feat: add httpc.Do & httpc.Service.Do (#1775)

* backup

* backup

* backup

* feat: add httpc.Do & httpc.Service.Do

* fix: not using strings.Cut, it's from Go 1.18

* chore: remove redudant code

* feat: httpc.Do finished

* chore: fix reviewdog

* chore: break loop if found

* add more tests

core/mapping/marshaler.go

@@ -0,0 +1,176 @@
+package mapping
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+const (
+	emptyTag       = ""
+	tagKVSeparator = ":"
+)
+
+// Marshal marshals the given val and returns the map that contains the fields.
+// optional=another is not implemented, and it's hard to implement and not common used.
+func Marshal(val interface{}) (map[string]map[string]interface{}, error) {
+	ret := make(map[string]map[string]interface{})
+	tp := reflect.TypeOf(val)
+	rv := reflect.ValueOf(val)
+
+	for i := 0; i < tp.NumField(); i++ {
+		field := tp.Field(i)
+		value := rv.Field(i)
+		if err := processMember(field, value, ret); err != nil {
+			return nil, err
+		}
+	}
+
+	return ret, nil
+}
+
+func getTag(field reflect.StructField) (string, bool) {
+	tag := string(field.Tag)
+	if i := strings.Index(tag, tagKVSeparator); i >= 0 {
+		return strings.TrimSpace(tag[:i]), true
+	}
+
+	return strings.TrimSpace(tag), false
+}
+
+func processMember(field reflect.StructField, value reflect.Value,
+	collector map[string]map[string]interface{}) error {
+	var key string
+	var opt *fieldOptions
+	var err error
+	tag, ok := getTag(field)
+	if !ok {
+		tag = emptyTag
+		key = field.Name
+	} else {
+		key, opt, err = parseKeyAndOptions(tag, field)
+		if err != nil {
+			return err
+		}
+
+		if err = validate(field, value, opt); err != nil {
+			return err
+		}
+	}
+
+	val := value.Interface()
+	if opt != nil && opt.FromString {
+		val = fmt.Sprint(val)
+	}
+
+	m, ok := collector[tag]
+	if ok {
+		m[key] = val
+	} else {
+		m = map[string]interface{}{
+			key: val,
+		}
+	}
+	collector[tag] = m
+
+	return nil
+}
+
+func validate(field reflect.StructField, value reflect.Value, opt *fieldOptions) error {
+	if opt == nil || !opt.Optional {
+		if err := validateOptional(field, value); err != nil {
+			return err
+		}
+	}
+
+	if opt == nil {
+		return nil
+	}
+
+	if len(opt.Options) > 0 {
+		if err := validateOptions(value, opt); err != nil {
+			return err
+		}
+	}
+
+	if opt.Range != nil {
+		if err := validateRange(value, opt); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func validateOptional(field reflect.StructField, value reflect.Value) error {
+	switch field.Type.Kind() {
+	case reflect.Ptr:
+		if value.IsNil() {
+			return fmt.Errorf("field %q is nil", field.Name)
+		}
+	case reflect.Array, reflect.Slice, reflect.Map:
+		if value.IsNil() || value.Len() == 0 {
+			return fmt.Errorf("field %q is empty", field.Name)
+		}
+	}
+
+	return nil
+}
+
+func validateOptions(value reflect.Value, opt *fieldOptions) error {
+	var found bool
+	val := fmt.Sprint(value.Interface())
+	for i := range opt.Options {
+		if opt.Options[i] == val {
+			found = true
+			break
+		}
+	}
+	if !found {
+		return fmt.Errorf("field %q not in options", val)
+	}
+
+	return nil
+}
+
+func validateRange(value reflect.Value, opt *fieldOptions) error {
+	var val float64
+	switch v := value.Interface().(type) {
+	case int:
+		val = float64(v)
+	case int8:
+		val = float64(v)
+	case int16:
+		val = float64(v)
+	case int32:
+		val = float64(v)
+	case int64:
+		val = float64(v)
+	case uint:
+		val = float64(v)
+	case uint8:
+		val = float64(v)
+	case uint16:
+		val = float64(v)
+	case uint32:
+		val = float64(v)
+	case uint64:
+		val = float64(v)
+	case float32:
+		val = float64(v)
+	case float64:
+		val = v
+	default:
+		return fmt.Errorf("unknown support type for range %q", value.Type().String())
+	}
+
+	// validates [left, right], [left, right), (left, right], (left, right)
+	if val < opt.Range.left ||
+		(!opt.Range.leftInclude && val == opt.Range.left) ||
+		val > opt.Range.right ||
+		(!opt.Range.rightInclude && val == opt.Range.right) {
+		return fmt.Errorf("%v out of range", value.Interface())
+	}
+
+	return nil
+}