1 files changed, 94 insertions, 0 deletions
diff --git a/serial.go b/serial.go
new file mode 100644
index 0000000..59a3118
--- /dev/null
+++ b/serial.go
@@ -0,0 +1,94 @@
+package serial
+
+import (
+	"io"
+	"reflect"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+type Encoder struct {
+	w      io.Writer
+	wg     sync.WaitGroup
+	groups []string
+}
+
+func (e *Encoder) Encode(entity interface{}) error {
+	t := reflect.TypeOf(entity)
+	v := reflect.ValueOf(entity)
+	if err := e.encodeField(t, v, e.w); err != nil {
+		return err
+	}
+	return nil
+}
+func (e *Encoder) encodeAny(entity interface{}, w io.Writer) error {
+	t := reflect.TypeOf(entity)
+	v := reflect.ValueOf(entity)
+	first := true
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		fv := v.Field(i)
+		if gr, ok := f.Tag.Lookup("group"); ok {
+			groups := strings.Split(gr, ",")
+			name := f.Name
+			if tname, ok := f.Tag.Lookup("json"); ok {
+				name = tname
+			}
+			if name != "-" && e.intersect(groups, e.groups) {
+				if !first {
+					w.Write([]byte(`,`))
+				}
+				w.Write([]byte(`"` + name + `":`))
+				e.encodeField(f.Type, fv, w)
+				first = false
+			}
+		}
+	}
+	return nil
+}
+
+func (e *Encoder) intersect(a []string, b []string) bool {
+	for _, sa := range a {
+		for _, sb := range b {
+			if sa == sb {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (e *Encoder) encodeField(ft reflect.Type, v reflect.Value, w io.Writer) error {
+	switch ft.Kind() {
+	case reflect.Struct:
+		w.Write([]byte("{"))
+		if err := e.encodeAny(v.Interface(), w); err != nil {
+			return err
+		}
+		w.Write([]byte("}"))
+	case reflect.String:
+		w.Write([]byte(`"` + v.String() + `"`))
+	case reflect.Bool:
+		if v.Bool() {
+			w.Write([]byte("true"))
+		} else {
+			w.Write([]byte("false"))
+		}
+	case reflect.Int, reflect.Int32, reflect.Int64:
+		w.Write([]byte(strconv.Itoa(int(v.Int()))))
+	case reflect.Float32, reflect.Float64:
+		w.Write([]byte(strconv.FormatFloat(v.Float(), 'f', -1, 64)))
+
+	}
+	return nil
+}
+
+func (e *Encoder) AddGroup(group string) *Encoder {
+	e.groups = append(e.groups, group)
+	return e
+}
+
+func NewEncoder(w io.Writer) *Encoder {
+	return &Encoder{w: w, groups: []string{}}
+}