// ── Shared line item helpers ──
// Format stored: "desc,qty,price,discount(0-1),total;desc,..."

let lineCount = 0;

function parseLines(content) {
  if (!content || !content.trim()) return [];
  return content.split(';').map(s => s.trim()).filter(Boolean).map(line => {
    const p = line.split(',');
    return {
      description: p[0] || '', quantity: parseFloat(p[1]) || 0, price: parseFloat(p[2]) || 0,
      discount: parseFloat(p[3]) || 0, total: parseFloat(p[4]) || 0
    };
  });
}

// Build back to "desc,qty,price,discount(0-1),total;" string
function buildContent() {
  let result = '';
  for (let i = 1; i <= lineCount; i++) {
    const row = document.getElementById('line-' + i);
    if (!row) continue;
    const desc = document.getElementById('ld_' + i)?.value || '';
    const qty = parseFloat(document.getElementById('lq_' + i)?.value) || 0;
    const price = parseFloat(document.getElementById('lp_' + i)?.value) || 0;
    const discPct = parseFloat(document.getElementById('ldis_' + i)?.value) || 0;
    const discRaw = discPct / 100; // convert % input to 0-1 for storage
    const total = parseFloat(document.getElementById('lt_' + i)?.value) || 0;
    result += desc + ',' + qty + ',' + price + ',' + discRaw + ',' + total + ';';
  }
  return result;
}

function calcLine(n) {
  const qty = parseFloat(document.getElementById('lq_' + n)?.value) || 0;
  const price = parseFloat(document.getElementById('lp_' + n)?.value) || 0;
  const discPct = parseFloat(document.getElementById('ldis_' + n)?.value) || 0;
  const total = qty * price * (1 - discPct / 100);
  const el = document.getElementById('lt_' + n);
  if (el) el.value = Math.round(total * 100) / 100;
  calcTotal();
}

function calcTotal() {
  let t = 0;
  for (let i = 1; i <= lineCount; i++) {
    const el = document.getElementById('lt_' + i);
    if (el && document.getElementById('line-' + i)) t += parseFloat(el.value) || 0;
  }
  const gt = document.getElementById('grand-total');
  if (gt) gt.textContent = 'R\u00a0' + t.toLocaleString('en-ZA', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
  return t;
}

function addLine(data) {
  lineCount++;
  const n = data ? lineCount : lineCount;
  const d = data || { description: '', quantity: 1, price: 0, discount: 0, total: 0 };
  // discount stored as 0-1, display as 0-100 %
  const discDisplay = data ? (d.discount * 100) : 0;

  const row = document.createElement('tr');
  row.id = 'line-' + n;
  const s = (id, val, ev) => `<input type="number" id="${id}" value="${val}" step="0.01" min="0"
    onchange="${ev}" oninput="${ev}"
    style="width:100%;padding:6px 8px;background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--radius);color:var(--text-primary);font-size:13px;">`;
  row.innerHTML = `
    <td><textarea id="ld_${n}" rows="2" style="resize:none;width:100%;padding:6px 8px;background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--radius);color:var(--text-primary);font-size:13px;">${d.description || ''}</textarea></td>
    <td>${s('lq_' + n, d.quantity || 1, 'calcLine(' + n + ')')}</td>
    <td>${s('lp_' + n, d.price || 0, 'calcLine(' + n + ')')}</td>
    <td>${s('ldis_' + n, discDisplay, 'calcLine(' + n + ')')}</td>
    <td><input type="number" id="lt_${n}" value="${d.total || 0}" readonly
      style="width:100%;padding:6px 8px;background:var(--bg-raised);border:1px solid var(--border);border-radius:var(--radius);color:var(--gold);font-size:13px;font-family:'DM Mono',monospace;font-weight:600;"></td>
    <td><button onclick="removeLine(${n})"
      style="background:rgba(224,49,49,.1);border:1px solid rgba(224,49,49,.25);color:var(--red);border-radius:var(--radius);padding:4px 10px;cursor:pointer;font-size:12px;">✕</button></td>`;
  document.getElementById('lines-body').appendChild(row);
  if (data) calcLine(n); // recalculate to confirm total
}

function removeLine(n) {
  document.getElementById('line-' + n)?.remove();
  calcTotal();
}