// Variables used by Scriptable.
// icon-color: green; icon-glyph: dollar-sign;
// Currency. widget for Scriptable. No API key, ads or subscriptions.
// Install guide: https://vishar-currency.pages.dev/install.html
// Tapping the widget opens the web app below. Nothing here needs editing.

const APP_URL = 'https://vishar-currency.pages.dev/';
const DEFAULT_PARAMETER = 'USD:100:GBP,RUB,EUR,AED,KZT,JPY,TRY';
// Widget Parameter syntax: BASE:AMOUNT:OTHER_CURRENCY_CODES
// Example: GBP:250:USD,EUR,RUB,KZT

const FLAGS = {
  USD:'🇺🇸', RUB:'🇷🇺', GBP:'🇬🇧', EUR:'🇪🇺', AED:'🇦🇪', KZT:'🇰🇿', JPY:'🇯🇵', TRY:'🇹🇷',
  KRW:'🇰🇷', EGP:'🇪🇬', CHF:'🇨🇭', CAD:'🇨🇦', AUD:'🇦🇺', CNY:'🇨🇳', INR:'🇮🇳', UAH:'🇺🇦',
  PLN:'🇵🇱', SEK:'🇸🇪', NOK:'🇳🇴', DKK:'🇩🇰', NZD:'🇳🇿', SGD:'🇸🇬', HKD:'🇭🇰', THB:'🇹🇭',
  VND:'🇻🇳', IDR:'🇮🇩', MYR:'🇲🇾', PHP:'🇵🇭', SAR:'🇸🇦', ILS:'🇮🇱', CZK:'🇨🇿', HUF:'🇭🇺',
  RON:'🇷🇴', BGN:'🇧🇬', BRL:'🇧🇷', MXN:'🇲🇽', ZAR:'🇿🇦', GEL:'🇬🇪', AMD:'🇦🇲', AZN:'🇦🇿',
  UZS:'🇺🇿', BYN:'🇧🇾', PKR:'🇵🇰', TWD:'🇹🇼'
};
const GREEN = new Color('#A6CD68');
const WHITE = new Color('#F5F6F2');
const MUTED = new Color('#99A293');
const BG = new Color('#151915');
const now = Date.now();

function parseParameter(value) {
  const pieces = String(value || DEFAULT_PARAMETER).trim().split(':');
  let base = (pieces[0] || 'USD').trim().toUpperCase();
  if (!/^[A-Z]{3}$/.test(base)) base = 'USD';
  let rawAmount = (pieces[1] || '100').replace(/[\s\u00a0']/g, '');
  if (rawAmount.includes('.') || /^\d{1,3}(,\d{3})+$/.test(rawAmount)) rawAmount = rawAmount.replace(/,/g, '');
  else rawAmount = rawAmount.replace(',', '.');
  let amount = Number(rawAmount);
  if (!isFinite(amount) || amount < 0 || amount > 1e12) amount = 100;
  let codes = (pieces[2] || 'GBP,RUB,EUR,AED,KZT,JPY,TRY').split(',').map(x => x.trim().toUpperCase()).filter(x => /^[A-Z]{3}$/.test(x) && x !== base);
  codes = codes.filter((x,i) => codes.indexOf(x) === i).slice(0,8);
  return {base, amount, codes};
}
function formatted(n) {
  if (!isFinite(n)) return '—';
  return n.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ',');
}
function valid(data, base) {
  return Boolean(data && typeof data.date === 'string' && /^\d{4}-\d{2}-\d{2}$/.test(data.date) && data[base.toLowerCase()] && data[base.toLowerCase()][base.toLowerCase()] === 1);
}
async function getRates(base) {
  const fm = FileManager.local();
  const file = fm.joinPath(fm.documentsDirectory(), 'currency-widget-' + base + '-v1.json');
  let saved = null;
  try { if (fm.fileExists(file)) saved = JSON.parse(fm.readString(file)); } catch (e) { console.log('Cannot read previous rate cache: ' + e); }
  if (saved && valid(saved.data, base) && now - saved.checkedAt < 6 * 60 * 60 * 1000) {
    return {data:saved.data, cached:true};
  }
  const urls = [
    'https://cdn.jsdelivr.net/npm/@fawazahmed0/currency-api@latest/v1/currencies/' + base.toLowerCase() + '.json',
    'https://latest.currency-api.pages.dev/v1/currencies/' + base.toLowerCase() + '.json'
  ];
  for (const url of urls) {
    try {
      const request = new Request(url);
      request.timeoutInterval = 9;
      const data = await request.loadJSON();
      if (!valid(data,base)) throw new Error('Invalid API response');
      try { fm.writeString(file,JSON.stringify({data:data,checkedAt:now})); } catch (e) { console.log('Could not save cache: ' + e); }
      return {data:data,cached:false};
    } catch(e) { console.log('Rate endpoint failed: ' + e); }
  }
  return saved && valid(saved.data,base) ? {data:saved.data,cached:true,stale:true} : null;
}
function txt(stack,value,size,color,font) {
  const t=stack.addText(value);
  t.font=font==='bold'?Font.boldSystemFont(size):(font==='mono'?Font.semiboldMonospacedSystemFont(size):Font.systemFont(size));
  t.textColor=color;
  t.lineLimit=1;
  t.minimumScaleFactor=0.6;
  return t;
}
function prettyDate(iso) {
  const m=['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'];
  const p=String(iso).split('-');
  return p.length===3 ? Number(p[2])+' '+(m[Number(p[1])-1]||p[1]) : String(iso);
}
// One rate row: flag + code on the left, amount pushed to the right edge.
function addLine(parent, code, n, fs) {
  const row=parent.addStack();row.layoutHorizontally();row.centerAlignContent();
  txt(row,(FLAGS[code]||'¤')+' '+code,fs.code,MUTED,'normal');
  row.addSpacer();
  const value=txt(row,formatted(n),fs.value,WHITE,'bold');
  value.rightAlignText();
  return row;
}
function rateRows(parent, limit, fs, gap) {
  if (!result) {
    txt(parent,'Rates unavailable',fs.code+1,WHITE,'bold');
    parent.addSpacer(3);
    txt(parent,'Connect and tap to retry',fs.code-2,MUTED,'normal');
    return;
  }
  const exchange=result.data[options.base.toLowerCase()];
  let rendered=0;
  for (const code of options.codes) {
    const rate=exchange[code.toLowerCase()];
    if (!(typeof rate==='number' && isFinite(rate) && rate>0)) continue;
    if (rendered>0) gap===null ? parent.addSpacer() : parent.addSpacer(gap);
    addLine(parent,code,options.amount*rate,fs);rendered++;
    if(rendered>=limit)break;
  }
  if(rendered===0)txt(parent,'Choose other currencies',fs.code,MUTED,'normal');
}
const options = parseParameter(args.widgetParameter);
const result = await getRates(options.base);
const size = config.widgetFamily || 'medium';
const small = size === 'small';
const large = size === 'large' || size === 'extraLarge';
const widget = new ListWidget();
widget.backgroundColor=BG;
widget.spacing=0;
widget.refreshAfterDate=new Date(now + 3*60*60*1000);
if (/^https:\/\/[^\s]+$/i.test(APP_URL)) widget.url = APP_URL;
const info = result ? prettyDate(result.data.date) + (result.stale?' · offline':'') : 'No saved rates';
const baseLabel=(FLAGS[options.base]||'¤')+' '+formatted(options.amount);

if (small) {
  widget.setPadding(13,14,12,14);
  const head=widget.addStack();head.layoutHorizontally();head.centerAlignContent();
  txt(head,'Currency.',12,GREEN,'bold');head.addSpacer();txt(head,options.base,10,MUTED,'normal');
  widget.addSpacer(4);
  txt(widget,baseLabel,20,WHITE,'bold');
  widget.addSpacer();
  rateRows(widget,2,{code:12,value:15},6);
  widget.addSpacer();
  txt(widget,info,9,MUTED,'normal');
} else if (large) {
  widget.setPadding(18,18,16,18);
  const head=widget.addStack();head.layoutHorizontally();head.centerAlignContent();
  txt(head,'Currency.',16,GREEN,'bold');head.addSpacer();txt(head,info,11,MUTED,'normal');
  widget.addSpacer(10);
  txt(widget,baseLabel,30,WHITE,'bold');
  widget.addSpacer(14);
  rateRows(widget,8,{code:15,value:19},null);
  widget.addSpacer(4);
} else {
  // Medium: base amount on the left, four rates in a right-aligned column.
  widget.setPadding(14,16,14,16);
  const main=widget.addStack();main.layoutHorizontally();
  const left=main.addStack();left.layoutVertically();left.size=new Size(112,0);
  txt(left,'Currency.',14,GREEN,'bold');
  left.addSpacer();
  txt(left,FLAGS[options.base]||'¤',20,WHITE,'normal');
  left.addSpacer(2);
  txt(left,formatted(options.amount),22,WHITE,'bold');
  txt(left,options.base,11,MUTED,'normal');
  left.addSpacer();
  txt(left,info,9,MUTED,'normal');
  main.addSpacer(14);
  const right=main.addStack();right.layoutVertically();
  rateRows(right,4,{code:13,value:17},null);
}
Script.setWidget(widget);
if (!config.runsInWidget) {
  if(small) await widget.presentSmall(); else if(large) await widget.presentLarge(); else await widget.presentMedium();
}
Script.complete();