Get all billable hours for a project from Freshbooks

billablehours.js

  let getBillableHours = function(projectId) {

          function sumTimes(times) {

            let billableHours = 0;
            for(let time of times) {
              billableHours += parseFloat(time.hours);
            }

            return billableHours;
          }

          return new Promise((resolve, reject) => {
            let timeEntries = new freshbooks.Time_Entry();
            let billableHours = 0;
            timeEntries.list({project_id: projectId, per_page: 100}, function(err, times, options) {

              if(err) {
                reject(err);
              } else {

                // grab the first page of times
                billableHours = sumTimes(times);

                // if there are more pages to process, get those...
                if(options.pages > 1) {
                  let pagesToProcess = [];
                  for(let i = 2; i <= options.pages; i++) {
                    pagesToProcess.push(new Promise((done, reject) => {
                      timeEntries.list({project_id: projectId, per_page: 100, page: i }, function(err, times, options) {
                        let extraHours = sumTimes(times);

                        done(extraHours);
                      });
                    }));
                  }

                  Promise.all(pagesToProcess).then((extraTimes) => {

                    freshbooksData.billableHours = billableHours + extraTimes.reduce(function(a,b) { return a + b; });
                    resolve(freshbooksData.billableHours);
                  });
                } else {
                  freshbooksData.billableHours = billableHours;
                  resolve(freshbooksData.billableHours);
                }
              }
            });
          });
        };