# encoding: UTF-8

# (c) Copyright 2014 Hewlett-Packard Development Company, L.P.
#
#    Licensed under the Apache License, Version 2.0 (the "License");
#    you may not use this file except in compliance with the License.
#    You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS,
#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#    See the License for the specific language governing permissions and
#    limitations under the License.


# This class describes how to process some actions, and will do everything prior
# this task to make it to work.

require 'yaml'

class YamlSchool
   attr_accessor :sFile
   attr_accessor :hData

   def initialize(sFile)
      @hData = { :students => []}
      @sFile = sFile
      load_data()
   end

   def load_data()
      if File.exists?(@sFile)
         @hData = YAML.load_file(@sFile)
         @hData = { :students => []} if not @hData
         @hData[:students] = [] unless @hData.key?(:students)
      end
   end

   def save_data()
         begin
            File.open(@sFile, 'w') do |out|
               YAML.dump(@hData, out)
            end
         rescue => e
            Lorj.error("%s\n%s" % [e.message, e.backtrace.join("\n")])
            return false
         end
      true
   end

   def create_student(name, fields)

      if fields[ :first_name].nil? or fields[ :last_name].nil?
         puts "YAML API: Unable to create a student. :first_name and :last_name required."
         return nil
      end

      result = fields.clone
      result[:name] = name
      result[:name] = "%s %s" % [result[:first_name], result[:first_name]] if name.nil?
      result[:status] = :active

      @hData[:students] << result

      result[:id] = @hData[:students].length()-1

      save_data()
      result
   end

   def delete_student(sId)
      return false unless File.exists?(sFile)

      @hData[:students].each { | value |
         hElem = value
         if value[:id] == sId
            @hData[:students][sId][:status] = :removed
            save_data()
            return 1
         end
      }
      0
   end

   def query_student(sQuery)

      result = []

      @hData[:students].each { | value |
         hElem = value
         sQuery.each { | query_key, query_value |
            hElem = nil if (
               value.key?(:status) and
               value[:status] != :active and
               not sQuery.key?(:status)) or
               not value.key?(query_key) or
               value[query_key] != query_value
         }
         result << hElem if hElem
      }
      result

   end

   def update_student(sId, fields)
      aList = query_student({ :id => Id})
      if aList.length == 1
         aList[0].merge(fields)
      end
      save_data()
   end

end