/**
 * 
 * 
 * 
 * 
 * 
 * 
 */

function get(url){   
    return new Promise((resolve,reject)=>{
        var xhr = new XMLHttpRequest()
        xhr.open('GET', url, true)
        xhr.onreadystatechange = function(){
            if(this.readyState === 4){
                if(this.readyState === 200){
                    resolve(this.responseText,this)
                }else{
                    var reJson = {code:this.status, response:this.response}
                    reject(reJson. this)
                }
            }
        }
        xhr.send()
    })
}

//general get
function getFunction(url,callback){
    url =url
    const xhr = new XMLHttpRequest()
    xhr.onreadystatechange = () => {
    if ((xhr.readyState === 4 && xhr.status === 200 && xhr.status <= 300) || xhr.status === 304) {
        data =  xhr.responseText
        callback(data)
        }}
    xhr.open('GET', url, true)
    xhr.setRequestHeader("If-Modified-Since","0")
    xhr.send()  
}

//general post
function postFunction(url, reback,data) {
    const xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function (){
    if ( xhr.status === 200 && xhr.readyState === 4 )
        {
        // console.log("post response status is",xhr.responseText)
        reback(xhr.responseText);
        }
        else
        {
        // console.log("xhr state is", xhr.status);
        }
    }
    xhr.open("POST", url, true);
    xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=UTF-8");
    // xhr.setRequestHeader("Content-Type", "application/application/wasm;charset=UTF-8");
    // xhr.setRequestHeader("Access-Control-Allow-Origin: *");
    // xhr.setRequestHeader("Access-Control-Allow-Methods: GET, POST, OPTIONS, PUT, DELETE");
    // xhr.setRequestHeader("Access-Control-Allow-Headers: X-Requested-With, Content-Type");
    xhr.send(data);
}


//put promise
function postPromise(url, data) {
    return new Promise((resolve, reject)=>{
        var xhr = new XMLHttpRequest()
        xhr.open("POST", url, true)
        // xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
        // xhr.setRequestHeader("Content-Type", "application/application/wasm; charset=UTF-8");
        // xhr.setRequestHeader("Access-Control-Allow-Origin: *");
        // xhr.setRequestHeader("Access-Control-Allow-Methods: GET, POST, OPTIONS, PUT, DELETE");
        // xhr.setRequestHeader("Access-Control-Allow-Headers: X-Requested-With, Content-Type");
      
        xhr.onreadystatechange = function () {
            if (this.readyState === 4) {
                if (this.status === 200) {
                    // resolve(JSON.parse(this.responseText), this)
                    resolve(this.responseText)
                } else {
                    // var resJson = { code: this.status, response: this.response }
                    // reject(resJson, this)
                    reject(this.status)
                }
            }
        }
        xhr.send(data)
    })
}

//put promise
function putPromise(url, data) {
    return new Promise((resolve, reject)=>{
        var xhr = new XMLHttpRequest()
        xhr.open("PUT", url, true)
        // xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
        xhr.setRequestHeader("Content-Type", "application/application/wasm; charset=UTF-8");
        // xhr.setRequestHeader("Access-Control-Allow-Origin: *");
        // xhr.setRequestHeader("Access-Control-Allow-Methods: GET, POST, OPTIONS, PUT, DELETE");
        // xhr.setRequestHeader("Access-Control-Allow-Headers: X-Requested-With, Content-Type");
        xhr.onreadystatechange = function () {
            if (this.readyState === 4) {
                if (this.status === 200) {
                    // resolve(JSON.parse(this.responseText), this)
                    resolve(this.responseText)
                } else {
                    // var resJson = { code: this.status, response: this.response }
                    // reject(resJson, this)
                    reject(this.status)
                }
            }
        }
        xhr.send(data)
    })
}