Files
appcore/dotenv/assign.go

83 lines
1.5 KiB
Go

package dotenv
import (
"errors"
"log/slog"
"reflect"
"strconv"
"strings"
)
// Assign env tag matching values from envMap
func Assign[T any](c *T, envMap map[string]string) error {
if c == nil {
return errors.New("nil arg")
}
slog.Info("env map", "v", envMap)
val := reflect.Indirect(reflect.ValueOf(c))
name := val.Type().Name()
for i := range val.NumField() {
f := val.Type().Field(i)
tag := f.Tag.Get("env")
if tag == "" {
continue
}
var v string
var ok bool
if multiTag := strings.Split(tag, ","); len(multiTag) > 1 {
// multi tags like env:"DB_URL,PG_DB_URL"
for _, mt := range multiTag {
if v, ok = envMap[strings.TrimSpace(mt)]; ok {
break
}
}
} else {
v, ok = envMap[tag]
}
if !ok {
continue
}
field := val.FieldByName(f.Name)
if !field.IsValid() {
continue
}
switch f.Type.Kind() {
case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Int:
if v, err := strconv.ParseInt(v, 10, 64); err != nil {
return err
} else {
field.SetInt(v)
}
case reflect.Float32, reflect.Float64:
if v, err := strconv.ParseFloat(v, 10); err != nil {
return err
} else {
field.SetFloat(v)
}
case reflect.Bool:
if strings.EqualFold(v, "true") {
field.SetBool(true)
} else {
field.SetBool(false)
}
default:
field.SetString(v)
}
if name == "" {
slog.Info("override value from env", "field", f.Name)
} else {
slog.Info("override value from env", "type", name, "field", f.Name)
}
}
return nil
}