/**
 * Created by dagan on 07/04/2014.
 */
'use strict';
/* global console, XsUtils */
window.XsUtils = window.XsUtils || (function () {

    function extend(object, defaultObject) {
        var result = defaultObject || {};
        var key;
        for (key in object) {
            if (object.hasOwnProperty(key)) {
                result[key] = object[key];
            }
        }
        return result;
    }

    //public interface
    return {
        extend: extend
    };
})();

window.xsLocalStorage = window.xsLocalStorage || (function () {
    var MESSAGE_NAMESPACE = "cross-domain-pa-cp-message",
        options = {
            iframeId: "cross-domain-iframe",
            iframeUrl: undefined,
            initCallback: function () { }
        };
    var requestId = -1;
    var iframe;
    var requests = {};
    var wasInit = false;
    var iframeReady = true;

    function applyCallback(data) {
        if (requests[data.id]) {
            requests[data.id](data);
            delete requests[data.id];
        }
    }

    function receiveMessage(event) {
        var data;
        try {
            data = JSON.parse(event.data);
        } catch (err) {
            //not our message, can ignore
        }
        if (data && data.namespace === MESSAGE_NAMESPACE) {
            if (data.id === 'iframe-ready') {
                iframeReady = true;
                options.initCallback();
            } else {
                applyCallback(data);
            }
        }
    }

    function buildMessage(action, key, value, callback) {
        requestId++;
        requests[requestId] = callback;
        var data = {
            namespace: MESSAGE_NAMESPACE,
            id: requestId,
            action: action,
            key: key,
            value: value
        };
        iframe.contentWindow.postMessage(JSON.stringify(data), '*');
    }

    function init(customOptions) {
        options = XsUtils.extend(customOptions, options);
        var temp = document.createElement('div');

        if (window.addEventListener) {
            window.addEventListener('message', receiveMessage, false);
        } else {
            window.attachEvent('onmessage', receiveMessage);
        }

        temp.innerHTML = '<iframe id="' + options.iframeId + '" src=' + options.iframeUrl + ' style="display: none;"></iframe>';
        document.body.appendChild(temp);
        iframe = document.getElementById(options.iframeId);
    }

    function isApiReady() {
        if (!wasInit) {
            return false;
        }
        if (!iframeReady) {
            return false;
        }
        return true;
    }

    function isDomReady() {
        return (document.readyState === 'complete');
    }

    return {
        //callback is optional for cases you use the api before window load.
        init: function (customOptions) {
            if (!customOptions.iframeUrl) {
                throw 'Please specify the iframe URL';
            }
            if (wasInit) {
                return;
            }
            wasInit = true;
            if (isDomReady()) {
                init(customOptions);
            } else {
                if (document.addEventListener) {
                    // All browsers expect IE < 9
                    document.addEventListener('readystatechange', function () {
                        if (isDomReady()) {
                            init(customOptions);
                        }
                    });
                } else {
                    // IE < 9
                    document.attachEvent('readystatechange', function () {
                        if (isDomReady()) {
                            init(customOptions);
                        }
                    });
                }
            }
        },
        setItem: function (key, value, callback) {
            if (!isApiReady()) {
                return;
            }
            buildMessage('set', key, value, callback);
        },

        getItem: function (key, callback) {
            if (!isApiReady()) {
                return;
            }
            buildMessage('get', key, null, callback);
        },
        removeItem: function (key, callback) {
            if (!isApiReady()) {
                return;
            }
            buildMessage('remove', key, null, callback);
        },
        key: function (index, callback) {
            if (!isApiReady()) {
                return;
            }
            buildMessage('key', index, null, callback);
        },
        getSize: function (callback) {
            if (!isApiReady()) {
                return;
            }
            buildMessage('size', null, null, callback);
        },
        getLength: function (callback) {
            if (!isApiReady()) {
                return;
            }
            buildMessage('length', null, null, callback);
        },
        clear: function (callback) {
            if (!isApiReady()) {
                return;
            }
            buildMessage('clear', null, null, callback);
        },
        wasInit: function () {
            return wasInit;
        }
    };
})();