// Decode converts Sass Value to Go compatible data types.
func Unmarshal(arg UnionSassValue, v ...interface{}) error {
var err error
if arg == nil {
return errors.New("I can't work with this. arg UnionSassValue must not be nil. - Unmarshaller")
} else if len(v) == 0 {
return errors.New("Cannot Unmarshal an empty value - Michael Scott")
} else if len(v) > 1 {
if len(v) < int(C.sass_list_get_length(arg)) { //check for optional arguements that are not passed and pad with nil
return fmt.Errorf("Arguments mismatch %d C arguments did not match %d",
int(C.sass_list_get_length(arg)), len(v))
}
for i := 0; i < int(C.sass_list_get_length(arg)); i++ {
err = unmarshal(C.sass_list_get_value(arg, C.size_t(i)), v[i])
if err != nil {
return err
}
}
return err
} else if C.sass_value_is_list(arg) && getKind(v[0]) != reflect.Slice && int(C.sass_list_get_length(arg)) == 1 { //arg is a slice of 1 but we want back a non slice
return unmarshal(C.sass_list_get_value(arg, C.size_t(0)), v[0])
} else if C.sass_value_is_list(arg) && getKind(v[0]) == reflect.Slice && C.sass_value_is_list(C.sass_list_get_value(arg, C.size_t(0))) && int(C.sass_list_get_length(arg)) == 1 { //arg is a list of single list and we only want back a list so we need to unwrap
return unmarshal(C.sass_list_get_value(arg, C.size_t(0)), v[0])
} else {
return unmarshal(arg, v[0])
}
}
func Len(usv UnionSassValue) int {
switch {
case IsList(usv):
return int(C.sass_list_get_length(usv))
case IsMap(usv):
return int(C.sass_map_get_length(usv))
}
panic("call of len on unknown type")
}
func unmarshal(arg UnionSassValue, v interface{}) error {
//Get the underlying value of v and its kind
f := reflect.ValueOf(v)
if f.Kind() == reflect.Ptr {
f = f.Elem()
}
k := f.Kind()
t := f.Type()
if k == reflect.Interface {
switch {
default:
return errors.New("Uncovertable interface value. Specify type desired.")
case bool(C.sass_value_is_null(arg)):
f.Set(reflect.ValueOf("<nil>"))
return nil
case bool(C.sass_value_is_string(arg)):
k = reflect.String
case bool(C.sass_value_is_boolean(arg)):
k = reflect.Bool
case bool(C.sass_value_is_color(arg)) ||
bool(C.sass_value_is_number(arg)):
k = reflect.Struct
case bool(C.sass_value_is_list(arg)):
k = reflect.Slice
t = reflect.SliceOf(t)
case bool(C.sass_value_is_error(arg)):
// This should get implemented as type error
k = reflect.String
}
}
switch k {
default:
return errors.New("Unsupported SassValue")
case reflect.Invalid:
return errors.New("Invalid SASS Value - Taylor Swift")
case reflect.String:
if C.sass_value_is_string(arg) || C.sass_value_is_error(arg) {
c := C.sass_string_get_value(arg)
gc := C.GoString(c)
//drop quotes
if t, err := strconv.Unquote(gc); err == nil {
gc = t
}
if strings.HasPrefix(gc, "'") && strings.HasSuffix(gc, "'") {
gc = gc[1 : len(gc)-1]
}
if !f.CanSet() {
return errors.New("Can not set string")
}
switch t := f.Kind(); t {
case reflect.String:
f.SetString(gc)
case reflect.Interface:
f.Set(reflect.ValueOf(gc))
}
} else {
return throwMisMatchTypeError(arg, "string")
}
case reflect.Bool:
if C.sass_value_is_boolean(arg) {
b := bool(C.sass_boolean_get_value(arg))
f.Set(reflect.ValueOf(b))
} else {
return throwMisMatchTypeError(arg, "bool")
}
case reflect.Struct:
//Check for color
if C.sass_value_is_color(arg) {
col := color.RGBA{
R: uint8(C.sass_color_get_r(arg)),
G: uint8(C.sass_color_get_g(arg)),
B: uint8(C.sass_color_get_b(arg)),
A: uint8(C.sass_color_get_a(arg)),
}
f.Set(reflect.ValueOf(col))
} else if C.sass_value_is_number(arg) {
u, err := getSassNumberUnit(arg)
if err != nil {
return err
}
sn := SassNumber{
Value: float64(C.sass_number_get_value(arg)),
Unit: u,
}
f.Set(reflect.ValueOf(sn))
} else {
return throwMisMatchTypeError(arg, "color.RGBA or SassNumber")
}
case reflect.Slice:
if C.sass_value_is_list(arg) {
newv := reflect.MakeSlice(t, int(C.sass_list_get_length(arg)), int(C.sass_list_get_length(arg)))
l := make([]interface{}, C.sass_list_get_length(arg))
for i := range l {
err := unmarshal(C.sass_list_get_value(arg, C.size_t(i)), &l[i])
if err != nil {
return err
}
newv.Index(i).Set(reflect.ValueOf(l[i]))
}
f.Set(newv)
} else {
return throwMisMatchTypeError(arg, "slice")
}
}
return nil
}