package mgocrud

import (
	"reflect"
	"strings"
	"time"

	"gopkg.in/mgo.v2/bson"
)

// ModelInterface is interface for mgo crud operations
type ModelInterface interface {
	PrepareInsert()
	PrepareUpdate()
	GetID() *bson.ObjectId
	SetID(id *bson.ObjectId)
	GetIdentSelector() (selector bson.M)
	SetIdent()
}

// Model is model with default fields
type Model struct {
	ID         *bson.ObjectId `json:"id,omitempty" bson:"_id" mapstructure:"id"`
	InsertTime *time.Time     `json:"insertTime,omitempty" bson:"insertTime,omitempty" index:"single" mapstructure:"Datum"`
	UpdateTime *time.Time     `json:"updateTime,omitempty" bson:"updateTime,omitempty" index:"single" mapstructure:"Datum"`
	Ident      []string       `json:"ident,omitempty" bson:"-" mapstructure:"-"`
}

// GetCollectionName gets name from type
func GetCollectionName(m ModelInterface) string {
	if i, ok := m.(interface {
		GetCollectionName() string
	}); ok {
		return i.GetCollectionName()
	}
	return strings.ToLower(
		reflect.TypeOf(
			reflect.Indirect(reflect.ValueOf(m)).Interface(),
		).Name())
}

// PrepareInsert creates new bson id and insert time
func (m *Model) PrepareInsert() {
	if m.ID == nil {
		id := bson.NewObjectId()
		m.ID = &id
	}
	now := time.Now()
	m.InsertTime = &now
	m.UpdateTime = &now
}

// PrepareUpdate updates UpdateTime
func (m *Model) PrepareUpdate() {
	now := time.Now()
	m.UpdateTime = &now
}

// GetID gets object id
func (m *Model) GetID() *bson.ObjectId {
	return m.ID
}

// SetID sets object id
func (m *Model) SetID(id *bson.ObjectId) {
	m.ID = id
}