git.scottworley.com Git - inverse-tax/blob - tax_ui.js

   1 "use strict";
   2
   3 function load_tax_table(table_id, deductible_id = null) {
   4   const deductible = deductible_id == null ? 0.0 : parseFloat(document.getElementById(deductible_id).value);
   5   return apply_deductible(parse_tax_table(document.getElementById(table_id).value), deductible);
   6 }
   7
   8 function format_number(n) {
   9   return n.toLocaleString('en', {useGrouping:true, style: 'currency', currency: 'USD'});
  10 }
  11
  12 function calculate() {
  13   const tax_tables = [
  14     load_tax_table('tax_table_1', 'deductible_1'),
  15     load_tax_table('tax_table_2', 'deductible_2'),
  16     load_tax_table('tax_table_3'),
  17     load_tax_table('tax_table_4')
  18   ];
  19   const after_tax = parseFloat(document.getElementById('after_tax').value);
  20
  21   const merged_tax_table = tax_tables.reduce(merge_tax_tables);
  22   const before_tax = invert(merged_tax_table)(after_tax);
  23   const taxes = tax_tables.map(t => tax(t, before_tax));
  24
  25   document.getElementById('before_tax').textContent = format_number(before_tax);
  26   document.getElementById('tax_1').textContent = format_number(taxes[0]);
  27   document.getElementById('tax_2').textContent = format_number(taxes[1]);
  28   document.getElementById('tax_3').textContent = format_number(taxes[2]);
  29   document.getElementById('tax_4').textContent = format_number(taxes[3]);
  30   document.getElementById('after_tax_verification').textContent = format_number(before_tax - sum(taxes));
  31 }