// HTML Truncator for jQuery
// by Henrik Nyh <http://henrik.nyh.se> 2008-02-28.
// Free to modify and redistribute with credit.

(function($) {

    var trailing_whitespace = true;

    $.fn.truncate = function(options) {

        var opts = $.extend({}, $.fn.truncate.defaults, options);

        $(this).each(function() {

            var content_length = $.trim(squeeze($(this).text())).length;
            if (content_length <= opts.max_length)
                return;  // bail early if not overlong

            var actual_max_length = opts.max_length - opts.more.length - 3;  // 3 for " ()"
            var truncated_node = recursivelyTruncate(this, actual_max_length);
            var full_node = $(this).hide();

            truncated_node.insertAfter(full_node);

            findNodeForMore(truncated_node).append('&#8230; (<a href="#show more content">' + opts.more + '</a>)');
            findNodeForLess(full_node).append(' (<a href="#show less content">' + opts.less + '</a>)');

            truncated_node.find('a:last').click(function() {
                truncated_node.hide(); full_node.show(); return false;
            });
            full_node.find('a:last').click(function() {
                truncated_node.show(); full_node.hide(); return false;
            });

        });
    }

    // Note that the " (…more)" bit counts towards the max length – so a max
    // length of 10 would truncate "1234567890" to "12 (…more)".
    $.fn.truncate.defaults = {
        max_length: 100,
        more: 'more',
        less: 'less'
    };

    function recursivelyTruncate(node, max_length) {
        return (node.nodeType == 3) ? truncateText(node, max_length) : truncateNode(node, max_length);
    }

    function truncateNode(node, max_length) {
        var node = $(node);
        var new_node = node.clone().empty();
        var truncatedChild;
        node.contents().each(function() {
            var remaining_length = max_length - new_node.text().length;
            if (remaining_length == 0) return;  // breaks the loop
            truncatedChild = recursivelyTruncate(this, remaining_length);
            if (truncatedChild) new_node.append(truncatedChild);
        });
        return new_node;
    }

    function truncateText(node, max_length) {
        var text = squeeze(node.data);
        if (trailing_whitespace)  // remove initial whitespace if last text
            text = text.replace(/^ /, '');  // node had trailing whitespace.
        trailing_whitespace = !!text.match(/ $/);
        var text = text.slice(0, max_length);
        // Ensure HTML entities are encoded
        // http://debuggable.com/posts/encode-html-entities-with-jquery:480f4dd6-13cc-4ce9-8071-4710cbdd56cb
        text = $('<div/>').text(text).html();
        return text;
    }

    // Collapses a sequence of whitespace into a single space.
    function squeeze(string) {
        return string.replace(/\s+/g, ' ');
    }

    // Finds the last, innermost block-level element
    function findNodeForMore(node) {
        var $node = $(node);
        var last_child = $node.children(":last");
        if (!last_child) return node;
        var display = last_child.css('display');
        if (!display || display == 'inline') return $node;
        return findNodeForMore(last_child);
    };

    // Finds the last child if it's a p; otherwise the parent
    function findNodeForLess(node) {
        var $node = $(node);
        var last_child = $node.children(":last");
        if (last_child && last_child.is('p')) return last_child;
        return node;
    };

})(jQuery);