const _ = require('lodash');
const WebSocket = require ('ws');

const WorkerState = require('../core/WorkerState');//singleton
const WebWorker = require('../core/WebWorker');//singleton
const log = new (require('../core/AppLogger'))().log;//singleton
const utils = require('../core/utils');

const cleanPeriod = 1*60*1000;//1 минута, не менять!
const cleanUnusedTokenTimeout = 5*60*1000;//5 минут
const closeSocketOnIdle = 5*60*1000;//5 минут

class WebSocketController {
    constructor(wss, config) {
        this.config = config;
        this.isDevelopment = (config.branch == 'development');

        this.freeAccess = (config.accessPassword === '');
        this.accessTimeout = config.accessTimeout*60*1000;
        this.accessMap = new Map();

        this.workerState = new WorkerState();
        this.webWorker = new WebWorker(config);

        this.wss = wss;

        wss.on('connection', (ws) => {
            ws.on('message', (message) => {
                this.onMessage(ws, message.toString());
            });

            ws.on('error', (err) => {
                log(LM_ERR, err);
            });
        });

        setTimeout(() => { this.periodicClean(); }, cleanPeriod);
    }

    periodicClean() {
        try {
            const now = Date.now();

            //почистим accessMap
            if (!this.freeAccess) {
                for (const [accessToken, accessRec] of this.accessMap) {
                    if (   !(accessRec.used > 0 || now - accessRec.time < cleanUnusedTokenTimeout)
                        || !(this.accessTimeout === 0 || now - accessRec.time < this.accessTimeout)
                        ) {
                        this.accessMap.delete(accessToken);
                    }
                }
            }

            //почистим ws-клиентов
            this.wss.clients.forEach((ws) => {
                if (!ws.lastActivity || now - ws.lastActivity > closeSocketOnIdle - 50) {
                    ws.terminate();
                }
            });
        } finally {
            setTimeout(() => { this.periodicClean(); }, cleanPeriod);
        }
    }

    hasAccess(accessToken) {
        if (this.freeAccess)
            return true;

        const accessRec = this.accessMap.get(accessToken);
        if (accessRec) {
            const now = Date.now();

            if (this.accessTimeout === 0 || now - accessRec.time < this.accessTimeout) {
                accessRec.used++;
                accessRec.time = now;
                return true;
            }
        }

        return false;
    }

    async onMessage(ws, message) {
        let req = {};
        try {
            if (this.isDevelopment) {
                log(`WebSocket-IN:  ${message.substr(0, 4000)}`);
            }

            req = JSON.parse(message);

            ws.lastActivity = Date.now();
            
            //pong for WebSocketConnection
            this.send({_rok: 1}, req, ws);

            //access
            if (!this.hasAccess(req.accessToken)) {
                await utils.sleep(500);
                const salt = utils.randomHexString(32);
                const accessToken = utils.getBufHash(this.config.accessPassword + salt, 'sha256', 'hex');
                this.accessMap.set(accessToken, {time: Date.now(), used: 0});

                this.send({error: 'need_access_token', salt}, req, ws);
                return;
            }

            //api
            switch (req.action) {
                case 'test':
                    await this.test(req, ws); break;
                case 'logout':
                    await this.logout(req, ws); break;
                case 'get-config':
                    await this.getConfig(req, ws); break;
                case 'get-worker-state':
                    await this.getWorkerState(req, ws); break;
                case 'search':
                    await this.search(req, ws); break;
                case 'get-author-book-list':
                    await this.getAuthorBookList(req, ws); break;
                case 'get-series-book-list':
                    await this.getSeriesBookList(req, ws); break;
                case 'get-genre-tree':
                    await this.getGenreTree(req, ws); break;
                case 'get-book-link':
                    await this.getBookLink(req, ws); break;
                case 'get-book-info':
                    await this.getBookInfo(req, ws); break;

                case 'get-inpx-file':
                    await this.getInpxFile(req, ws); break;

                default:
                    throw new Error(`Action not found: ${req.action}`);
            }
        } catch (e) {
            this.send({error: e.message}, req, ws);
        }
    }

    send(res, req, ws) {
        if (ws.readyState == WebSocket.OPEN) {
            ws.lastActivity = Date.now();
            let r = res;
            if (req.requestId)
                r = Object.assign({requestId: req.requestId}, r);

            const message = JSON.stringify(r);
            ws.send(message);

            if (this.isDevelopment) {
                log(`WebSocket-OUT: ${message.substr(0, 200)}`);
            }

        }
    }

    //Actions ------------------------------------------------------------------
    async test(req, ws) {
        this.send({message: `${this.config.name} project is awesome`}, req, ws);
    }

    async logout(req, ws) {
        this.accessMap.delete(req.accessToken);
        this.send({success: true}, req, ws);
    }

    async getConfig(req, ws) {
        const config = _.pick(this.config, this.config.webConfigParams);
        config.dbConfig = await this.webWorker.dbConfig();
        config.freeAccess = this.freeAccess;

        this.send(config, req, ws);
    }

    async getWorkerState(req, ws) {
        if (!req.workerId)
            throw new Error(`key 'workerId' is empty`);

        const state = this.workerState.getState(req.workerId);
        this.send((state ? state : {}), req, ws);
    }

    async search(req, ws) {
        if (!req.query)
            throw new Error(`query is empty`);
        if (!req.from)
            throw new Error(`from is empty`);

        const result = await this.webWorker.search(req.from, req.query);

        this.send(result, req, ws);
    }

    async getAuthorBookList(req, ws) {
        const result = await this.webWorker.getAuthorBookList(req.authorId);

        this.send(result, req, ws);
    }

    async getSeriesBookList(req, ws) {
        const result = await this.webWorker.getSeriesBookList(req.series);

        this.send(result, req, ws);
    }

    async getGenreTree(req, ws) {
        const result = await this.webWorker.getGenreTree();

        this.send(result, req, ws);
    }

    async getBookLink(req, ws) {
        if (!utils.hasProp(req, 'bookUid'))
            throw new Error(`bookUid is empty`);

        const result = await this.webWorker.getBookLink(req.bookUid);

        this.send(result, req, ws);
    }

    async getBookInfo(req, ws) {
        if (!utils.hasProp(req, 'bookUid'))
            throw new Error(`bookUid is empty`);

        const result = await this.webWorker.getBookInfo(req.bookUid);

        this.send(result, req, ws);
    }

    async getInpxFile(req, ws) {
        if (!this.config.allowRemoteLib)
            throw new Error('Remote lib access disabled');

        const result = await this.webWorker.getInpxFile(req);

        this.send(result, req, ws);
    }

}

module.exports = WebSocketController;