const ObjectID    = require("mongodb").ObjectID;
const {connect}   = require('mm')

module.exports = async (dbName='snippet') => {
    const {Savable, slice} = await connect(dbName)

    async function getModels({id}){
        const SlicedSavable = slice([id, 'user'])

        class User extends SlicedSavable {
            constructor(...params){
                super(...params)
                //TODO: calc likes count by getter (no two-way relation for this to avoid overflow on many Kilos of likes
                //cached like count, which incremented and decremented
                //
                //following and followers array

            }

            async getACL(){
                return [this._id.toString(), "user"]
            }

            static get relations(){ //don't needed due to ___owner in most cases
                return {
                    avatar : "userAvatar",
                }
            }
        }
        SlicedSavable.addClass(User)

        class OwnerSlicedSavable extends SlicedSavable {
            get owner(){
                if (!this.___owner) return this.___owner

                return SlicedSavable.m.User.findOne({_id: ObjectID(this.___owner)})
            }
        }


        class Image extends OwnerSlicedSavable {
            constructor(...params){
                super(...params)
            }


            static async fromFileData(fileData){
		try {
			let image  = new Image({})
			image.fileData = fileData
			image.url      = `images/${fileData.filename}`
			image.originalFileName = fileData.originalname
			await image.save()
			return image;
		}
		catch(e){
		    console.log('wrong file')
		}
            }

            static get relations(){
                return {
                    userAvatar: "avatar", //if it is ava
                }
            }

        }
        SlicedSavable.addClass(Image)


        class Snippet extends OwnerSlicedSavable {
            constructor(...params){
                super(...params)
            }


            static get relations(){
                return {
                    comments: "snippet",
                    files: "snippet",
                }
            }

            static get guestRelations(){
                return ["comments"]
            }

        }
        SlicedSavable.addClass(Snippet)


        class Comment extends OwnerSlicedSavable {
            constructor(...params){
                super(...params)
                //TODO: calc likes count by getter (no two-way relation for this to avoid overflow on many Kilos of likes
                //cached like count, which incremented and decremented
            }


            static get relations(){
                return {
                    snippet: ["comments"],
                    answers: "answerTo",
                    answerTo: ["answers"],
                }
            }

            static get guestRelations(){
                return ["answers"]
            }
        }
        SlicedSavable.addClass(Comment)


        class File extends OwnerSlicedSavable {
            constructor(...params){
                super(...params)
            }


            static get relations(){
                return {
                    snippet: ["files"],
                }
            }
        }
        SlicedSavable.addClass(File)



        const thisUser = await Savable.m.User.findOne({_id: ObjectID(id)})

        return {models: {
                            SlicedSavable, ...SlicedSavable.classes
                        }, 
                thisUser}
    }

    return {
        Savable, 
        slice,
        getModels
    }
}