// RecordDelete implements gaia's response to a DELETE request to the '/record/' endpoint.
//
// Assumptions: The user has been authenticated.
//
// Proceedings: Parses the url parameters, and retrieves the kind and id parameters (both required).
// Then checks for authorization to delete, carries it out if allowed.
//
// Success:
// * StatusNoContent indicating a succesful deletion
//
// Errors:
// * InternalServerError: failure to parse the parameters, database connections, json marshalling
// * BadRequest: no kind param, unrecognized kind, no id param, invalid id param
// * NotFound: unauthorized, record actually doesn't exist
// * Unauthorized: not authorized to delete that record, database access denial
func RecordDELETE(ctx context.Context, w http.ResponseWriter, r *http.Request, logger services.Logger, db services.DB) {
l := logger.WithPrefix("RecordDELETE: ")
// Parse the form
if err := r.ParseForm(); err != nil {
l.Printf("error parsing form: %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
// Retrieve the kind parameter
k := r.FormValue(kindParam)
if k == "" {
l.Printf("no kind specified")
http.Error(w, fmt.Sprintf("You must specify a %q parameter", kindParam), http.StatusBadRequest)
return
}
kind := data.Kind(k)
// Retrieve the id parameter
i := r.FormValue(idParam)
if i == "" {
l.Printf("no id specified")
http.Error(w, fmt.Sprintf("You must specify a %q parameter", idParam), http.StatusBadRequest)
return
}
// Verify the kind is recognized
_, ok := models.Kinds[kind]
if !ok {
l.Printf("unrecognized kind: %q", kind)
http.Error(w, fmt.Sprintf("The kind %q is not recognized", kind), http.StatusBadRequest)
return
}
// Verify the id is valid
id, err := db.ParseID(i)
if err != nil {
l.Printf("invalid id: %q, error: %s", i, err)
http.Error(w, fmt.Sprintf("The id %q is invalid", i), http.StatusBadRequest)
return
}
// Get the record, so that we can decide whether we have permission to delete it
m := models.ModelFor(kind)
m.SetID(id)
if err = db.PopulateByID(m); err != nil {
l.Printf("db.PopulateByID error: %s", err)
switch err {
case data.ErrAccessDenial:
fallthrough // don't leak information (were we denied access, this record doesn't exist)
case data.ErrNotFound:
http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
case data.ErrNoConnection:
fallthrough
case data.ErrInvalidID:
fallthrough
default:
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
}
return
}
// Retrieve the user we are authenticated as
u, ok := user.FromContext(ctx)
if !ok {
l.Print("faild to retrieve user from context")
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
return
}
// check for authorization
if allowed, err := access.CanDelete(db, u, m); err != nil {
// TODO(nclandolfi) standardize this with the POST and GET where we handle the possible errors
l.Printf("RecordDELETE Error: %s", err)
http.Error(w, "database error", http.StatusInternalServerError)
return
} else if !allowed {
// in order to not leak information, we treat this as a not found
http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
return
}
if err := db.Delete(m); err != nil {
switch err {
case data.ErrAccessDenial:
http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound) // don't leak information
case data.ErrNotFound:
// this shouldn't happen unless it was deleted by another process
// in between when we populated the record by id, in which case it was successful
goto successfulDelete
// all of these errors, we can't guarantee deletion
case data.ErrNoConnection:
fallthrough
case data.ErrInvalidID:
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
default:
l.Printf("RecordDELETE Error: %s", err)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
}
return
}
successfulDelete:
w.WriteHeader(http.StatusNoContent)
}
