#!/usr/bin/node
/* jshint esnext:true */
"use strict";

const amqp = require("amqplib"),
    Promise = require("bluebird"),
    winston = require("winston"),
    loggly = require("winston-loggly-bulk"),
    request = require("request-promise"),
    sleep = require("sleep-promise"),
    jsonapi = require("../orm/jsonapi");

const MADGLORY_TOKEN = process.env.MADGLORY_TOKEN,
    QUEUE = process.env.QUEUE || "grab",
    PROCESS_QUEUE = process.env.PROCESS_QUEUE || "process",
    SAMPLE_QUEUE = process.env.SAMPLE_QUEUE || "sample",
    RABBITMQ_URI = process.env.RABBITMQ_URI || "amqp://localhost",
    LOGGLY_TOKEN = process.env.LOGGLY_TOKEN,
    GRABBERS = parseInt(process.env.GRABBERS) || 4;
if (MADGLORY_TOKEN == undefined) throw "Need an API token";

const logger = new (winston.Logger)({
    transports: [
        new (winston.transports.Console)({
            timestamp: true,
            colorize: true
        })
    ]
});

// loggly integration
if (LOGGLY_TOKEN)
    logger.add(winston.transports.Loggly, {
        inputToken: LOGGLY_TOKEN,
        subdomain: "kvahuja",
        tags: ["backend", "apigrabber", QUEUE],
        json: true
    });

(async () => {
    let rabbit, ch;

    while (true) {
        try {
            rabbit = await amqp.connect(RABBITMQ_URI);
            ch = await rabbit.createChannel();
            await ch.assertQueue(QUEUE, {durable: true});
            await ch.assertQueue(PROCESS_QUEUE, {durable: true});
            break;
        } catch (err) {
            logger.error("error connecting", err);
            await sleep(5000);
        }
    }

    await ch.prefetch(GRABBERS);
    // main queue
    ch.consume(QUEUE, async (msg) => {
        let payload = JSON.parse(msg.content.toString()),
            notify = msg.properties.headers.notify;  // where to send progress report
        if (msg.properties.type == "matches")
            await getAPI(payload, "matches", notify);
        if (msg.properties.type == "samples")
            await getAPI(payload, "samples");

        logger.info("done", payload);
        ch.ack(msg);
    }, { noAck: false });

    // loop over API data pages, notify of progress
    async function getAPI(payload, where, notify="global") {
        let exhausted = false;
        payload.params["page[limit]"] = payload.params["page[limit]"] || 50;
        payload.params["page[offset]"] = payload.params["page[offset]"] || 0;

        while (!exhausted) {
            let opts = {
                uri: "https://api.dc01.gamelockerapp.com/shards/" + payload.region + "/" + where,
                headers: {
                    "X-Title-ID": "semc-vainglory",
                    "Authorization": MADGLORY_TOKEN
                },
                json: true,
                gzip: true,
                time: true,
                forever: true,
                strictSSL: true,
                resolveWithFullResponse: true
            }, failed = false, response;
            opts.qs = payload.params;
            try {
                logger.info("API request", { uri: opts.uri, qs: opts.qs });
                response = await request(opts);
                const data = jsonapi.parse(response.body);
                if (where == "matches")
                    // send match structure
                    await Promise.map(data, (match) =>
                        ch.sendToQueue(PROCESS_QUEUE, new Buffer(JSON.stringify(match)),
                            { persistent: true, type: "match" }));
                if (where == "samples")
                    // forward to sampler
                    await Promise.map(data,
                        (sample) => ch.sendToQueue(SAMPLE_QUEUE,
                            new Buffer(JSON.stringify(sample.attributes.URL)),
                            { persistent: true, type: "sample" }));
                // tell web about progress
                await ch.publish("amq.topic", notify, new Buffer("grab_success"));
            } catch (err) {
                response = err.response;
                if (err.statusCode == 429) {
                    await sleep(1000);
                } else if (err.statusCode == 404) {
                    exhausted = true;
                } else {
                    try {
                        logger.error("API error",
                            { uri: err.options.uri, qs: err.options.qs, error: err.response.body });
                    } catch (whatever) {
                        logger.error("weird API error", err);
                    }
                    exhausted = true;
                }
                failed = true;
            } finally {
                if (response)
                    logger.info("API response",
                        { status: response.statusCode, connection_start: response.timings.connect, connection_end: response.timings.end, ratelimit_remaining: response.headers["x-ratelimit-remaining"] });
            }

            // next page
            if (!failed)
                payload.params["page[offset]"] += payload.params["page[limit]"]
        }
        await ch.publish("amq.topic", notify,
            new Buffer("grab_done"));
    }
})();

process.on("unhandledRejection", err => {
    logger.error("Uncaught Promise Error:", err.stack);
});