func compositeISBNLookup(ctx ae.Context, country string, isbn isbn13.ISBN13) (resp *data.BookMetaData, err error) {
// look in my own library first - if this fails badly, abort anything further
if shelf, err := persistence.LookupBookshelf(ctx); err == nil {
if book := shelf.LookupInfo(isbn); book != nil {
return book, nil
}
} else {
return nil, err
}
var errors ae.MultiError
if book, err := persistence.LookupISBN(ctx, country, isbn); err == nil {
return book, nil
} else {
errors = append(errors, err)
}
if r, err := googlebooks.LookupISBN(ctx, country, isbn); err == nil {
persistence.StoreISBNResult(ctx, country, isbn, r)
return r, nil
} else {
errors = append(errors, err)
}
return nil, errors
}
func normalize(call *Call, info *data.BookMetaData) {
var isbn isbn13.ISBN13
var err error
if isbn, err = isbn13.New(info.ISBN); err == nil {
var base *data.BookMetaData
if base, err = persistence.LookupISBN(call.Context, call.DetermineCountry(), isbn); err == nil {
info.Volume.Images = base.Volume.Images
return
} else {
info.Volume.Images = data.ImageLinks{}
}
} else {
call.Context.Errorf("Could not normalize data for %s: %s", info.ISBN, err.Error())
}
}