package geagle

import (
	"encoding/xml"
	"io"
)

// A Gate
// multiple gates form a device
type Gate struct {
	Point
	Name   string `xml:"name,attr"`
	Symbol string `xml:"symbol,attr"`
}

// A list of technologies
type Technology struct {
	Name string `xml:"name,attr"`
}

// A connection
// Connectes Pads of one package with the pins of
// all gates a device posseses
type Connection struct {
	Gate string `xml:"gate,attr"`
	Pin  string `xml:"pin,attr"`
	Pad  string `xml:"pad,attr"`
}

// A 3d package
// new in Eagle 8 and above
// only contains a urn for the autodesk library service
type Package3d struct {
	Urn string `xml:"package3d_urn,attr"`
}

// A device
// bundles multiple gates and packages
// then defines how they are connected
type Device struct {
	Name    string `xml:"name,attr"`
	Package string `xml:"package,attr"`

	Package3d    []Package3d  `xml:package3dinstances>package3dinstance"`
	Technologies []Technology `xml:"technologies>technology"`
	Connections  []Connection `xml:"connects>connect"`
}

type Deviceset struct {
	Name        string `xml:"name,attr"`
	Prefix      string `xml:"prefix,attr"`
	Description string `xml:"description,omitempty"`
	Urn         string `xml:"urn,attr,omitempty"`

	Gates   []Gate   `xml:"gates>gate"`
	Devices []Device `xml:"devices>device"`
}

type Library struct {
	Packages   []Package   `xml:"packages>package"`
	Symbols    []Symbol    `xml:"symbols>symbol"`
	Devicesets []Deviceset `xml:"devicesets>deviceset"`
}

type Drawing struct {
	Grid    Grid    `xml:"grid"`
	Layers  []Layer `xml:"layers>layer"`
	Library Library `xml:"library"`
}

type FileHeader struct {
	Version string `xml:"version,attr"`
}

func ParseLibrary(in io.Reader) (result Drawing, err error) {
	file := struct {
		Eagle   FileHeader
		Drawing Drawing `xml:"drawing"`
	}{}

	decoder := xml.NewDecoder(in)
	err = decoder.Decode(&file)
	return file.Drawing, err
}

// defines an eagle file
type eagle struct {
	FileHeader
	Drawing *Drawing `xml:"drawing"`
}

func (drw *Drawing) WriteTo(out io.Writer) error {
	// write DOCTYPE and xml header
	io.WriteString(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>")
	io.WriteString(out, "<!DOCTYPE eagle SYSTEM \"eagle.dtd\">")

	encoder := xml.NewEncoder(out)

	file := eagle{
		FileHeader: FileHeader{"8.3.2"},
		Drawing:    drw,
	}

	return encoder.Encode(&file)
}