'use strict';

exports = module.exports = {
    getSystem,
    getContainerStats
};

const apps = require('./apps.js'),
    assert = require('assert'),
    BoxError = require('./boxerror.js'),
    docker = require('./docker.js'),
    os = require('os'),
    safe = require('safetydance'),
    services = require('./services.js'),
    superagent = require('superagent');

// for testing locally: curl 'http://${graphite-ip}:8000/graphite-web/render?format=json&from=-1min&target=absolute(collectd.localhost.du-docker.capacity-usage)'
// the datapoint is (value, timestamp) https://graphite.readthedocs.io/en/latest/
async function getGraphiteUrl() {
    const [error, result] = await safe(docker.inspect('graphite'));
    if (error && error.reason === BoxError.NOT_FOUND) return { status: exports.SERVICE_STATUS_STOPPED };
    if (error) throw error;

    const ip = safe.query(result, 'NetworkSettings.Networks.cloudron.IPAddress', null);
    if (!ip) throw new BoxError(BoxError.INACTIVE, 'Error getting IP of graphite service');

    return `http://${ip}:8000/graphite-web/render`;
}

async function getContainerStats(name, fromMinutes, noNullPoints) {
    assert.strictEqual(typeof name, 'string');
    assert.strictEqual(typeof fromMinutes, 'number');
    assert.strictEqual(typeof noNullPoints, 'boolean');

    const timeBucketSize = fromMinutes > (24 * 60) ? (6*60) : 5;
    const graphiteUrl = await getGraphiteUrl();

    // https://collectd.org/wiki/index.php/Data_source . the gauge is point in time value. counter is the change of value
    const targets = [
        `summarize(collectd.localhost.docker-stats-${name}.gauge-cpu-perc, "${timeBucketSize}min", "avg")`,
        `summarize(collectd.localhost.docker-stats-${name}.gauge-mem-used, "${timeBucketSize}min", "avg")`,
        // `summarize(collectd.localhost.docker-stats-${name}.gauge-mem-max, "${timeBucketSize}min", "avg")`,
        `summarize(collectd.localhost.docker-stats-${name}.counter-blockio-read, "${timeBucketSize}min", "sum")`,
        `summarize(collectd.localhost.docker-stats-${name}.counter-blockio-write, "${timeBucketSize}min", "sum")`,
        `summarize(collectd.localhost.docker-stats-${name}.counter-network-read, "${timeBucketSize}min", "sum")`,
        `summarize(collectd.localhost.docker-stats-${name}.counter-network-write, "${timeBucketSize}min", "sum")`,
        `summarize(collectd.localhost.docker-stats-${name}.gauge-blockio-read, "${fromMinutes}min", "max")`,
        `summarize(collectd.localhost.docker-stats-${name}.gauge-blockio-write, "${fromMinutes}min", "max")`,
        `summarize(collectd.localhost.docker-stats-${name}.gauge-network-read, "${fromMinutes}min", "max")`,
        `summarize(collectd.localhost.docker-stats-${name}.gauge-network-write, "${fromMinutes}min", "max")`,
    ];

    const results = [];

    for (const target of targets) {
        const query = {
            target: target,
            format: 'json',
            from: `-${fromMinutes}min`,
            until: 'now',
            noNullPoints: !!noNullPoints
        };

        const [error, response] = await safe(superagent.get(graphiteUrl).query(query).timeout(30 * 1000).ok(() => true));
        if (error) throw new BoxError(BoxError.NETWORK_ERROR, error.message);
        if (response.status !== 200) throw new BoxError(BoxError.EXTERNAL_ERROR, `Unknown error with ${target}: ${response.status} ${response.text}`);

        results.push(response.body[0] && response.body[0].datapoints ? response.body[0].datapoints : []);
    }

    // results are datapoints[[value, ts], [value, ts], ...];
    return {
        cpu: results[0],
        memory: results[1],
        blockRead: results[2],
        blockWrite: results[3],
        networkRead: results[4],
        networkWrite: results[5],
        blockReadTotal: results[6][0] && results[6][0][0] ? results[6][0][0] : 0,
        blockWriteTotal: results[7][0] && results[7][0][0] ? results[7][0][0] : 0,
        networkReadTotal: results[8][0] && results[8][0][0] ? results[8][0][0] : 0,
        networkWriteTotal: results[9][0] && results[9][0][0] ? results[9][0][0] : 0,
        cpuCount: os.cpus().length
    };
}

async function getSystem(fromMinutes, noNullPoints) {
    assert.strictEqual(typeof fromMinutes, 'number');
    assert.strictEqual(typeof noNullPoints, 'boolean');

    const timeBucketSize = fromMinutes > (24 * 60) ? (6*60) : 5;
    const graphiteUrl = await getGraphiteUrl();

    const cpuQuery = `summarize(sum(collectd.localhost.aggregation-cpu-sum.cpu-system, collectd.localhost.aggregation-cpu-sum.cpu-user), "${timeBucketSize}min", "avg")`;
    const memoryQuery = `summarize(collectd.localhost.memory.memory-used, "${timeBucketSize}min", "avg")`;

    const query = {
        target: [ cpuQuery, memoryQuery ],
        format: 'json',
        from: `-${fromMinutes}min`,
        until: 'now'
    };

    const [memCpuError, memCpuResponse] = await safe(superagent.get(graphiteUrl).query(query).timeout(30 * 1000).ok(() => true));
    if (memCpuError) throw new BoxError(BoxError.NETWORK_ERROR, memCpuError.message);
    if (memCpuResponse.status !== 200) throw new BoxError(BoxError.EXTERNAL_ERROR, `Unknown error: ${memCpuResponse.status} ${memCpuResponse.text}`);

    const appResponses = {};
    for (const app of await apps.list()) {
        appResponses[app.id] = await getContainerStats(app.id, fromMinutes, noNullPoints);
    }

    const serviceResponses = {};
    for (const serviceId of await services.listServices()) {
        serviceResponses[serviceId] = await getContainerStats(serviceId, fromMinutes, noNullPoints);
    }

    return {
        cpu: memCpuResponse.body[0] && memCpuResponse.body[0].datapoints ? memCpuResponse.body[0].datapoints : [],
        memory: memCpuResponse.body[1] && memCpuResponse.body[1].datapoints ? memCpuResponse.body[1].datapoints : [],
        apps: appResponses,
        services: serviceResponses,
        cpuCount: os.cpus().length
    };
}