'use strict';

const config = require('config');
const util = require('util');
const fs = require('fs-extra');
const snoowrap = require('snoowrap');

require('promise.prototype.finally').shim();
require('array.prototype.flatten').shim();

const reddit = new snoowrap(config.reddit.api);

const curatePosts = require('./curate/posts.js');
const curateUser = require('./curate/user.js');

const interpolate = require('./interpolate.js');

const attachContentInfo = require('./fetch/info.js');
const fetchContent = require('./fetch/content.js');

const archives = require('./archives/archives.js');

const save = require('./save/save.js');
const saveProfileDetails = require('./save/profileDetails.js');

const args = require('./cli.js');

if(!(args.users && args.users.length) && !(args.posts && args.posts.length)) {
    return console.log('\x1b[31m%s\x1b[0m', 'Please supply at least one user with --user <user> or one post with --post <post-id>. See --help for more options.');
}

Promise.resolve().then(() => {
    if(args.users) {
        return getUserPosts(args.users);
    }

    return [];
}).then(userPosts => {
    if(args.posts) {
        return getPosts(args.posts).then(posts => posts.concat(userPosts));
    }

    return userPosts;
}).then(posts => {
    return curatePosts(posts, args.ignore).slice(0, args.limit);
}).then(posts => {
    return attachContentInfo(posts).then(info => posts);
}).then(posts => {
    return fetchContent(posts);
}).catch(error => {
    return console.error(error);
});

function getUserPosts(usernames) {
    return usernames.reduce((chain, username) => {
        return chain.then(accPosts => {
            return reddit.getUser(username).fetch().then(curateUser).then(saveProfileDetails).then(user => ({
                user,
                accPosts
            }));
        }).then(({user, accPosts}) => {
            return reddit.getUser(username).getSubmissions({
                sort: args.sort,
                limit: Infinity
            }).then(posts => ({
                user,
                accPosts: accPosts.concat(posts)
            }));
        }).then(({user, accPosts}) => {
            if(args.archives || config.fetch.archives.search) {
                return getArchivePostIds(username, accPosts.map(post => post.id)).then(postIds => {
                    return Promise.all(postIds.map(postId => {
                        return reddit.getSubmission(postId).fetch();
                    }));
                }).then(archivedPosts => {
                    return {
                        user,
                        accPosts: accPosts.concat(archivedPosts)
                    };
                });
            }

            return {user, accPosts};
        }).then(({user, accPosts}) => {
            return accPosts.map(post => Object.assign(post, {user}));
        });
    }, Promise.resolve([]));
};

function getPosts(postIds) {
    return postIds.reduce((chain, postId) => {
        return chain.then(acc => {
            return reddit.getSubmission(postId).fetch().then(post => ({post, acc}));
        }).then(({post, acc}) => {
            if(acc.users[post.author.name]) {
                return {post, acc, user: acc.users[post.author.name]}
            }

            if(post.author.name === '[deleted]') {
                return {post, acc, user: {name: '[deleted]'}};
            }

            return reddit.getUser(post.author.name).fetch().then(curateUser).then(saveProfileDetails).then(user => ({post, acc, user}));
        }).then(({post, acc, user}) => {
            post.user = user;
            acc.posts.push(post);

            // keep track of users to prevent fetching one user multiple times
            acc.users[user.name] = user;

            return acc;
        });
    }, Promise.resolve({
        posts: [],
        users: {}
    })).then(({posts, users}) => {
        return posts;
    });
};

function getArchivePostIds(username, exclude) {
    console.log('Searching archives for posts...');

    return Promise.all(config.fetch.archives.reddit.map(source => archives[source](username))).then(postIds => postIds.flatten()).then(postIds => {
        return exclude ? postIds.filter(postId => !exclude.includes(postId)) : postIds;
    }).then(postIds => {
        console.log(`Found ${postIds.length} unique archived posts`);

        return postIds;
    });
};