'use strict';

exports = module.exports = {
    get,
    stopTask,
    list,

    getLogs,
    getLogStream
};

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

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

    const [error] = await safe(tasks.stopTask(req.params.taskId));
    if (error) return next(BoxError.toHttpError(error));

    next(new HttpSuccess(204, {}));
}

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

    const [error, task] = await safe(tasks.get(req.params.taskId));
    if (error) return next(BoxError.toHttpError(error));
    if (!task) return next(new HttpError(404, 'task not found'));

    next(new HttpSuccess(200, tasks.removePrivateFields(task)));
}

async function list(req, res, next) {
    const page = typeof req.query.page !== 'undefined' ? parseInt(req.query.page) : 1;
    if (!page || page < 0) return next(new HttpError(400, 'page query param has to be a postive number'));

    const perPage = typeof req.query.per_page !== 'undefined'? parseInt(req.query.per_page) : 25;
    if (!perPage || perPage < 0) return next(new HttpError(400, 'per_page query param has to be a postive number'));

    if (req.query.type && typeof req.query.type !== 'string') return next(new HttpError(400, 'type must be a string'));

    let [error, result] = await safe(tasks.listByTypePaged(req.query.type || null, page, perPage));
    if (error) return next(BoxError.toHttpError(error));

    result = result.map(tasks.removePrivateFields);

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

async function getLogs(req, res, next) {
    assert.strictEqual(typeof req.params.taskId, '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 logStream = tasks.getLogs(req.params.taskId, options);

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

// this route is for streaming logs
async function getLogStream(req, res, next) {
    assert.strictEqual(typeof req.params.taskId, '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: 'json'
    };

    const logStream = tasks.getLogs(req.params.taskId, options);

    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.monotonicTimestamp, JSON.stringify(obj))); // send timestamp as id
    });
    logStream.on('end', res.end.bind(res));
    logStream.on('error', res.end.bind(res, null));
}