# SPDX-License-Identifier: Apache-2.0
# Copyright (C) 2021 OKTET Labs Ltd. All rights reserved.

#
# Class LDAP::Cache for Diary Management Application.
#

require 'ldap'

class LDAP::Cache < Hash
    def initialize(ldap, base_dn, scope, field)
        @ldap = ldap
        @base_dn = base_dn
        @scope = scope
        @field = field
        @lists = Hash.new
        super(0)
    end

    attr_reader :ldap, :lists
    attr_accessor :base_dn, :scope, :field

    def search(filter)
        list = Array.new
        begin
            @ldap.search(@base_dn, @scope, filter) do |entry|
                hash = Hash.new
                entry.to_hash.each do |key, value|
                    hash[key] = value[0]
                end
                self[hash[@field]] = hash
                list.push(hash)
            end
        rescue
            $stderr.printf "Failed to search in LDAP\n"
            exit (-1)
        end
        list
    end
    private :search

    def list(filter, main_value)
        if not @lists[filter]
            @lists[filter] = search(filter).sort_by do |entry|
                entry[main_value]
            end.collect do |entry|
                [entry[@field], entry[main_value]]
            end

        end
        @lists[filter]
    end

    def [](key)
        if super(key) == 0
            list = search("(#{@field}=#{key})")
            if list.length != 1
                self[key] = nil
            else
                self[key] = list[0]
            end
        end
        super(key)
    end
end