micro/config/default.go
Vasiliy Tolstov 8c504bd029 handle before/after inside config implementations
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2020-12-18 03:37:18 +03:00

249 lines
5.3 KiB
Go

package config
import (
"context"
"reflect"
"strconv"
"strings"
)
type defaultConfig struct {
opts Options
}
func (c *defaultConfig) Options() Options {
return c.opts
}
func (c *defaultConfig) Init(opts ...Option) error {
for _, o := range opts {
o(&c.opts)
}
return nil
}
func (c *defaultConfig) Load(ctx context.Context) error {
for _, fn := range c.opts.BeforeLoad {
if err := fn(ctx, c); err != nil {
return err
}
}
valueOf := reflect.ValueOf(c.opts.Struct)
if err := c.fillValues(ctx, valueOf); err != nil {
return err
}
for _, fn := range c.opts.AfterLoad {
if err := fn(ctx, c); err != nil {
return err
}
}
return nil
}
func (c *defaultConfig) fillValue(ctx context.Context, value reflect.Value, val string) error {
switch value.Kind() {
case reflect.Map:
t := value.Type()
nvals := strings.FieldsFunc(val, func(c rune) bool { return c == ',' || c == ';' })
if value.IsNil() {
value.Set(reflect.MakeMapWithSize(t, len(nvals)))
}
kt := t.Key()
et := t.Elem()
for _, nval := range nvals {
kv := strings.FieldsFunc(nval, func(c rune) bool { return c == '=' })
mkey := reflect.Indirect(reflect.New(kt))
mval := reflect.Indirect(reflect.New(et))
if err := c.fillValue(ctx, mkey, kv[0]); err != nil {
return err
}
if err := c.fillValue(ctx, mval, kv[1]); err != nil {
return err
}
value.SetMapIndex(mkey, mval)
}
case reflect.Slice, reflect.Array:
nvals := strings.FieldsFunc(val, func(c rune) bool { return c == ',' || c == ';' })
value.Set(reflect.MakeSlice(reflect.SliceOf(value.Type().Elem()), len(nvals), len(nvals)))
for idx, nval := range nvals {
nvalue := reflect.Indirect(reflect.New(value.Type().Elem()))
if err := c.fillValue(ctx, nvalue, nval); err != nil {
return err
}
value.Index(idx).Set(nvalue)
}
case reflect.Bool:
v, err := strconv.ParseBool(val)
if err != nil {
return err
}
value.Set(reflect.ValueOf(v))
case reflect.String:
value.Set(reflect.ValueOf(val))
case reflect.Float32:
v, err := strconv.ParseFloat(val, 32)
if err != nil {
return err
}
value.Set(reflect.ValueOf(float32(v)))
case reflect.Float64:
v, err := strconv.ParseFloat(val, 64)
if err != nil {
return err
}
value.Set(reflect.ValueOf(float64(v)))
case reflect.Int:
v, err := strconv.ParseInt(val, 10, 0)
if err != nil {
return err
}
value.Set(reflect.ValueOf(int(v)))
case reflect.Int8:
v, err := strconv.ParseInt(val, 10, 8)
if err != nil {
return err
}
value.Set(reflect.ValueOf(v))
case reflect.Int16:
v, err := strconv.ParseInt(val, 10, 16)
if err != nil {
return err
}
value.Set(reflect.ValueOf(int16(v)))
case reflect.Int32:
v, err := strconv.ParseInt(val, 10, 32)
if err != nil {
return err
}
value.Set(reflect.ValueOf(int32(v)))
case reflect.Int64:
v, err := strconv.ParseInt(val, 10, 64)
if err != nil {
return err
}
value.Set(reflect.ValueOf(int64(v)))
case reflect.Uint:
v, err := strconv.ParseUint(val, 10, 0)
if err != nil {
return err
}
value.Set(reflect.ValueOf(uint(v)))
case reflect.Uint8:
v, err := strconv.ParseUint(val, 10, 8)
if err != nil {
return err
}
value.Set(reflect.ValueOf(uint8(v)))
case reflect.Uint16:
v, err := strconv.ParseUint(val, 10, 16)
if err != nil {
return err
}
value.Set(reflect.ValueOf(uint16(v)))
case reflect.Uint32:
v, err := strconv.ParseUint(val, 10, 32)
if err != nil {
return err
}
value.Set(reflect.ValueOf(uint32(v)))
case reflect.Uint64:
v, err := strconv.ParseUint(val, 10, 64)
if err != nil {
return err
}
value.Set(reflect.ValueOf(uint64(v)))
}
return nil
}
func (c *defaultConfig) fillValues(ctx context.Context, valueOf reflect.Value) error {
var values reflect.Value
if valueOf.Kind() == reflect.Ptr {
values = valueOf.Elem()
} else {
values = valueOf
}
if values.Kind() == reflect.Invalid {
return ErrInvalidStruct
}
fields := values.Type()
for idx := 0; idx < fields.NumField(); idx++ {
field := fields.Field(idx)
value := values.Field(idx)
if !value.CanSet() {
continue
}
if len(field.PkgPath) != 0 {
continue
}
switch value.Kind() {
case reflect.Struct:
value.Set(reflect.Indirect(reflect.New(value.Type())))
if err := c.fillValues(ctx, value); err != nil {
return err
}
continue
case reflect.Ptr:
if value.IsNil() {
if value.Type().Elem().Kind() != reflect.Struct {
// nil pointer to a non-struct: leave it alone
break
}
// nil pointer to struct: create a zero instance
value.Set(reflect.New(value.Type().Elem()))
}
value = value.Elem()
if err := c.fillValues(ctx, value); err != nil {
return err
}
continue
}
tag, ok := field.Tag.Lookup(c.opts.StructTag)
if !ok {
continue
}
if err := c.fillValue(ctx, value, tag); err != nil {
return err
}
}
return nil
}
func (c *defaultConfig) Save(ctx context.Context) error {
for _, fn := range c.opts.BeforeSave {
if err := fn(ctx, c); err != nil {
return err
}
}
for _, fn := range c.opts.AfterSave {
if err := fn(ctx, c); err != nil {
return err
}
}
return nil
}
func (c *defaultConfig) String() string {
return "default"
}
func NewConfig(opts ...Option) Config {
options := NewOptions(opts...)
if len(options.StructTag) == 0 {
options.StructTag = "default"
}
return &defaultConfig{opts: options}
}