(function () {

    "use strict";

    var Post,
        Posts,
        _ = require('underscore'),
        when = require('when'),
        Showdown = require('showdown'),
        converter = new Showdown.converter(),
        User = require('./user').User,
        GhostBookshelf = require('./base');

    Post = GhostBookshelf.Model.extend({

        tableName: 'posts',

        hasTimestamps: true,

        defaults: {
            status: 'draft'
        },

        initialize: function () {
            this.on('creating', this.creating, this);
            this.on('saving', this.saving, this);
        },

        saving: function () {
            if (!this.get('title')) {
                throw new Error('Post title cannot be blank');
            }
            this.set('content_html', converter.makeHtml(this.get('content')));

            // refactoring of ghost required in order to make these details available here
            // this.set('language', this.get('language') || ghost.config().defaultLang);
            // this.set('status', this.get('status') || ghost.statuses().draft);
        },

        creating: function () {
            if (!this.get('slug')) {
                this.generateSlug();
            }
        },

        generateSlug: function () {
            return this.set('slug', this.get('title').replace(/\:/g, '').replace(/\s/g, '-').toLowerCase());
        },

        user: function () {
            return this.belongsTo(User, 'created_by');
        },

        author: function () {
            return this.belongsTo(User, 'author_id');
        }

    }, {

        /**
         * Find results by page - returns an object containing the
         * information about the request (page, limit), along with the
         * info needed for pagination (pages, total).
         *
         * {
         *   posts: [
         *    {...}, {...}, {...}
         *   ],
         *   page: __,
         *   limit: __,
         *   pages: __,
         *   total: __
         * }
         *
         * @params opts
         */
        findPage: function (opts) {
            var postCollection;

            // Allow findPage(n)
            if (_.isString(opts) || _.isNumber(opts)) {
                opts = {page: opts};
            }

            opts = _.extend({
                page: 1,
                limit: 15,
                where: {},
                status: 'published',
                orderBy: 'published_at DESC'
            }, opts);

            postCollection = Posts.forge();

            // Unless `all` is passed as an option, filter on
            // the status provided.
            if (opts.status !== 'all') {
                opts.where.status = opts.status;
            }

            // If there are where conditionals specified, add those
            // to the query.
            if (opts.where) {
                postCollection.query('where', opts.where);
            }

            // Set the limit & offset for the query, fetching
            // with the opts (to specify any eager relations, etc.)
            // Omitting the `page`, `limit`, `where` just to be sure
            // aren't used for other purposes.
            return postCollection
                .query('limit', opts.limit)
                .query('offset', opts.limit * (opts.page - 1))
                .query('orderBy', opts.orderBy)
                .fetch(_.omit(opts, 'page', 'limit', 'where', 'status', 'orderBy'))
                .then(function (collection) {
                    var qb;

                    // After we're done, we need to figure out what
                    // the limits are for the pagination values.
                    qb = GhostBookshelf.Knex(_.result(collection, 'tableName'));

                    if (opts.where) {
                        qb.where(opts.where);
                    }

                    return qb.count(_.result(collection, 'idAttribute')).then(function (resp) {
                        var totalPosts = resp[0].aggregate;
                        return {
                            posts: collection.toJSON(),
                            page: opts.page,
                            limit: opts.limit,
                            pages: Math.ceil(totalPosts / opts.limit),
                            total: totalPosts
                        };
                    });
                });
        },

        permissable: function (postModelOrId, userId, action_type, userPermissions) {
            var self = this,
                hasPermission,
                postModel = postModelOrId;

            // If we passed in an id instead of a model, get the model
            // then check the permissions
            if (_.isNumber(postModelOrId) || _.isString(postModelOrId)) {
                return this.read({id: postModelOrId}).then(function (foundPostModel) {
                    return self.permissable(foundPostModel, userId, action_type, userPermissions);
                });
            }

            // TODO: This logic is temporary, will probably need to be updated

            hasPermission = _.any(userPermissions, function (perm) {
                if (perm.get('object_type') !== 'post') {
                    return false;
                }

                // True, if no object_id specified, or it matches
                return !perm.get('object_id') || perm.get('object_id') === postModel.id;
            });

            // If this is the author of the post, allow it.
            hasPermission = hasPermission || userId === postModel.get('author_id');

            if (hasPermission) {
                return when.resolve();
            }

            // Otherwise, you shall not pass.
            return when.reject();
        }

    });

    Posts = GhostBookshelf.Collection.extend({

        model: Post

    });

    module.exports = {
        Post: Post,
        Posts: Posts
    };

}());