// 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"

)

const (

	// Version of RFC 3920 that we implement.

	Version = "1.0"

	nsStreams = "urn:ietf:params:xml:ns:xmpp-streams"

	nsStream = "http://etherx.jabber.org/streams"

	nsTLS = "urn:ietf:params:xml:ns:xmpp-tls"

)

// 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 {

	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

}

type errText struct {

	Lang string `xml:"attr"`

	Text string `xml:"chardata"`

}

var _ xml.Marshaler = &errText{}

type Unrecognized struct {

	XMLName xml.Name

}

func (jid *JID) String() string {

	result := jid.Domain

	if jid.Node != nil {

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

	}

	if jid.Resource != nil {

		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]

	if parts[5] == "" {

		jid.Resource = nil

	} else {

		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, `"`)

	}

}