jackd248 / lighthouse-garden

document.addEventListener("DOMContentLoaded", function() {

        var templates = {

            prefix: "",

            suffix: " ago",

            seconds: "less than a minute",

            minute: "about a minute",

            minutes: "%d minutes",

            hour: "about an hour",

            hours: "about %d hours",

            day: "a day",

            days: "%d days",

            month: "about a month",

            months: "%d months",

            year: "about a year",

            years: "%d years"

        };

        var template = function(t, n) {

            return templates[t] && templates[t].replace(/%d/i, Math.abs(Math.round(n)));

        };

        var timer = function(time) {

            if (!time)

            time = time.replace(/\.\d+/, ""); // remove milliseconds

            time = time.replace(/-/, "/").replace(/-/, "/");

            time = time.replace(/T/, " ").replace(/Z/, " UTC");

            time = time.replace(/([\+\-]\d\d)\:?(\d\d)/, " $1$2"); // -04:00 -> -0400

            time = new Date(time * 1000 || time);

            var now = new Date();

            var seconds = ((now.getTime() - time) * .001) >> 0;

            var minutes = seconds / 60;

            var hours = minutes / 60;

            var days = hours / 24;

            var years = days / 365;

            return templates.prefix + (

                    seconds < 45 && template('seconds', seconds) ||

                    seconds < 90 && template('minute', 1) ||

                    minutes < 45 && template('minutes', minutes) ||

                    minutes < 90 && template('hour', 1) ||

                    hours < 24 && template('hours', hours) ||

                    hours < 42 && template('day', 1) ||

                    days < 30 && template('days', days) ||

                    days < 45 && template('month', 1) ||

                    days < 365 && template('months', days / 30) ||

                    years < 1.5 && template('year', 1) ||

                    template('years', years)

                    ) + templates.suffix;

        };

        var elements = document.getElementsByClassName('timeago');

        for (var i = 0; i < elements.length; ++i) {

            var $this = elements[i];

            if (typeof $this === 'object') {

                $this.innerHTML = timer($this.getAttribute('data-datetime'));

            }

        }

        // update time every minute

        setTimeout(timeAgo, 60000);

    })();

});