(function() {

    var feeds = [];
    var queue = [];
    var queue_length = 5;


    function download_item()
    {
        // Change link container
        var container = document.getElementById("download-item");
        if (! container) return;

        var item_id = container.getAttribute("data-item-id");
        var message = container.getAttribute("data-before-message");

        var img = document.createElement("img");
        img.src = "assets/img/refresh.gif";

        container.innerHTML = "";
        container.className = "downloading";
        container.appendChild(img);
        container.appendChild(document.createTextNode(" " + message));

        var request = new XMLHttpRequest();

        request.onload = function() {

            var response = JSON.parse(request.responseText);

            if (response.result) {

                var content = document.getElementById("item-content");
                if (content) content.innerHTML = response.content;

                if (container) {

                    var message = container.getAttribute("data-after-message");

                    container.innerHTML = "";
                    container.appendChild(document.createTextNode(" " + message));
                }
            }
            else {

                if (container) {

                    var message = container.getAttribute("data-failure-message");

                    container.innerHTML = "";
                    container.appendChild(document.createTextNode(" " + message));
                }
            }
        };

        request.open("POST", "?action=download-item&id=" + item_id, true);
        request.send();
    }


    function switch_status(item_id, hide)
    {
        var request = new XMLHttpRequest();

        request.onload = function() {

            if (is_listing()) {

                var response = JSON.parse(request.responseText);

                if (response.status == "read" || response.status == "unread") {

                    find_next_item();
                    if (hide) remove_item(response.item_id);
                }
            }
        }

        request.open("POST", "?action=change-item-status&id=" + item_id, true);
        request.send();
    }


    function mark_items_as_read()
    {
        var articles = document.getElementsByTagName("article");
        var idlist = [];

        for (var i = 0, ilen = articles.length; i < ilen; i++) {
            idlist.push(articles[i].getAttribute("data-item-id"));
        }

        var request = new XMLHttpRequest();

        request.onload = function() {

            window.location.href = "?action=unread";
        };

        request.open("POST", "?action=mark-items-as-read", true);
        request.send(JSON.stringify(idlist));
    }


    function mark_as_read(item_id)
    {
        var request = new XMLHttpRequest();

        request.onload = function() {

            //find_next_item();
            remove_item(item_id);
        };

        request.open("POST", "?action=mark-item-read&id=" + item_id, true);
        request.send();
    }


    function mark_as_unread(item_id)
    {
        var request = new XMLHttpRequest();

        request.onload = function() {

            //find_next_item();
            remove_item(item_id);
        };

        request.open("POST", "?action=mark-item-unread&id=" + item_id, true);
        request.send();
    }


    function bookmark_item()
    {
        var item = document.getElementById("current-item");

        if (item) {

            var item_id = item.getAttribute("data-item-id");
            var link = document.getElementById("bookmark-" + item_id);

            if (link) link.click();
        }
    }


    function show_refresh_icon(feed_id)
    {
        var container = document.getElementById("loading-feed-" + feed_id);

        if (container) {

            var img = document.createElement("img");
            img.src = "assets/img/refresh.gif";

            container.appendChild(img);
        }
    }


    function hide_refresh_icon(feed_id)
    {
        var container = document.getElementById("loading-feed-" + feed_id);
        if (container) container.innerHTML = "";
    }


    function refresh_feed(feed_id, callback)
    {
        if (! feed_id) return false;

        show_refresh_icon(feed_id);

        var request = new XMLHttpRequest();

        request.onreadystatechange = function() {

            if (request.readyState === 4) {

                hide_refresh_icon(feed_id);

                try {

                    var response = JSON.parse(this.responseText);

                    if (callback) {

                        callback(response);
                    }
                }
                catch (e) {}
            }
        };

        request.open("POST", "?action=refresh-feed&feed_id=" + feed_id, true);
        request.send();

        return true;
    }


    function get_feeds()
    {
        var links = document.getElementsByTagName("a");

        for (var i = 0, ilen = links.length; i < ilen; i++) {

            var feed_id = links[i].getAttribute('data-feed-id');

            if (feed_id) {

                feeds.push(parseInt(feed_id));
            }
        }
    }


    function refresh_all()
    {
        get_feeds();

        var interval = setInterval(function() {

            while (feeds.length > 0 && queue.length < queue_length) {

                var feed_id = feeds.shift();

                queue.push(feed_id);

                refresh_feed(feed_id, function(response) {

                    var index = queue.indexOf(response.feed_id);

                    if (index >= 0) {

                        queue.splice(index, 1);
                    }

                    if (feeds.length == 0 && queue.length == 0) {

                        clearInterval(interval);
                        window.location.href = "?action=unread";
                    }
                });
            }

        }, 100);
    }


    function open_next_page()
    {
        var link = document.getElementById("next-page");
        if (link) link.click();
    }


    function open_previous_page()
    {
        var link = document.getElementById("previous-page");
        if (link) link.click();
    }


    function remove_item(item_id)
    {
        var item = document.getElementById("item-" + item_id);

        if (! item) {

            item = document.getElementById("current-item");
            if (item.getAttribute("data-item-id") != item_id) item = false;
        }

        if (item) {

            item.parentNode.removeChild(item);

            var container = document.getElementById("page-counter");

            if (container) {

                counter = parseInt(container.textContent.trim(), 10) - 1;

                if (counter == 0) {

                    window.location = "?action=feeds&nothing_to_read=1";
                }
                else {

                    container.textContent = counter + " ";
                    document.title = "miniflux (" + counter + ")";
                    document.getElementById("nav-counter").textContent = "(" + counter + ")";
                }
            }
        }
    }


    function open_original_item()
    {
        var link = document.getElementById("original-item");

        if (link) {

            if (is_listing() && link.getAttribute("data-hide")) {
                mark_as_read(link.getAttribute("data-item-id"));
            }

            link.removeAttribute("data-action");
            link.click();
        }
    }


    function open_item()
    {
        var link = document.getElementById("open-item");
        if (link) link.click();
    }


    function open_next_item()
    {
        var link = document.getElementById("next-item");

        if (link) {

            link.click();
        }
        else if (is_listing()) {

            find_next_item();
        }
    }


    function open_previous_item()
    {
        var link = document.getElementById("previous-item");

        if (link) {

            link.click();
        }
        else if (is_listing()) {

            find_previous_item();
        }
    }


    function change_item_status()
    {
        if (is_listing() && ! document.getElementById("current-item")) {
            find_next_item();
        }

        var item = document.getElementById("current-item");

        if (item) {
            switch_status(item.getAttribute("data-item-id"), item.getAttribute("data-hide"));
        }
    }


    function scroll_page_to(item)
    {
        var clientHeight = pageYOffset + document.documentElement.clientHeight;
        var itemPosition = item.offsetTop + item.offsetHeight;

        if (clientHeight - itemPosition < 0 || clientHeight - item.offsetTop > document.documentElement.clientHeight) {
            window.scrollTo(0, item.offsetTop - 10);
        }
    }


    function set_links_item(item_id)
    {
        var link = document.getElementById("current-item");
        if (link) scroll_page_to(link);

        var link = document.getElementById("original-item");
        if (link) link.id = "original-" + link.getAttribute("data-item-id");

        var link = document.getElementById("open-item");
        if (link) link.id = "open-" + link.getAttribute("data-item-id");

        var link = document.getElementById("original-" + item_id);
        if (link) link.id = "original-item";

        var link = document.getElementById("open-" + item_id);
        if (link) link.id = "open-item";
    }


    function find_next_item()
    {
        var items = document.getElementsByTagName("article");

        if (! document.getElementById("current-item")) {

            items[0].id = "current-item";
            set_links_item(items[0].getAttribute("data-item-id"));
        }
        else {

            for (var i = 0, ilen = items.length; i < ilen; i++) {

                if (items[i].id == "current-item") {

                    items[i].id = "item-" + items[i].getAttribute("data-item-id");

                    if (i + 1 < ilen) {

                        items[i + 1].id = "current-item";
                        set_links_item(items[i + 1].getAttribute("data-item-id"));
                    }

                    break;
                }
            }
        }
    }


    function find_previous_item()
    {
        var items = document.getElementsByTagName("article");

        if (! document.getElementById("current-item")) {

            items[items.length - 1].id = "current-item";
            set_links_item(items[items.length - 1].getAttribute("data-item-id"));
        }
        else {

            for (var i = items.length - 1; i >= 0; i--) {

                if (items[i].id == "current-item") {

                    items[i].id = "item-" + items[i].getAttribute("data-item-id");

                    if (i - 1 >= 0) {

                        items[i - 1].id = "current-item";
                        set_links_item(items[i - 1].getAttribute("data-item-id"));
                    }

                    break;
                }
            }
        }
    }


    function is_listing()
    {
        if (document.getElementById("listing")) return true;
        return false;
    }


    document.onclick = function(e) {

        var action = e.target.getAttribute("data-action");

        if (action) {

            switch (action) {
                case 'refresh-all':
                    e.preventDefault();
                    refresh_all();
                    break;
                case 'refresh-feed':
                    e.preventDefault();
                    var feed_id = e.target.getAttribute("data-feed-id");
                    refresh_feed(feed_id);
                    break;
                case 'mark-read':
                    e.preventDefault();
                    var item_id = e.target.getAttribute("data-item-id");
                    mark_as_read(item_id);
                    break;
                case 'mark-unread':
                    e.preventDefault();
                    var item_id = e.target.getAttribute("data-item-id");
                    mark_as_unread(item_id);
                    break;
                case 'mark-all-read':
                    e.preventDefault();
                    mark_items_as_read();
                    break;
                case 'original-link':
                    var item_id = e.target.getAttribute("data-item-id");
                    mark_as_read(item_id);
                    break;
                case 'download-item':
                    e.preventDefault();
                    download_item();
                    break;
            }
        }
    };

    document.onkeypress = function(e) {

        switch (e.keyCode || e.which) {
            case 100: // d
                download_item();
                break;
            case 112: // p
            case 107: // k
                open_previous_item();
                break;
            case 110: // n
            case 106: // j
                open_next_item();
                break;
            case 118: // v
                open_original_item();
                break;
            case 111: // o
                open_item();
                break;
            case 109: // m
                change_item_status();
                break;
            case 102: // f
                bookmark_item();
                break;
            case 104: // h
                open_previous_page();
                break
            case 108: // l
                open_next_page();
                break;
            case 63: // ?
                open("?action=show-help", "Help", "width=320,height=400,location=no,scrollbars=no,status=no,toolbar=no");
                break;
        }
    };

})();