package orm

import (
	"fmt"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"reflect"
	"strings"
)

func panik(err error) {
	if err != nil {
		panic(err)
	}
}

func nameOf(i interface{}) string {
	v := reflect.ValueOf(i)
	var n string
	switch v.Kind() {
	case reflect.Slice, reflect.Map:
		if v.Type().Elem().Kind() == reflect.Pointer {
			n = v.Type().Elem().Elem().Name()
		}
	case reflect.Pointer:
		n = nameOf(reflect.Indirect(v).Interface())
	default:
		n = v.Type().Name()
	}
	return n
}

func valueOf(i interface{}) reflect.Value {
	v := reflect.ValueOf(i)
	if v.Type().Kind() == reflect.Pointer {
		v = valueOf(reflect.Indirect(v).Interface())
	}
	return v
}

func iFace(input interface{}) interface{} {
	return reflect.ValueOf(input).Interface()
}

func iFaceSlice(input interface{}) []interface{} {
	ret := make([]interface{}, 0)
	fv := reflect.ValueOf(input)
	if fv.Type().Kind() != reflect.Slice {
		return ret
	}
	for i := 0; i < fv.Len(); i++ {
		ret = append(ret, fv.Index(i).Interface())
	}
	return ret
}

func coerceInt(input reflect.Value, dst reflect.Value) interface{} {
	if input.Type().Kind() == reflect.Pointer {
		input = input.Elem()
	}
	if dst.Type().Kind() == reflect.Pointer {
		dst = dst.Elem()
	}
	if input.Type().ConvertibleTo(dst.Type()) {
		return input.Convert(dst.Type()).Interface()
	}
	return nil
}

func getNested(field string, value reflect.Value) (*reflect.StructField, *reflect.Value, error) {
	if strings.HasPrefix(field, ".") || strings.HasSuffix(field, ".") {
		return nil, nil, fmt.Errorf("Malformed field name %s passed", field)
	}
	dots := strings.Split(field, ".")
	if value.Kind() != reflect.Struct {
		return nil, nil, fmt.Errorf("This value is not a struct!")
	}
	ref := value
	if ref.Kind() == reflect.Pointer {
		ref = ref.Elem()
	}
	fv := ref.FieldByName(dots[0])
	ft, _ := ref.Type().FieldByName(dots[0])
	if len(dots) > 1 {
		return getNested(strings.Join(dots[1:], "."), fv)
	} else {
		return &ft, &fv, nil
	}
}
func makeSettable(rval reflect.Value, value interface{}) reflect.Value {
	if !rval.CanSet() {
		nv := reflect.New(rval.Type())
		nv.Elem().Set(reflect.ValueOf(value))
		return nv
	}
	return rval
}

func incrementInterface(t interface{}) interface{} {
	switch pt := t.(type) {
	case uint:
		t = pt + 1
	case uint32:
		t = pt + 1
	case uint64:
		t = pt + 1
	case int:
		t = pt + 1
	case int32:
		t = pt + 1
	case int64:
		t = pt + 1
	case string:
		t = NextStringID()
	case primitive.ObjectID:
		t = primitive.NewObjectID()
	default:
		panic("unknown or unsupported id type")
	}
	return t
}

func pull(s reflect.Value, idx int, typ reflect.Type) reflect.Value {
	retI := reflect.New(reflect.SliceOf(typ))
	for i := 0; i < s.Len(); i++ {
		if i == idx {
			continue
		}
		retI.Elem().Set(reflect.Append(retI.Elem(), s.Index(i)))
	}
	return retI.Elem()
}