@extends('layouts.app')

@section('title', 'Edit Invoice')
@section('page-title', 'Edit Invoice ' . $invoice->invoice_number)
@section('breadcrumbs')
    <li class="breadcrumb-item"><a href="{{ route('invoices.index') }}">Invoices</a></li>
    <li class="breadcrumb-item active">Edit</li>
@endsection

@section('content')
<form method="POST" action="{{ route('invoices.update', $invoice) }}" id="invoice-form">
    @csrf
    @method('PUT')
    <div class="card">
        <div class="card-body">
            <div class="row g-3">
                <div class="col-md-4">
                    <label class="form-label">Customer *</label>
                    <select name="customer_id" class="form-select" required>
                        @foreach ($customers as $customer)
                            <option value="{{ $customer->id }}" @selected(old('customer_id', $invoice->customer_id) == $customer->id)>{{ $customer->name }}</option>
                        @endforeach
                    </select>
                </div>
                <div class="col-md-4">
                    <label class="form-label">Issue Date *</label>
                    <input type="date" name="issue_date" class="form-control" value="{{ old('issue_date', $invoice->issue_date->format('Y-m-d')) }}" required>
                </div>
                <div class="col-md-4">
                    <label class="form-label">Due Date</label>
                    <input type="date" name="due_date" class="form-control" value="{{ old('due_date', optional($invoice->due_date)->format('Y-m-d')) }}">
                </div>
            </div>
        </div>
    </div>

    <div class="card">
        <div class="card-header d-flex justify-content-between align-items-center">
            <h3 class="card-title">Line Items</h3>
            <button type="button" class="btn btn-sm btn-outline-info" id="add-item"><i class="fas fa-plus me-1"></i>Add Item</button>
        </div>
        <div class="card-body table-responsive p-0">
            <table class="table mb-0" id="items-table">
                <thead>
                    <tr>
                        <th style="width:45%">Description</th>
                        <th style="width:15%">Qty</th>
                        <th style="width:20%">Unit Price ($)</th>
                        <th style="width:15%">Line Total</th>
                        <th style="width:5%"></th>
                    </tr>
                </thead>
                <tbody id="items-body"></tbody>
            </table>
        </div>
    </div>

    <div class="row">
        <div class="col-md-6">
            <div class="card">
                <div class="card-header"><h3 class="card-title">Notes</h3></div>
                <div class="card-body">
                    <textarea name="notes" rows="4" class="form-control">{{ old('notes', $invoice->notes) }}</textarea>
                </div>
            </div>
        </div>
        <div class="col-md-6">
            <div class="card">
                <div class="card-header"><h3 class="card-title">Totals</h3></div>
                <div class="card-body">
                    <div class="row g-2 mb-2">
                        <div class="col-6"><label class="form-label">Discount ($)</label>
                            <input type="number" step="0.01" min="0" name="discount" id="discount" class="form-control" value="{{ old('discount', $invoice->discount) }}">
                        </div>
                        <div class="col-6"><label class="form-label">Tax Rate (%)</label>
                            <input type="number" step="0.01" min="0" max="100" name="tax_rate" id="tax_rate" class="form-control" value="{{ old('tax_rate', $invoice->tax_rate) }}">
                        </div>
                    </div>
                    <table class="table table-sm mb-0">
                        <tr><td>Subtotal</td><td class="text-end" id="subtotal-display">$0.00</td></tr>
                        <tr><td>Tax</td><td class="text-end" id="tax-display">$0.00</td></tr>
                        <tr><td>Discount</td><td class="text-end" id="discount-display">-$0.00</td></tr>
                        <tr class="fw-bold fs-5"><td>Total</td><td class="text-end" id="total-display">$0.00</td></tr>
                    </table>
                </div>
            </div>
        </div>
    </div>

    <div class="mb-4">
        <button class="btn btn-info text-white"><i class="fas fa-save me-1"></i> Update Invoice</button>
        <a href="{{ route('invoices.show', $invoice) }}" class="btn btn-outline-secondary">Cancel</a>
    </div>
</form>
@endsection

@push('scripts')
<script>
(function () {
    const tbody = document.getElementById('items-body');
    const addBtn = document.getElementById('add-item');
    const discountInput = document.getElementById('discount');
    const taxInput = document.getElementById('tax_rate');
    let rowIndex = 0;

    const existingItems = @json($invoice->items->map(fn ($i) => [
        'description' => $i->description,
        'quantity' => (float) $i->quantity,
        'unit_price' => (float) $i->unit_price,
    ]));

    function rowTemplate(index, values = {}) {
        const tr = document.createElement('tr');
        tr.innerHTML = `
            <td><input type="text" name="items[${index}][description]" class="form-control form-control-sm item-desc" value="${values.description || ''}" required></td>
            <td><input type="number" step="0.01" min="0.01" name="items[${index}][quantity]" class="form-control form-control-sm item-qty" value="${values.quantity || 1}" required></td>
            <td><input type="number" step="0.01" min="0" name="items[${index}][unit_price]" class="form-control form-control-sm item-price" value="${values.unit_price || 0}" required></td>
            <td class="align-middle line-total">$0.00</td>
            <td class="text-end"><button type="button" class="btn btn-sm btn-outline-danger remove-row"><i class="fas fa-times"></i></button></td>
        `;
        return tr;
    }

    function addRow(values = {}) {
        const tr = rowTemplate(rowIndex++, values);
        tbody.appendChild(tr);
        recalc();
    }

    function recalc() {
        let subtotal = 0;
        tbody.querySelectorAll('tr').forEach(tr => {
            const qty = parseFloat(tr.querySelector('.item-qty').value) || 0;
            const price = parseFloat(tr.querySelector('.item-price').value) || 0;
            const lineTotal = qty * price;
            tr.querySelector('.line-total').textContent = '$' + lineTotal.toFixed(2);
            subtotal += lineTotal;
        });

        const discount = parseFloat(discountInput.value) || 0;
        const taxRate = parseFloat(taxInput.value) || 0;
        const taxAmount = subtotal * (taxRate / 100);
        const total = subtotal - discount + taxAmount;

        document.getElementById('subtotal-display').textContent = '$' + subtotal.toFixed(2);
        document.getElementById('tax-display').textContent = '$' + taxAmount.toFixed(2);
        document.getElementById('discount-display').textContent = '-$' + discount.toFixed(2);
        document.getElementById('total-display').textContent = '$' + total.toFixed(2);
    }

    tbody.addEventListener('input', recalc);
    tbody.addEventListener('click', function (e) {
        if (e.target.closest('.remove-row')) {
            e.target.closest('tr').remove();
            recalc();
        }
    });
    discountInput.addEventListener('input', recalc);
    taxInput.addEventListener('input', recalc);
    addBtn.addEventListener('click', () => addRow());

    if (existingItems.length) {
        existingItems.forEach(item => addRow(item));
    } else {
        addRow();
    }
})();
</script>
@endpush