var currentCustomer;
var apiMode = 0;
const myShopifyDomain = window.Shopify.shop; // Makes sure to get the myshopify domain instead of the custom domain

if(document.readyState === 'loading') {
  document.addEventListener('DOMContentLoaded', startScript());
} else {
  startScript();
}

/**
 * Gets a script from a specified source which is then added to the page in order to be
 * executed from the function that is passed as argument
 * @param {String} url The source of the script
 * @param {Oject} success The function that will be executed after getting the script
 */
function getScript(url,success){
  var head = document.getElementsByTagName("head")[0], done = false;
  var script = document.createElement("script");
  script.src = url;

  script.onload = script.onreadystatechange = function(){
      if ( !done && (!this.readyState ||
              this.readyState == "loaded" || this.readyState == "complete") ) {
          done = true;
          success();
      }
  };

  head.appendChild(script);
}

/**
 * The main validations are done here.
 * The script checks if the domain is valid and the customer ID exists,
 * respectively.
 * If both values are valid, then the token generation is executed.
 */
function startScript() {
  if (myShopifyDomain !== undefined && __st.cid !== undefined) {
    currentCustomer = __st.cid;
    getScript('https://cdn.bayonet.io/fingerprinting-2.0.min.js',function(){ 
      initBayonet();
    });
  }
}

/**
 * Generates the device fingerprint token.
 * First it retrieves the API key from the server, if the key has
 * a valid value, then the generation of the token proceeds.
 * Once the token is generated, the script executes the callback
 * function to assign that token to the customer.
 */
async function initBayonet() {
  var apiData = await getApiData();

  if (apiData && apiData.length === 3) {
    if (parseInt(apiData[0]) === 1) {
      apiMode = apiData[2];
      _bayonet.init({
        js_key: apiData[1],
        callback_function: "getResponse"
      });
      _bayonet.track();
    }
  }
}

/**
 * Gets the response from requesting the API data corresponding to the
 * Device Fingerprint API which includes the current active mode,
 * the API key for a shop and the current API mode.
 * It returns either an array containing the active mode, the key and
 * the API mode or null if an error occurs.
 */
async function getApiData() {
  var apiData = null;
  const url = `/tools/bayonet-fingerprint/?shopDomain=${myShopifyDomain}&requestOrigin=fingerprintScript`;
  const params = {
    method: "GET"
  };

  await fetch(url, params)
  .then(function(response) {
    return response.json();
  })
  .then(function(data) {
    apiData = data.data;
  })
  .catch(function(error) {
    console.log(error);
  });

  return apiData;
}

/**
 * Validates if a token was actually generated; and if that is true the script
 * makes a call to the server to set that token to the logged in customer.
 * @param {Object} response The response retrieved from the token generation
 */
function getResponse(response) {
  if (response.bayonet_fingerprint_token) {
    const url = `/tools/bayonet-fingerprint/`;
    const requestBody = {
      "shopDomain": myShopifyDomain,
      "customer": currentCustomer,
      "token": response.bayonet_fingerprint_token,
      "requestOrigin": "fingerprintScript",
      "apiMode": apiMode
    };
    const params = {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json'
      },
      body: JSON.stringify(requestBody)
    };

    fetch(url,params)
    .catch(function(error) {
      console.log(error);
    });
  }
}