mgoapi/helper.go

package mgoapi

import (
	"errors"
	"reflect"
	"regexp"
	"strings"

	"gitbase.de/gopackage/mgocrud"
	"github.com/gin-gonic/gin"
	mgo "gopkg.in/mgo.v2"
	"gopkg.in/mgo.v2/bson"
)

func errorObject(err error) bson.M {
	o := bson.M{"error": err.Error()}
	if e, ok := err.(*mgocrud.ErrorWithStack); ok {
		o["stack"] = e.Stack()
	}
	return o
}

func modelTypeOf(m interface{}) reflect.Type {
	return reflect.TypeOf(
		reflect.ValueOf(m).Elem().Interface(),
	)
}

func newModelOf(m interface{}) interface{} {
	return reflect.New(
		modelTypeOf(m),
	).Interface()
}

func string2ObjectID(id string) (objectID *bson.ObjectId, err error) {
	defer func() {
		if r := recover(); r != nil {
			switch x := r.(type) {
			case string:
				err = errors.New(x)
			case error:
				err = x
			default:
				err = errors.New("Unknown panic in: string2ObjectID")
			}
		}
	}()
	oID := bson.ObjectIdHex(id)
	return &oID, err
}

func getStructMeta(s reflect.Type, dontRecurse map[string]bool) []map[string]interface{} {
	if s.Kind() == reflect.Ptr {
		s = s.Elem()
	}

	numField := s.NumField()
	meta := make([]map[string]interface{}, 0, numField+3)

	for i := 0; i < numField; i++ {
		f := s.Field(i)
		jsonTag := strings.Split(f.Tag.Get("json"), ",")

		if jsonTag[0] != "-" {
			_type := f.Type

			kind := f.Type.Kind()
			if kind == reflect.Ptr {
				_type = _type.Elem()
			}

			if f.Anonymous {
				// embed directly
				embed := getStructMeta(_type, dontRecurse)
				for _, e := range embed {
					meta = append(meta, e)
				}
			} else {
				fMeta := make(map[string]interface{})

				fName := f.Name
				if jsonTag[0] != "" {
					fName = jsonTag[0]
				}
				fMeta["name"] = fName

				fType := _type.Name()
				if fType == "" {
					fType = _type.String()
				}
				//fType = strings.Replace(fType, "*", "", -1)
				fType = regexp.MustCompile("\\*[a-zA-Z0-9]*\\.?").ReplaceAllString(fType, "")
				fMeta["type"] = fType
				kind = _type.Kind()
				fMeta["kind"] = kind.String()

				if vT := f.Tag.Get("validator"); vT != "" {
					fMeta["validator"] = strings.Split(vT, ",")
				}
				/*

					if vT := f.Tag.Get("class"); vT != "" {
						fMeta["class"] = strings.Split(vT, ",")
					}

					if lT := f.Tag.Get("label"); lT != "" {
						fMeta["label"] = lT
					}
				*/
				if vM := f.Tag.Get("meta"); vM != "" {
					m := strings.Split(vM, ";")
					for _, mP := range m {
						p := strings.Split(mP, "=")
						if len(p) > 1 {
							pp := strings.Split(p[1], ",")
							if len(pp) == 1 {
								fMeta[p[0]] = pp[0]
							} else {
								fMeta[p[0]] = pp
							}
						}
					}
				}

				if kind == reflect.Struct && !dontRecurse[fType] {
					dontRecurse[fType] = true
					fMeta[kind.String()+"Of"] = getStructMeta(_type, dontRecurse)
				} else if kind == reflect.Slice && !dontRecurse[fType] {
					sliceEl := _type.Elem()
					if sliceEl.Kind() == reflect.Ptr {
						sliceEl = sliceEl.Elem()
					}
					if sliceEl.Kind() == reflect.Struct {
						dontRecurse[fType] = true
						fMeta[kind.String()+"Of"] = getStructMeta(sliceEl, dontRecurse)
					} else {
						fMeta[kind.String()+"Of"] = sliceEl.String()
					}
				}

				meta = append(meta, fMeta)
			}

		}
	}

	return meta
}

func getModelMeta(m mgocrud.ModelInterface) []map[string]interface{} {
	dontRecurse := map[string]bool{
		"Time":     true,
		"ObjectId": true,
	}
	modelType := reflect.ValueOf(m).Elem().Type()

	return getStructMeta(modelType, dontRecurse)
}

func getDocument(c *gin.Context, db *mgo.Database, m mgocrud.ModelInterface, selector bson.M) (mgocrud.ModelInterface, error) {
	objectID, err := string2ObjectID(c.Param("id"))
	if err != nil {
		return nil, err
	}
	newM := newModelOf(m).(mgocrud.ModelInterface)
	newM.SetID(objectID)
	err = mgocrud.ReadDocument(db, newM, selector)
	if err != nil {
		return nil, err
	}
	return newM, nil
}