module LectureModule;

from interacting import all;

export all;

object Lecture is 
   components:  LectureTitle and RenderedHtml and HtmlContent and ToBeRendered and ToBeUpdated and LineNumber and Layer;
   description:  (*
	A lecture is a title, rendered Html content to be displayed, HTML content from which the rendered HTML was created, a boolean that tracks if any changes have been made to the raw HTML, a boolean that tracks if any changes have been made to the rendered HTML, the location of the cursor in the lecture, and a layer associated with that topic for drawing;
	*);
end Lecture;

object LectureTitle is string;
object ToBeRendered is boolean;
object ToBeUpdated is boolean;

object LectureElement is
   components:  Topic or Image or SlideBreak or PlainText or SlideNumber;
   description:  (*
	A LectureElement is a component of a lecture, it is either a text topic, an image, a slide break or a slide number
	*);
 end LectureElement;

object Topic is
   components: LineNumber and string and Topic* or Image* and Expanded and LevelNumber and Visible;
   description:  (*
	A topic has the text to be displayed, line location where to be displayed on a slide, a collection of its subtopics, a Boolean indicating expansion, level number specifying outline level of this topic and a visible boolean indicating if it is visible
	*);
end Topic;

object Expanded is boolean;
object LevelNumber is integer;
object LineNumber is integer;
object Visible is boolean;

object Image is
   components: LineNumber and string and Topic* and Image* and Expanded and LevelNumber and Visible and Dimensions;
   description:  (*
	An Image has the location of an image to be displayed, line location where to be displayed on a slide, a collection of its subtopics or subimages, a Boolean indicating expansion and level number specifying outline level of this topic
	*);
end Image;

object Dimensions is Width and Hight;
object Width is integer;
object Hight is integer;

object SlideBreak is integer;
object PlainText is string;
object SlideNumber is integer;

object HtmlContent is
   components: HtmlTag* and RawContent*;
   description:  (*
	HtmlContent is HTML code that meets WC3 standards for HTML. The content is then interpreted into RenderedHtml
		*);
end HtmlContent;

object RawContent is string;

object RenderedHtml is
   components: LectureElement*;
   description:  (*
	RenderedHtml has a collection of LectureElements that are intepreted from an HtmlContent
		*);
end RenderedHtml;

object HtmlTag is 
    components: OrderedListTag or UnorderedListTag or ListItemTag or HeaderTag or SlideBreakTag or OtherHtmlTag;
end HtmlTag;
   
object OtherHtmlTag
  description: (*
      For a complete specification of HTML as published by the W3C organization, visit: <a href="http://www.w3.org/MarkUp">http://www.w3.org/MarkUp"</a>.
   *);
end OtherHtmlTag;

object OrderedListTag is string;
object UnorderedListTag is string;
object ListItemTag is string;
object HeaderTag is string;
object SlideBreakTag is string;


operation expand is
    inputs:   t: Topic;
    outputs: t': Topic;
    (* Expand takes a topic and sets the expanded flag of that topic as well as the visibility of its sub-topics so that they are visible. *)

    precondition:
	t.Expanded = false
	and
        t.Visible = false;
    postcondition:
        t'.Expanded = true
	and
        t'.Visible = true;

end expand;

operation collapse is
    inputs:   t: Topic;
    outputs: t': Topic;
    (* Collapse takes a topic and resets the expanded flag of that topic as well as the visibility of its sub-topics so that they are not visible in the lecture *)

    precondition:
        t.Expanded = true
	and
        t.Visible = true;
    postcondition:
	t'.Expanded = false
	and
        t'.Visible = false;

end collapse;

operation renderHtml is
    inputs: lect: Lecture;
    outputs: lect': Lecture;
    (* RenderHtml takes plain HTML code and interprets it into a series of lecture elements in a renderedHtml object that can be interpreted by e-Class as an expandable lecture presentation. *)
	
    precondition:
	lect.ToBeRendered = true;
    postcondition:
	(* the lectures renderedHtml should con*)
	lect'.ToBeRendered = false;

end renderHtml;

operation updateRawHtml is
    inputs: lect: Lecture;
    outputs: lect': Lecture;
    (* UpdateRawHtml takes a RenderedHtml and interprets it back to raw HTML content.  This operation is used to reflect any changes that are made to a renderedHtml file in outline mode *) 

    precondition:
	lect.ToBeUpdated = true;
    postcondition:
	(* because the program is already able to interpret HTML code, going from renderedHtml code back to HTML should be a reverse process *)
	lect'.ToBeUpdated = false;

end updateRawHtml;

operation importHtml is
    inputs: fs: FileSpace, t: ToBeUpdated, fn:FileName;
    outputs: h': HtmlContent, t': ToBeUpdated;
	
    (* importHtml takes an external HTML file with the given filename and imports it into the HtmlContent of a lecture*)

   precondition:
      (exists(file in fs) (file.name = fn) and (file.file_type?html_type));

   postcondition: 
      (* A new  *)
	t' = true;	

end importHtml;

object FileName is string;
object FileSpace;

operation insertTopic is
    inputs: lect: Lecture, t: string;
    outputs: t': Topic, lect': Lecture;
    
    (* insertTopic creates a new topic and inserts it into an existing RenderedHtml object of the input Lecture *) 
    precondition:(* *); 
    postcondition:(* Topic is created and inserted into the RenderedHtml of the lecture and ToBeUpdated is set *)

    exists(t' in lect'.renderedHtml) (t'.string = t) and (t'.LineNumber = lect.LineNumber);


end insertTopic;

operation insertSubTopic is
    inputs: lect: Lecture, top: Topic, t: string;
    outputs: t':Topic, lect': Lecture;
    
    (* insertSubTopic creates a new subtopic and inserts it into an existing RenderedHtml object of the input Lecture *) 
    precondition:(* *);
    postcondition: (* Topic is created and inserted into the RenderedHtml of the lecture and ToBeUpdated is set *)

    exists(t' in lect'.renderedHtml)((t'.string = t) and (t'.LineNumber = lect.LineNumber));

end insertSubTopic;

operation insertImage is
    inputs: lect: Lecture, img: string;
    outputs: t':Topic, lect': Lecture;
    (* insertImage creates a new Image and inserts it into an existing RenderedHtml object of the input Lecture.  An image is like a topic, but the text is the location of the image to be displayed *)
    
    precondition:(* *);
    postcondition:(* *)
    
    exists(t' in lect'.renderedHtml)((t'.string = img) and (t'.LineNumber = lect.LineNumber));

end insertImage;

end LectureModule;