import (
    "net/http"

    "github.com/airbrake/gobrake"
)

const (
    projectID = 1
    key = "apikey"
    secure = true
)

var Notifier gobrake.Notifier

func init() {
    transport := gobrake.NewJSONTransport(&http.Client{}, projectID, key, secure)
    Notifier = gobrake.NewNotifier(transport)
    Notifier.SetContext("environment", "production")
    Notifier.SetContext("version", "1.0")
}

func handler(w http.ResponseWriter, r *http.Request) {
    defer func() {
        if iface := recover(); iface != nil {
            Notifier.Panic(iface, r, nil)
        }
    }()

    if err := process(r); err != nil {
        go Notifier.Notify(err, r, nil)
    }
}

import (
    "net/http"

    "appengine/urlfetch"
    "github.com/airbrake/gobrake"
)

var (
    Notifier *ErrorNotifier
)

func init() {
    transport := gobrake.NewJSONTransport(
        nil, config.AirbrakeProjectID, config.AirbrakeKey, config.AirbrakeSecure)
    Notifier := gobrake.NewNotifier(transport)
    Notifier.SetContext("environment", config.Env)
    Notifier.SetContext("version", config.Version)

    Notifier = &ErrorNotifier{N: Notifier}
    http.Handle("/", &RecoverHandler{H: Router})
}

type ErrorNotifier struct {
    N gobrake.Notifier
}

func (n *ErrorNotifier) Notify(
    c appengine.Context, e error, r *http.Request, session map[string]interface{},
) {
    if v, ok := n.N.Transport().(*gobrake.JSONTransport); ok {
        v.Client = urlfetch.Client(c)
    }
    if err := n.N.Notify(e, r, session); err != nil {
        c.Errorf("Notify failed: %v", err)
    }
}

func (n *ErrorNotifier) Panic(
    c appengine.Context, e interface{}, r *http.Request, session map[string]interface{},
) {
    if v, ok := n.N.Transport().(*gobrake.JSONTransport); ok {
        v.Client = urlfetch.Client(c)
    }
    if err := n.N.Panic(e, r, session); err != nil {
        c.Errorf("Notify failed: %v", err)
    }
}

type RecoverHandler struct {
    H http.Handler
}

func (h *RecoverHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    defer func() {
        if iface := recover(); iface != nil {
            c := appengine.NewContext(r)
            Notifier.Panic(c, iface, r, nil)
            panic(iface)
        }
    }()
    h.H.ServeHTTP(w, r)
}