package models

import (
	"encoding/xml"
)

type MxGraphModel struct {
	XMLName xml.Name `xml:"mxGraphModel"`

	Root struct {
		XMLName 	xml.Name 	`xml:"root"`
		MxCell		[]MxCell	`xml:"mxCell"`
		MxObject	*[]MxObject	`xml:"object"`
		MxLink		[]MxLink
	}
}

type MxCell struct {
	XMLName xml.Name	`xml:"mxCell"` 	
	ID      string  	`xml:"id,attr"`
	RID     *string 	`xml:"rID,attr"`
	Rtype	string  	`xml:"rType,attr"`
	Parent  *string 	`xml:"parent,attr"`
	Edge	*string		`xml:"edge,attr"`
	Source  *string 	`xml:"source,attr"`
	Target  *string 	`xml:"target,attr"`
}

type MxLink struct {
	ID      string   	`xml:"id,attr"`
	Source	string		`xml:"source,attr"`
	Target	string		`xml:"target,attr"`
}

type MxObject struct {
	XMLName xml.Name 	`xml:"object"`
	ID		string		`xml:"id,attr"`
	Settings []xml.Attr	`xml:",any,attr"`
	MxCell	MxCell		`xml:"mxCell"`	
}

// Didn't manage to differentiate Links and cells containing components using 
// only structures and unmarshal, so we use this method post-umarshalling
func (g *MxGraphModel) createLinks()  {
	var cells_without_links []MxCell 

	
	for i, mxcell := range g.Root.MxCell {
		
		if mxcell.Edge != nil {	
			mxcell.processLinks()
			newLink := MxLink{mxcell.ID,*mxcell.Source,*mxcell.Target}
			g.Root.MxLink = append(g.Root.MxLink,newLink)
		} else {
			cells_without_links = append(cells_without_links,g.Root.MxCell[i])
		}
	}

	
	g.Root.MxCell = nil
	g.Root.MxCell = cells_without_links

}

func (cell *MxCell) processLinks() {
	v := ""
	if cell.Source == nil {
		cell.Source = &v
	}
	if cell.Target == nil {
		cell.Target = &v
	}
}

type mxissue struct {
	msg string
}

func (m *mxissue) Error() string {
	return m.msg
}

func newMxIssue(message string) error {
	return &mxissue{message}
}