// (c) Bernhard Tittelbach, 2013

package r3xmppbot

import (
	xmpp "code.google.com/p/goexmpp"
    "time"
    "encoding/xml"    
)

// XMPP Ping
type XMPPPing struct {
        XMLName xml.Name     `xml:"urn:xmpp:ping ping"`
}

func HandleServerToClientPing(iq *xmpp.Iq, xmppout chan<- xmpp.Stanza) bool {
    ///<iq from='juliet@capulet.lit/balcony' to='capulet.lit' id='s2c1' type='result'/>
    if iq.Type != "get" { return false}
    for _, ele := range iq.Nested {
        if _, ok := ele.(*XMPPPing); ok {
            xmppout <- &xmpp.Iq{Header: xmpp.Header{To: iq.From, From: iq.To, Id: iq.Id, Type: "result" }}
            return true
        }
    }
    return false
}

func (botdata *XmppBot) PingServer(timeout_ms time.Duration) (is_up bool) {
///<iq from='juliet@capulet.lit/balcony' to='capulet.lit' id='c2s1' type='get'>
///  <ping xmlns='urn:xmpp:ping'/>
///</iq>
    server_jid := new(xmpp.JID)
    server_jid.Set(botdata.my_jid_)
    iqping := &xmpp.Iq{Header: xmpp.Header{To: server_jid.Domain,
                                                            From: botdata.my_jid_,
                                                            Id: <-xmpp.Id,
                                                            Type: "get",
                                                            Nested: []interface{}{XMPPPing{}}   }   }
    pong := make(chan bool, 1)
    defer close(pong)
    f := func(v xmpp.Stanza) bool {
        defer recover() //recover from writing to possibly already closed chan
        let_others_handle_stanza := false
        iq, ok := v.(*xmpp.Iq)
        if !ok {
            Syslog_.Printf("response to iq ping wasn't iq: %s", v)
            pong <- false
            return true //let other handlers process reply
        }
        if iq.Type == "error" && iq.Error != nil && iq.Error.Type == "cancel"{
            Debug_.Printf("response to iq ping was cancel, server does not support ping")
            //server does not support ping, but at least we know server is still there
        } else if iq.Type != "result" {
            Syslog_.Printf("response to iq ping was not pong: %s", v)
            let_others_handle_stanza = true //let other handlers process reply
        }
        pong <- true
        return let_others_handle_stanza // return false so that Stanza v will not be appear in xmppclient_.Out()
    }
    botdata.xmppclient_.HandleStanza(iqping.Id, f)
    botdata.xmppclient_.Out <- iqping    
    go func() {
        defer func() {if x:= recover(); x == nil { Syslog_.Printf("response to iq ping timed out !!") }}() //recover from writing to possibly already closed chan. If we did not need to recover, then Handler did not receive reply
        time.Sleep(timeout_ms * time.Millisecond)
        pong <- false   //xmpp ping timed out
    }()
    return <- pong
}