initial public commit

tools/types/datetime.go

@@ -0,0 +1,93 @@
+package types
+
+import (
+	"database/sql/driver"
+	"encoding/json"
+	"time"
+
+	"github.com/spf13/cast"
+)
+
+// DefaultDateLayout specifies the default app date strings layout.
+const DefaultDateLayout = "2006-01-02 15:04:05.000"
+
+// NowDateTime returns new DateTime instance with the current local time.
+func NowDateTime() DateTime {
+	return DateTime{t: time.Now()}
+}
+
+// ParseDateTime creates a new DateTime from the provided value
+// (could be [cast.ToTime] supported string, [time.Time], etc.).
+func ParseDateTime(value any) (DateTime, error) {
+	d := DateTime{}
+	err := d.Scan(value)
+	return d, err
+}
+
+// DateTime represents a [time.Time] instance in UTC that is wrapped
+// and serialized using the app default date layout.
+type DateTime struct {
+	t time.Time
+}
+
+// Time returns the internal [time.Time] instance.
+func (d DateTime) Time() time.Time {
+	return d.t
+}
+
+// IsZero checks whether the current DateTime instance has zero time value.
+func (d DateTime) IsZero() bool {
+	return d.Time().IsZero()
+}
+
+// String serializes the current DateTime instance into a formated
+// UTC date string.
+//
+// The zero value is serialized to an empty string.
+func (d DateTime) String() string {
+	if d.IsZero() {
+		return ""
+	}
+	return d.Time().UTC().Format(DefaultDateLayout)
+}
+
+// MarshalJSON implements the [json.Marshaler] interface.
+func (d DateTime) MarshalJSON() ([]byte, error) {
+	return json.Marshal(d.String())
+}
+
+// UnmarshalJSON implements the [json.Unmarshaler] interface.
+func (d *DateTime) UnmarshalJSON(b []byte) error {
+	var raw string
+	if err := json.Unmarshal(b, &raw); err != nil {
+		return err
+	}
+	return d.Scan(raw)
+}
+
+// Value implements the [driver.Valuer] interface.
+func (d DateTime) Value() (driver.Value, error) {
+	return d.String(), nil
+}
+
+// Scan implements [sql.Scanner] interface to scan the provided value
+// into the current DateTime instance.
+func (d *DateTime) Scan(value any) error {
+	switch v := value.(type) {
+	case DateTime:
+		d.t = v.Time()
+	case time.Time:
+		d.t = v
+	case int:
+		d.t = cast.ToTime(v)
+	default:
+		str := cast.ToString(v)
+		if str == "" {
+			d.t = time.Time{}
+		} else {
+			d.t = cast.ToTime(str)
+		}
+	}
+
+	return nil
+}