import {estimateHomeCosts} from './homebuyer-cost.mjs';

const fields = [
  ['price','Home price ($)',350000],['down','Down payment ($)',35000],
  ['rate','Annual note rate (%)',6],['years','Fixed term (years)',30],
  ['closing','Closing costs excluding prepaids ($)',7000],
  ['prepaids','Prepaids and initial escrow ($)',3000],
  ['credits','Applicable confirmed credits ($)',3000],
  ['deposit','Deposit already credited ($)',5000],
  ['tax','Annual property tax ($)',3600],['insurance','Annual homeowners insurance ($)',1500],
  ['pmi','Monthly mortgage insurance ($)',90],['hoa','Monthly HOA dues ($)',0],
  ['maintenance','Annual maintenance reserve ($)',3500],
  ['overlap','Prepaid taxes or insurance also counted in year one ($)',1200],
];
const form = document.querySelector('[data-homebuyer-form]');
const results = document.querySelector('[data-homebuyer-result]');
const status = document.querySelector('[data-homebuyer-status]');
const money = new Intl.NumberFormat('en-US',{style:'currency',currency:'USD'});
const compare = form.querySelector('[name="compare"]');
const lists = [...form.querySelectorAll('[data-scenario]')];
const print = document.querySelector('[data-homebuyer-print]');
for (const [index,list] of lists.entries()) {
  for (const [name,caption,initial] of fields) {
    const label = document.createElement('label');
    const input = document.createElement('input');
    label.append(caption);
    input.name = name + index;
    input.type = 'number';
    input.required = true;
    input.min = '0';
    input.max = String(name === 'rate' ? 100 : name === 'years' ? 50 : 1000000000);
    input.step = name === 'years' ? '1' : '.01';
    input.value = String(index === 1 && name === 'price' ? 375000 : initial);
    label.append(input);
    list.append(label);
  }
}
function updateComparison() {
  lists[1].disabled = lists[1].hidden = !compare.checked;
}
updateComparison();
compare.addEventListener('change',updateComparison);
function hideResults() {
  results.hidden = true;
  print.hidden = true;
  status.textContent = '';
}
form.addEventListener('input',hideResults);
form.addEventListener('submit',event=>{
  event.preventDefault();
  hideResults();
  const data = new FormData(form);
  try {
    const modeled = (compare.checked ? [0,1] : [0]).map(index=>{
      try {
        return estimateHomeCosts(Object.fromEntries(fields.map(([name])=>[name,Number(data.get(name+index))])));
      } catch (error) {
        throw new Error('Home '+(index ? 'B' : 'A')+': '+error.message);
      }
    });
    const table = document.createElement('table');
    const caption = table.createCaption();
    caption.textContent = 'Estimated homebuying costs in US dollars';
    const header = table.createTHead().insertRow();
    for(const label of ['Estimate',...modeled.map((_,i)=>i?'Home B':'Home A')]){
      const cell=document.createElement('th');
      cell.scope='col';cell.textContent=label;header.append(cell);
    }
    const body = table.createTBody();
    for (const [key,label] of Object.entries({
      cashToClose:'Cash still due at closing',totalUpfront:'Total upfront cash including deposit',
      principalInterest:'Monthly principal and interest',monthlyHousing:'Estimated monthly housing budget',
      firstYear:'Estimated cash budget through the first year',
    })) {
      const row = body.insertRow();
      const title = document.createElement('th');
      title.scope = 'row';title.textContent = label;row.append(title);
      for(const item of modeled)row.insertCell().textContent=money.format(item[key]);
    }
    results.replaceChildren(table);
    results.hidden = print.hidden = false;
    status.textContent = modeled.length === 2 ? 'Comparison ready for both homes.' : 'Estimate ready for Home A.';
    window.gtag?.('event',modeled.length === 2?'homebuyer_comparison_complete':'homebuyer_estimate_complete',{tool:'homebuyer-cost-comparison',surface:window.self===window.top?'site':'embed'});
  } catch(error) {
    status.textContent = error.message;
  }
});
print.addEventListener('click',()=>window.print());
const attribution = document.querySelector('[data-homebuyer-attribution]');
if (attribution && new URLSearchParams(location.search).get('attribution') === 'off') attribution.hidden = true;
const partner = new URLSearchParams(location.search).get('partner');
if (attribution) {
  const destination = new URL(attribution.closest('a').href);
  destination.searchParams.set('utm_source',partner && /^[a-z0-9-]{1,60}$/.test(partner) ? partner : 'homebuyer_widget');
  destination.searchParams.set('utm_medium','referral');
  destination.searchParams.set('utm_campaign','homebuying_costs');
  attribution.closest('a').href = destination.href;
}