/*
 	 * @author Robert Strutts
	 * @copyright 2019
     * @license MIT
     * AJAX
     */

    tts.grab_form = function (form_id) {
        try {
            let myForm = document.getElementById(form_id);
            let arr = {};
            for (var i = 0; i < myForm.elements.length; i++) {
                let id = myForm.elements[i].id;
                let value = myForm.elements[i].value;
                let node = myForm.elements[i].nodeName;
                if ((node == "INPUT" || node == "TEXTAREA" || node == "SELECT") && (typeof id !== "undefined" && id !== "")) {
                    arr[id] = value;
                }
            }
            return arr;
        } catch (e) {
            tts.logger(e);
            return false;
        }
    };

    function json_parse(json) {
        try {
            var obj = JSON.parse(json);
            var unfetched = obj.unfetched;
            if (typeof unfetched !== "undefined") {
                console.warn(`You have some unFetched JSON Vars: ${unfetched}`);
            }
            var err = obj.error;
            if (typeof err === "undefined") {
                return obj;
            } else if (err !== null) {
                throw err;
            }
        } catch (e) {
            return e;
        }
    }

    tts.send_json = function (php_script, args) {
        let myPromise = new Promise(function (myResolve, myReject) {
            if (args === false) {
                let nodata = "No Data from Form!";
                throw nodata;
            }
            var xmlhttp = new XMLHttpRequest();   // new HttpRequest instance
            xmlhttp.open("POST", php_script);
            xmlhttp.setRequestHeader("Content-Type", "application/json;charset=UTF-8");

            xmlhttp.onreadystatechange = function () {
                if (this.readyState == 4) {
                    if (this.status == 200) {
                        myResolve(json_parse(this.response));
                    } else {
                        myReject(json_parse(this.response));
                    }
                }
            };
            xmlhttp.send(JSON.stringify(args));
        });
        return myPromise;
    };

    tts.Post = function (url, data) {
        return new Promise((resolve, reject) => {
            var request = new XMLHttpRequest();
            request.open("POST", url, true);
            request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
            request.onload = function (d) {
                resolve(d.currentTarget.responseText);
            };
            try {
                request.send(data);
            } catch (err) {
                reject(err);
            }
        });
    };

    function doProgress(eventName, evt) {
        if (eventName !== false && evt.lengthComputable) {
            var percentComplete = (evt.loaded / evt.total) * 100;
            var pc = Math.round(percentComplete);
            var event = new CustomEvent(eventName, {detail: {progress: pc}});
            var el = document.getElementsByTagName('body')[0];
            el.dispatchEvent(event);
        }
    }
    function setHTML(elementID, html) {
        try {
            return document.getElementById(elementID).innerHTML = html;
        } catch (e) {
            tts.logger("ID of " + elementID + " not found...!", "warn");
        }
    }
    tts.lastAjax = false; /* So you can use the xmlHttp Request later on... if not cached... */
    let ajaxCallback = function (url, resolve, reject, options) {
        var doCache = tts.getValue(options.useCache, false), eventName = tts.getValue(options.eventName, false);
        var elementID = tts.getValue(options.elementID, false), ts = tts.getValue(options.ts, "");
        if (doCache) {
            var myCache = new tts.store();
            if (myCache) {
                let stored_data = myCache.get(url + ts); /* timestamp cache buster */
                let done = tts.getValue(stored_data, false);
                if (!tts.isEmpty(done)) {
                    tts.logger('Used cache, on ' + url + ' !');
                    tts.lastAjax = false;
                    doProgress(eventName, {lengthComputable: true, loaded: 100, total: 100});
                    if (elementID) {
                        setHTML(elementID, stored_data);
                    }
                    return resolve(stored_data);
                } else {
                    tts.logger('Adding to cache, for ' + url + ' !');
                }
            } else {
                tts.logger('No Cache Engine enabled, for ' + url + ' !');
            }
        } else {
            tts.logger('No Caching, for ' + url);
        }
        var xmlHttp = new XMLHttpRequest();
        tts.lastAjax = xmlHttp;
        xmlHttp.upload.addEventListener("progress", function (evt) {
            doProgress(eventName, evt);
        });
        xmlHttp.addEventListener("progress", function (evt) {
            doProgress(eventName, evt);
        });
        xmlHttp.onreadystatechange = function () {
            var result;
            if (xmlHttp.readyState == 4) {
                if (xmlHttp.status == 200) {
                    switch (options.dataType) {
                        case 'xml':
                            result = xmlHttp.responseXML;
                            break;
                        case 'json':
                            result = JSON.parse(xmlHttp.responseText);
                            break;
                        default:
                            result = xmlHttp.responseText;
                            break;
                    }
                    if (myCache && doCache) {
                        myCache.set(url + ts, result);
                    }
                    if (elementID) {
                        setHTML(elementID, result);
                    }
                    resolve(result);
                } else if (reject) {
                    reject('Ajax error: ' + xmlHttp.status + ' url: ' + url);
                }
            }
        };
        xmlHttp.open(options.method || 'GET', url, true);
        if (options.headers) {
            for (var key in options.headers) {
                xmlHttp.setRequestHeader(key, options.headers[key]);
            }
        }
        xmlHttp.send(options.data || '');
    };
    tts.ajax = function (url, options) {
        if (typeof options === "undefined") {
            options = {};
        }
        return new Promise(function (resolve, reject) {
            ajaxCallback(url, resolve, reject, options);
        });
    };

    /*
     * End of AJAX 
     */