'use strict';

const config = require('config');
const Promise = require('bluebird');

const saveProfileDetails = require('../save/profileDetails.js');
const fetchItem = require('./item.js');
const interpolate = require('../interpolate.js');
const save = require('../save/save.js');
const textToStream = require('../save/textToStream.js');
const saveMeta = require('../save/meta.js');
const mux = require('../save/mux.js');
const writeToIndex = require('../save/writeToIndex.js');

async function getStreams(item, post) {
    if (item.self) {
        return [textToStream(item.text)];
    }

    const sources = item.mux ? [item.url].concat(item.mux) : [item.url];
    const streams = await Promise.map(sources, source => fetchItem(source, 0, post));

    if (streams.filter(stream => stream).length > 0) {
        return streams;
    }

    return null;
}

async function addMeta(filepath, item, post, user, ep) {
    if (item.type !== 'image/jpeg') {
        return false;
    }

    const meta = Object.entries(config.library.meta).reduce((acc, [key, value]) => {
        const interpolatedValue = interpolate(value, user, post, item);

        return interpolatedValue ? { ...acc, [key]: interpolatedValue } : acc;
    }, {});

    if (Object.keys(meta).length > 0) {
        return saveMeta(filepath, meta, ep);
    }

    return false;
}

function getFilepath(item, post, user) {
    const type = item.type.split('/')[0];

    return post.content.album
        ? interpolate(config.library.album[type], user, post, item)
        : interpolate(config.library[type], user, post, item);
}

async function fetchSaveContent(user, ep, args) {
    const profilePaths = await saveProfileDetails(user, args);

    const posts = await Promise.map(user.posts, async (post) => {
        await Promise.reduce(post.content.items, async (accItems, originalItem, index) => {
            const item = { ...originalItem, index };
            const streams = await getStreams(item, post);

            // no streams, ignore item
            if (!streams || streams.length <= 0) {
                return accItems;
            }

            const filepath = getFilepath(item, post, user);
            const sourcePaths = await save(filepath, streams, item, post);

            if (item.mux) {
                await mux(filepath, sourcePaths, item);
            }

            await addMeta(filepath, item, post, user, ep);

            return sourcePaths;
        }, []);

        return post;
    }, {
        concurrency: config.fetch.concurrency,
    });

    return writeToIndex(posts, profilePaths, user, args);
}

module.exports = fetchSaveContent;