{% extends "base.html" %}
{% block content %}
  <h1>{% if is_new %}{{ t('form_new_ledger') }}{% else %}{{ t('form_edit_ledger') }}{% if ch.room %} – {{ t('form_room', room=ch.room) }}{% endif %}{% endif %}</h1>
  <form class="card" method="post"{% if is_new %} action="{{ url_for('ledger_new') }}"{% endif %}>
    {% if is_new %}
    <div class="field"><label>{{ t('col_room') }}</label>
      <select name="room_id"><option value="">—</option>
        {% for r in rooms %}<option value="{{ r.id }}">{{ r.number }}</option>{% endfor %}</select></div>
    {% endif %}
    <div class="grid2">
      <div class="field"><label>{{ t('col_occupant') }}</label>
        <input type="text" name="occupant" value="{{ ch.occupant or '' }}" autofocus></div>
      <div class="field"><label>{{ t('col_gb_number') }}</label>
        <input type="text" name="gb_ref" value="{{ ch.gb_ref or '' }}"></div>
    </div>
    <div class="grid2">
      <div class="field"><label>{{ t('col_from') }}</label>
        <input type="date" name="period_from" value="{{ ch.period_from or '' }}"></div>
      <div class="field"><label>{{ t('col_to') }}</label>
        <input type="date" name="period_to" value="{{ ch.period_to or '' }}"></div>
    </div>
    <div class="grid2">
      <div class="field"><label>{{ t('col_persons') }}</label>
        <input type="number" name="persons" step="1" min="0" value="{{ ch.persons if ch.persons is not none else '' }}"></div>
      <div class="field"><label>{{ t('col_qty') }}</label>
        <input type="number" name="quantity" step="any" min="0" value="{{ ch.quantity if ch.quantity is not none else '' }}"></div>
    </div>
    <div class="grid2">
      <div class="field"><label>{{ t('col_unit_type') }}</label>
        <select name="unit_type">
          {% for v, lbl in t('unit_types').items() %}
            <option value="{{ v }}" {{ 'selected' if ch.unit_type==v }}>{{ lbl }}</option>{% endfor %}</select></div>
      <div class="field"><label>{{ t('col_rate_per_unit') }}</label>
        <input type="number" name="gross_per_unit" step="0.01" min="0" value="{{ ch.gross_per_unit if ch.gross_per_unit is not none else '' }}"></div>
    </div>
    <div class="grid2">
      <div class="field"><label>{{ t('col_amount_eur') }}</label>
        <input type="number" name="betrag" step="0.01" min="0" value="{{ ch.betrag if ch.betrag is not none else '' }}"></div>
      <div class="field"><label>{{ t('col_tourism_tax') }} (€)</label>
        <input type="number" name="tourism_tax" step="0.01" min="0" data-rate="{{ tourism_rate }}"
               value="{{ ch.tourism_tax if ch.tourism_tax is not none else '' }}"></div>
    </div>
    <div class="grid2">
      <div class="field"><label>{{ t('col_art') }}</label>
        <input type="text" name="art" value="{{ ch.art or '' }}"></div>
      <div class="field"></div>
    </div>
    <div class="grid2">
      <div class="field"><label>{{ t('col_payer') }}</label>
        <input type="text" name="payer" value="{{ ch.payer or '' }}"></div>
      <div class="field"><label>{{ t('col_invoice') }}</label>
        <input type="text" name="rnr" value="{{ ch.rnr or '' }}"></div>
    </div>
    <div class="field"><label>{{ t('col_notes') }}</label>
      <input type="text" name="notes" value="{{ ch.notes or '' }}"></div>
    <div class="grid2">
      <div class="field"><label>{{ t('col_payment') }}</label>
        <select name="paid_status">
          <option value="" {{ 'selected' if not ch.paid_status }}>—</option>
          <option value="paid" {{ 'selected' if ch.paid_status=='paid' }}>{{ t('payment_paid') }}</option>
          <option value="open" {{ 'selected' if ch.paid_status=='open' }}>{{ t('payment_open') }}</option>
          <option value="cash" {{ 'selected' if ch.paid_status=='cash' }}>{{ t('payment_cash') }}</option></select></div>
      <div class="field"><label>{{ t('lbl_paid_date') }}</label>
        <input type="date" name="paid_date" value="{{ ch.paid_date or '' }}"></div>
    </div>
    {# Payments in parts, each with date and amount (paid without the Ortstaxe, or in two instalments).
       For the usual ONE full payment "bezahlt am" above is enough. #}
    <div class="field"><label>{{ t('lbl_payments') }}</label>
      <div id="payLines">
        {% for d, a in (ch.payments or []) %}
        <div class="pay-line"><input type="date" name="pay_date" value="{{ d }}" required>
          <input type="number" name="pay_amount" step="0.01" min="0" value="{{ '%.2f'|format(a) }}"></div>
        {% endfor %}
        <div class="pay-line"><input type="date" name="pay_date">
          <input type="number" name="pay_amount" step="0.01" min="0" placeholder="€"></div>
      </div>
      <button type="button" class="btn secondary small" id="addPayment">{{ t('btn_add_payment') }}</button>
      <small>{{ t('hint_payments') }}</small></div>
    <div class="formactions">
      <button class="btn" type="submit">{{ t('btn_save') }}</button>
      {% if not is_new %}
      {# month end: bill up to the invoice date and let the occupancy run on from that day #}
      <button class="btn secondary" type="submit" name="action" value="continue"
              title="{{ t('hint_continue') }}">{{ t('btn_continue') }}</button>
      {% endif %}
      <a class="btn secondary" href="{{ url_for('ledger') }}">{{ t('btn_cancel') }}</a>
    </div>
  </form>
  {% if ch.id %}
  <form class="formactions" method="post" action="{{ url_for('ledger_delete', charge_id=ch.id) }}"
        onsubmit="return confirm('{{ t('confirm_delete') }}')">
    <button class="btn danger" type="submit">{{ t('btn_delete') }}</button>
  </form>
  {% endif %}
  <script>
    // Editing Satz, Anzahl or Personen recomputes the Betrag the way the ledger counts it:
    // Anzahl x Satz x PERSONEN (2 Pers. x 1 Woche x 161 = 322, not 161). Betrag stays a normal input,
    // so a negotiated amount typed by hand sticks until one of the three changes again.
    const rate = document.querySelector('[name=gross_per_unit]'),
          qty = document.querySelector('[name=quantity]'),
          betrag = document.querySelector('[name=betrag]'),
          taxe = document.querySelector('[name=tourism_tax]'),
          persons = document.querySelector('[name=persons]'),
          from = document.querySelector('[name=period_from]'),
          to = document.querySelector('[name=period_to]'),
          unit = document.querySelector('[name=unit_type]');
    function recalc() {
      const r = parseFloat(rate.value), q = parseFloat(qty.value), p = parseFloat(persons.value) || 1;
      if (!isNaN(r) && !isNaN(q)) betrag.value = (q * r * p).toFixed(2);
    }
    // Changing Von/Bis fills the Anzahl: for Wochen a started week counts in full from 4 nights on, like the
    // invoice (compute.weeks_for_period: 12 nights are 2 weeks), a shorter stay the fraction priced by
    // hand; the plain day count for Tag/Nacht. Anzahl stays an ordinary input, so a value typed by hand
    // stands until a date moves again. Monat/gesamt derive nothing.
    const PER_UNIT = { week: 7, day: 1, night: 1 };
    function recalcQty() {
      const a = Date.parse(from.value), b = Date.parse(to.value), per = PER_UNIT[unit.value];
      if (isNaN(a) || isNaN(b) || !per) return;
      const nights = (b - a) / 86400000;                    // both dates parse as UTC -> exact day count
      qty.value = unit.value === 'week' && nights >= 4 ? Math.ceil(nights / 7) : +(nights / per).toFixed(6);
      recalc();
      recalcTaxe(nights);
    }
    // Ortstaxe = Nächte x Satz x Personen, but only for a stay of at most 10 nights: longer professional
    // stays are exempt (T-AAG §4). A hand-typed amount is left alone, like the Betrag.
    function recalcTaxe(nights) {
      const rate = parseFloat(taxe.dataset.rate), p = parseFloat(persons.value) || 1;
      if (isNaN(rate) || nights <= 0) return;
      taxe.value = nights > 10 ? '' : (nights * rate * p).toFixed(2);
    }
    // entering a payment date means paid — set the dropdown with it instead of asking for it twice
    const paidStatus = document.querySelector('[name=paid_status]'),
          paidDate = document.querySelector('[name=paid_date]'),
          payLines = document.getElementById('payLines');
    paidDate.addEventListener('change', function () {
      if (paidDate.value && !paidStatus.value) paidStatus.value = 'paid';
    });
    // Payments in parts decide by themselves, like the server (repo._settle): once they cover Betrag +
    // Ortstaxe the row is paid — on the day of the last one —, otherwise it stays open. Typing an amount
    // requires a date with it: a payment without a date belongs to no quarter.
    function checkPayments() {
      let sum = 0, last = '';
      payLines.querySelectorAll('.pay-line').forEach(function (z) {
        const d = z.querySelector('[name=pay_date]'), a = parseFloat(z.querySelector('[name=pay_amount]').value);
        d.required = !isNaN(a);
        if (!isNaN(a) && d.value) { sum += a; if (d.value > last) last = d.value; }
      });
      if (!last) return;
      paidStatus.value = sum + 0.005 >= total() ? 'paid' : 'open';
      paidDate.value = last;
    }
    payLines.addEventListener('input', checkPayments);
    document.getElementById('addPayment').addEventListener('click', function () {
      const line = payLines.lastElementChild.cloneNode(true);
      line.querySelectorAll('input').forEach(function (i) { i.value = ''; i.required = false; });
      payLines.appendChild(line);
      line.querySelector('input').focus();
    });
    function total() {
      return (parseFloat(betrag.value) || 0) + (parseFloat(taxe.value) || 0);
    }
    rate.addEventListener('input', recalc);
    qty.addEventListener('input', recalc);
    persons.addEventListener('input', recalc);
    [from, to, unit, persons].forEach(el => el.addEventListener('change', recalcQty));
  </script>
{% endblock %}