import {
    ObjectID, Db, Binary, InsertOneWriteOpResult, DeleteWriteOpResultObject, ObjectId, MapReduceOptions, CollectionInsertOneOptions, UpdateWriteOpResult, WriteOpResult
} from "mongodb";
import { MongoClient } from "mongodb";
import { Base, Rights, WellknownIds } from "./base";
import winston = require("winston");
import { Crypt } from "./Crypt";
import { Config } from "./Config";
import { TokenUser } from "./TokenUser";
import { Ace } from "./Ace";
import { Role } from "./Role";
import { UpdateOneMessage } from "./Messages/UpdateOneMessage";
import { UpdateManyMessage } from "./Messages/UpdateManyMessage";
import { InsertOrUpdateOneMessage } from "./Messages/InsertOrUpdateOneMessage";
import { User } from "./User";
// tslint:disable-next-line: typedef
const safeObjectID = (s: string | number | ObjectID) => ObjectID.isValid(s) ? new ObjectID(s) : null;
export declare function emit(k, v);
export type mapFunc = () => void;
export type reduceFunc = (key: string, values: any[]) => any;
export type finalizeFunc = (key: string, value: any) => any;
const isoDatePattern = new RegExp(/\d{4}-[01]\d-[0-3]\dT[0-2]\d:[0-5]\d:[0-5]\d\.\d+([+-][0-2]\d:[0-5]\d|Z)/);
export class DatabaseConnection {
    private mongodburl: string;
    private cli: MongoClient;
    private db: Db;
    private _logger: winston.Logger;
    private _dbname: string;
    constructor(logger: winston.Logger, mongodburl: string, dbname: string) {
        this._logger = logger;
        this._dbname = dbname;
        this.mongodburl = mongodburl;
    }
    /**
     * Connect to MongoDB
     * @returns Promise<void>
     */
    async connect(): Promise<void> {
        if (this.cli !== null && this.cli !== undefined && this.cli.isConnected) {
            return;
        }
        this.cli = await MongoClient.connect(this.mongodburl, { autoReconnect: false, useNewUrlParser: true });
        this.cli.on("error", (error) => {
            this._logger.error(error);
        });
        this.db = this.cli.db(this._dbname);
    }


    /**
     * Send a query to the database.
     * @param {any} query MongoDB Query
     * @param {Object} projection MongoDB projection
     * @param {number} top Limit result to X number of results
     * @param {number} skip Skip a number of records (Paging)
     * @param {Object|string} orderby MongoDB orderby, or string with name of a single field to orderby
     * @param {string} collectionname What collection to query
     * @param {string} jwt JWT of user who is making the query, to limit results based on permissions
     * @returns Promise<T[]> Array of results
     */
    // tslint:disable-next-line: max-line-length
    async query<T extends Base>(query: any, projection: Object, top: number, skip: number, orderby: Object | string, collectionname: string, jwt: string): Promise<T[]> {
        var arr: T[] = [];
        await this.connect();
        var mysort: Object = {};
        if (orderby) {
            if (typeof orderby === "string" || orderby instanceof String) {
                mysort[(orderby as string)] = 1;
            } else {
                mysort = orderby;
            }
        }
        for (let key in query) {
            if (key === "_id") {
                var id: string = query._id;
                var safeid = safeObjectID(id);
                if (safeid !== null && safeid !== undefined) {
                    delete query._id;
                    query.$or = [{ _id: id }, { _id: safeObjectID(id) }];
                }
            }
        }

        if (query !== null && query !== undefined) {
            var json: any = query;
            if (typeof json !== 'string' && !(json instanceof String)) {
                json = JSON.stringify(json, (key, value) => {
                    if (value instanceof RegExp)
                        return ("__REGEXP " + value.toString());
                    else
                        return value;
                });
            }
            query = JSON.parse(json, (key, value) => {
                if (typeof value === 'string' && value.match(isoDatePattern)) {
                    return new Date(value); // isostring, so cast to js date
                } else if (value != null && value != undefined && value.toString().indexOf("__REGEXP ") == 0) {
                    var m = value.split("__REGEXP ")[1].match(/\/(.*)\/(.*)?/);
                    return new RegExp(m[1], m[2] || "");
                } else
                    return value; // leave any other value as-is
            });
        }
        var user: TokenUser = Crypt.verityToken(jwt);
        var _query: Object = {};
        if (collectionname === "files") { collectionname = "fs.files"; }
        if (collectionname === "fs.files") {
            _query = { $and: [query, this.getbasequery(jwt, "metadata._acl", [Rights.read])] };
        } else {
            if (!collectionname.endsWith("_hist")) {
                _query = { $and: [query, this.getbasequery(jwt, "_acl", [Rights.read])] };
            } else {
                // todo: enforcer permissions when fetching _hist ?
                _query = query;
            }
        }
        if (!top) { top = 500; }
        if (!skip) { skip = 0; }
        // if (collectionname == "openrpa") {
        //     var user: TokenUser = Crypt.verityToken(jwt);
        //     arr = await this.db.collection(collectionname).find(query).limit(top).skip(skip).toArray();
        //     _query = { $and: [query, this.getbasequery(jwt, "_acl", [Rights.read])] };
        // }
        if (projection != null) {
            arr = await this.db.collection(collectionname).find(_query).project(projection).sort(mysort).limit(top).skip(skip).toArray();
        } else {
            arr = await this.db.collection(collectionname).find(_query).sort(mysort).limit(top).skip(skip).toArray();
        }
        for (var i: number = 0; i < arr.length; i++) { arr[i] = this.decryptentity(arr[i]); }
        this.traversejsondecode(arr);
        this._logger.debug("[" + user.username + "] query gave " + arr.length + " results " + JSON.stringify(query));
        return arr;
    }
    /**
     * Get a single item based on id
     * @param  {string} id Id to search for
     * @param  {string} collectionname Collection to search
     * @param  {string} jwt JWT of user who is making the query, to limit results based on permissions
     * @returns Promise<T>
     */
    async getbyid<T extends Base>(id: string, collectionname: string, jwt: string): Promise<T> {
        if (id === null || id === undefined) { throw Error("Id cannot be null"); }
        var arr: T[] = await this.query<T>({ _id: id }, null, 1, 0, null, collectionname, jwt);
        if (arr === null || arr.length === 0) { return null; }
        return arr[0];
    }
    /**
     * Do MongoDB aggregation
     * @param  {any} aggregates
     * @param  {string} collectionname
     * @param  {string} jwt
     * @returns Promise
     */
    async aggregate<T extends Base>(aggregates: object[], collectionname: string, jwt: string): Promise<T[]> {
        await this.connect();
        // todo: add permissions check on aggregates
        // aggregates.unshift(this.getbasequery(jwt, [Rights.read]));
        var items: T[] = await this.db.collection(collectionname).aggregate(aggregates).toArray();
        this.traversejsondecode(items);
        return items;
    }
    /**
     * Do MongoDB map reduce
     * @param  {any} aggregates
     * @param  {string} collectionname
     * @param  {string} jwt
     * @returns Promise
     */
    async MapReduce<T>(map: mapFunc, reduce: reduceFunc, finalize: finalizeFunc, query: any, out: string | any, collectionname: string, scope: any, jwt: string): Promise<T[]> {
        await this.connect();

        if (query !== null && query !== undefined) {
            var json: any = query;
            if (typeof json !== 'string' && !(json instanceof String)) {
                json = JSON.stringify(json, (key, value) => {
                    if (value instanceof RegExp)
                        return ("__REGEXP " + value.toString());
                    else
                        return value;
                });
            }
            query = JSON.parse(json, (key, value) => {
                if (typeof value === 'string' && value.match(isoDatePattern)) {
                    return new Date(value); // isostring, so cast to js date
                } else if (value != null && value != undefined && value.toString().indexOf("__REGEXP ") == 0) {
                    var m = value.split("__REGEXP ")[1].match(/\/(.*)\/(.*)?/);
                    return new RegExp(m[1], m[2] || "");
                } else
                    return value; // leave any other value as-is
            });
        }
        var q: any = query;
        if (query !== null && query !== undefined) {
            q = { $and: [query, this.getbasequery(jwt, "_acl", [Rights.read])] };
        } else {
            q = this.getbasequery(jwt, "_acl", [Rights.read]);
        }

        var inline: boolean = false;
        var opt: MapReduceOptions = { query: q, out: { replace: "map_temp_res" }, finalize: finalize };
        var outcol: string = "map_temp_res";
        if (out === null || out === undefined || out === "") {
            opt.out = { replace: outcol };
        } else if (typeof out === 'string' || out instanceof String) {
            outcol = (out as string);
            opt.out = { replace: outcol };
        } else {
            opt.out = out;
            if (out.hasOwnProperty("replace")) { outcol = out.replace; }
            if (out.hasOwnProperty("merge")) { outcol = out.merge; }
            if (out.hasOwnProperty("reduce")) { outcol = out.reduce; }
            if (out.hasOwnProperty("inline")) { inline = true; }
        }
        opt.scope = scope;

        // var result:T[] = await this.db.collection(collectionname).mapReduce(map, reduce, {query: q, out : {inline : 1}});
        if (inline) {
            var result: T[] = await this.db.collection(collectionname).mapReduce(map, reduce, opt);
            return result;
        } else {
            await this.db.collection(collectionname).mapReduce(map, reduce, opt);
            return [];
        }
        // var result:T[] = await this.db.collection(outcol).find({}).toArray(); // .limit(top)
        // // this.db.collection("map_temp_res").deleteMany({});
        // return result;
    }
    /**
     * Create a new document in the database
     * @param  {T} item Item to create
     * @param  {string} collectionname The collection to create item in
     * @param  {number} w Write Concern ( 0:no acknowledgment, 1:Requests acknowledgment, 2: Requests acknowledgment from 2, 3:Requests acknowledgment from 3)
     * @param  {boolean} j Ensure is written to the on-disk journal.
     * @param  {string} jwt JWT of the user, creating the item, to ensure rights and permission
     * @returns Promise<T> Returns the new item added
     */
    async InsertOne<T extends Base>(item: T, collectionname: string, w: number, j: boolean, jwt: string): Promise<T> {
        if (item === null || item === undefined) { throw Error("Cannot create null item"); }
        await this.connect();
        item = this.ensureResource(item);
        this.traversejsonencode(item);
        if (jwt === null || jwt === undefined && collectionname === "jslog") {
            jwt = TokenUser.rootToken();
        }
        var user: TokenUser = Crypt.verityToken(jwt);
        if (!this.hasAuthorization(user, item, "create")) { throw new Error("Access denied"); }
        item._createdby = user.name;
        item._createdbyid = user._id;
        item._created = new Date(new Date().toISOString());
        item._modifiedby = user.name;
        item._modifiedbyid = user._id;
        item._modified = item._created;
        var hasUser: Ace = item._acl.find(e => e._id === user._id);
        if ((hasUser === null || hasUser === undefined)) {
            if (collectionname != "audit") { this._logger.debug("[" + user.username + "] Adding self " + user.username + " to object " + (item.name || item._name)); }
            item.addRight(user._id, user.name, [Rights.full_control]);
        }
        if (collectionname != "audit") { this._logger.debug("[" + user.username + "] Adding " + (item.name || item._name) + " to database"); }

        item = this.encryptentity<T>(item);
        if (!item._id) { item._id = new ObjectID().toHexString(); }

        if (collectionname === "users" && item._type === "user" && item.hasOwnProperty("newpassword")) {
            (item as any).passwordhash = await Crypt.hash((item as any).newpassword);
            delete (item as any).newpassword;
        }
        j = ((j as any) === 'true' || j === true);
        w = parseInt((w as any));

        item._version = await this.SaveDiff(collectionname, null, item);

        // var options:CollectionInsertOneOptions = { writeConcern: { w: parseInt((w as any)), j: j } };
        var options: CollectionInsertOneOptions = { w: w, j: j };
        //var options: CollectionInsertOneOptions = { w: "majority" };
        var result: InsertOneWriteOpResult = await this.db.collection(collectionname).insertOne(item, options);
        item = result.ops[0];
        if (item !== null && item !== undefined) {
            this._logger.debug("[" + user.username + "] Inserted " + (item.name || item._name) + " with id " + item._id);
        }
        if (collectionname === "users" && item._type === "user") {
            var users: Role = await Role.FindByNameOrId("users", jwt);
            users.AddMember(item);
            await users.Save(jwt)
        }
        this.traversejsondecode(item);
        return item;
    }
    /**
     * Update entity in database
     * @param  {T} item Item to update
     * @param  {string} collectionname Collection containing item
     * @param  {number} w Write Concern ( 0:no acknowledgment, 1:Requests acknowledgment, 2: Requests acknowledgment from 2, 3:Requests acknowledgment from 3)
     * @param  {boolean} j Ensure is written to the on-disk journal.
     * @param  {string} jwt JWT of user who is doing the update, ensuring rights
     * @returns Promise<T>
     */
    async _UpdateOne<T extends Base>(query: any, item: T, collectionname: string, w: number, j: boolean, jwt: string): Promise<T> {
        var q = new UpdateOneMessage<T>();
        q.query = query; q.item = item; q.collectionname = collectionname; q.w = w; q.j; q.jwt = jwt;
        q = await this.UpdateOne(q);
        if (q.opresult.result.ok == 1) {
            if (q.opresult.modifiedCount == 0) {
                throw Error("item not found!");
            } else if (q.opresult.modifiedCount == 1 || q.opresult.modifiedCount == undefined) {
                q.item = q.item;
            } else {
                throw Error("More than one item was updated !!!");
            }
        } else {
            throw Error("UpdateOne failed!!!");
        }
        return q.result;
    }
    async UpdateOne<T extends Base>(q: UpdateOneMessage<T>): Promise<UpdateOneMessage<T>> {
        var itemReplace: boolean = true;
        if (q === null || q === undefined) { throw Error("UpdateOneMessage cannot be null"); }
        if (q.item === null || q.item === undefined) { throw Error("Cannot update null item"); }
        await this.connect();
        var user: TokenUser = Crypt.verityToken(q.jwt);
        if (!this.hasAuthorization(user, q.item, "update")) { throw new Error("Access denied"); }

        var original: T = null;
        // assume empty query, means full document, else update document
        if (q.query === null || q.query === undefined) {
            // this will add an _acl so needs to be after we checked old item
            if (!q.item.hasOwnProperty("_id")) {
                throw Error("Cannot update item without _id");
            }
            original = await this.getbyid<T>(q.item._id, q.collectionname, q.jwt);
            if (!original) { throw Error("item not found!"); }
            q.item._modifiedby = user.name;
            q.item._modifiedbyid = user._id;
            q.item._modified = new Date(new Date().toISOString());
            // now add all _ fields to the new object
            var keys: string[] = Object.keys(original);
            for (let i: number = 0; i < keys.length; i++) {
                let key: string = keys[i];
                if (key === "_created") {
                    q.item[key] = new Date(original[key]);
                } else if (key === "_createdby" || key === "_createdbyid") {
                    q.item[key] = original[key];
                } else if (key === "_modifiedby" || key === "_modifiedbyid" || key === "_modified") {
                    // allready updated
                } else if (key.indexOf("_") === 0) {
                    if (!q.item.hasOwnProperty(key)) {
                        q.item[key] = original[key]; // add missing key
                    } else if (q.item[key] === null) {
                        delete q.item[key]; // remove key
                    } else {
                        // key allready exists, might been updated since last save
                    }
                }
            }
            if (q.item._acl === null || q.item._acl === undefined) {
                q.item._acl = original._acl;
                q.item._version = original._version;
            }
            q.item = this.ensureResource(q.item);
            this.traversejsonencode(q.item);
            q.item = this.encryptentity<T>(q.item);
            var hasUser: Ace = q.item._acl.find(e => e._id === user._id);
            if ((hasUser === null || hasUser === undefined) && q.item._acl.length == 0) {
                if (q.collectionname != "audit") { this._logger.debug("[" + user.username + "] Adding self " + user.username + " to object " + (q.item.name || q.item._name)); }
                q.item.addRight(user._id, user.name, [Rights.full_control]);
            }
            q.item._version = await this.SaveDiff(q.collectionname, original, q.item);
        } else {
            itemReplace = false;
            var _version = await this.SaveUpdateDiff(q, user);
            if ((q.item["$set"]) === undefined) { (q.item["$set"]) = {} };
            (q.item["$set"])._version = _version;
        }

        if (q.collectionname === "users" && q.item._type === "user" && q.item.hasOwnProperty("newpassword")) {
            (q.item as any).passwordhash = await Crypt.hash((q.item as any).newpassword);
            delete (q.item as any).newpassword;
        }
        this._logger.debug("[" + user.username + "] Updating " + (q.item.name || q.item._name) + " in database");
        // await this.db.collection(collectionname).replaceOne({ _id: item._id }, item, options);

        if (q.query === null || q.query === undefined) {
            q.query = { _id: q.item._id };
        }
        var _query: Object = {};
        if (q.collectionname === "files") { q.collectionname = "fs.files"; }
        if (q.collectionname === "fs.files") {
            _query = { $and: [q.query, this.getbasequery(q.jwt, "metadata._acl", [Rights.update])] };
        } else {
            if (!q.collectionname.endsWith("_hist")) {
                _query = { $and: [q.query, this.getbasequery(q.jwt, "_acl", [Rights.update])] };
            } else {
                // todo: enforcer permissions when fetching _hist ?
                _query = q.query;
            }
        }

        q.j = ((q.j as any) === 'true' || q.j === true);
        if ((q.w as any) !== "majority") q.w = parseInt((q.w as any));

        var options: CollectionInsertOneOptions = { w: q.w, j: q.j };
        q.opresult = null;
        try {
            if (itemReplace) {
                q.opresult = await this.db.collection(q.collectionname).replaceOne(_query, q.item, options);
            } else {
                if ((q.item["$set"]) === undefined) { (q.item["$set"]) = {} };
                (q.item["$set"])._modifiedby = user.name;
                (q.item["$set"])._modifiedbyid = user._id;
                (q.item["$set"])._modified = new Date(new Date().toISOString());
                if ((q.item["$inc"]) === undefined) { (q.item["$inc"]) = {} };
                (q.item["$inc"])._version = 1;
                q.opresult = await this.db.collection(q.collectionname).updateOne(_query, q.item, options);
            }
            q.item = this.decryptentity<T>(q.item);
            this.traversejsondecode(q.item);
            q.result = q.item;
        } catch (error) {
            throw error;
        }
        return q;
    }
    /**
    * Update multiple documents in database based on update document
    * @param {any} query MongoDB Query
    * @param  {T} item Update document
    * @param  {string} collectionname Collection containing item
    * @param  {number} w Write Concern ( 0:no acknowledgment, 1:Requests acknowledgment, 2: Requests acknowledgment from 2, 3:Requests acknowledgment from 3)
    * @param  {boolean} j Ensure is written to the on-disk journal.
    * @param  {string} jwt JWT of user who is doing the update, ensuring rights
    * @returns Promise<T>
    */
    async UpdateMany<T extends Base>(q: UpdateManyMessage<T>): Promise<UpdateManyMessage<T>> {
        if (q === null || q === undefined) { throw Error("UpdateManyMessage cannot be null"); }
        if (q.item === null || q.item === undefined) { throw Error("Cannot update null item"); }
        await this.connect();
        var user: TokenUser = Crypt.verityToken(q.jwt);
        if (!this.hasAuthorization(user, q.item, "update")) { throw new Error("Access denied"); }

        if (q.collectionname === "users" && q.item._type === "user" && q.item.hasOwnProperty("newpassword")) {
            (q.item as any).passwordhash = await Crypt.hash((q.item as any).newpassword);
            delete (q.item as any).newpassword;
        }
        for (let key in q.query) {
            if (key === "_id") {
                var id: string = q.query._id;
                delete q.query._id;
                q.query.$or = [{ _id: id }, { _id: safeObjectID(id) }];
            }
        }
        var _query: Object = {};
        if (q.collectionname === "files") { q.collectionname = "fs.files"; }
        if (q.collectionname === "fs.files") {
            _query = { $and: [q.query, this.getbasequery(q.jwt, "metadata._acl", [Rights.update])] };
        } else {
            if (!q.collectionname.endsWith("_hist")) {
                _query = { $and: [q.query, this.getbasequery(q.jwt, "_acl", [Rights.update])] };
            } else {
                // todo: enforcer permissions when fetching _hist ?
                _query = q.query;
            }
        }

        if ((q.item["$set"]) === undefined) { (q.item["$set"]) = {} };
        (q.item["$set"])._modifiedby = user.name;
        (q.item["$set"])._modifiedbyid = user._id;
        (q.item["$set"])._modified = new Date(new Date().toISOString());


        this._logger.debug("[" + user.username + "] UpdateMany " + (q.item.name || q.item._name) + " in database");

        q.j = ((q.j as any) === 'true' || q.j === true);
        if ((q.w as any) !== "majority") q.w = parseInt((q.w as any));
        var options: CollectionInsertOneOptions = { w: q.w, j: q.j };
        try {
            q.opresult = await this.db.collection(q.collectionname).updateMany(_query, q.item, options);
            // if (res.modifiedCount == 0) {
            //     throw Error("item not found!");
            // }
            // if (res.result.ok == 1) {
            //     if (res.modifiedCount == 0) {
            //         throw Error("item not found!");
            //     } else if (res.modifiedCount == 1 || res.modifiedCount == undefined) {
            //         q.item = q.item;
            //     }
            // } else {
            //     throw Error("UpdateOne failed!!!");
            // }
            return q;
        } catch (error) {
            throw error;
        }
        // this.traversejsondecode(item);
        // return item;
    }
    /**
    * Insert or Update depending on document allready exists.
    * @param  {T} item Item to insert or update
    * @param  {string} collectionname Collection containing item
    * @param  {string} uniqeness List of fields to combine for uniqeness
    * @param  {number} w Write Concern ( 0:no acknowledgment, 1:Requests acknowledgment, 2: Requests acknowledgment from 2, 3:Requests acknowledgment from 3)
    * @param  {boolean} j Ensure is written to the on-disk journal.
    * @param  {string} jwt JWT of user who is doing the update, ensuring rights
    * @returns Promise<T>
    */
    async InsertOrUpdateOne<T extends Base>(q: InsertOrUpdateOneMessage<T>): Promise<InsertOrUpdateOneMessage<T>> {
        var query: any = null;
        if (q.uniqeness !== null && q.uniqeness !== undefined && q.uniqeness !== "") {
            query = {};
            var arr = q.uniqeness.split(",");
            arr.forEach(field => {
                if (field.trim() !== "") {
                    query[field] = q.item[field];
                }
            });
        } else {
            query = { _id: q.item._id };
        }
        var exists = await this.query(query, { name: 1 }, 2, 0, null, q.collectionname, q.jwt);
        console.log(JSON.stringify(query, null, 2));
        if (exists.length == 1) {
            q.item._id = exists[0]._id;
        }
        else if (exists.length > 1) {
            throw JSON.stringify(query) + " is not uniqe, more than 1 item in collection matches this";
        }
        var user: TokenUser = Crypt.verityToken(q.jwt);
        if (!this.hasAuthorization(user, q.item, "update")) { throw new Error("Access denied"); }
        // if (q.item._id !== null && q.item._id !== undefined && q.item._id !== "") {
        if (exists.length == 1) {
            this._logger.debug("[" + user.username + "] InsertOrUpdateOne, Updating found one in database");
            var uq = new UpdateOneMessage<T>();
            // uq.query = query; 
            uq.item = q.item; uq.collectionname = q.collectionname; uq.w = q.w; uq.j; uq.jwt = q.jwt;
            uq = await this.UpdateOne(uq);
            q.opresult = uq.opresult;
            q.result = uq.result;
        } else {
            this._logger.debug("[" + user.username + "] InsertOrUpdateOne, Inserting as new in database");
            q.result = await this.InsertOne(q.item, q.collectionname, q.w, q.j, q.jwt);
        }
        return q;
    }
    /**
     * @param  {string} id id of object to delete
     * @param  {string} collectionname collectionname Collection containing item
     * @param  {string} jwt JWT of user who is doing the delete, ensuring rights
     * @returns Promise<void>
     */
    async DeleteOne(id: string | any, collectionname: string, jwt: string): Promise<void> {
        if (id === null || id === undefined || id === "") { throw Error("id cannot be null"); }
        await this.connect();
        var user: TokenUser = Crypt.verityToken(jwt);
        // var original:Base = await this.getbyid(id, collectionname, jwt);
        // if(!original) { throw Error("item not found!"); }
        // if(!this.hasAuthorization(user, original, "delete")) { throw new Error("Access denied"); }
        var _query: any = {};
        if (typeof id === 'string' || id instanceof String) {
            _query = { $and: [{ _id: id }, this.getbasequery(jwt, "_acl", [Rights.delete])] };
            //_query = { $and: [{ _id: { $ne: user._id } }, _query] };
        } else {
            _query = { $and: [{ id }, this.getbasequery(jwt, "_acl", [Rights.delete])] };
            //_query = { $and: [{ _id: { $ne: user._id } }, _query] };
        }


        // var arr = await this.db.collection(collectionname).find(_query).toArray();

        this._logger.debug("[" + user.username + "] Deleting " + id + " in database");
        var res: DeleteWriteOpResultObject = await this.db.collection(collectionname).deleteOne(_query);

        // var res:DeleteWriteOpResultObject = await this.db.collection(collectionname).deleteOne({_id:id});
        // var res:DeleteWriteOpResultObject = await this.db.collection(collectionname).deleteOne(id);
        if (res.deletedCount === 0) { throw Error("item not found!"); }
    }
    /**
     * Helper function used to check if field needs to be encrypted
     * @param  {string[]} keys List of fields that needs to be encrypted
     * @param  {string} key Current field
     * @param  {object=null} value value of field, ensuring we can actully encrypt the field
     * @returns boolean
     */
    private _shouldEncryptValue(keys: string[], key: string, value: object = null): boolean {
        const shouldEncryptThisKey: boolean = keys.includes(key);
        const isString: boolean = typeof value === "string";
        return value && shouldEncryptThisKey && isString;
    }
    /**
     * Enumerate object, encrypting fields that needs to be encrypted
     * @param  {T} item Item to enumerate
     * @returns T Object with encrypted fields
     */
    public encryptentity<T extends Base>(item: T): T {
        if (item == null || item._encrypt === undefined || item._encrypt === null) { return item; }
        var me: DatabaseConnection = this;
        return (Object.keys(item).reduce((newObj, key) => {
            const value: any = item[key];
            try {
                newObj[key] = this._shouldEncryptValue(item._encrypt, key, value) ? Crypt.encrypt(value) : value;
            } catch (err) {
                me._logger.error("encryptentity " + err.message);
                newObj[key] = value;
            }
            return newObj;
        }, item) as T);
    }
    /**
     * Enumerate object, decrypting fields that needs to be decrypted
     * @param  {T} item Item to enumerate
     * @returns T Object with decrypted fields
     */
    public decryptentity<T extends Base>(item: T): T {
        if (item == null || item._encrypt === undefined || item._encrypt === null) { return item; }
        var me: DatabaseConnection = this;
        return (Object.keys(item).reduce((newObj, key) => {
            const value: any = item[key];
            try {
                newObj[key] = this._shouldEncryptValue(item._encrypt, key, value) ? Crypt.decrypt(value) : value;
            } catch (err) {
                me._logger.error("decryptentity " + err.message);
                newObj[key] = value;
            }
            return newObj;
        }, {}) as T);
    }
    /**
     * Create a MongoDB query filtering result based on permission of current user and requested permission
     * @param  {string} jwt JWT of the user creating the query
     * @param  {number[]} bits Permission wanted on objects
     * @returns Object MongoDB query
     */
    private getbasequery(jwt: string, field: string, bits: number[]): Object {
        if (Config.api_bypass_perm_check) {
            return { _id: { $ne: "bum" } };
        }
        var user: TokenUser = Crypt.verityToken(jwt);
        if (user._id === WellknownIds.root) {
            return { _id: { $ne: "bum" } };
        }
        var isme: any[] = [];
        isme.push({ _id: user._id });
        for (var i: number = 0; i < bits.length; i++) {
            bits[i]--; // bitwize matching is from offset 0, when used on bindata
        }
        user.roles.forEach(role => {
            isme.push({ _id: role._id });
        });
        var finalor: any[] = [];
        var q = {};
        // todo: add check for deny's
        q[field] = {
            $elemMatch: {
                rights: { $bitsAllSet: bits },
                deny: false,
                $or: isme
            }
        };
        finalor.push(q);
        if (field === "_acl") {
            var q2 = {};
            q2["value._acl"] = {
                $elemMatch: {
                    rights: { $bitsAllSet: bits },
                    deny: false,
                    $or: isme
                }
            };
            finalor.push(q2);
        }
        // 
        if (bits.length > 0 && (bits[0] + 1) == Rights.read) {
            this._logger.debug("[" + user.username + "] Include isme in base query");
            return { $or: finalor.concat(isme) };
        } else if (bits.length > 0) {
            this._logger.debug("[" + user.username + "] Skip isme in base query, not read (" + bits[0] + ")");
        } else {
            this._logger.debug("[" + user.username + "] Skip isme in base query, bits missing!");
        }
        return { $or: finalor.concat() };
    }
    /**
     * Ensure _type and _acs on object
     * @param  {T} item Object to validate
     * @returns T Validated object
     */
    ensureResource<T extends Base>(item: T): T {
        if (!item.hasOwnProperty("_type") || item._type === null || item._type === undefined) {
            item._type = "unknown";
        }
        item._type = item._type.toLowerCase();
        if (!item._acl) { item._acl = []; }
        item._acl.forEach((a, index) => {
            if (typeof a.rights === "string") {
                item._acl[index].rights = new Binary(Buffer.from(a.rights, "base64"), 0);
            }
        });
        if (item._acl.length === 0) {
            item = Base.assign<T>(item);
            item.addRight(WellknownIds.admins, "admins", [Rights.full_control]);
        } else {
            item = Base.assign<T>(item);
        }
        return item;
    }
    /**
     * Validated user has rights to perform the requested action ( create is missing! )
     * @param  {TokenUser} user User requesting permission
     * @param  {any} item Item permission is needed on
     * @param  {string} action Permission wanted (create, update, delete)
     * @returns boolean Is allowed
     */
    hasAuthorization(user: TokenUser, item: any, action: string): boolean {
        if (Config.api_bypass_perm_check) { return true; }
        if (user._id === WellknownIds.root) { return true; }
        if (action === "create" || action === "delete") {
            if (item._type === "role") {
                if (item.name.toLowerCase() === "users" || item.name.toLowerCase() === "admins" || item.name.toLowerCase() === "workflow") {
                    return false;
                }
            }
            if (item._type === "user") {
                if (item.name === "workflow") {
                    return false;
                }
            }
        }
        if (action === "update" && item._id === WellknownIds.admins && item.name.toLowerCase() !== "admins") {
            return false;
        }
        if (action === "update" && item._id === WellknownIds.users && item.name.toLowerCase() !== "users") {
            return false;
        }
        if (action === "update" && item._id === WellknownIds.root && item.name.toLowerCase() !== "root") {
            return false;
        }
        if (item.userid === user.username || item.userid === user._id || item.user === user.username) {
            return true;
        } else if (item._id === user._id) {
            if (action === "delete") { this._logger.error("[" + user.username + "] hasAuthorization, cannot delete self!"); return false; }
            return true;
        }
        return true;
    }
    replaceAll(target, search, replacement) {
        //var target = this;
        // return target.replace(new RegExp(search, 'g'), replacement);
        return target.split(search).join(replacement);
    };
    /**
     * Helper function to clean item before saving in MongoDB ( normalize ACE rights and remove illegal key $$ )
     * @param  {object} o Item to clean
     * @returns void Clean object
     */
    traversejsonencode(o) {
        var keys = Object.keys(o);
        for (let i = 0; i < keys.length; i++) {
            let key = keys[i];
            if (key.indexOf('.') > -1) {
                try {
                    // var newkey = key.replace(new RegExp('.', 'g'), '____');
                    var newkey = this.replaceAll(key, ".", "____");
                    o[newkey] = o[key];
                    delete o[key];
                    key = newkey;
                } catch (error) {
                }
            }
            if (key.startsWith('$$')) {
                delete o[key];
            } else if (o[key]) {
                if (typeof o[key] == 'string') {
                    if (o[key].length == 24 && o[key].endsWith('Z')) {
                        o[key] = new Date(o[key]);
                    }
                }
                if (typeof (o[key]) == "object") {
                    this.traversejsonencode(o[key]);
                }
            }

        }

    }
    traversejsondecode(o) {
        var keys = Object.keys(o);
        for (let i = 0; i < keys.length; i++) {
            let key = keys[i];
            if (key.indexOf('____') > -1) {
                try {
                    // var newkey = key.replace(new RegExp('____', 'g'), '.');
                    var newkey = this.replaceAll(key, "____", ".");
                    o[newkey] = o[key];
                    delete o[key];
                    key = newkey;
                } catch (error) {
                }
            }
            if (key.startsWith('$$')) {
                delete o[key];
            } else if (o[key]) {
                if (typeof o[key] == 'string') {
                    if (o[key].length == 24 && o[key].endsWith('Z')) {
                        o[key] = new Date(o[key]);
                    }
                }
                if (typeof (o[key]) == "object") {
                    this.traversejsondecode(o[key]);
                }
            }

        }

    }

    async SaveUpdateDiff<T extends Base>(q: UpdateOneMessage<T>, user: TokenUser) {
        var _skip_array: string[] = Config.skip_history_collections.split(",");
        var skip_array: string[] = [];
        _skip_array.forEach(x => skip_array.push(x.trim()));
        if (skip_array.indexOf(q.collectionname) > -1) { return 0; }
        var res = await this.query<T>(q.query, null, 1, 0, null, q.collectionname, q.jwt);
        var name: string = "unknown";
        var _id: string = "";
        if (res.length > 0) {
            var _version = 1;
            var original = res[0];
            name = original.name;
            _id = original._id;
            delete original._modifiedby;
            delete original._modifiedbyid;
            delete original._modified;
            if (original._version != undefined && original._version != null) {
                _version = original._version + 1;
            }
        }
        var updatehist = {
            _modified: new Date(new Date().toISOString()),
            _modifiedby: user.name,
            _modifiedbyid: user._id,
            _created: new Date(new Date().toISOString()),
            _createdby: user.name,
            _createdbyid: user._id,
            name: name,
            id: _id,
            update: q.item,
            _version: _version,
            reason: ""
        }
        await this.db.collection(q.collectionname + '_hist').insertOne(updatehist);
    }
    async SaveDiff(collectionname: string, original: any, item: any) {
        if (item._type == 'instance' && collectionname == 'workflows') return 0;
        if (item._type == 'instance' && collectionname == 'workflows') return 0;
        var _modified = item._modified;
        var _modifiedby = item._modifiedby;
        var _modifiedbyid = item._modifiedbyid;
        var _version = 0;
        var _acl = item._acl;
        var _type = item._type;
        var reason = item._updatereason;
        try {
            var _skip_array: string[] = Config.skip_history_collections.split(",");
            var skip_array: string[] = [];
            _skip_array.forEach(x => skip_array.push(x.trim()));
            if (skip_array.indexOf(collectionname) > -1) { return 0; }

            if (original != null) {
                delete original._modifiedby;
                delete original._modifiedbyid;
                delete original._modified;
                if (original._version != undefined && original._version != null) {
                    _version = original._version + 1;
                }
            }
            var jsondiffpatch = require('jsondiffpatch').create({
                objectHash: function (obj, index) {
                    // try to find an id property, otherwise just use the index in the array
                    return obj.name || obj.id || obj._id || '$$index:' + index;
                }
            });
            var delta: any = null;
            // for backward comp, we cannot assume all objects have an history
            // we create diff from version 0
            // var delta_collections = Config.history_delta_collections.split(',');
            // var full_collections = Config.history_full_collections.split(',');
            // if (delta_collections.indexOf(collectionname) == -1 && full_collections.indexOf(collectionname) == -1) return 0;

            item._version = _version;
            delete item._modifiedby;
            delete item._modifiedbyid;
            delete item._modified;
            delete item._updatereason;

            // if (original != null && _version > 0 && delta_collections.indexOf(collectionname) > -1) {
            if (original != null && _version > 0) {
                delta = jsondiffpatch.diff(original, item);
                if (delta == undefined || delta == null) return 0;
                var deltahist = {
                    _acl: _acl,
                    _type: _type,
                    _modified: _modified,
                    _modifiedby: _modifiedby,
                    _modifiedbyid: _modifiedbyid,
                    _created: _modified,
                    _createdby: _modifiedby,
                    _createdbyid: _modifiedbyid,
                    name: item.name,
                    id: item._id,
                    item: original,
                    delta: delta,
                    _version: _version,
                    reason: reason
                }
                await this.db.collection(collectionname + '_hist').insertOne(deltahist);
            }
            else {
                var fullhist = {
                    _acl: _acl,
                    _type: _type,
                    _modified: _modified,
                    _modifiedby: _modifiedby,
                    _modifiedbyid: _modifiedbyid,
                    _created: _modified,
                    _createdby: _modifiedby,
                    _createdbyid: _modifiedbyid,
                    name: item.name,
                    id: item._id,
                    item: item,
                    _version: _version,
                    reason: reason
                }
                await this.db.collection(collectionname + '_hist').insertOne(fullhist);
            }
            item._modifiedby = _modifiedby;
            item._modifiedbyid = _modifiedbyid;
            item._modified = _modified;
        } catch (error) {
            this._logger.error(error);
        }
        return _version;
    }


}