// Copyright 2011 The Go Authors.  All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

package xmpp

// This file contains data structures.

import (

	"bytes"

	"flag"

	"fmt"

	"io"

	"os"

	"regexp"

	"strings"

	"xml"

)

// JID represents an entity that can communicate with other

// entities. It looks like node@domain/resource. Node and resource are

// sometimes optional.

type JID struct {

	// TODO Make this not a pointer.

	Node *string

	Domain string

	Resource string

}

var _ fmt.Stringer = &JID{}

var _ flag.Value = &JID{}

// XMPP's <stream:stream> XML element

type Stream struct {

	To string `xml:"attr"`

	From string `xml:"attr"`

	Id string `xml:"attr"`

	Lang string `xml:"attr"`

	Version string `xml:"attr"`

}

var _ xml.Marshaler = &Stream{}

var _ fmt.Stringer = &Stream{}

// <stream:error>

type StreamError struct {

	Any definedCondition

	Text *errText

}

var _ xml.Marshaler = &StreamError{}

type definedCondition struct {

	// Must always be in namespace nsStreams

	XMLName xml.Name

	Chardata string `xml:"chardata"`

}

type errText struct {

	Lang string `xml:"attr"`

	Text string `xml:"chardata"`

}

var _ xml.Marshaler = &errText{}

type Features struct {

	Starttls *starttls

	Mechanisms mechs

	Bind *Unrecognized

}

type starttls struct {

	XMLName xml.Name

}

type mechs struct {

	Mechanism []string

}

type auth struct {

	XMLName xml.Name

	Chardata string `xml:"chardata"`

	Mechanism string `xml:"attr"`

	Any *Unrecognized

}

type Stanza interface {

	XName() string

	XTo() string

	XFrom() string

	XId() string

	XType() string

	XLang() string

	XError() *Error

	XChild() *Unrecognized

}

type Message struct {

	To string `xml:"attr"`

	From string `xml:"attr"`

	Id string `xml:"attr"`

	Type string `xml:"attr"`

	Lang string `xml:"attr"`

	Error *Error

	Any *Unrecognized

}

var _ xml.Marshaler = &Message{}

var _ Stanza = &Message{}

type Presence struct {

	To string `xml:"attr"`

	From string `xml:"attr"`

	Id string `xml:"attr"`

	Type string `xml:"attr"`

	Lang string `xml:"attr"`

	Error *Error

	Any *Unrecognized

}

var _ xml.Marshaler = &Presence{}

var _ Stanza = &Presence{}

type Iq struct {

	To string `xml:"attr"`

	From string `xml:"attr"`

	Id string `xml:"attr"`

	Type string `xml:"attr"`

	Lang string `xml:"attr"`

	Error *Error

	Any *Unrecognized

}

var _ xml.Marshaler = &Iq{}

var _ Stanza = &Iq{}

type Error struct {

	Type string `xml:"attr"`

	Any *Unrecognized

}

var _ xml.Marshaler = &Error{}

// TODO Rename this to something like Generic.

type Unrecognized struct {

	XMLName xml.Name

	Any *Unrecognized

	Chardata string `xml:"chardata"`

}

var _ fmt.Stringer = &Unrecognized{}

func (jid *JID) String() string {

	result := jid.Domain

	if jid.Node != nil {

		result = *jid.Node + "@" + result

	}

	if jid.Resource != "" {

		result = result + "/" + jid.Resource

	}

	return result

}

func (jid *JID) Set(val string) bool {

	r := regexp.MustCompile("^(([^@/]+)@)?([^@/]+)(/([^@/]+))?$")

	parts := r.FindStringSubmatch(val)

	if parts == nil {

		return false

	}

	if parts[2] == "" {

		jid.Node = nil

	} else {

		jid.Node = &parts[2]

	}

	jid.Domain = parts[3]

	jid.Resource = parts[5]

	return true

}

func (s *Stream) MarshalXML() ([]byte, os.Error) {

	buf := bytes.NewBuffer(nil)

	buf.WriteString("<stream:stream")

	writeField(buf, "xmlns", "jabber:client")

	writeField(buf, "xmlns:stream", nsStream)

	writeField(buf, "to", s.To)

	writeField(buf, "from", s.From)

	writeField(buf, "id", s.Id)

	writeField(buf, "xml:lang", s.Lang)

	writeField(buf, "version", s.Version)

	buf.WriteString(">")

	// We never write </stream:stream>

	return buf.Bytes(), nil

}

func (s *Stream) String() string {

	result, _ := s.MarshalXML()

	return string(result)

}

func parseStream(se xml.StartElement) (*Stream, os.Error) {

	s := &Stream{}

	for _, attr := range se.Attr {

		switch strings.ToLower(attr.Name.Local) {

		case "to":

			s.To = attr.Value

		case "from":

			s.From = attr.Value

		case "id":

			s.Id = attr.Value

		case "lang":

			s.Lang = attr.Value

		case "version":

			s.Version = attr.Value

		}

	}

	return s, nil

}

func (s *StreamError) MarshalXML() ([]byte, os.Error) {

	buf := bytes.NewBuffer(nil)

	buf.WriteString("<stream:error>")

	xml.Marshal(buf, s.Any)

	if s.Text != nil {

		xml.Marshal(buf, s.Text)

	}

	buf.WriteString("</stream:error>")

	return buf.Bytes(), nil

}

func (e *errText) MarshalXML() ([]byte, os.Error) {

	buf := bytes.NewBuffer(nil)

	buf.WriteString("<text")

	writeField(buf, "xmlns", nsStreams)

	writeField(buf, "xml:lang", e.Lang)

	buf.WriteString(">")

	xml.Escape(buf, []byte(e.Text))

	buf.WriteString("</text>")

	return buf.Bytes(), nil

}

func writeField(w io.Writer, field, value string) {

	if value != "" {

		io.WriteString(w, " ")

		io.WriteString(w, field)

		io.WriteString(w, `="`)

		xml.Escape(w, []byte(value))

		io.WriteString(w, `"`)

	}

}

func (u *Unrecognized) String() string {

	var sub string

	if u.Any != nil {

		sub = u.Any.String()

	}

	return fmt.Sprintf("<%s %s>%s%s</%s %s>", u.XMLName.Space,

		u.XMLName.Local, sub, u.Chardata, u.XMLName.Space,

		u.XMLName.Local)

}

func marshalXML(st Stanza) ([]byte, os.Error) {

	buf := bytes.NewBuffer(nil)

	buf.WriteString("<")

	buf.WriteString(st.XName())

	if st.XTo() != "" {

		writeField(buf, "to", st.XTo())

	}

	if st.XFrom() != "" {

		writeField(buf, "from", st.XFrom())

	}

	if st.XId() != "" {

		writeField(buf, "id", st.XId())

	}

	if st.XType() != "" {

		writeField(buf, "type", st.XType())

	}

	if st.XLang() != "" {

		writeField(buf, "xml:lang", st.XLang())

	}

	buf.WriteString(">")

	if st.XError() != nil {

		bytes, _ := st.XError().MarshalXML()

		buf.WriteString(string(bytes))

	}

	if st.XChild() != nil {

		xml.Marshal(buf, st.XChild())

	}

	buf.WriteString("</")

	buf.WriteString(st.XName())

	buf.WriteString(">")

	return buf.Bytes(), nil

}

func (er *Error) MarshalXML() ([]byte, os.Error) {

	buf := bytes.NewBuffer(nil)

	buf.WriteString("<error")

	writeField(buf, "type", er.Type)

	buf.WriteString(">")

	if er.Any != nil {

		xml.Marshal(buf, er.Any)

	}

	buf.WriteString("</error>")

	return buf.Bytes(), nil

}

func (m *Message) XName() string {

	return "message"

}

func (m *Message) XTo() string {

	return m.To

}

func (m *Message) XFrom() string {

	return m.From

}

func (m *Message) XId() string {

	return m.Id

}

func (m *Message) XType() string {

	return m.Type

	}

func (m *Message) XLang() string {

	return m.Lang

}

func (m *Message) XError() *Error {

	return m.Error

}

func (m *Message) XChild() *Unrecognized {

	return m.Any

}

func (m *Message) MarshalXML() ([]byte, os.Error) {

	return marshalXML(m)

}

func (p *Presence) XName() string {