scheme == 'ldaps' ? 'start_tls' : 'plain_ldap',
      account: url.user,
      account_password: url.password,
      base_dn: url.dn,
      onthefly_register: !!ActiveModel::Type::Boolean.new.cast(args[:onthefly]),
      attr_login: args[:map_login],
      attr_firstname: args[:map_firstname],
      attr_lastname: args[:map_lastname],
      attr_mail: args[:map_mail],
      attr_admin: args[:map_admin]
    }

    if source.save
      puts "Saved LDAP auth source #{args[:name]}."
    else
      raise "Failed to save auth source: #{source.errors.full_messages.join("\n")}"
    end
  end

  desc 'Creates a dummy LDAP auth source for logging in any user using the password "dummy".'
  task create_dummy: :environment do
    source_name = 'DerpLAP'
    otf_reg = ARGV.include?('onthefly_register')

    source = DummyAuthSource.create name: source_name, onthefly_register: otf_reg

    puts
    if source.valid?
      puts "Created dummy auth source called \"#{source_name}\""
      puts 'On-the-fly registration support: ' + otf_reg.to_s
      unless otf_reg
        puts "use `rake ldap:create_dummy[onthefly_register]` to enable on-the-fly registration"
      end
    else
      puts "Dummy auth source already exists. It's called \"#{source_name}\"."
    end

    puts
    puts 'Note: Dummy auth sources cannot be edited, so clicking on them'
    puts "      in the 'LDAP Authentication' view will result in an error. Bummer!"
  end

  desc 'Delete all Dummy auth sources'
  task delete_dummies: :environment do
    DummyAuthSource.destroy_all

    puts
    puts 'Deleted all dummy auth sources. Users who used it are out of luck! :o'
  end
end