import * as plugins from './smartdata.plugins'
import { Objectmap } from 'lik'

import { DbCollection } from './smartdata.classes.dbcollection'

/**
 * interface - indicates the database type
 */
export type TDbType = 'mongodb' | 'nedb'

/**
 * interface - indicates the connection status of the db
 */
export type TConnectionStatus = 'disconnected' | 'connected' | 'failed'

export class Db {
    dbType: TDbType
    dbUrl: string
    db: plugins.mongodb.Db
    status: TConnectionStatus
    collections = new Objectmap<DbCollection<any>>()

    constructor(dbUrlArg: string, dbTypeArg: TDbType = 'mongodb') {
        this.dbType = dbTypeArg
        this.dbUrl = dbUrlArg
    }

    // basic connection stuff ----------------------------------------------

    /**
     * connects to the database that was specified during instance creation
     */
    connect(): plugins.q.Promise<any> {
        let done = plugins.q.defer()
        if (this.dbType === 'mongodb') {
            plugins.mongodb.MongoClient.connect(this.dbUrl, (err, db) => {
                if (err) { console.log(err) }
                plugins.assert.equal(null, err)
                this.db = db
                plugins.beautylog.success(`connected to database at ${this.dbUrl}`)
                done.resolve(this.db)
            })
        } else if (this.dbType === 'nedb') {
            this.db = null
        }
        return done.promise
    }

    /**
     * closes the connection to the databse
     */
    close(): plugins.q.Promise<any> {
        let done = plugins.q.defer()
        if (this.dbType === 'mongodb') {
            this.db.close()
        }
        plugins.beautylog.ok(`disconnected to database at ${this.dbUrl}`)
        done.resolve()
        return done.promise
    }

    // advanced communication with the database --------------------------------

    /**
     * gets a collection by name: string
     */
    getCollectionByName<T>(nameArg: string): plugins.q.Promise<DbCollection<T>> {
        let done = plugins.q.defer<DbCollection<any>>()
        let resultCollection = this.collections.find((dbCollectionArg) => {
            return dbCollectionArg.name === nameArg
        })
        if (resultCollection !== null) {
            done.resolve(resultCollection)
        }
        return done.promise
    };

    addCollection(dbCollectionArg: DbCollection<any>) {
        this.collections.add(dbCollectionArg)
    }
    
}