window.fwip = (function() {
    this.ipv4s = document.querySelectorAll('[data-ipv="4"]');
    this.ipv6s = document.querySelectorAll('[data-ipv="6"]');

    this.doAddressLookup = function(version, callback) {
        version = parseInt(version || 4).toString();
        var url = '//ipv' + version + '.flash.moe/json';

        fetch(url)
            .then(resp => resp.json())
            .then(data => callback(data))
            .catch(err => callback({error: 'not available'}));
    };

    var lookupCallback = function(set) {
        return function(result) {
            for(var i = 0; i < set.length; ++i) {
                if(!result.a)
                    set[i].classList.add('ip-lookup-failed');
                else {
                    var copyTarget = set[i],
                        clickTarget = set[i].parentNode.parentNode;
                    clickTarget.onclick = function() { this.doAddressCopy(copyTarget) }.bind(this);
                }
                set[i].textContent = result.a || result.error || 'gone';
            }
        }.bind(this);
    }.bind(this);

    this.doAddressLookup(4, lookupCallback(this.ipv4s));
    this.doAddressLookup(6, lookupCallback(this.ipv6s));

    this.selectTextInElement = function(elem) {
        // MSIE
        if(document.body.createTextRange) {
            var range = document.body.createTextRange();
            range.moveToElementText(elem);
            range.select();
            return;
        }

        // Mozilla
        if(window.getSelection) {
            var select = window.getSelection(),
                range  = document.createRange();
            range.selectNodeContents(elem);
            select.removeAllRanges();
            select.addRange(range);
            return;
        }

        console.warn('Unable to select text.');
    };

    this.copySelectedText = function() {
        if(document.execCommand) {
            document.execCommand('copy');
            return;
        }

        console.warn('Unable to copy text.');
    };

    this.selectNothing = function() {
        // MSIE
        if(document.body.createTextRange) {
            document.body.createTextRange().select();
            return;
        }

        // Mozilla
        if(window.getSelection) {
            window.getSelection().removeAllRanges();
            return;
        }

        console.warn('Unable to select text.');
    };

    this.doAddressCopy = function(elem) {
        this.selectTextInElement(elem);
        this.copySelectedText();
        //this.selectNothing();
    };

    return this;
}).call(window.fwip || {});