var Datepicker;

(function (window, $, undefined) {
    var pluginName = 'datepicker',
        $body, $datepickersContainer,
        baseTemplate = '' +
            '<div class="datepicker">' +
            '<nav class="datepicker--nav"></nav>' +
            '<div class="datepicker--content"></div>' +
            '</div>',
        defaults = {
            inline: true,
            region: 'ru',
            firstDay: 1, // Week's first day
            start: '', // Start date
            weekends: [6, 0],
            defaultView: 'days',
            dateFormat: 'dd.mm.yyyy',

            // navigation
            prevHtml: '&laquo;',
            nextHtml: '&raquo;',

            // events
            onChange: ''
        };

    Datepicker  = function (el, options) {
        this.$el = typeof el == 'string' ? $(el) : el;

        this.opts = $.extend({}, defaults, options);

        if (!this.opts.start) {
            this.opts.start = new Date();
        }
        if (this.containerBuilt && !this.opts.inline) {
            this._buildDatepickersContainer();
        }

        this.loc = Datepicker.region[this.opts.region];

        if ($body == undefined) {
            $body = $('body');
        }

        this.inited = false;

        this.currentDate = this.opts.start;
        this.currentView = this.opts.defaultView;
        this.views = {};

        this.init()
    };


    Datepicker.prototype = {
        containerBuilt: false,
        init: function () {
            this._buildBaseHtml();

            this.nav = new Datepicker.Navigation(this, this.opts);
            this.views[this.currentView] = new Datepicker.Body(this, this.currentView, this.opts);

            this.views[this.currentView].show();

            this.inited = true;
        },

        isWeekend: function (day) {
            return this.opts.weekends.indexOf(day) !== -1;
        },

        _buildDatepickersContainer: function () {
            this.containerBuilt = true;
            $body.append('<div class="datepickers-container" id="datepickers-container"></div>')
            $datepickersContainer = $('#datepickers-container');
        },

        _buildBaseHtml: function () {
            var $appendTarget = this.$el;
            if(!this.opts.inline) {
                $appendTarget = $datepickersContainer;
            }
            this.$datepicker = $(baseTemplate).appendTo($appendTarget);
            this.$content = $('.datepicker--content', this.$datepicker);
            this.$nav = $('.datepicker--nav', this.$datepicker);
        },

        _defineDOM: function () {

        },

        _triggerOnChange: function (cellType) {
            var dateString = this.formatDate(this.opts.dateFormat, this.date);

            this.opts.onChange(dateString, this.date, this);
        },

        next: function () {
            var d = this.parsedDate;
            switch (this.view) {
                case 'days':
                    this.date = new Date(d.year, d.month + 1, 1);
                    break;
                case 'months':
                    this.date = new Date(d.year + 1, d.month, 1);
                    break;
                case 'years':
                    this.date = new Date(d.year + 10, 0, 1);
                    break;
            }

        },

        prev: function () {
            var d = this.parsedDate;
            switch (this.view) {
                case 'days':
                    this.date = new Date(d.year, d.month - 1, 1);
                    break;
                case 'months':
                    this.date = new Date(d.year - 1, d.month, 1);
                    break;
                case 'years':
                    this.date = new Date(d.year - 10, 0, 1);
                    break;
            }
        },

        formatDate: function (string, date) {
            var result = string,
                d = this.parsedDate;

            switch (true) {
                case /dd/.test(result):
                    result = result.replace('dd', d.fullDate);
                case /d/.test(result):
                    result = result.replace('d', d.date);
                case /mm/.test(result):
                    result = result.replace('mm',d.fullMonth);
                case /m/.test(result):
                    result = result.replace('m',d.month + 1);
                case /MM/.test(result):
                    result = result.replace('MM', this.loc.months[d.month]);
                case /yyyy/.test(result):
                    result = result.replace('yyyy', d.year);
                case /yy/.test(result):
                    result = result.replace('yy', d.year.toString().slice(-2));
            }

            return result;
        },

        get parsedDate() {
            return Datepicker.getParsedDate(this.date);
        },

        set date (val) {
            this.currentDate = val;

            if (this.inited) {
                this.views[this.view]._render();
                this.nav._render();
            }

            return val;
        },

        get date () {
            return this.currentDate
        },

        set view (val) {
            this.prevView = this.currentView;
            this.currentView = val;

            if (this.inited) {
                if (!this.views[val]) {
                    this.views[val] = new Datepicker.Body(this, val, this.opts)
                } else {
                    this.views[val]._render();
                }

                this.views[this.prevView].hide();
                this.views[val].show();
                this.nav._render();
            }

            return val
        },

        get view() {
            return this.currentView;
        }
    };

    Datepicker.getDaysCount = function (date) {
        return new Date(date.getFullYear(), date.getMonth() + 1, 0).getDate();
    };

    Datepicker.getParsedDate = function (date) {
        return {
            year: date.getFullYear(),
            month: date.getMonth(),
            fullMonth: (date.getMonth() + 1) < 10 ? '0' + (date.getMonth() + 1) : date.getMonth() + 1, // One based
            date: date.getDate(),
            fullDate: date.getDate() < 10 ? '0' + date.getDate() : date.getDate(),
            day: date.getDay()
        }
    };

    Datepicker.getDecade = function (date) {
        var firstYear = Math.floor(date.getFullYear() / 10) * 10;

        return [firstYear, firstYear + 9];
    };

    Datepicker.template = function (str, data) {
        return str.replace(/#\{([\w]+)\}/g, function (source, match) {
            if (data[match] || data[match] === 0) {
                return data[match]
            }
        });
    };

    $.fn[pluginName] = function ( options ) {
        if (Datepicker.prototype[options]) {
            Datepicker.prototype[options].apply(this.data(pluginName), Array.prototype.slice.call(arguments, 1));
        } else {
            return this.each(function () {
                if (!$.data(this, pluginName)) {
                    $.data(this,  pluginName,
                        new Datepicker( this, options ));
                } else {
                    var _this = $.data(this, pluginName),
                        oldOpts = _this.opts;

                    _this.opts = $.extend({}, oldOpts, options);
                }
            });
        }
    };

})(window, jQuery, '');
;(function () {
    Datepicker.region = {
        'ru': {
            days: ['Вс','Пн','Вт','Ср','Чт','Пт','Сб'],
            months: ['Январь', 'Февраль', 'Март', 'Апрель', 'Май', 'Июнь', 'Июль', 'Август', 'Сентябрь', 'Октябрь', 'Ноябрь', 'Декабрь']
        }
    }
})();

;(function () {
    var template = '' +
        '<div class="datepicker--nav-action" data-action="prev">#{prevHtml}</div>' +
        '<div class="datepicker--nav-title">#{title}</div>' +
        '<div class="datepicker--nav-action" data-action="next">#{nextHtml}</div>';

    Datepicker.Navigation = function (d, opts) {
        this.d = d;
        this.opts = opts;

        this.init();
    };

    Datepicker.Navigation.prototype = {
        init: function () {
            this._buildBaseHtml();
            this._bindEvents();
        },

        _bindEvents: function () {
            this.d.$nav.on('click', '.datepicker--nav-action', $.proxy(this._onClickNavButton, this));
            this.d.$nav.on('click', '.datepicker--nav-title', $.proxy(this._onClickNavTitle, this));
        },

        _buildBaseHtml: function () {
            this._render();
            this.$navButton = $('.datepicker--nav-action', this.d.$nav);
        },

        _render: function () {
            var title = this._getTitle(this.d.currentDate),
                html = Datepicker.template(template, $.extend({title: title}, this.opts));

            this.d.$nav.html(html);
        },

        _getTitle: function (date) {
            var month = this.d.loc.months[date.getMonth()],
                year = date.getFullYear(),
                decade = Datepicker.getDecade(date),
                types = {
                    days: month + ', ' + year,
                    months: year,
                    years: decade[0] + ' - ' + decade[1]
                };

            return types[this.d.view];
        },

        _onClickNavButton: function (e) {
            var $el = $(e.target),
                action = $el.data('action');

            this.d[action]();
        },

        _onClickNavTitle: function () {
            if (this.d.view == 'days') {
                return this.d.view = 'months'
            }

            this.d.view = 'years';
        }
    }

})();

Datepicker.Cell = function () {

};
;(function () {
    var templates = {
        days:'' +
        '<div class="datepicker--days datepicker--body">' +
        '<div class="datepicker--days-names"></div>' +
        '<div class="datepicker--cells datepicker--cells-days"></div>' +
        '</div>',
        months: '' +
        '<div class="datepicker--months datepicker--body">' +
        '<div class="datepicker--cells datepicker--cells-months"></div>' +
        '</div>',
        years: '' +
        '<div class="datepicker--years datepicker--body">' +
        '<div class="datepicker--cells datepicker--cells-years"></div>' +
        '</div>'
    };

    Datepicker.Body = function (d, type, opts) {
        this.d = d;
        this.type = type;
        this.opts = opts;

        this.init();
    };

    Datepicker.Body.prototype = {
        init: function () {
            this._buildBaseHtml();
            this._render();

            this._bindEvents();
        },

        _bindEvents: function () {
            this.$el.on('click', '.datepicker--cell', $.proxy(this._onClickCell, this));
        },

        _buildBaseHtml: function () {
            this.$el = $(templates[this.type]).appendTo(this.d.$content);
            this.$names = $('.datepicker--days-names', this.$el);
            this.$cells = $('.datepicker--cells', this.$el);
        },

        _getDayNamesHtml: function (firstDay, curDay, html, i) {
            curDay = curDay != undefined ? curDay : firstDay;
            html = html ? html : '';
            i = i != undefined ? i : 0;

            if (i > 7) return html;
            if (curDay == 7) return this._getDayNamesHtml(firstDay, 0, html, ++i);

            html += '<div class="datepicker--day-name' + (this.d.isWeekend(curDay) ? " -weekend-" : "") + '">' + this.d.loc.days[curDay] + '</div>';

            return this._getDayNamesHtml(firstDay, ++curDay, html, ++i);
        },

        /**
         * Calculates days number to render. Generates days html and returns it.
         * @param {object} date - Date object
         * @returns {string}
         * @private
         */
        _getDaysHtml: function (date) {
            var totalMonthDays = Datepicker.getDaysCount(date),
                firstMonthDay = new Date(date.getFullYear(), date.getMonth(), 1).getDay(),
                lastMonthDay = new Date(date.getFullYear(), date.getMonth(), totalMonthDays).getDay(),
                daysFromPevMonth = firstMonthDay - this.opts.firstDay,
                daysFromNextMonth = 6 - lastMonthDay + this.opts.firstDay;

            daysFromPevMonth = daysFromPevMonth < 0 ? daysFromPevMonth + 7 : daysFromPevMonth;
            daysFromNextMonth = daysFromNextMonth > 6 ? daysFromNextMonth - 7 : daysFromNextMonth;

            var startDayIndex = -daysFromPevMonth + 1,
                m, y,
                html = '';

            for (var i = startDayIndex, max = totalMonthDays + daysFromNextMonth; i <= max; i++) {
                y = date.getFullYear();
                m = date.getMonth();

                html += this._getDayHtml(new Date(y, m, i))
            }

            return html;
        },

        _getDayHtml: function (date) {
            var _class = "datepicker--cell datepicker--cell-day";

            if (this.d.isWeekend(date.getDay())) _class += " -weekend-";
            if (date.getMonth() != this.d.currentDate.getMonth()) _class += " -another-month-";

            return '<div class="' + _class + '" data-date="' + date.getDate() + '">' + date.getDate() + '</div>';
        },

        /**
         * Generates months html
         * @param {object} date - date instance
         * @returns {string}
         * @private
         */
        _getMonthsHtml: function (date) {
            var html = '',
                d = Datepicker.getParsedDate(date),
                i = 0;

            while(i < 12) {
                html += this._getMonthHtml(new Date(d.year, i));
                i++
            }

            return html;
        },

        _getMonthHtml: function (date) {
            var _class = "datepicker--cell datepicker--cell-month",
                d = Datepicker.getParsedDate(date),
                loc = this.d.loc;

            return '<div class="' + _class + '" data-month="' + d.month + '">' + loc.months[d.month] + '</div>'
        },

        _getYearsHtml: function (date) {
            var d = Datepicker.getParsedDate(date),
                decade = Datepicker.getDecade(date),
                firstYear = decade[0] - 1,
                html = '',
                i = firstYear;

            for (i; i <= decade[1] + 1; i++) {
                html += this._getYearHtml(new Date(i , 0));
            }

            return html;
        },

        _getYearHtml: function (date) {
            var _class = "datepicker--cell datepicker--cell-year",
                decade = Datepicker.getDecade(this.d.date),
                d = Datepicker.getParsedDate(date);

            if (d.year < decade[0] || d.year > decade[1]) {
                _class += ' -another-decade-';
            }

            return '<div class="' + _class + '" data-year="' + d.year + '">' + d.year + '</div>'
        },

        _renderTypes: {
            days: function () {
                var dayNames = this._getDayNamesHtml(this.opts.firstDay),
                    days = this._getDaysHtml(this.d.currentDate);

                this.$cells.html(days);
                this.$names.html(dayNames)
            },
            months: function () {
                var html = this._getMonthsHtml(this.d.currentDate);

                this.$cells.html(html)
            },
            years: function () {
                var html = this._getYearsHtml(this.d.currentDate);

                this.$cells.html(html)
            }
        },

        _render: function () {
            this._renderTypes[this.type].bind(this)()
        },

        show: function () {
            this.$el.addClass('active');
            this.acitve = true;
        },

        hide: function () {
            this.$el.removeClass('active');
            this.active = false;
        },

        //  Events
        // -------------------------------------------------

        _handleClick: {
            days: function (el) {
                var date = el.data('date'),
                    d = this.d.parsedDate;

                this.d.date = new Date(d.year, d.month, date);

                if (this.d.opts.onChange) {
                    this.d._triggerOnChange()
                }
            },
            months: function (el) {
                var month = el.data('month'),
                    d = this.d.parsedDate;

                this.d.date = new Date(d.year, month, 1);
                this.d.view = 'days';
            },
            years: function (el) {
                var year = el.data('year');

                this.d.date = new Date(year, 0, 1);
                this.d.view = 'months';
            }
        },

        _onClickCell: function (e) {
            var $el = $(e.target).closest('.datepicker--cell');

            this._handleClick[this.d.currentView].bind(this)($el);
        }
    };
})();