feat: added exercises handler/service/repo

internal/domain/exercise_load.go

@@ -0,0 +1,95 @@
+package domain
+
+import (
+	"database/sql/driver"
+	"fmt"
+)
+
+type Load int
+
+const (
+	LoadUnknown Load = iota
+	LoadBodyweight
+	LoadExternal
+)
+
+var loadNames = [...]string{
+	LoadUnknown:    "",
+	LoadBodyweight: "bodyweight",
+	LoadExternal:   "external",
+}
+
+var loadValues = func() map[string]Load {
+	m := make(map[string]Load, len(loadNames))
+	for i, name := range loadNames {
+		m[name] = Load(i)
+	}
+	return m
+}()
+
+func (l Load) String() string {
+	if l < 0 || int(l) > len(loadNames) {
+		return ""
+	}
+	return loadNames[l]
+}
+
+func ParseLoad(s string) (Load, error) {
+	if l, ok := loadValues[s]; ok {
+		return l, nil
+	}
+	return LoadUnknown, fmt.Errorf("load: unknown value %q", s)
+}
+
+//func (l Load) MarshalJSON() ([]byte, error) {
+//	s := l.String()
+//	if s == "" {
+//		return nil, fmt.Errorf("load: cannot marshal value %d", int(l))
+//	}
+//	return json.Marshal(s)
+//}
+//
+//func (l *Load) UnmarshalJSON(data []byte) error {
+//	var s string
+//	if err := json.Unmarshal(data, &s); err != nil {
+//		return err
+//	}
+//
+//	v, err := ParseLoad(s)
+//	if err != nil {
+//		return err
+//	}
+//
+//	*l = v
+//	return nil
+//}
+
+func (l *Load) Scan(src any) error {
+	var s string
+	switch v := src.(type) {
+	case nil:
+		return fmt.Errorf("load: unexpected NULL")
+	case string:
+		s = v
+	case []byte:
+		s = string(v)
+	default:
+		return fmt.Errorf("load: cannot scan %T", src)
+	}
+
+	parsed, err := ParseLoad(s)
+	if err != nil {
+		return err
+	}
+
+	*l = parsed
+	return nil
+}
+
+func (l Load) Value() (driver.Value, error) {
+	s := l.String()
+	if s == "" {
+		return nil, fmt.Errorf("load: cannot store value %d", int(l))
+	}
+	return s, nil
+}