const o = require('odata').o;
//For polyfill, v16.20.2
const fetch = require('node-fetch');
global.Request = fetch.Request;       // Polyfill for Request
global.Headers = fetch.Headers;       // Polyfill for Headers
global.Response = fetch.Response;     // Polyfill for Response
global.fetch = fetch;                 // Polyfill for Fetch

// OAuth2.0 details
const tokenUrl = 'https://login.microsofxxxxxxx.com/xxxxx-xxxx-xxxx-xxxx-xxxxxx/oauth2/v2.0/token';
const clientId = 'yyyyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy';
const clientSecret = 'xxxyyyxxxxyyyyxxxxxx';
const scope = 'https://api.busixxxxxxx.yyyyyyy.zzzzz/.default';

//Base URL
BC_URL = 'https://api.businesscexxxxx.zzzzzzzz.com/v2.0/aaaaaaaa-bbbb-bbbb-bbbb-bbbbbbbbbbbb/Dev/api/updateAB/pcws/v2.0/companies(vvvvvvvv-gggg-gggg-gggg-gggggggggggg)/';

//Token data for OAuth2.0
let tokenCreatedDateTime = null;
let tokenExpirationInSeconds = null;
let accessToken = null;
let tokenExpiryDateTime = null;

// Oauth2.0 handler, setting the Authorization when fetching the oauth2.0 token 
let oHandler = o(BC_URL, {
  headers: {
    //Authorization: `Bearer ${currentOathToken}`,  
    Authorization: ``,  
    'Content-type': 'application/json;odata=verbose'
  }
});


//Creates a new valid oauth2.0 token
async function getOAuthToken() {
    const params = new URLSearchParams({
      client_id: clientId,
      client_secret: clientSecret,
      scope: scope,
      grant_type: 'client_credentials'  // Use client_credentials flow
    });
  
    const response = await fetch(tokenUrl, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded'
      },
      body: params.toString()
    });
  
    const tokenData = await response.json();
    tokenCreatedDateTime = new Date();

  
    if (!response.ok) {
      throw new Error(`Error fetching token: ${tokenData.error_description}`);
    }
  
    //set access token = 
    accessToken = tokenData.access_token; 
    //get expiration time in seconds
    tokenExpirationInSeconds = tokenData.expires_in;

    //Time for token created
    tokenCreatedDateTime = new Date();  
    //set expiration time for access token (in seconds)
    tokenExpiryDateTime = new Date(tokenCreatedDateTime.getTime() + tokenExpirationInSeconds * 1000);// getTime return time in miliseconds


    //Create the handler here
    //oHandler = await createOHandler();

    //Print all values
    console.log("Token created at time: " + tokenCreatedDateTime)
    console.log("Token expires in: " + tokenExpiryDateTime);
    console.log();
    console.log("The new Token created is:");
    console.log(accessToken);


    //The return token
    return tokenData.access_token;
  }

    //Returns a bool 
    function isTokenExpired(){
      letCurrentDate = new Date();
      return !accessToken || letCurrentDate >= tokenExpiryDateTime;
    }

    //Returna valid oauth2.0 token
    async function getValidToken(){
      console.log();
      console.log();
      console.log('Token validyCheck made at time: ' + new Date());
      console.log();
      
      if (isTokenExpired()){ 
        console.log('Token is expired or not present. Fetching a new one from API...');
        return await getOAuthToken();        
      }
      
      console.log('Using existing token that expiras at - ' + tokenExpiryDateTime + ' - Current active token is');
      console.log(accessToken);
      return accessToken;
    }
    
    //Creates a new OHandler
    async function createOHandler() {
      //Gets a new OR existing token
      let currentOathToken = await getValidToken();

      //This section creates a new hander      
      let oHandlerTemp = o(BC_URL, {
        headers: {
          Authorization: `Bearer ${currentOathToken}`,  // Use the OAuth 2.0 token
          //Authorization: `Bearer ${accessToken}`,  // Use the OAuth 2.0 token
          'Content-type': 'application/json;odata=verbose'
        }
      });

      //oHandler = oHandlerTemp;
    
      return oHandlerTemp;            
    }

    
    async function getOHandler(){
      //Gets a new OR existing token
      let currentOathToken = await getValidToken();

      //This section updates the handler with token
      oHandler.headers.Authorization = `Bearer ${currentOathToken}`;

      return oHandler;
    }



//Fetching all products
async function unitSizes() {
    try {
      const queryParams =
      {
        $top: 3 //Limit to 3 result elements  
      };
  
      let oHandlerTemp = await createOHandler();
      console.log(oHandlerTemp);

      //let response = await oHandlerTemp.get('itemUnitofMeasures').query(queryParams);   
      //const response = await oHandler.get('itemUnitofMeasures').query(queryParams);      
      //const response = oHandler.get('itemUnitofMeasures').query(queryParams);
      //console.log(response);
    }
    catch (error) {
      console.error('Error units sizes products:', error);
    }
  }


  async function runEveryMinute() {
    //console.log("This runs every minute.");
    
    //Fectes the valid token correctly every time
    //await getValidToken(); // Await the async function

    await unitSizes();
}

// Run the function immediately and then set an interval
runEveryMinute(); // Call it once immediately

//setInterval(runEveryMinute, 10000); // Set interval to run every 10 seconds
setInterval(runEveryMinute, 60000); // Set interval to run every minute
//setInterval(runEveryMinute, 300000); // Set interval to run every 5 minute
//setInterval(runEveryMinute, 600000); // Set interval to run every 10 minute