const fs = require('fs-extra');
const path = require('path');

const express = require('express');
const compression = require('compression');
const http = require('http');
const WebSocket = require ('ws');

const ayncExit = new (require('./core/AsyncExit'))();
const utils = require('./core/utils');

const maxPayloadSize = 50;//in MB

let log;
let config;
let argv;
let branch = '';
const argvStrings = ['lib-dir', 'inpx'];

function showHelp() {
    console.log(utils.versionText(config));
    console.log(
`Usage: ${config.name} [options]

Options:
  --help              Print ${config.name} command line options
  --lib-dir=<dirpath> Set library directory, default: the same as ${config.name} executable's
  --inpx=<filepath>   Set INPX collection file, default: the one that found in library dir
  --recreate          Force recreation of the search database on start
`
    );
}

async function init() {
    argv = require('minimist')(process.argv.slice(2), {string: argvStrings});

    //config
    const configManager = new (require('./config'))();//singleton
    await configManager.init();
    //configManager.userConfigFile = argv.config;
    await configManager.load();
    config = configManager.config;
    branch = config.branch;

    //logger
    const appLogger = new (require('./core/AppLogger'))();//singleton
    await appLogger.init(config);
    log = appLogger.log;

    //dirs
    await fs.ensureDir(config.dataDir);
    await fs.ensureDir(config.tempDir);
    await fs.emptyDir(config.tempDir);

    //web app
    const createWebApp = require('./createWebApp');
    await createWebApp(config);

    //cli
    if (argv.help) {
        showHelp();
        ayncExit.exit(0);
    } else {
        log(utils.versionText(config));
        log('Initializing');
    }

    const libDir = argv['lib-dir'];
    if (libDir) {
        if (await fs.pathExists(libDir)) {
            config.libDir = libDir;
        } else {
            throw new Error(`Directory "${libDir}" not exists`);
        }
    } else {
        config.libDir = config.execDir;
    }

    if (argv.inpx) {
        if (await fs.pathExists(argv.inpx)) {
            config.inpxFile = argv.inpx;
        } else {
            throw new Error(`File "${argv.inpx}" not found`);
        }
    } else {
        const inpxFiles = [];
        await utils.findFiles((file) => {
            if (path.extname(file) == '.inpx')
                inpxFiles.push(file);
        }, config.libDir, false);

        if (inpxFiles.length) {
            if (inpxFiles.length == 1) {
                config.inpxFile = inpxFiles[0];
            } else {
                throw new Error(`Found more than one .inpx files: \n${inpxFiles.join('\n')}`);
            }
        } else {
            throw new Error(`No .inpx files found here: ${config.libDir}`);
        }
    }

    config.recreateDb = argv.recreate || false;

    //app
    const appDir = `${config.publicDir}/app`;
    const appNewDir = `${config.publicDir}/app_new`;
    if (await fs.pathExists(appNewDir)) {
        await fs.remove(appDir);
        await fs.move(appNewDir, appDir);
    }
}

async function main() {
    const log = new (require('./core/AppLogger'))().log;//singleton

    //server
    const app = express();

    const server = http.createServer(app);
    const wss = new WebSocket.Server({ server, maxPayload: maxPayloadSize*1024*1024 });

    const serverConfig = Object.assign({}, config, config.server);

    let devModule = undefined;
    if (serverConfig.branch == 'development') {
        const devFileName = './dev.js'; //require ignored by pkg -50Mb executable size
        devModule = require(devFileName);
        devModule.webpackDevMiddleware(app);
    }

    app.use(compression({ level: 1 }));
    //app.use(express.json({limit: `${maxPayloadSize}mb`}));
    if (devModule)
        devModule.logQueries(app);

    initStatic(app, config);
    
    const { WebSocketController } = require('./controllers');
    new WebSocketController(wss, config);

    if (devModule) {
        devModule.logErrors(app);
    } else {
        app.use(function(err, req, res, next) {// eslint-disable-line no-unused-vars
            log(LM_ERR, err.stack);
            res.sendStatus(500);
        });
    }

    server.listen(serverConfig.port, serverConfig.ip, () => {
        log(`Server is ready on http://${serverConfig.ip}:${serverConfig.port}`);
    });
}

function initStatic(app, config) {
    const WebWorker = require('./core/WebWorker');//singleton
    const webWorker = new WebWorker(config);

    //загрузка или восстановление файлов в /files, при необходимости
    app.use(async(req, res, next) => {
        if ((req.method !== 'GET' && req.method !== 'HEAD') ||
            !(req.path.indexOf('/files/') === 0)
            ) {
            return next();
        }

        const publicPath = `${config.publicDir}${req.path}`;

        let downFileName = '';
        //восстановим
        try {
            if (!await fs.pathExists(publicPath)) {
                downFileName = await webWorker.restoreBookFile(publicPath);
            } else {
                downFileName = await webWorker.getDownFileName(publicPath);                    
            }
        } catch(e) {
            //quiet
        }

        if (downFileName)
            res.downFileName = downFileName;

        return next();
    });

    //заголовки при отдаче
    const filesDir = `${config.publicDir}/files`;
    app.use(express.static(config.publicDir, {
        maxAge: '30d',

        setHeaders: (res, filePath) => {
            if (path.dirname(filePath) == filesDir) {
                res.set('Content-Encoding', 'gzip');

                if (res.downFileName)
                    res.set('Content-Disposition', `inline; filename*=UTF-8''${encodeURIComponent(res.downFileName)}`);
            }
        },
    }));
}

(async() => {
    try {
        await init();
        await main();
    } catch (e) {
        if (log)
            log(LM_FATAL, (branch == 'development' ? e.stack : e.message));
        else
            console.error(branch == 'development' ? e.stack : e.message);

        ayncExit.exit(1);
    }
})();