package awsutil import ( "reflect" "regexp" "strconv" "strings" "github.com/jmespath/go-jmespath" ) var indexRe = regexp.MustCompile(`(.+)\[(-?\d+)?\]$`) // rValuesAtPath returns a slice of values found in value v. The values // in v are explored recursively so all nested values are collected. func rValuesAtPath(v interface{}, path string, createPath, caseSensitive, nilTerm bool) []reflect.Value { pathparts := strings.Split(path, "||") if len(pathparts) > 1 { for _, pathpart := range pathparts { vals := rValuesAtPath(v, pathpart, createPath, caseSensitive, nilTerm) if len(vals) > 0 { return vals } } return nil } values := []reflect.Value{reflect.Indirect(reflect.ValueOf(v))} components := strings.Split(path, ".") for len(values) > 0 && len(components) > 0 { var index *int64 var indexStar bool c := strings.TrimSpace(components[0]) if c == "" { // no actual component, illegal syntax return nil } else if caseSensitive && c != "*" && strings.ToLower(c[0:1]) == c[0:1] { // TODO normalize case for user return nil // don't support unexported fields } // parse this component if m := indexRe.FindStringSubmatch(c); m != nil { c = m[1] if m[2] == "" { index = nil indexStar = true } else { i, _ := strconv.ParseInt(m[2], 10, 32) index = &i indexStar = false } } nextvals := []reflect.Value{} for _, value := range values { // pull component name out of struct member if value.Kind() != reflect.Struct { continue } if c == "*" { // pull all members for i := 0; i < value.NumField(); i++ { if f := reflect.Indirect(value.Field(i)); f.IsValid() { nextvals = append(nextvals, f) } } continue } value = value.FieldByNameFunc(func(name string) bool { if c == name { return true } else if !caseSensitive && strings.ToLower(name) == strings.ToLower(c) { return true } return false }) if nilTerm && value.Kind() == reflect.Ptr && len(components[1:]) == 0 { if !value.IsNil() { value.Set(reflect.Zero(value.Type())) } return []reflect.Value{value} } if createPath && value.Kind() == reflect.Ptr && value.IsNil() { // TODO if the value is the terminus it should not be created // if the value to be set to its position is nil. value.Set(reflect.New(value.Type().Elem())) value = value.Elem() } else { value = reflect.Indirect(value) } if value.Kind() == reflect.Slice || value.Kind() == reflect.Map { if !createPath && value.IsNil() { value = reflect.ValueOf(nil) } } if value.IsValid() { nextvals = append(nextvals, value) } } values = nextvals if indexStar || index != nil { nextvals = []reflect.Value{} for _, valItem := range values { value := reflect.Indirect(valItem) if value.Kind() != reflect.Slice { continue } if indexStar { // grab all indices for i := 0; i < value.Len(); i++ { idx := reflect.Indirect(value.Index(i)) if idx.IsValid() { nextvals = append(nextvals, idx) } } continue } // pull out index i := int(*index) if i >= value.Len() { // check out of bounds if createPath { // TODO resize slice } else { continue } } else if i < 0 { // support negative indexing i = value.Len() + i } value = reflect.Indirect(value.Index(i)) if value.Kind() == reflect.Slice || value.Kind() == reflect.Map { if !createPath && value.IsNil() { value = reflect.ValueOf(nil) } } if value.IsValid() { nextvals = append(nextvals, value) } } values = nextvals } components = components[1:] } return values } // ValuesAtPath returns a list of values at the case insensitive lexical // path inside of a structure. func ValuesAtPath(i interface{}, path string) ([]interface{}, error) { result, err := jmespath.Search(path, i) if err != nil { return nil, err } v := reflect.ValueOf(result) if !v.IsValid() || (v.Kind() == reflect.Ptr && v.IsNil()) { return nil, nil } if s, ok := result.([]interface{}); ok { return s, err } if v.Kind() == reflect.Map && v.Len() == 0 { return nil, nil } if v.Kind() == reflect.Slice { out := make([]interface{}, v.Len()) for i := 0; i < v.Len(); i++ { out[i] = v.Index(i).Interface() } return out, nil } return []interface{}{result}, nil } // SetValueAtPath sets a value at the case insensitive lexical path inside // of a structure. func SetValueAtPath(i interface{}, path string, v interface{}) { if rvals := rValuesAtPath(i, path, true, false, v == nil); rvals != nil { for _, rval := range rvals { if rval.Kind() == reflect.Ptr && rval.IsNil() { continue } setValue(rval, v) } } } func setValue(dstVal reflect.Value, src interface{}) { if dstVal.Kind() == reflect.Ptr { dstVal = reflect.Indirect(dstVal) } srcVal := reflect.ValueOf(src) if !srcVal.IsValid() { // src is literal nil if dstVal.CanAddr() { // Convert to pointer so that pointer's value can be nil'ed // dstVal = dstVal.Addr() } dstVal.Set(reflect.Zero(dstVal.Type())) } else if srcVal.Kind() == reflect.Ptr { if srcVal.IsNil() { srcVal = reflect.Zero(dstVal.Type()) } else { srcVal = reflect.ValueOf(src).Elem() } dstVal.Set(srcVal) } else { if dstVal.Kind() == reflect.String { dstVal.SetString(srcVal.String()) } else { dstVal.Set(srcVal) } } }