var router = require('express').Router();
var mongoose = require('mongoose');
var Comment = mongoose.model('Comment');
var User = mongoose.model('User');
var auth = require('../auth');

// return an article's comments
router.get('/:article/comments', auth.optional, function (req, res, next) {
    Promise.resolve(req.payload ? User.findById(req.payload.id) : null).then(function (user) {
        return req.article.populate({
            path: 'comments',
            populate: {
                path: 'author'
            },
            options: {
                sort: {
                    createdAt: 'desc'
                }
            }
        }).then(function (article) {
            return res.json({
                comments: req.article.comments.map(function (comment) {
                    return comment.toJSONFor(user);
                })
            });
        });
    }).catch(next);
});

// create a new comment
router.post('/:article/comments', auth.required, function (req, res, next) {
    User.findById(req.payload.id).then(function (user) {
        if (!user) {
            return res.sendStatus(401);
        }
        var comment = new Comment(req.body.comment);
        comment.article = req.article;
        comment.author = user;

        return comment.save().then(function () {
            req.article.comments.push(comment);

            return req.article.save().then(function (article) {
                res.json({ comment: comment.toJSONFor(user) });
            });
        });
    }).catch(next);
});

router.delete('/:article/comments/:comment', auth.required, function (req, res, next) {
    if (req.comment.author.toString() === req.payload.id.toString()) {
        req.article.comments.remove(req.comment._id);
        req.article.save()
            .then(Comment.find({ _id: req.comment._id }).remove().exec())
            .then(function () {
                res.sendStatus(204);
            });
    } else {
        res.sendStatus(403);
    }
});

module.exports = router;