module RCAP
  module Base
    class Info
      include Validation

      CATEGORY_GEO       = "Geo"
      CATEGORY_MET       = "Met"
      CATEGORY_SAFETY    = "Safety"
      CATEGORY_SECURITY  = "Security"
      CATEGORY_RESCUE    = "Rescue"
      CATEGORY_FIRE      = "Fire"
      CATEGORY_HEALTH    = "Health"
      CATEGORY_ENV       = "Env"
      CATEGORY_TRANSPORT = "Transport"
      CATEGORY_INFRA     = "Infra"
      CATEGORY_CBRNE     = "CBRNE"
      CATEGORY_OTHER     = "Other"
      # Valid values for categories
      VALID_CATEGORIES = [ CATEGORY_GEO, CATEGORY_MET, CATEGORY_SAFETY,
        CATEGORY_SECURITY, CATEGORY_RESCUE,   CATEGORY_FIRE, CATEGORY_HEALTH,
        CATEGORY_ENV, CATEGORY_TRANSPORT, CATEGORY_INFRA, CATEGORY_CBRNE,
        CATEGORY_OTHER ]

      URGENCY_IMMEDIATE = "Immediate"
      URGENCY_EXPECTED  = "Expected"
      URGENCY_FUTURE    = "Future"
      URGENCY_PAST      = "Past"
      URGENCY_UNKNOWN   = "Unknown"
      # Valid values for urgency
      VALID_URGENCIES = [ URGENCY_IMMEDIATE, URGENCY_EXPECTED, URGENCY_FUTURE,
        URGENCY_PAST, URGENCY_UNKNOWN ]

      SEVERITY_EXTREME  = "Extreme"
      SEVERITY_SEVERE   = "Severe"
      SEVERITY_MODERATE = "Moderate"
      SEVERITY_MINOR    = "Minor"
      SEVERITY_UNKNOWN  = "Unknown"
      # Valid values for severity
      VALID_SEVERITIES = [ SEVERITY_EXTREME, SEVERITY_SEVERE, SEVERITY_MODERATE,
        SEVERITY_MINOR, SEVERITY_UNKNOWN ]

      CERTAINTY_VERY_LIKELY = "Very Likely"
      CERTAINTY_LIKELY      = "Likely"
      CERTAINTY_POSSIBLE    = "Possible"
      CERTAINTY_UNLIKELY    = "Unlikely"
      CERTAINTY_UNKNOWN     = "Unknown"
      # Valid valies for certainty
      VALID_CERTAINTIES = [ CERTAINTY_VERY_LIKELY, CERTAINTY_LIKELY,
        CERTAINTY_POSSIBLE, CERTAINTY_UNLIKELY, CERTAINTY_UNKNOWN ]

      XML_ELEMENT_NAME           = 'info'
      LANGUAGE_ELEMENT_NAME      = 'language'
      CATEGORY_ELEMENT_NAME      = 'category'
      EVENT_ELEMENT_NAME         = 'event'
      URGENCY_ELEMENT_NAME       = 'urgency'
      SEVERITY_ELEMENT_NAME      = 'severity'
      CERTAINTY_ELEMENT_NAME     = 'certainty'
      AUDIENCE_ELEMENT_NAME      = 'audience'
      EVENT_CODE_ELEMENT_NAME    = 'eventCode'
      EFFECTIVE_ELEMENT_NAME     = 'effective'
      ONSET_ELEMENT_NAME         = 'onset'
      EXPIRES_ELEMENT_NAME       = 'expires'
      SENDER_NAME_ELEMENT_NAME   = 'senderName'
      HEADLINE_ELEMENT_NAME      = 'headline'
      DESCRIPTION_ELEMENT_NAME   = 'description'
      INSTRUCTION_ELEMENT_NAME   = 'instruction'
      WEB_ELEMENT_NAME           = 'web'
      CONTACT_ELEMENT_NAME       = 'contact'

      XPATH               = "cap:#{ XML_ELEMENT_NAME }"
      LANGUAGE_XPATH      = "cap:#{ LANGUAGE_ELEMENT_NAME }"
      EVENT_XPATH         = "cap:#{ EVENT_ELEMENT_NAME }"
      URGENCY_XPATH       = "cap:#{ URGENCY_ELEMENT_NAME }"
      CATEGORY_XPATH      = "cap:#{ CATEGORY_ELEMENT_NAME }"
      SEVERITY_XPATH      = "cap:#{ SEVERITY_ELEMENT_NAME }"
      CERTAINTY_XPATH     = "cap:#{ CERTAINTY_ELEMENT_NAME }"
      AUDIENCE_XPATH      = "cap:#{ AUDIENCE_ELEMENT_NAME }"
      EVENT_CODE_XPATH    = "cap:#{ EVENT_CODE_ELEMENT_NAME }"
      EFFECTIVE_XPATH     = "cap:#{ EFFECTIVE_ELEMENT_NAME }"
      ONSET_XPATH         = "cap:#{ ONSET_ELEMENT_NAME }"
      EXPIRES_XPATH       = "cap:#{ EXPIRES_ELEMENT_NAME }"
      SENDER_NAME_XPATH   = "cap:#{ SENDER_NAME_ELEMENT_NAME }"
      HEADLINE_XPATH      = "cap:#{ HEADLINE_ELEMENT_NAME }"
      DESCRIPTION_XPATH   = "cap:#{ DESCRIPTION_ELEMENT_NAME }"
      INSTRUCTION_XPATH   = "cap:#{ INSTRUCTION_ELEMENT_NAME }"
      WEB_XPATH           = "cap:#{ WEB_ELEMENT_NAME }"
      CONTACT_XPATH       = "cap:#{ CONTACT_ELEMENT_NAME }"

      DEFAULT_LANGUAGE = 'en-US'

      validates_presence_of( :event )
      validates_presence_of( :urgency )
      validates_presence_of( :severity )
      validates_presence_of( :certainty )
      validates_inclusion_of( :severity, :allow_nil  => true, :in => VALID_SEVERITIES,  :message => "can only be assigned the following values: #{ VALID_SEVERITIES.join(', ') }" )
      validates_inclusion_of( :urgency, :allow_nil   => true, :in => VALID_URGENCIES,   :message => "can only be assigned the following values: #{ VALID_URGENCIES.join(', ') }" )
      validates_inclusion_of_members_of( :categories, :in  => VALID_CATEGORIES, :allow_blank => true )
      validates_collection_of( :resources, :areas, :event_codes, :parameters )

      # @return [String]
      attr_accessor( :event )
      # @return [String] Value can only be one of {VALID_URGENCIES}
      attr_accessor( :urgency )
      # @return [String] Value can only be one of {VALID_SEVERITIES}
      attr_accessor( :severity )
      # @return [String] Value can only be one of {VALID_CERTAINTIES}
      attr_accessor( :certainty )
      # @return [String]
      attr_accessor( :language )
      # @return [String]
      attr_accessor( :audience )
      # @return [DateTime] Effective start time of information
      attr_accessor( :effective )
      # @return [DateTime] Expected start of event
      attr_accessor( :onset )
      # @return [DateTime] Effective expiry time of information
      attr_accessor( :expires )
      # @return [String]
      attr_accessor( :sender_name )
      # @return [String]
      attr_accessor( :headline )
      # @return [String]
      attr_accessor( :description )
      # @return [String]
      attr_accessor( :instruction )
      # @return [String]
      attr_accessor( :web )
      # @return [String]
      attr_accessor( :contact )

      # @return [Array<String>] Collection of textual categories; elements can be one of {VALID_CATEGORIES}
      attr_reader( :categories )
      # @return [Array<EventCode>] Collection of {EventCode} objects
      attr_reader( :event_codes )
      # @return [Array<Parameter>] Collection of {Parameter} objects
      attr_reader( :parameters )
      # @return [Array<Resource> Collection of {Resource} objects
      attr_reader( :resources )
      # @return [Array<Area>] Collection of {Area} objects
      attr_reader( :areas )


      # Initialises a new Info object which will be yielded to an attached block if given
      #
      # @return [RCAP::CAP_1_0::Info,RCAP::CAP_1_1::Info,RCAP::CAP_1_2::Info]
      def initialize
        @language       = DEFAULT_LANGUAGE
        @categories     = []
        @event_codes    = []
        @parameters     = []
        @resources      = []
        @areas          = []
        yield( self ) if block_given?
      end

      # Creates a new EventCode object and adds it to the event_codes array.
      #
      # @return [EventCode]
      def add_event_code
        event_code = self.event_code_class.new
        yield( event_code ) if block_given?
        @event_codes << event_code
        event_code
      end

      # Creates a new Parameter object and adds it to the parameters array.
      #
      # @return [Parameter]
      def add_parameter
        parameter = self.parameter_class.new
        yield( parameter ) if block_given?
        @parameters << parameter
        parameter
      end

      # Creates a new Resource object and adds it to the resources array.
      #
      # @return [Resource]
      def add_resource
        resource = self.resource_class.new
        yield( resource ) if block_given?
        @resources << resource
        resource
      end

      # Creates a new Area object and adds it to the areas array.
      #
      # @return [Area]
      def add_area
        area = self.area_class.new
        yield( area ) if block_given?
        @areas << area
        area
      end

      # @return [REXML::Element]
      def to_xml_element
        xml_element = REXML::Element.new( XML_ELEMENT_NAME )
        xml_element.add_element( LANGUAGE_ELEMENT_NAME ).add_text( @language ) if @language
        @categories.each do |category|
          xml_element.add_element( CATEGORY_ELEMENT_NAME ).add_text( category )
        end
        xml_element.add_element( EVENT_ELEMENT_NAME ).add_text( @event )
        xml_element.add_element( URGENCY_ELEMENT_NAME ).add_text( @urgency )
        xml_element.add_element( SEVERITY_ELEMENT_NAME ).add_text( @severity )
        xml_element.add_element( CERTAINTY_ELEMENT_NAME ).add_text( @certainty )
        xml_element.add_element( AUDIENCE_ELEMENT_NAME ).add_text( @audience ) if @audience
        @event_codes.each do |event_code|
          xml_element.add_element( event_code.to_xml_element )
        end
        xml_element.add_element( EFFECTIVE_ELEMENT_NAME ).add_text( @effective.to_s_for_cap ) if @effective
        xml_element.add_element( ONSET_ELEMENT_NAME ).add_text( @onset.to_s_for_cap )         if @onset
        xml_element.add_element( EXPIRES_ELEMENT_NAME ).add_text( @expires.to_s_for_cap )     if @expires
        xml_element.add_element( SENDER_NAME_ELEMENT_NAME ).add_text( @sender_name )          if @sender_name
        xml_element.add_element( HEADLINE_ELEMENT_NAME ).add_text( @headline )                if @headline
        xml_element.add_element( DESCRIPTION_ELEMENT_NAME ).add_text( @description )          if @description
        xml_element.add_element( INSTRUCTION_ELEMENT_NAME ).add_text( @instruction )          if @instruction
        xml_element.add_element( WEB_ELEMENT_NAME ).add_text( @web )                          if @web
        xml_element.add_element( CONTACT_ELEMENT_NAME ).add_text( @contact )                  if @contact
        @parameters.each do |parameter|
          xml_element.add_element( parameter.to_xml_element )
        end
        @resources.each do |resource|
          xml_element.add_element( resource.to_xml_element )
        end
        @areas.each do |area|
          xml_element.add_element( area.to_xml_element )
        end
        xml_element
      end

      # @return [String]
      def to_xml
        self.to_xml_element.to_s
      end

      # @param [REXML::Element] info_xml_element
      # @return [Info]
      def self.from_xml_element( info_xml_element )
        self.new do |info|
          info.language       = RCAP.xpath_text( info_xml_element, LANGUAGE_XPATH, info.xmlns ) || DEFAULT_LANGUAGE

          RCAP.xpath_match( info_xml_element, CATEGORY_XPATH, info.xmlns ).each do |element|
            info.categories << element.text
          end

          info.event          = RCAP.xpath_text( info_xml_element, EVENT_XPATH, info.xmlns )
          info.urgency        = RCAP.xpath_text( info_xml_element, URGENCY_XPATH, info.xmlns )
          info.severity       = RCAP.xpath_text( info_xml_element, SEVERITY_XPATH, info.xmlns )
          info.certainty      = RCAP.xpath_text( info_xml_element, CERTAINTY_XPATH, info.xmlns )
          info.audience       = RCAP.xpath_text( info_xml_element, AUDIENCE_XPATH, info.xmlns )
          info.effective      = RCAP.parse_datetime( RCAP.xpath_text( info_xml_element, EFFECTIVE_XPATH, info.xmlns ))
          info.onset          = RCAP.parse_datetime( RCAP.xpath_text( info_xml_element, ONSET_XPATH, info.xmlns ))
          info.expires        = RCAP.parse_datetime( RCAP.xpath_text( info_xml_element, EXPIRES_XPATH, info.xmlns ))
          info.sender_name    = RCAP.xpath_text( info_xml_element, SENDER_NAME_XPATH, info.xmlns )
          info.headline       = RCAP.xpath_text( info_xml_element, HEADLINE_XPATH, info.xmlns )
          info.description    = RCAP.xpath_text( info_xml_element, DESCRIPTION_XPATH, info.xmlns )
          info.instruction    = RCAP.xpath_text( info_xml_element, INSTRUCTION_XPATH, info.xmlns )
          info.web            = RCAP.xpath_text( info_xml_element, WEB_XPATH, info.xmlns )
          info.contact        = RCAP.xpath_text( info_xml_element, CONTACT_XPATH, info.xmlns )

          RCAP.xpath_match( info_xml_element, info.event_code_class::XPATH, info.xmlns ).each do |element|
            info.event_codes << info.event_code_class.from_xml_element( element )
          end

          RCAP.xpath_match( info_xml_element, info.parameter_class::XPATH, info.xmlns ).each do |element|
            info.parameters <<  info.parameter_class.from_xml_element( element )
          end

          RCAP.xpath_match( info_xml_element, info.resource_class::XPATH, info.xmlns ).each do  |element|
           info.resources <<  info.resource_class.from_xml_element( element )
          end

          RCAP.xpath_match( info_xml_element, info.area_class::XPATH, info.xmlns ).each do |element|
            info.areas << info.area_class.from_xml_element( element )
          end
        end
      end

      # @return [String]
      def inspect
        info_inspect = "Language:       #{ @language }\n"+
        "Categories:     #{ @categories.to_s_for_cap }\n"+
        "Event:          #{ @event }\n"+
        "Urgency:        #{ @urgency }\n"+
        "Severity:       #{ @severity }\n"+
        "Certainty:      #{ @certainty }\n"+
        "Audience:       #{ @audience }\n"+
        "Event Codes:    #{ @event_codes.inspect }\n"+
        "Effective:      #{ @effective }\n"+
        "Onset:          #{ @onset }\n"+
        "Expires:        #{ @expires }\n"+
        "Sender Name:    #{ @sender_name }\n"+
        "Headline:       #{ @headline }\n"+
        "Description:\n"+
          @description.to_s.lines.map{ |line| "  " + line }.join( "\n")+"\n"+
          "Instruction:    #{ @instruction }\n"+
        "Web:            #{ @web }\n"+
        "Contact:        #{ @contact }\n"+
        "Parameters:\n"+
          @parameters.map{ |parameter| "  " + parameter.inspect }.join( "\n" )+"\n"+
          "Resources:\n"+
          @resources.map{ |resource| "  " + resource.inspect }.join( "\n" )+"\n"+
          "Area:\n"+
          @areas.map{ |area| "  #{ area }" }.join( "\n" )+"\n"
        RCAP.format_lines_for_inspect( 'INFO', info_inspect )
      end

      # Returns a string representation of the event of the form
      #  event(urgency/severity/certainty)
      #
      # @return [String]
      def to_s
        "#{ @event }(#{ @urgency }/#{ @severity }/#{ @certainty })"
      end

      LANGUAGE_YAML       = 'Language'
      CATEGORIES_YAML     = 'Categories'
      EVENT_YAML          = 'Event'
      URGENCY_YAML        = 'Urgency'
      SEVERITY_YAML       = 'Severity'
      CERTAINTY_YAML      = 'Certainty'
      AUDIENCE_YAML       = 'Audience'
      EFFECTIVE_YAML      = 'Effective'
      ONSET_YAML          = 'Onset'
      EXPIRES_YAML        = 'Expires'
      SENDER_NAME_YAML    = 'Sender Name'
      HEADLINE_YAML       = 'Headline'
      DESCRIPTION_YAML    = 'Description'
      INSTRUCTION_YAML    = 'Instruction'
      WEB_YAML            = 'Web'
      CONTACT_YAML        = 'Contact'
      EVENT_CODES_YAML    = 'Event Codes'
      PARAMETERS_YAML     = 'Parameters'
      RESOURCES_YAML      = 'Resources'
      AREAS_YAML          = 'Areas'

      # @return [String]
      def to_yaml( options = {} )
        parameter_to_hash = lambda{ |hash, parameter| hash.merge( parameter.name => parameter.value )}

        RCAP.attribute_values_to_hash( [ LANGUAGE_YAML,       @language ],
                                       [ CATEGORIES_YAML,     @categories ],
                                       [ EVENT_YAML,          @event ],
                                       [ URGENCY_YAML,        @urgency ],
                                       [ SEVERITY_YAML,       @severity ],
                                       [ CERTAINTY_YAML,      @certainty ],
                                       [ AUDIENCE_YAML,       @audience ],
                                       [ EFFECTIVE_YAML,      @effective ],
                                       [ ONSET_YAML,          @onset ],
                                       [ EXPIRES_YAML,        @expires ],
                                       [ SENDER_NAME_YAML,    @sender_name ],
                                       [ HEADLINE_YAML,       @headline ],
                                       [ DESCRIPTION_YAML,    @description ],
                                       [ INSTRUCTION_YAML,    @instruction ],
                                       [ WEB_YAML,            @web ],
                                       [ CONTACT_YAML,        @contact ],
                                       [ EVENT_CODES_YAML,    @event_codes.inject({}, &parameter_to_hash )],
                                       [ PARAMETERS_YAML,     @parameters.inject({}, &parameter_to_hash )],
                                       [ RESOURCES_YAML,      @resources ],
                                       [ AREAS_YAML,          @areas ]).to_yaml( options )
      end

      # @param [Hash] info_yaml_data
      # @return [Info]
      def self.from_yaml_data( info_yaml_data )
        self.new do |info|
          info.language    = info_yaml_data [ LANGUAGE_YAML ]
          Array( info_yaml_data [ CATEGORIES_YAML ]).each do |category|
            info.categories << category
          end
          info.event       = info_yaml_data [ EVENT_YAML ]
          info.urgency     = info_yaml_data [ URGENCY_YAML ]
          info.severity    = info_yaml_data [ SEVERITY_YAML ]
          info.certainty   = info_yaml_data [ CERTAINTY_YAML ]
          info.audience    = info_yaml_data [ AUDIENCE_YAML ]
          info.effective   = RCAP.parse_datetime( info_yaml_data[ EFFECTIVE_YAML ])
          info.onset       = RCAP.parse_datetime( info_yaml_data[ ONSET_YAML ])
          info.expires     = RCAP.parse_datetime( info_yaml_data[ EXPIRES_YAML ])
          info.sender_name = info_yaml_data [ SENDER_NAME_YAML ]
          info.headline    = info_yaml_data [ HEADLINE_YAML ]
          info.description = info_yaml_data [ DESCRIPTION_YAML ]
          info.instruction = info_yaml_data [ INSTRUCTION_YAML ]
          info.web         = info_yaml_data [ WEB_YAML ]
          info.contact     = info_yaml_data [ CONTACT_YAML ]

          Array( info_yaml_data [ EVENT_CODES_YAML ]).each do  |name,value|
            info.add_event_code do |event_code|
              event_code.name = name
              event_code.value = value
            end
          end

          Array( info_yaml_data [ PARAMETERS_YAML ]).each do |name,value|
            info.add_parameter do |parameter|
              parameter.name = name
              parameter.value = value
            end
          end

          Array( info_yaml_data [ RESOURCES_YAML ]).each do |resource_yaml_data|
            info.resources << info.resource_class.from_yaml_data( resource_yaml_data )
          end

          Array( info_yaml_data [ AREAS_YAML ]).each do |area_yaml_data|
            info.areas << info.area_class.from_yaml_data( area_yaml_data )
          end
        end
      end

      LANGUAGE_KEY       = 'language'
      CATEGORIES_KEY     = 'categories'
      EVENT_KEY          = 'event'
      URGENCY_KEY        = 'urgency'
      SEVERITY_KEY       = 'severity'
      CERTAINTY_KEY      = 'certainty'
      AUDIENCE_KEY       = 'audience'
      EFFECTIVE_KEY      = 'effective'
      ONSET_KEY          = 'onset'
      EXPIRES_KEY        = 'expires'
      SENDER_NAME_KEY    = 'sender_name'
      HEADLINE_KEY       = 'headline'
      DESCRIPTION_KEY    = 'description'
      INSTRUCTION_KEY    = 'instruction'
      WEB_KEY            = 'web'
      CONTACT_KEY        = 'contact'
      RESOURCES_KEY      = 'resources'
      EVENT_CODES_KEY    = 'event_codes'
      PARAMETERS_KEY     = 'parameters'
      AREAS_KEY          = 'areas'

      # @return [Hash]
      def to_h
        RCAP.attribute_values_to_hash( [ LANGUAGE_KEY,      @language ],
                                       [ CATEGORIES_KEY,     @categories ],
                                       [ EVENT_KEY,          @event ],
                                       [ URGENCY_KEY,        @urgency ],
                                       [ SEVERITY_KEY,       @severity ],
                                       [ CERTAINTY_KEY,      @certainty ],
                                       [ AUDIENCE_KEY,       @audience ],
                                       [ EFFECTIVE_KEY,      RCAP.to_s_for_cap( @effective )],
                                       [ ONSET_KEY,          RCAP.to_s_for_cap( @onset )],
                                       [ EXPIRES_KEY,        RCAP.to_s_for_cap( @expires )],
                                       [ SENDER_NAME_KEY,    @sender_name ],
                                       [ HEADLINE_KEY,       @headline ],
                                       [ DESCRIPTION_KEY,    @description ],
                                       [ INSTRUCTION_KEY,    @instruction ],
                                       [ WEB_KEY,            @web ],
                                       [ CONTACT_KEY,        @contact ],
                                       [ RESOURCES_KEY,      @resources.map{ |resource| resource.to_h } ],
                                       [ EVENT_CODES_KEY,    @event_codes.map{ |event_code| event_code.to_h } ],
                                       [ PARAMETERS_KEY,     @parameters.map{ |parameter| parameter.to_h } ],
                                       [ AREAS_KEY,          @areas.map{ |area| area.to_h }])
      end

      # @param [Hash] info_hash
      # @return [Info]
      def self.from_h( info_hash )
        self.new do |info|
          info.language       = info_hash[ LANGUAGE_KEY ]
          Array( info_hash[ CATEGORIES_KEY ]).each do |category|
            info.categories << category
          end
          info.event          = info_hash[ EVENT_KEY ]
          info.urgency        = info_hash[ URGENCY_KEY ]
          info.severity       = info_hash[ SEVERITY_KEY ]
          info.certainty      = info_hash[ CERTAINTY_KEY ]
          info.audience       = info_hash[ AUDIENCE_KEY ]
          info.effective      = RCAP.parse_datetime( info_hash[ EFFECTIVE_KEY ])
          info.onset          = RCAP.parse_datetime( info_hash[ ONSET_KEY ])
          info.expires        = RCAP.parse_datetime( info_hash[ EXPIRES_KEY ])
          info.sender_name    = info_hash[ SENDER_NAME_KEY ]
          info.headline       = info_hash[ HEADLINE_KEY ]
          info.description    = info_hash[ DESCRIPTION_KEY ]
          info.instruction    = info_hash[ INSTRUCTION_KEY ]
          info.web            = info_hash[ WEB_KEY ]
          info.contact        = info_hash[ CONTACT_KEY ]

          Array( info_hash[ RESOURCES_KEY ]).each do |resource_hash|
            info.resources << info.resource_class.from_h( resource_hash )
          end

          Array( info_hash[ EVENT_CODES_KEY ]).each do |event_code_hash|
            info.event_codes << info.event_code_class.from_h( event_code_hash )
          end

          Array( info_hash[ PARAMETERS_KEY ]).each do |parameter_hash|
            info.parameters << info.parameter_class.from_h( parameter_hash )
          end

          Array( info_hash[ AREAS_KEY ]).each do |area_hash|
           info.areas <<  info.area_class.from_h( area_hash )
          end
        end
      end
    end
  end
end