goext/wmo/reflection.go

package wmo

import (
	"errors"
	"fmt"
	"gogs.mikescher.com/BlackForestBytes/goext/langext"
	"reflect"
	"strconv"
	"time"
)

func (c *Coll[TData]) init() {

	c.dataTypeMap = make(map[string]fullTypeRef[TData])

	example := *new(TData)

	v := reflect.ValueOf(example)

	c.initFields("", v, make([]int, 0))

}

func (c *Coll[TData]) initFields(prefix string, rval reflect.Value, idxarr []int) {

	rtyp := rval.Type()

	for i := 0; i < rtyp.NumField(); i++ {

		rsfield := rtyp.Field(i)
		rvfield := rval.Field(i)

		if !rsfield.IsExported() {
			continue
		}

		bsonkey, found := rsfield.Tag.Lookup("bson")
		if !found || bsonkey == "-" {
			continue
		}

		fullKey := prefix + bsonkey

		newIdxArr := langext.ArrCopy(idxarr)
		newIdxArr = append(newIdxArr, i)

		if rvfield.Type().Kind() == reflect.Pointer {

			c.dataTypeMap[fullKey] = fullTypeRef[TData]{
				IsPointer:      true,
				Kind:           rvfield.Type().Elem().Kind(),
				Type:           rvfield.Type().Elem(),
				UnderlyingType: langext.Underlying(rvfield.Type().Elem()),
				Name:           rsfield.Name,
				Index:          newIdxArr,
			}

		} else {

			c.dataTypeMap[fullKey] = fullTypeRef[TData]{
				IsPointer:      false,
				Kind:           rvfield.Type().Kind(),
				Type:           rvfield.Type(),
				UnderlyingType: langext.Underlying(rvfield.Type()),
				Name:           rsfield.Name,
				Index:          newIdxArr,
			}

		}

		if rvfield.Kind() == reflect.Struct {
			c.initFields(fullKey+".", rvfield, newIdxArr)
		}

	}

}

func (c *Coll[TData]) getTokenValueAsMongoType(value string, fieldName string) (any, error) {
	fref := c.dataTypeMap[fieldName]

	if fref.IsPointer && value == "" {
		pointertype := reflect.New(fref.Type).Type()
		nilvalue := reflect.Zero(pointertype)
		outvalue := nilvalue.Interface()
		return outvalue, nil
	}

	pointerize := func(v any) any {
		if !fref.IsPointer {
			return v
		}

		rval1 := reflect.ValueOf(v)
		rval2 := rval1.Convert(fref.Type)
		rval3 := reflect.New(fref.Type)
		rval3.Elem().Set(rval2)
		return rval3.Interface()
	}

	if fref.UnderlyingType == reflect.TypeOf("") {

		rt, ok := langext.TryCastType(value, fref.Type)
		if !ok {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' from string to %s", fieldName, fref.Type.String()))
		}

		return pointerize(rt), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(time.Time{}) {

		t, err := time.Parse(time.RFC3339Nano, value)
		if err != nil {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' as time.Time ('%s')", fieldName, value))
		}

		rt, ok := langext.TryCastType(t, fref.Type)
		if !ok {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' from time.Time to %s", fieldName, fref.Type.String()))
		}

		return pointerize(rt), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(int(0)) {

		t, err := strconv.ParseInt(value, 10, 64)
		if err != nil {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' as int64 ('%s')", fieldName, value))
		}

		rt, ok := langext.TryCastType(int(t), fref.Type)
		if !ok {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' from int to %s", fieldName, fref.Type.String()))
		}

		return pointerize(rt), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(int32(0)) {

		t, err := strconv.ParseInt(value, 10, 64)
		if err != nil {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' as int32 ('%s')", fieldName, value))
		}

		rt, ok := langext.TryCastType(int32(t), fref.Type)
		if !ok {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' from int32 to %s", fieldName, fref.Type.String()))
		}

		return pointerize(rt), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(int64(0)) {

		t, err := strconv.ParseInt(value, 10, 64)
		if err != nil {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' as int64 ('%s')", fieldName, value))
		}

		rt, ok := langext.TryCastType(int64(t), fref.Type)
		if !ok {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' from int64 to %s", fieldName, fref.Type.String()))
		}

		return pointerize(rt), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(float32(0)) {

		t, err := strconv.ParseFloat(value, 64)
		if err != nil {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' as float32 ('%s')", fieldName, value))
		}

		rt, ok := langext.TryCastType(float32(t), fref.Type)
		if !ok {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' from float32 to %s", fieldName, fref.Type.String()))
		}

		return pointerize(rt), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(float64(0)) {

		t, err := strconv.ParseFloat(value, 64)
		if err != nil {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' as float64 ('%s')", fieldName, value))
		}

		rt, ok := langext.TryCastType(float64(t), fref.Type)
		if !ok {
			return nil, errors.New(fmt.Sprintf("failed to parse field '%s' from float64 to %s", fieldName, fref.Type.String()))
		}

		return pointerize(rt), nil
	}

	return nil, errors.New(fmt.Sprintf("failed to parse field '%s' of type %s (%s)", fieldName, fref.Type.String(), fref.UnderlyingType.String()))
}

func (c *Coll[TData]) getFieldValueAsTokenString(entity TData, fieldName string) (string, error) {
	fref := c.dataTypeMap[fieldName]

	realValue := c.getFieldValue(entity, fieldName)

	if langext.IsNil(realValue) {
		return "", nil
	}

	reflValue := reflect.ValueOf(realValue)
	if reflValue.Kind() == reflect.Pointer {
		reflValue = reflValue.Elem()
		realValue = reflValue.Interface()
	}

	if fref.UnderlyingType == reflect.TypeOf("") {

		rt, ok := langext.TryCastType(realValue, reflect.TypeOf(""))
		if !ok {
			return "", errors.New(fmt.Sprintf("failed to cast field '%s' from %s to string", fieldName, fref.Type.String()))
		}

		return rt.(string), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(time.Time{}) {
		rt, ok := langext.TryCastType(realValue, reflect.TypeOf(time.Time{}))
		if !ok {
			return "", errors.New(fmt.Sprintf("failed to cast field '%s' from %s to time.Time", fieldName, fref.Type.String()))
		}

		return rt.(time.Time).Format(time.RFC3339Nano), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(int(0)) {
		rt, ok := langext.TryCastType(realValue, reflect.TypeOf(int(0)))
		if !ok {
			return "", errors.New(fmt.Sprintf("failed to cast field '%s' from %s to int", fieldName, fref.Type.String()))
		}

		return strconv.Itoa(rt.(int)), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(int32(0)) {
		rt, ok := langext.TryCastType(realValue, reflect.TypeOf(int32(0)))
		if !ok {
			return "", errors.New(fmt.Sprintf("failed to cast field '%s' from %s to int32", fieldName, fref.Type.String()))
		}

		return strconv.FormatInt(int64(rt.(int32)), 10), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(int64(0)) {
		rt, ok := langext.TryCastType(realValue, reflect.TypeOf(int64(0)))
		if !ok {
			return "", errors.New(fmt.Sprintf("failed to cast field '%s' from %s to int64", fieldName, fref.Type.String()))
		}

		return strconv.FormatInt(rt.(int64), 10), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(float32(0)) {
		rt, ok := langext.TryCastType(realValue, reflect.TypeOf(float32(0)))
		if !ok {
			return "", errors.New(fmt.Sprintf("failed to cast field '%s' from %s to float32", fieldName, fref.Type.String()))
		}

		return strconv.FormatFloat(float64(rt.(float32)), 'f', -1, 32), nil
	}

	if fref.UnderlyingType == reflect.TypeOf(float64(0)) {
		rt, ok := langext.TryCastType(realValue, reflect.TypeOf(float64(0)))
		if !ok {
			return "", errors.New(fmt.Sprintf("failed to cast field '%s' from %s to float64", fieldName, fref.Type.String()))
		}

		return strconv.FormatFloat(rt.(float64), 'f', -1, 64), nil
	}

	return "", errors.New(fmt.Sprintf("failed to parse field '%s' of type %s (%s)", fieldName, fref.Type.String(), fref.UnderlyingType.String()))
}

func (c *Coll[TData]) getFieldType(fieldName string) fullTypeRef[TData] {
	return c.dataTypeMap[fieldName]
}

func (c *Coll[TData]) getFieldValue(data TData, fieldName string) any {
	fref := c.dataTypeMap[fieldName]
	rval := reflect.ValueOf(data)
	return rval.FieldByIndex(fref.Index).Interface()
}