require 'json'
require 'ostruct'
require 'kvom'

module RailsConnector
  # The CMS file class
  # @api public
  class Obj
    extend ActiveModel::Naming
    include Kvom::ModelIdentity

    include DateAttribute
    include SEO

    # Create a new Obj instance with the given values and attributes.
    # Normally this method should not be used.
    # Instead Objs should be loaded from the cms database.
    def initialize(obj_data = {})
      if !obj_data.respond_to?(:value_and_type_of)
        obj_data = ObjDataFromHash.new(obj_data)
      end

      update_data(obj_data)
    end

    # instantiate an Obj instance from obj_data.
    # May result in an instance of a subclass of Obj according to STI rules.
    def self.instantiate(obj_data)
      obj_class = obj_data.value_of("_obj_class")
      Obj.compute_type(obj_class).new(obj_data)
    end

    # @api public
    def id
      read_attribute('_id')
    end

    ### FINDERS ####################

    # Find an Obj by it's id.
    # If the paremeter is an Array containing ids, return a list of corresponding Objs.
    # @api public
    def self.find(id_or_list)
      case id_or_list
      when Array
        find_objs_by(:id, id_or_list).map(&:first)
      else
        obj = find_objs_by(:id, [id_or_list.to_s]).first.first
        obj or raise ResourceNotFound, "Could not find #{self} with id #{id_or_list}"
      end
    end

    # Returns a {ObjSearchEnumerator} of all Objs.
    # If invoked on a subclass of Obj, the result will be restricted to Obj of that subclass.
    def self.all
      if self.name == 'RailsConnector::Obj'
        ObjSearchEnumerator.new(nil)
      else
        find_all_by_obj_class(self.name)
      end
    end

    # Returns an {ObjSearchEnumerator} of all Objs with the given obj_class.
    def self.find_all_by_obj_class(obj_class)
      ObjSearchEnumerator.new([{:field => '_obj_class', :operator => 'equal', :value => obj_class}])
    end

    # Find the Obj with the given path.
    # Returns nil if no matching Obj exists.
    # @api public
    def self.find_by_path(path)
      find_objs_by(:path, [path]).first.first
    end

    def self.find_many_by_paths(pathes)
      find_objs_by(:path, pathes).map(&:first)
    end

    # Find an Obj with the given name.
    # If several Objs exist with the given name, one of them is chosen and returned.
    # If no Obj with the name exits, nil is returned.
    def self.find_by_name(name)
      enum = ObjSearchEnumerator.new(
          [{:field => '_name', :operator => 'equal', :value => name}], {:batch_size => 1})
      enum.first
    end

    # Returns an {ObjSearchEnumerator} of all Objs with the given name.
    def self.find_all_by_name(name)
      ObjSearchEnumerator.new([{:field => '_name', :operator => 'equal', :value => name}])
    end

    # Return the Obj with the given permalink or nil if no matching Obj exists.
    # @api public
    def self.find_by_permalink(permalink)
      find_objs_by(:permalink, [permalink]).first.first
    end

    # Return the Obj with the given permalink or raise ResourceNotFound if no matching Obj exists.
    # @api public
    def self.find_by_permalink!(permalink)
      find_by_permalink(permalink) or
        raise ResourceNotFound, "Could not find #{self} with permalink '#{permalink}'"
    end

    # accepts the name of an "obj_by" - view and a list of keys.
    # returns a list of lists of Objs: a list of Objs for each given keys.
    def self.find_objs_by(view, keys)
      CmsBackend.find_obj_data_by(Workspace.current.data, view, keys).map do |list|
        list.map { |obj_data| Obj.instantiate(obj_data) }
      end
    end

    def to_param
      id
    end

    def self.configure_for_content(mode)
      # this method exists only for compatibility with the fiona connector.
    end

    # A CMS administrator can specify the <tt>obj_class</tt> for a given CMS object.
    # In Rails, this could be either:
    #
    # * A valid and existing model name
    # * A valid and non-existing model name
    # * An invalid model name
    #
    # Rails' STI mechanism only considers the first case.
    # In any other case, RailsConnector::Obj is used, except when explicitly asked
    # for a model in the RailsConnector namespace (RailsConnector::Permission etc.)

    def self.compute_type(type_name)
      @compute_type_cache ||= {}
      @compute_type_cache [type_name] ||= try_type { type_name.constantize } || self
    end

    # return the Obj that is the parent of this Obj.
    # returns nil for the root Obj.
    # @api public
    def parent
      root? ? nil : Obj.find_by_path(parent_path)
    end

    # Returns an Array of all the ancestor objects, starting at the root and ending at this object's parent.
    # @api public
    def ancestors
      return [] if root?
      ancestor_paths = parent_path.scan(/\/[^\/]+/).inject([""]) do |list, component|
        list << list.last + component
      end
      ancestor_paths[0] = "/"
      Obj.find_many_by_paths(ancestor_paths)
    end

    # return a list of all child Objs.
    # @api public
    def children
      Obj.find_objs_by(:ppath, [path]).first
    end

    ### ATTRIBUTES #################

    # returns the Obj's path as a String.
    # @api public
    def path
      read_attribute('_path') or raise "Obj without path"
    end

    # returns the Obj's name, i.e. the last component of the path.
    # @api public
    def name
      if root?
        ""
      else
        path.match(/[^\/]+$/)[0]
      end
    end

    def permissions
      # FIXME permissions
      @permissions ||= OpenStruct.new({
        :live => permitted_groups,
        :read => [],
        :write => [],
        :root => [],
        :create_children => [],
      })
    end

    def permitted_for_user?(user)
      if permitted_groups.blank?
        true
      else
        if user
          (permitted_groups & user.live_server_groups).any?
        else
          false
        end
      end
    end

    # Returns the root Obj, i.e. the Obj with the path "/"
    # @api public
    def self.root
      Obj.find_by_path("/") or raise ResourceNotFound, "Obj.root not found: There is no Obj with path '/'."
    end

    # Returns the homepage object. This can be overwritten in your application's +ObjExtensions+.
    # Use <tt>Obj#homepage?</tt> to check if an object is the homepage.
    # @api public
    def self.homepage
      root
    end

    # returns the obj's permalink.
    # @api public
    def permalink
      read_attribute('_permalink')
    end

    # This method determines the controller that should be invoked when the Obj is requested.
    # By default a controller matching the Obj's obj_class will be used.
    # If the controller does not exist, the CmsController will be used as a fallback.
    # Overwrite this method to force a different controller to be used.
    # @api public
    def controller_name
      obj_class
    end

    # This method determines the action that should be invoked when the Obj is requested.
    # The default action is 'index'.
    # Overwrite this method to force a different action to be used.
    # @api public
    def controller_action_name
      "index"
    end

    # Returns true if the current object is the homepage object.
    # @api public
    def homepage?
      self == self.class.homepage
    end

    # Returns the title of the content or the name.
    # @api public
    def display_title
      self.title || name
    end

    # @api public
    def title
      read_attribute('title')
    end

    # Returns the type of the object: :document, :publication, :image or :generic
    def object_type
      read_attribute('_obj_type').to_sym
    end

    # Returns true if image? or generic?
    def binary?
      [:image, :generic].include? object_type
    end

    # Returns true if object_type == :image
    def image?
      object_type == :image
    end

    # Returns true if object_type == :generic
    def generic?
      object_type == :generic
    end

    # Returns true if object_type == :publication (for folders)
    def publication?
      object_type == :publication
    end

    # Returns true if object_type == :document
    def document?
      object_type == :document
    end

    # Returns true if this object is active (time_when is in object's time interval)
    # @api public
    def active?(time_when = nil)
      return false unless valid_from
      time_then = time_when || Obj.preview_time
      valid_from <= time_then && (!valid_until || time_then <= valid_until)
    end

    # compatibility with legacy apps.
    def suppress_export
      suppressed? ? 1 : 0
    end

    # Returns true if the Obj is suppressed.
    # A suppressed Obj does not represent an entire web page, but only a part of a page
    # (for example a teaser) and will not be delivered by the rails application
    # as a standalone web page.
    def suppressed?
      read_attribute('_suppress_export') ? true : false
    end

    # Returns true if the export of the object is not suppressed and the content is active?
    def exportable?(current_time = nil)
      !suppressed? && active?(current_time)
    end

    # Returns the file name to which the Content.file_extension has been appended.
    def filename
      Rails.logger.warn(
        "DEPRECATION WARNING: "\
        "The Method Obj#filename is no longer supported. Please use Obj#name instead. "\
        "From: #{caller[0]}"
      )

      name
    end

    # Returns an array with the names of groups that are permitted to access this Obj.
    # This corresponds to the cms permission "permissionLiveServerRead".
    def permitted_groups
      # FIXME permissions not yet implemented in fiona 7
      []
    end

    # Returns true if this object is the root object.
    # @api public
    def root?
      path == "/"
    end

    # Returns a list of exportable? children excluding the binary? ones unless :all is specfied.
    # This is mainly used for navigations.
    # @api public
    def toclist(*args)
      return [] unless publication?
      time = args.detect {|value| value.kind_of? Time}
      toclist = children.select{ |toc| toc.exportable?(time) }
      toclist = toclist.reject { |toc| toc.binary? } unless args.include?(:all)
      toclist
    end

    # Returns the sorted +toclist+, respecting sort order and type of this Obj.
    # @api public
    def sorted_toclist(*args)
      list = self.toclist(*args)
      return [] if list.blank?

      cached_sort_key1 = self.sort_key1
      cached_sort_type1 = self.sort_type1

      sorted_list =
        if cached_sort_key1.blank?
          list.sort { |left_obj, right_obj| left_obj.name <=> right_obj.name }
        else
          cached_sort_key2 = self.sort_key2
          cached_sort_type2 = self.sort_type2
          cached_sort_key3 = self.sort_key3
          cached_sort_type3 = self.sort_type3

          list.sort do |left_obj, right_obj|
            compare = compare_on_sort_key(left_obj, right_obj, cached_sort_key1, cached_sort_type1)
            if compare == 0 && cached_sort_key2
              compare = compare_on_sort_key(left_obj, right_obj, cached_sort_key2, cached_sort_type2)
              if compare == 0 && cached_sort_key3
                compare = compare_on_sort_key(left_obj, right_obj, cached_sort_key3, cached_sort_type3)
              end
            end
            compare
          end
        end

      return self.sort_order == "descending" ? sorted_list.reverse : sorted_list
    end

    def sort_order
      read_attribute('_sort_order') == 1 ? "descending" : "ascending"
    end

    def sort_type1
      converted_sort_type('_sort_type1')
    end

    def sort_type2
      converted_sort_type('_sort_type2')
    end

    def sort_type3
      converted_sort_type('_sort_type3')
    end

    def sort_key1
      read_attribute('_sort_key1')
    end

    def sort_key2
      read_attribute('_sort_key2')
    end

    def sort_key3
      read_attribute('_sort_key3')
    end

    # Returns the Object with the given name next in the hierarchy
    # returns nil if no object with the given name was found.
    # @api public
    def find_nearest(name)
      obj = self.class.find_by_path(root? ? "/#{name}" : "#{path}/#{name}")
      return obj if obj and obj.active?
      parent.find_nearest(name) unless self.root?
    end

    # This should be a SET, because it's faster in this particular case.
    OLD_INTERNAL_KEYS = Set.new(%w[
      body
      id
      last_changed
      name
      obj_class
      obj_type
      object_type
      path
      permalink
      sort_key1
      sort_key2
      sort_key3
      sort_order
      sort_type1
      sort_type2
      sort_type3
      suppress_export
      text_links
      title
      valid_from
      valid_until
    ])

    # Returns the value of an internal or external attribute specified by its name.
    # Passing an invalid key will not raise an error, but return nil.
    # @api public
    def [](key)
      key = key.to_s
      if OLD_INTERNAL_KEYS.include?(key)
        send(key)
      elsif key.start_with?('_') && OLD_INTERNAL_KEYS.include?(internal_key = key[1..-1])
        # For backwards compatibility reasons
        send(internal_key)
      elsif has_attribute?(key)
        read_attribute(key)
      else
        nil
      end
    end

    # Reloads the attributes of this object from the database.
    # Notice that the ruby class of this Obj instance will NOT change,
    # even if the obj_class in the database has changed.
    # @api public
    def reload
      obj_data = CmsBackend.find_obj_data_by(Workspace.current.data, :id, [id.to_s]).first.first
      update_data(obj_data)
    end

    def text_links
      read_attribute('_text_links')
    end

    # @api public
    def obj_class
      read_attribute('_obj_class')
    end

    # @api public
    def last_changed
      read_attribute('_last_changed')
    end

    # @api public
    def valid_from
      read_attribute('_valid_from')
    end

    # @api public
    def valid_until
      read_attribute('_valid_until')
    end

    # For a binary Obj, the content_type is equal to the content_type of it's body (i.e. it's data).
    # For non-binary Objs, a the default content_type is "text/html".
    # Override this method in subclasses to define a different content_type.
    # Note that only Objs with content_type "text/html"
    # will be rendered with layout and templates by the DefaultCmsController.
    # @api public
    def content_type
      if binary?
        body_content_type
      else
        "text/html"
      end
    end
    alias mime_type content_type

    # returns the extension (the part after the last dot) from the Obj's name.
    # returns an empty string if no extension is present in the Obj's name.
    # @api public
    def file_extension
      File.extname(name)[1..-1] || ""
    end

    # Returns the body (main content) of the Obj for non-binary Objs.
    # Returns nil for binary Objs.
    # @api public
    def body
      if binary?
        nil
      else
        StringTagging.tag_as_html(read_attribute('body'), self)
      end
    end

    # for binary Objs body_length equals the file size
    # for non-binary Objs body_length equals the number of characters in the body (main content)
    # @api public
    def body_length
      if binary?
        blob = find_blob
        blob ? blob.length : 0
      else
        (body || "").length
      end
    end

    # returns an URL to retrieve the Obj's body for binary Objs.
    # returns nil for non-binary Objs.
    # @api public
    def body_data_url
      if binary?
        blob = find_blob
        blob.url if blob
      end
    end

    def body_data_path
      # not needed/supported when using cloud connector.
      nil
    end

    # returns the content type of the Obj's body for binary Objs.
    # returns nil for non-binary Objs.
    # @api public
    def body_content_type
      if binary?
        blob = find_blob
        if blob
          blob.content_type
        else
          "application/octet-stream"
        end
      end
    end

    def to_liquid
      LiquidSupport::ObjDrop.new(self)
    end

    def respond_to?(method_id, include_private=false)
      if has_attribute?(method_id)
        true
      else
        super
      end
    end

    def self.preview_time=(t)
      Thread.current[:preview_time] = t
    end

    def self.preview_time
      Thread.current[:preview_time] || Time.now
    end

    def inspect
      "<#{self.class} id=\"#{id}\" path=\"#{path}\">"
    end

    def has_attribute?(name)
      data_from_cms.has_custom_attribute?(name.to_s)
    end

    private

    attr_accessor :data_from_cms

    def update_data(data)
      self.data_from_cms = data
      @attribute_cache = {}
    end

    def read_attribute(attribute_name)
      @attribute_cache.fetch(attribute_name) do
        (raw_value, attribute_type) = data_from_cms.value_and_type_of(attribute_name)
        @attribute_cache[attribute_name] =
          prepare_attribute_value(raw_value, attribute_type)
      end
    end

    def prepare_attribute_value(attribute_value, attribute_type)
      case attribute_type
      when "markdown"
        StringTagging.tag_as_markdown(attribute_value, self)
      when "html"
        StringTagging.tag_as_html(attribute_value, self)
      when "date"
        DateAttribute.parse(attribute_value) if attribute_value
      when "linklist"
        LinkList.new(attribute_value)
      else
        attribute_value
      end
    end

    def parent_path
      raise "parent_path called for root" if root?
      path.gsub(/\/[^\/]+$/, "").presence || "/"
    end

    def as_date(value)
      DateAttribute.parse(value) unless value.nil?
    end

    def find_blob
      blob_spec = read_attribute('blob')
      Blob.find(blob_spec["id"]) if blob_spec
    end

    def method_missing(method_name, *args)
      if has_attribute?(method_name)
        read_attribute(method_name.to_s)
      else
        super
      end
    end

    def compare_on_sort_key(left_obj, right_obj, my_sort_key, my_sort_type)
      left_value = left_obj[my_sort_key]
      right_value = right_obj[my_sort_key]

      if left_value.nil?
        1
      elsif right_value.nil?
        -1
      # hardcoded type check needed for speed
      elsif left_value.is_a?(Time) && right_value.is_a?(Time)
        left_value <=> right_value
      else
        if my_sort_type == "numeric"
          (left_value.to_i rescue 0) <=> (right_value.to_i rescue 0)
        else
          left_value.to_s.downcase <=> right_value.to_s.downcase
        end
      end
    end

    def converted_sort_type(attribute)
      read_attribute(attribute) == 1 ? "numeric" : "alphaNumeric"
    end

    class << self
      private

      def try_type
        result = yield
        result if subclass_of_obj(result)
      rescue NameError
        nil
      end

      def subclass_of_obj(klass)
        if klass == Obj
          true
        else
          klass.superclass && subclass_of_obj(klass.superclass)
        end
      end

    end
  end

end