@extends('layouts.app')

@section('content')
<div class="container-xxl px-0">
    <div class="module-shell">

        {{-- Nagłówek --}}
        <div class="d-flex justify-content-between align-items-start mb-4">
            <div>
                <h1 class="h3 mb-1">Nowa faktura – pozycje</h1>
                <p class="text-muted mb-0">
                    Krok 3 z 5 &mdash; pozycje faktury (<code>FaWiersz</code> w FA(3))
                </p>
            </div>
            <div class="text-end small text-muted d-none d-md-block">
                <div>Struktura: <strong>FA(3)</strong></div>
                <div>Elementy: <code>P_7</code>, <code>P_8A</code>, <code>P_8B</code>, ceny netto/brutto, VAT i wartości</div>
            </div>
        </div>

        {{-- Pasek kroków kreatora --}}
        <ul class="nav nav-pills nav-justified mb-4 small invoice-stepper">
            <li class="nav-item">
                <a href="{{ route('faktury.edit.header', $faktura->id) }}" class="nav-link">
                    <span class="badge bg-light text-muted me-2">1</span> Ogólne
                </a>
            </li>
            <li class="nav-item">
                <a href="{{ route('faktury.edit.parties', $faktura->id) }}" class="nav-link">
                    <span class="badge bg-light text-muted me-2">2</span> Podmioty
                </a>
            </li>
            <li class="nav-item">
                <span class="nav-link active">
                    <span class="badge bg-light text-primary me-2">3</span> Pozycje
                </span>
            </li>
            <li class="nav-item">
                <span class="nav-link disabled">
                    <span class="badge bg-light text-muted me-2">4</span> Płatność
                </span>
            </li>
            <li class="nav-item">
                <span class="nav-link disabled">
                    <span class="badge bg-light text-muted me-2">5</span> Podsumowanie
                </span>
            </li>
        </ul>

        {{-- Błędy walidacji --}}
        @if($errors->any())
            <div class="alert alert-danger alert-dismissible fade show" role="alert">
                <strong>Nie udało się zapisać pozycji faktury.</strong>
                <p class="mb-1">Popraw wskazane pola (ilości, ceny, stawki VAT itd.).</p>
                <ul class="mb-0 ps-3">
                    @foreach($errors->all() as $e)
                        <li>{{ $e }}</li>
                    @endforeach
                </ul>
                <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Zamknij"></button>
            </div>
        @endif

        <form method="POST" action="{{ route('faktury.update.lines', $faktura->id) }}" novalidate>
            @csrf

            {{-- Główna sekcja z tabelą pozycji --}}
            <div class="invoice-section-soft mb-3">
                <div class="d-flex justify-content-between align-items-center">
                    <div class="d-flex flex-column">
                        <span class="fw-semibold">Pozycje faktury</span>
                        <small class="text-muted">
                            Dla każdej pozycji wymagaj: <code>P_7</code>, <code>P_8A</code>, <code>P_8B</code>, stawkę VAT
                            i dokładnie jedną cenę jednostkową (netto lub brutto).
                        </small>
                    </div>
                    <span class="badge bg-primary-subtle text-primary border border-primary-subtle">
                        &lt;FaWiersz&gt;
                    </span>
                </div>

                <div class="mt-3 border rounded-3 overflow-hidden bg-white">
                    <div class="table-responsive">
                        <table class="table table-sm align-middle mb-0" id="lines-table">
                            <thead class="table-light">
                            <tr class="text-nowrap small">
                                <th style="width:80px;">LP</th>
                                <th style="min-width:220px;">
                                    Nazwa towaru/usługi
                                    <div class="text-muted fw-normal"><code>P_7</code></div>
                                </th>
                                <th style="min-width:190px;">
                                    PKWiU / kod
                                    <div class="text-muted fw-normal">opcjonalne identyfikatory</div>
                                </th>
                                <th style="width:120px;">
                                    Ilość
                                    <div class="text-muted fw-normal"><code>P_8A</code></div>
                                </th>
                                <th style="width:120px;">
                                    JM
                                    <div class="text-muted fw-normal"><code>P_8B</code></div>
                                </th>
                                <th style="width:140px;">Cena netto</th>
                                <th style="width:140px;">Cena brutto</th>
                                <th style="width:120px;">Stawka VAT</th>
                                <th style="width:150px;">Wart. netto</th>
                                <th style="width:150px;">Kwota VAT</th>
                                <th style="width:150px;">Wart. brutto</th>
                                <th style="width:40px;"></th>
                            </tr>
                            </thead>
                            <tbody>
                            @php
                                $oldLines = old('lines', $lines->toArray());
                            @endphp

                            @forelse($oldLines as $i => $line)
                                <tr>
                                    {{-- LP --}}
                                    <td>
                                        <input type="number" style="max-width: 90px;"
                                               name="lines[{{ $i }}][lp]"
                                               class="form-control form-control-sm text-center @error("lines.$i.lp") is-invalid @enderror"
                                               value="{{ $line['lp'] ?? ($i+1) }}">
                                        @error("lines.$i.lp")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Nazwa P_7 --}}
                                    <td>
                                        <input type="text"
                                               name="lines[{{ $i }}][nazwa]"
                                               class="form-control form-control-sm @error("lines.$i.nazwa") is-invalid @enderror"
                                               value="{{ $line['nazwa'] ?? '' }}"
                                               placeholder="Opis towaru/usługi">
                                        <div class="form-text small">Nazwa pozycji wykazywana w <code>P_7</code>.</div>
                                        @error("lines.$i.nazwa")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- PKWiU / kod --}}
                                    <td>
                                        <input type="text"
                                               name="lines[{{ $i }}][pkwiu]"
                                               class="form-control form-control-sm mb-1 @error("lines.$i.pkwiu") is-invalid @enderror"
                                               placeholder="PKWiU"
                                               value="{{ $line['pkwiu'] ?? '' }}">
                                        <input type="text"
                                               name="lines[{{ $i }}][kod_towaru]"
                                               class="form-control form-control-sm @error("lines.$i.kod_towaru") is-invalid @enderror"
                                               placeholder="Kod towaru/usługi"
                                               value="{{ $line['kod_towaru'] ?? '' }}">
                                        @error("lines.$i.pkwiu")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                        @error("lines.$i.kod_towaru")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Ilość P_8A --}}
                                    <td>
                                        <input type="number"
                                               step="0.001"
                                               name="lines[{{ $i }}][ilosc]"
                                               class="form-control form-control-sm text-end @error("lines.$i.ilosc") is-invalid @enderror"
                                               value="{{ $line['ilosc'] ?? '1.000' }}">
                                        @error("lines.$i.ilosc")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- JM P_8B --}}
                                    <td>
                                        <input type="text"
                                               name="lines[{{ $i }}][jm]"
                                               class="form-control form-control-sm @error("lines.$i.jm") is-invalid @enderror"
                                               value="{{ $line['jm'] ?? 'szt.' }}"
                                               placeholder="np. szt.">
                                        @error("lines.$i.jm")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Cena netto --}}
                                    <td>
                                        <input type="number"
                                               step="0.0001"
                                               name="lines[{{ $i }}][cena_netto]"
                                               class="form-control form-control-sm text-end @error("lines.$i.cena_netto") is-invalid @enderror"
                                               value="{{ $line['cena_netto'] ?? '' }}"
                                               placeholder="0.0000">
                                        @error("lines.$i.cena_netto")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Cena brutto --}}
                                    <td>
                                        <input type="number"
                                               step="0.0001"
                                               name="lines[{{ $i }}][cena_brutto]"
                                               class="form-control form-control-sm text-end @error("lines.$i.cena_brutto") is-invalid @enderror"
                                               value="{{ $line['cena_brutto'] ?? '' }}"
                                               placeholder="0.0000">
                                        <div class="form-text small">
                                            <span class="text-muted">Wypełnij tylko jedną cenę: netto <strong>lub</strong> brutto.</span>
                                        </div>
                                        @error("lines.$i.cena_brutto")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Stawka VAT --}}
                                    <td>
                                        <select name="lines[{{ $i }}][stawka_vat]"
                                                class="form-select form-select-sm @error("lines.$i.stawka_vat") is-invalid @enderror">
                                            @foreach(['23','8','5','0','ZW','NP','OO'] as $st)
                                                <option value="{{ $st }}"
                                                        @selected(($line['stawka_vat'] ?? '23') == $st)>
                                                    {{ $st }}
                                                </option>
                                            @endforeach
                                        </select>
                                        @error("lines.$i.stawka_vat")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Wartość netto --}}
                                    <td>
                                        <input type="number"
                                               step="0.01"
                                               name="lines[{{ $i }}][wartosc_netto]"
                                               class="form-control form-control-sm text-end @error("lines.$i.wartosc_netto") is-invalid @enderror"
                                               value="{{ $line['wartosc_netto'] ?? '0.00' }}">
                                        @error("lines.$i.wartosc_netto")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Kwota VAT --}}
                                    <td>
                                        <input type="number"
                                               step="0.01"
                                               name="lines[{{ $i }}][wartosc_vat]"
                                               class="form-control form-control-sm text-end @error("lines.$i.wartosc_vat") is-invalid @enderror"
                                               value="{{ $line['wartosc_vat'] ?? '0.00' }}">
                                        @error("lines.$i.wartosc_vat")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Wartość brutto --}}
                                    <td>
                                        <input type="number"
                                               step="0.01"
                                               name="lines[{{ $i }}][wartosc_brutto]"
                                               class="form-control form-control-sm text-end @error("lines.$i.wartosc_brutto") is-invalid @enderror"
                                               value="{{ $line['wartosc_brutto'] ?? '0.00' }}">
                                        @error("lines.$i.wartosc_brutto")
                                            <div class="invalid-feedback">{{ $message }}</div>
                                        @enderror
                                    </td>

                                    {{-- Usuń --}}
                                    <td class="text-center">
                                        <button type="button"
                                                class="btn btn-sm btn-outline-danger btn-remove-line"
                                                title="Usuń pozycję">
                                            &times;
                                        </button>
                                    </td>
                                </tr>
                            @empty
                                {{-- Wiersz startowy gdy brak danych --}}
                                <tr>
                                    <td>
                                        <input type="number"
                                               name="lines[0][lp]"
                                               class="form-control form-control-sm text-center"
                                               value="1">
                                    </td>
                                    <td>
                                        <input type="text"
                                               name="lines[0][nazwa]"
                                               class="form-control form-control-sm"
                                               placeholder="Opis towaru/usługi">
                                        <div class="form-text small">Nazwa pozycji wykazywana w <code>P_7</code>.</div>
                                    </td>
                                    <td>
                                        <input type="text"
                                               name="lines[0][pkwiu]"
                                               class="form-control form-control-sm mb-1"
                                               placeholder="PKWiU">
                                        <input type="text"
                                               name="lines[0][kod_towaru]"
                                               class="form-control form-control-sm"
                                               placeholder="Kod towaru/usługi">
                                    </td>
                                    <td>
                                        <input type="number"
                                               step="0.001"
                                               name="lines[0][ilosc]"
                                               class="form-control form-control-sm text-end"
                                               value="1.000">
                                    </td>
                                    <td>
                                        <input type="text"
                                               name="lines[0][jm]"
                                               class="form-control form-control-sm"
                                               value="szt."
                                               placeholder="np. szt.">
                                    </td>
                                    <td>
                                        <input type="number"
                                               step="0.0001"
                                               name="lines[0][cena_netto]"
                                               class="form-control form-control-sm text-end"
                                               placeholder="0.0000">
                                    </td>
                                    <td>
                                        <input type="number"
                                               step="0.0001"
                                               name="lines[0][cena_brutto]"
                                               class="form-control form-control-sm text-end"
                                               placeholder="0.0000">
                                        <div class="form-text small">
                                            Wypełnij tylko jedną cenę: netto <strong>lub</strong> brutto.
                                        </div>
                                    </td>
                                    <td>
                                        <select name="lines[0][stawka_vat]"
                                                class="form-select form-select-sm">
                                            @foreach(['23','8','5','0','ZW','NP','OO'] as $st)
                                                <option value="{{ $st }}" @selected($st=='23')>{{ $st }}</option>
                                            @endforeach
                                        </select>
                                    </td>
                                    <td>
                                        <input type="number"
                                               step="0.01"
                                               name="lines[0][wartosc_netto]"
                                               class="form-control form-control-sm text-end"
                                               value="0.00">
                                    </td>
                                    <td>
                                        <input type="number"
                                               step="0.01"
                                               name="lines[0][wartosc_vat]"
                                               class="form-control form-control-sm text-end"
                                               value="0.00">
                                    </td>
                                    <td>
                                        <input type="number"
                                               step="0.01"
                                               name="lines[0][wartosc_brutto]"
                                               class="form-control form-control-sm text-end"
                                               value="0.00">
                                    </td>
                                    <td class="text-center">
                                        <button type="button"
                                                class="btn btn-sm btn-outline-danger btn-remove-line"
                                                title="Usuń pozycję">
                                            &times;
                                        </button>
                                    </td>
                                </tr>
                            @endforelse
                            </tbody>
                        </table>
                    </div>
                </div>

                {{-- Pasek pod tabelą --}}
                <div class="d-flex flex-wrap justify-content-between align-items-center gap-2 mt-3">
                    <div class="d-flex align-items-center gap-2">
                        <button type="button" class="btn btn-sm btn-outline-secondary" id="btn-add-line">
                            + Dodaj pozycję
                        </button>
                        <span class="small text-muted">
                            Łączna liczba pozycji: <span id="lines-count">{{ count($oldLines) ?: 1 }}</span>
                        </span>
                    </div>
                    <div class="text-end small text-muted">
                        Wartości mogą być dodatkowo przeliczone i zaokrąglone po stronie serwera zgodnie z FA(3).
                    </div>
                </div>
            </div>

            {{-- Przyciski nawigacji kreatora --}}
            <div class="d-flex justify-content-between align-items-center mt-3">
                <a href="{{ route('faktury.edit.parties', $faktura->id) }}" class="btn btn-outline-secondary">
                    &laquo; Wróć do podmiotów
                </a>
                <button type="submit" class="btn btn-primary">
                    Zapisz i przejdź do płatności &raquo;
                </button>
            </div>
        </form>
    </div>
</div>

<script>
    (function () {
        const tableBody = document.querySelector('#lines-table tbody');
        const btnAdd = document.getElementById('btn-add-line');
        const linesCount = document.getElementById('lines-count');

        function updateLinesCount() {
            if (!linesCount) return;
            const rows = tableBody.querySelectorAll('tr');
            linesCount.textContent = rows.length;
        }

        function reindex() {
            const rows = tableBody.querySelectorAll('tr');
            rows.forEach((tr, i) => {
                tr.querySelectorAll('input, select').forEach(input => {
                    const name = input.getAttribute('name');
                    if (!name) return;
                    input.setAttribute('name', name.replace(/lines\[\d+]/, 'lines[' + i + ']'));
                });

                const lpInput = tr.querySelector('input[name$="[lp]"]');
                if (lpInput && !lpInput.value) {
                    lpInput.value = i + 1;
                }
            });
            updateLinesCount();
        }

        function parseNumber(value) {
            if (value === null || value === undefined) return 0;
            const v = parseFloat(value.toString().replace(',', '.'));
            return isNaN(v) ? 0 : v;
        }

        function round(value, decimals) {
            const factor = Math.pow(10, decimals);
            return Math.round(value * factor) / factor;
        }

        function getVatRate(selectValue) {
            const numeric = parseFloat(selectValue);
            if (!isNaN(numeric)) {
                return numeric;
            }
            return 0; // ZW / NP / OO → 0%
        }

        function recalcRow(tr) {
            const qtyInput     = tr.querySelector('input[name$="[ilosc]"]');
            const netInput     = tr.querySelector('input[name$="[cena_netto]"]');
            const grossInput   = tr.querySelector('input[name$="[cena_brutto]"]');
            const vatSelect    = tr.querySelector('select[name$="[stawka_vat]"]');
            const valNetInput  = tr.querySelector('input[name$="[wartosc_netto]"]');
            const valVatInput  = tr.querySelector('input[name$="[wartosc_vat]"]');
            const valGrInput   = tr.querySelector('input[name$="[wartosc_brutto]"]');

            if (!qtyInput || !netInput || !grossInput || !vatSelect ||
                !valNetInput || !valVatInput || !valGrInput) {
                return;
            }

            const qty     = parseNumber(qtyInput.value || '0');
            const vatRate = getVatRate(vatSelect.value || '0');
            const rate    = vatRate / 100.0;

            let netUnit = 0;
            let grossUnit = 0;

            const netRaw   = netInput.value !== '' ? parseNumber(netInput.value) : 0;
            const grossRaw = grossInput.value !== '' ? parseNumber(grossInput.value) : 0;

            if (netRaw > 0) {
                netUnit = netRaw;
            } else if (grossRaw > 0) {
                grossUnit = grossRaw;
                if (rate > 0) {
                    netUnit = round(grossUnit / (1 + rate), 4);
                } else {
                    netUnit = grossUnit;
                }
            }

            if (qty <= 0 || netUnit <= 0) {
                valNetInput.value = '0.00';
                valVatInput.value = '0.00';
                valGrInput.value  = '0.00';
                return;
            }

            let valueNet = round(qty * netUnit, 2);
            let valueVat = 0;
            let valueGr  = 0;

            if (rate > 0) {
                valueVat = round(valueNet * rate, 2);
            }
            valueGr = round(valueNet + valueVat, 2);

            valNetInput.value = valueNet.toFixed(2);
            valVatInput.value = valueVat.toFixed(2);
            valGrInput.value  = valueGr.toFixed(2);
        }

        tableBody.addEventListener('click', function (e) {
            if (e.target.classList.contains('btn-remove-line')) {
                const rows = tableBody.querySelectorAll('tr');
                if (rows.length > 1) {
                    e.target.closest('tr').remove();
                    reindex();
                }
            }
        });

        if (btnAdd) {
            btnAdd.addEventListener('click', function () {
                const rows = tableBody.querySelectorAll('tr');
                const index = rows.length;
                const first = rows[0];
                const clone = first.cloneNode(true);

                clone.querySelectorAll('input').forEach(input => {
                    const name = input.getAttribute('name') || '';
                    if (name.endsWith('[lp]')) {
                        input.value = index + 1;
                    } else if (name.endsWith('[ilosc]')) {
                        input.value = '1.000';
                    } else if (name.endsWith('[jm]')) {
                        input.value = 'szt.';
                    } else if (name.endsWith('[wartosc_netto]') || name.endsWith('[wartosc_vat]') || name.endsWith('[wartosc_brutto]')) {
                        input.value = '0.00';
                    } else {
                        input.value = '';
                    }
                    input.classList.remove('is-invalid');
                });

                clone.querySelectorAll('select').forEach(select => {
                    select.classList.remove('is-invalid');
                    const option23 = Array.from(select.options).find(o => o.value === '23');
                    if (option23) {
                        select.value = '23';
                    } else {
                        select.selectedIndex = 0;
                    }
                });

                tableBody.appendChild(clone);
                reindex();
            });
        }

        tableBody.addEventListener('input', function (e) {
            const target = e.target;
            if (!(target instanceof HTMLElement)) return;

            const name = target.getAttribute('name') || '';
            const tr = target.closest('tr');
            if (!tr) return;

            if (name.endsWith('[cena_netto]')) {
                const netVal = parseNumber(target.value || '0');
                if (netVal > 0) {
                    const grossInput = tr.querySelector('input[name$="[cena_brutto]"]');
                    if (grossInput) grossInput.value = '';
                }
                recalcRow(tr);
            } else if (name.endsWith('[cena_brutto]')) {
                const grVal = parseNumber(target.value || '0');
                if (grVal > 0) {
                    const netInput = tr.querySelector('input[name$="[cena_netto]"]');
                    if (netInput) netInput.value = '';
                }
                recalcRow(tr);
            } else if (name.endsWith('[ilosc]')) {
                recalcRow(tr);
            }
        });

        tableBody.addEventListener('change', function (e) {
            const target = e.target;
            if (!(target instanceof HTMLElement)) return;

            const name = target.getAttribute('name') || '';
            if (!name.endsWith('[stawka_vat]')) return;

            const tr = target.closest('tr');
            if (tr) recalcRow(tr);
        });

        reindex();
    })();
</script>
@endsection