/*
 * Stretchy: Form element autosizing, the way it should be.
 * by Lea Verou http://lea.verou.me
 * MIT license
 */
(function() {

if (!self.Element) {
    return; // super old browser
}

if (!Element.prototype.matches) {
    Element.prototype.matches = Element.prototype.webkitMatchesSelector || Element.prototype.mozMatchesSelector || Element.prototype.msMatchesSelector || Element.prototype.oMatchesSelector || null;
}

if (!Element.prototype.matches) {
    return;
}

function $$(expr, con) {
    return expr instanceof Node || expr instanceof Window? [expr] :
           [].slice.call(typeof expr == "string"? (con || document).querySelectorAll(expr) : expr || []);
}

var _ = self.Stretchy = {
    selectors: {
        base: '.amoforms__fields__edit__textarea',
        filter: "*"
    },

    // Script element this was included with, if any
    script: $$("script").pop(),

    // Autosize one element. The core of Stretchy.
    resize: function(element) {
        if (!_.resizes(element)) {
            return;
        }

        var cs = getComputedStyle(element);
        var offset = 0;

        if (!element.value && element.placeholder) {
            var empty = true;
            element.value = element.placeholder;
        }

        var type = element.nodeName.toLowerCase();

        if (type == "textarea") {
            //element.style.height = "0";

            if (cs.boxSizing == "border-box") {
                offset = element.offsetHeight;
            }
            else if (cs.boxSizing == "content-box") {
                offset = -element.clientHeight;
            }

            //element.style.height = element.scrollHeight + "px";
        }
        else if(type == "input") {
            element.style.width = "0";

            if (cs.boxSizing == "border-box") {
                offset = element.offsetWidth;
            }
            else if (cs.boxSizing == "padding-box") {
                offset = element.clientWidth;
            }

            // Safari misreports scrollWidth, so we will instead set scrollLeft to a
            // huge number, and read that back to see what it was clipped to
            element.scrollLeft = 1e+10;

            var width = Math.max(element.scrollLeft + offset, element.scrollWidth - element.clientWidth);

            element.style.width = width + "px";
        }
        else if (type == "select") {
            // Need to use dummy element to measure :(
            var option = document.createElement("_");
            option.textContent = element.options[element.selectedIndex].textContent;
            element.parentNode.insertBefore(option, element.nextSibling);

            // The name of the appearance property, as it might be prefixed
            var appearance;

            for (var property in cs) {
                if (!/^(width|webkitLogicalWidth)$/.test(property)) {
                    option.style[property] = cs[property];

                    if (/appearance$/i.test(property)) {
                        appearance = property;
                    }
                }
            }

            option.style.width = "";

            if (option.offsetWidth > 0) {
                element.style.width = option.offsetWidth + "px";

                if (!cs[appearance] || cs[appearance] !== "none") {
                    // Account for arrow
                    element.style.width = "calc(" + element.style.width + " + 2em)";
                }
            }

            option.parentNode.removeChild(option);
            option = null;
        }

        if (empty) {
            element.value = "";
        }
    },

    // Autosize multiple elements
    resizeAll: function(elements) {
        $$(elements || _.selectors.base).forEach(function (element) {
            _.resize(element);
        });
    },

    active: true,

    // Will stretchy do anything for this element?
    resizes: function(element) {
        return element &&
               element.parentNode &&
               element.matches &&
               element.matches(_.selectors.base) &&
               element.matches(_.selectors.filter);
    },

    init: function(){
        _.selectors.filter = _.script.getAttribute("data-filter") ||
                             ($$("[data-stretchy-filter]").pop() || document.body).getAttribute("data-stretchy-filter") || "*";

        _.resizeAll();
    },

    $$: $$
};

// Autosize all elements once the DOM is loaded

// DOM already loaded?
if (document.readyState !== "loading") {
    _.init();
}
else {
    // Wait for it
    document.addEventListener("DOMContentLoaded", _.init);
}

// Listen for changes
var listener = function(evt) {
    if (_.active) {
        _.resize(evt.target);
    }
};

document.body.addEventListener("input", listener);

(function ($) {
  $(document).on('textarea:resize:manual', function (e) {
    _.resize(e.target);
  });
}(jQuery));

// Firefox fires a change event instead of an input event
document.body.addEventListener("change", listener);


// Listen for new elements
if (self.MutationObserver) {
    (new MutationObserver(function(mutations) {
        if (_.active) {
            mutations.forEach(function(mutation) {
                if (mutation.type == "childList") {
                    Stretchy.resizeAll(mutation.addedNodes);
                }
            });
        }
    })).observe(document.body, {
        childList: true,
        subtree: true
    });
}

})();