var Bookshelf = require('bookshelf'),
    when      = require('when'),
    moment    = require('moment'),
    _         = require('lodash'),
    uuid      = require('node-uuid'),
    config    = require('../config'),
    unidecode = require('unidecode'),
    sanitize  = require('validator').sanitize,
    schema    = require('../data/schema'),
    validation     = require('../data/validation'),

    ghostBookshelf;

// Initializes a new Bookshelf instance, for reference elsewhere in Ghost.
ghostBookshelf = Bookshelf.ghost = Bookshelf.initialize(config().database);
ghostBookshelf.client = config().database.client;


// The Base Model which other Ghost objects will inherit from,
// including some convenience functions as static properties on the model.
ghostBookshelf.Model = ghostBookshelf.Model.extend({

    hasTimestamps: true,

    // get permitted attributs from schema.js
    permittedAttributes: function () {
        return _.keys(schema.tables[this.tableName]);
    },

    defaults: function () {
        return {
            uuid: uuid.v4()
        };
    },

    initialize: function () {
        var self = this;
        this.on('creating', this.creating, this);
        this.on('saving', function (model, attributes, options) {
            return when(self.saving(model, attributes, options)).then(function () {
                return self.validate(model, attributes, options);
            });
        });
    },

    validate: function () {
        validation.validateSchema(this.tableName, this.toJSON());
    },

    creating: function () {
        if (!this.get('created_by')) {
            this.set('created_by', 1);
        }
    },

    saving: function () {
         // Remove any properties which don't belong on the model
        this.attributes = this.pick(this.permittedAttributes());

        // sessions do not have 'updated_by' column
        if (this.tableName !== 'sessions') {
            this.set('updated_by', 1);
        }
    },

    // Base prototype properties will go here
    // Fix problems with dates
    fixDates: function (attrs) {
        _.each(attrs, function (value, key) {
            if (key.substr(-3) === '_at' && value !== null) {
                attrs[key] = moment(attrs[key]).toDate();
            }
        });

        return attrs;
    },

    // Convert bools to ints to be consistent
    // across db providers
    fixBools: function (attrs) {
        _.each(attrs, function (value, key) {
            if (typeof value === "boolean") {
                attrs[key] = value ? 1 : 0;
            }
        });

        return attrs;
    },

    format: function (attrs) {
        return this.fixBools(this.fixDates(attrs));
    },

    toJSON: function (options) {
        var attrs = this.fixBools(this.fixDates(_.extend({}, this.attributes))),
            relations = this.relations;

        if (options && options.shallow) {
            return attrs;
        }

        _.each(relations, function (relation, key) {
            if (key.substring(0, 7) !== '_pivot_') {
                attrs[key] = relation.toJSON ? relation.toJSON() : relation;
            }
        });

        return attrs;
    },

    sanitize: function (attr) {
        return sanitize(this.get(attr)).xss();
    }

}, {

    /**
     * Naive find all
     * @param options (optional)
     */
    findAll:  function (options) {
        options = options || {};
        return ghostBookshelf.Collection.forge([], {model: this}).fetch(options);
    },

    browse: function () {
        return this.findAll.apply(this, arguments);
    },

    /**
     * Naive find one where args match
     * @param args
     * @param options (optional)
     */
    findOne: function (args, options) {
        options = options || {};
        return this.forge(args).fetch(options);
    },

    read: function () {
        return this.findOne.apply(this, arguments);
    },

    /**
     * Naive edit
     * @param editedObj
     * @param options (optional)
     */
    edit: function (editedObj, options) {
        options = options || {};
        return this.forge({id: editedObj.id}).fetch(options).then(function (foundObj) {
            if (foundObj) {
                return foundObj.save(editedObj, options);
            }
        });
    },

    update: function () {
        return this.edit.apply(this, arguments);
    },

    /**
     * Naive create
     * @param newObj
     * @param options (optional)
     */
    add: function (newObj, options) {
        options = options || {};
        var instance = this.forge(newObj);
        // We allow you to disable timestamps
        // when importing posts so that
        // the new posts `updated_at` value
        // is the same as the import json blob.
        // More details refer to https://github.com/TryGhost/Ghost/issues/1696
        if (options.importing) {
            instance.hasTimestamps = false;
        }
        return instance.save(null, options);
    },

    create: function () {
        return this.add.apply(this, arguments);
    },

    /**
     * Naive destroy
     * @param _identifier
     * @param options (optional)
     */
    destroy: function (_identifier, options) {
        options = options || {};
        return this.forge({id: _identifier}).destroy(options);
    },

    'delete': function () {
        return this.destroy.apply(this, arguments);
    },

    // #### generateSlug
    // Create a string act as the permalink for an object.
    generateSlug: function (Model, base, readOptions) {
        var slug,
            slugTryCount = 1,
            baseName = Model.prototype.tableName.replace(/s$/, ''),
            // Look for a post with a matching slug, append an incrementing number if so
            checkIfSlugExists;

        checkIfSlugExists = function (slugToFind) {
            var args = {slug: slugToFind};
            //status is needed for posts
            if (readOptions && readOptions.status) {
                args.status = readOptions.status;
            }
            return Model.findOne(args, readOptions).then(function (found) {
                var trimSpace;

                if (!found) {
                    return when.resolve(slugToFind);
                }

                slugTryCount += 1;

                // If this is the first time through, add the hyphen
                if (slugTryCount === 2) {
                    slugToFind += '-';
                } else {
                    // Otherwise, trim the number off the end
                    trimSpace = -(String(slugTryCount - 1).length);
                    slugToFind = slugToFind.slice(0, trimSpace);
                }

                slugToFind += slugTryCount;

                return checkIfSlugExists(slugToFind);
            });
        };

        slug = base.trim();

        // Remove non ascii characters
        slug = unidecode(slug);

        // Remove URL reserved chars: `:/?#[]@!$&'()*+,;=` as well as `\%<>|^~£"`
        slug = slug.replace(/[:\/\?#\[\]@!$&'()*+,;=\\%<>\|\^~£"]/g, '')
            // Replace dots and spaces with a dash
            .replace(/(\s|\.)/g, '-')
            // Convert 2 or more dashes into a single dash
            .replace(/-+/g, '-')
            // Make the whole thing lowercase
            .toLowerCase();

        // Remove trailing hyphen
        slug = slug.charAt(slug.length - 1) === '-' ? slug.substr(0, slug.length - 1) : slug;

        // Check the filtered slug doesn't match any of the reserved keywords
        slug = /^(ghost|ghost\-admin|admin|wp\-admin|wp\-login|dashboard|logout|login|signin|signup|signout|register|archive|archives|category|categories|tag|tags|page|pages|post|posts|user|users|rss|feed)$/g
            .test(slug) ? slug + '-' + baseName : slug;

        //if slug is empty after trimming use "post"
        if (!slug) {
            slug = baseName;
        }
        // Test for duplicate slugs.
        return checkIfSlugExists(slug);
    }

});

module.exports = ghostBookshelf;