'use strict';

exports = module.exports = {
    reboot,
    isRebootRequired,
    getDisks,
    getDiskUsage,
    updateDiskUsage,
    getMemory,
    getLogs,
    getLogStream,
    getSystemGraphs,
    getBlockDevices,
    getCpus,
    getDmi
};

const assert = require('assert'),
    BoxError = require('../boxerror.js'),
    graphs = require('../graphs.js'),
    HttpError = require('connect-lastmile').HttpError,
    HttpSuccess = require('connect-lastmile').HttpSuccess,
    safe = require('safetydance'),
    system = require('../system.js');

async function reboot(req, res, next) {
    // Finish the request, to let the appstore know we triggered the reboot
    next(new HttpSuccess(202, {}));

    await safe(system.reboot());
}

async function isRebootRequired(req, res, next) {
    const [error, rebootRequired] = await safe(system.isRebootRequired());
    if (error) return next(BoxError.toHttpError(error));

    next(new HttpSuccess(200, { rebootRequired }));
}

async function getDisks(req, res, next) {
    const [getDisksError, disks] = await safe(system.getDisks());
    if (getDisksError) return next(BoxError.toHttpError(getDisksError));

    let [getSwapsError, swaps] = await safe(system.getSwaps());
    if (getSwapsError) return next(BoxError.toHttpError(getSwapsError));

    next(new HttpSuccess(200, { disks, swaps }));
}

async function getDiskUsage(req, res, next) {
    const [error, result] = await safe(system.getDiskUsage());
    if (error) return next(BoxError.toHttpError(error));

    next(new HttpSuccess(200, { usage: result }));
}

async function updateDiskUsage(req, res, next) {
    const [error, taskId] = await safe(system.startUpdateDiskUsage());
    if (error) return next(BoxError.toHttpError(error));

    next(new HttpSuccess(201, { taskId }));
}

async function getMemory(req, res, next) {
    const [error, result] = await safe(system.getMemory());
    if (error) return next(BoxError.toHttpError(error));

    next(new HttpSuccess(200, result));
}

async function getLogs(req, res, next) {
    assert.strictEqual(typeof req.params.unit, 'string');

    const lines = 'lines' in req.query ? parseInt(req.query.lines, 10) : 10; // we ignore last-event-id
    if (isNaN(lines)) return next(new HttpError(400, 'lines must be a number'));

    const options = {
        lines: lines,
        follow: false,
        format: req.query.format || 'json'
    };

    const [error, logStream] = await safe(system.getLogs(req.params.unit, options));
    if (error) return next(BoxError.toHttpError(error));

    res.writeHead(200, {
        'Content-Type': 'application/x-logs',
        'Content-Disposition': `attachment; filename="${req.params.unit}.log"`,
        'Cache-Control': 'no-cache',
        'X-Accel-Buffering': 'no' // disable nginx buffering
    });
    logStream.pipe(res);
}

async function getLogStream(req, res, next) {
    assert.strictEqual(typeof req.params.unit, 'string');

    const lines = 'lines' in req.query ? parseInt(req.query.lines, 10) : 10; // we ignore last-event-id
    if (isNaN(lines)) return next(new HttpError(400, 'lines must be a valid number'));

    function sse(id, data) { return 'id: ' + id + '\ndata: ' + data + '\n\n'; }

    if (req.headers.accept !== 'text/event-stream') return next(new HttpError(400, 'This API call requires EventStream'));

    const options = {
        lines: lines,
        follow: true,
        format: req.query.format || 'json'
    };

    const [error, logStream] = await safe(system.getLogs(req.params.unit, options));
    if (error) return next(BoxError.toHttpError(error));

    res.writeHead(200, {
        'Content-Type': 'text/event-stream',
        'Cache-Control': 'no-cache',
        'Connection': 'keep-alive',
        'X-Accel-Buffering': 'no', // disable nginx buffering
        'Access-Control-Allow-Origin': '*'
    });
    res.write('retry: 3000\n');
    res.on('close', logStream.close);
    logStream.on('data', function (data) {
        const obj = JSON.parse(data);
        res.write(sse(obj.realtimeTimestamp, JSON.stringify(obj))); // send timestamp as id
    });
    logStream.on('end', res.end.bind(res));
    logStream.on('error', res.end.bind(res, null));
}

async function getSystemGraphs(req, res, next) {
    if (!req.query.fromMinutes || !parseInt(req.query.fromMinutes)) return next(new HttpError(400, 'fromMinutes must be a number'));

    const fromMinutes = parseInt(req.query.fromMinutes);
    const noNullPoints = !!req.query.noNullPoints;
    const [error, result] = await safe(graphs.getSystem(fromMinutes, noNullPoints));
    if (error) return next(new HttpError(500, error));

    next(new HttpSuccess(200, result));
}

async function getBlockDevices(req, res, next) {
    const [error, devices] = await safe(system.getBlockDevices());
    if (error) return next(new HttpError(500, error));

    next(new HttpSuccess(200, { devices }));
}

async function getCpus(req, res, next) {
    const [error, cpus] = await safe(system.getCpus());
    if (error) return next(BoxError.toHttpError(error));

    next(new HttpSuccess(200, { cpus }));
}

async function getDmi(req, res, next) {
    const [error, dmi] = await safe(system.getDmi());
    if (error) return next(BoxError.toHttpError(error));

    next(new HttpSuccess(200, { dmi }));
}