@extends('layouts.app')

@section('title', 'Edit Invoice - Quick OMS')

@section('content')
@push('css')
<link href="https://cdn.jsdelivr.net/npm/select2@4.1.0-rc.0/dist/css/select2.min.css" rel="stylesheet" />
<style>
    .select2-container .select2-selection--single { height: 46px; border: 1px solid #CFD9E8; border-radius: 8px; }
    .select2-container--default .select2-selection--single .select2-selection__rendered { line-height: 44px; padding-left: 12px; }
    .select2-container--default .select2-selection--single .select2-selection__arrow { height: 44px; }
    .select2-dropdown { border: 1px solid #CFD9E8; border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.1); }
    .editDraftInvoice { background: #fff; padding: 30px; border-radius: 12px; box-shadow: 0 4px 20px rgba(0,0,0,0.05); }
    .section h3, .company h3, .items-section h3 { margin-bottom: 20px; font-family: 'Rajdhani', sans-serif; font-weight: 700; color: #1B79B5; font-size: 20px; text-transform: uppercase; border-bottom: 1px solid #eee; padding-bottom: 10px; }
    .grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
    .field-group { margin-bottom: 15px; }
    .field-group label { display: block; margin-bottom: 8px; font-weight: 600; color: #444; }
    .input { width: 100%; padding: 12px; border: 1px solid #CFD9E8; border-radius: 8px; font-family: 'Outfit', sans-serif; transition: all 0.3s; }
    .input:focus { border-color: #1B79B5; outline: none; box-shadow: 0 0 0 3px rgba(27, 121, 181, 0.1); }
    .items-table { width: 100%; border-collapse: collapse; margin-top: 10px; }
    .items-table th { text-align: left; background: #f8faff; padding: 12px; border-bottom: 2px solid #eee; color: #666; font-size: 14px; }
    .items-table td { padding: 12px; border-bottom: 1px solid #eee; vertical-align: top; }
    .price-wrap { display: flex; align-items: center; gap: 5px; }
    .remove-row { background: #fee; color: #d33; border: none; width: 30px; height: 30px; border-radius: 50%; cursor: pointer; display: flex; align-items: center; justify-content: center; font-size: 20px; }
    .remove-row:hover { background: #fdd; }
    .totals-area { background: #f9fbff; padding: 20px; border-radius: 12px; border: 1px solid #eef2f8; }
    .total-row { display: flex; justify-content: space-between; margin-bottom: 10px; font-size: 16px; color: #555; }
    .grand-total { border-top: 2px solid #ddd; padding-top: 15px; margin-top: 15px; font-weight: 700; font-size: 24px; color: #1B79B5; }
    .btn-large { padding: 15px 40px; font-size: 18px; font-weight: 700; border-radius: 30px; }
    .error-text { color: #d33; font-size: 12px; margin-top: 5px; display: block; }
</style>
@endpush

<div class="welcome">
    <h3>Edit Invoice #{{ $invoice->invoice_number }}</h3>
</div>

<form action="{{ route('admin.invoices.update', $invoice->id) }}" method="POST" id="invoiceForm">
    @csrf
    <div class="editDraftInvoice">

        <!-- TOP SECTION -->
        <div class="section">
            <div class="grid">
                <!-- ISSUE DATE -->
                <div class="field-group">
                    <label>Issue Date</label>
                    <div class="input-wrap">
                        <input type="date" name="issue_date" class="input @error('issue_date') is-invalid @enderror" value="{{ old('issue_date', $invoice->issue_date) }}" required>
                        @error('issue_date') <span class="error-text">{{ $message }}</span> @enderror
                    </div>
                </div>

                <!-- EXPIRY DATE -->
                <div class="field-group">
                    <label>Expiry Date</label>
                    <div class="input-wrap">
                        <input type="date" name="expiry_date" class="input @error('expiry_date') is-invalid @enderror" value="{{ old('expiry_date', $invoice->expiry_date) }}" required>
                        @error('expiry_date') <span class="error-text">{{ $message }}</span> @enderror
                    </div>
                </div>
            </div>

            <!-- SUBJECT -->
            <div class="mt field-group">
                <label>Subject</label>
                <input type="text" name="subject" class="input @error('subject') is-invalid @enderror" value="{{ old('subject', $invoice->subject) }}" placeholder="Invoice Subject" required>
                @error('subject') <span class="error-text">{{ $message }}</span> @enderror
            </div>
        </div>

        <!-- COMPANY & CLIENT -->
        <div class="company section mt-4">
            <h3>Company & Billing Details</h3>
            <div class="grid">
                <div class="field-group">
                    <label>Select Company</label>
                    <select name="company_id" id="company_id" class="input @error('company_id') is-invalid @enderror" required>
                        <option value="">-- Select Company --</option>
                        @foreach($companies as $company)
                            <option value="{{ $company->id }}" {{ old('company_id', $invoice->company_id) == $company->id ? 'selected' : '' }}>{{ $company->name }}</option>
                        @endforeach
                    </select>
                    @error('company_id') <span class="error-text">{{ $message }}</span> @enderror
                </div>

                <div class="field-group">
                    <label>Invoice to (Client)</label>
                    <select name="user_id" id="user_id" class="input @error('user_id') is-invalid @enderror" required>
                        <option value="">-- Select Client --</option>
                        @foreach($clients as $client)
                            <option value="{{ $client->id }}" {{ old('user_id', $invoice->user_id) == $client->id ? 'selected' : '' }}>{{ $client->name }}</option>
                        @endforeach
                    </select>
                    @error('user_id') <span class="error-text">{{ $message }}</span> @enderror
                </div>
            </div>
        </div>

        <!-- ITEMS SECTION -->
        <div class="items-section mt-4">
            <h3>Line Items</h3>
            <div class="table-responsive">
                <table class="items-table" id="itemsTable">
                    <thead>
                        <tr>
                            <th style="width: 40%;">Product/Service</th>
                            <th style="width: 15%;">Quantity</th>
                            <th style="width: 15%;">Unit Price</th>
                            <th style="width: 10%;">Discount ($)</th>
                            <th style="width: 15%;">Total</th>
                            <th style="width: 5%;"></th>
                        </tr>
                    </thead>
                    <tbody id="itemsBody">
                        @foreach($invoice->items as $index => $item)
                        <tr class="item-row">
                            <td>
                                <select name="items[{{ $index }}][inventory_id]" class="input inventory-select" required>
                                    <option value="">-- Select Product --</option>
                                    @foreach($inventories as $inv)
                                        <option value="{{ $inv->id }}" data-price="{{ $inv->unit_price }}" data-tax="{{ $inv->tax->rate ?? 0 }}" {{ $item->inventory_id == $inv->id ? 'selected' : '' }}>
                                            {{ $inv->name }} (SKU: {{ $inv->sku }})
                                        </option>
                                    @endforeach
                                </select>
                            </td>
                            <td>
                                <input type="number" name="items[{{ $index }}][quantity]" class="input qty-input" value="{{ $item->quantity }}" min="0.01" step="0.01" required>
                            </td>
                            <td>
                                <div class="price-wrap">
                                    <span>$</span>
                                    <input type="number" name="items[{{ $index }}][unit_price]" class="input price-input" value="{{ $item->unit_price }}" min="0" step="0.01" required>
                                </div>
                            </td>
                            <td>
                                <input type="number" name="items[{{ $index }}][discount]" class="input discount-input" value="{{ $item->discount }}" min="0" step="0.01">
                            </td>
                            <td class="text-right">
                                <span class="line-total">${{ number_format($item->total, 2) }}</span>
                            </td>
                            <td>
                                <button type="button" class="remove-row">&times;</button>
                            </td>
                        </tr>
                        @endforeach
                    </tbody>
                </table>
            </div>
            
            <div class="mt-3">
                <button type="button" class="btn btn-secondary" id="addItemBtn">+ Add Item</button>
            </div>
        </div>

        <!-- SUMMARY & NOTES -->
        <div class="summary-section grid mt-4">
            <div class="notes-area">
                <label>Note :</label>
                <textarea name="note" rows="5" class="input">{{ old('note', $invoice->note) }}</textarea>
            </div>
            
            <div class="totals-area">
                <div class="total-row">
                    <span>Subtotal:</span>
                    <span id="subtotalDisplay">$0.00</span>
                </div>
                <div class="total-row">
                    <span>Tax (GST):</span>
                    <span id="taxDisplay">$0.00</span>
                </div>
                <div class="total-row grand-total">
                    <span>Grand Total:</span>
                    <span id="grandTotalDisplay">$0.00</span>
                </div>
            </div>
        </div>

        <!-- SUBMIT -->
        <div class="mt-5 text-right">
            <button type="submit" class="btn btn-primary btn-large">Update Invoice</button>
        </div>

    </div>
</form>

<!-- TEMPLATES -->
<template id="itemRowTemplate">
    <tr class="item-row">
        <td>
            <select name="items[INDEX][inventory_id]" class="input inventory-select" required>
                <option value="">-- Select Product --</option>
                @foreach($inventories as $inv)
                    <option value="{{ $inv->id }}" data-price="{{ $inv->unit_price }}" data-tax="{{ $inv->tax->rate ?? 0 }}">
                        {{ $inv->name }} (SKU: {{ $inv->sku }})
                    </option>
                @endforeach
            </select>
        </td>
        <td>
            <input type="number" name="items[INDEX][quantity]" class="input qty-input" value="1" min="0.01" step="0.01" required>
        </td>
        <td>
            <div class="price-wrap">
                <span>$</span>
                <input type="number" name="items[INDEX][unit_price]" class="input price-input" value="0.00" min="0" step="0.01" required>
            </div>
        </td>
        <td>
            <input type="number" name="items[INDEX][discount]" class="input discount-input" value="0" min="0" step="0.01">
        </td>
        <td class="text-right">
            <span class="line-total">$0.00</span>
        </td>
        <td>
            <button type="button" class="remove-row">&times;</button>
        </td>
    </tr>
</template>

@push('scripts')
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/select2@4.1.0-rc.0/dist/js/select2.min.js"></script>
<script>
document.addEventListener('DOMContentLoaded', function() {
    const companySelect = $('#company_id');
    const userSelect = $('#user_id');
    const addItemBtn = document.getElementById('addItemBtn');
    const itemsBody = document.getElementById('itemsBody');
    const template = document.getElementById('itemRowTemplate');
    
    let rowIndex = {{ count($invoice->items) }};

    // Initialize Base Selects
    companySelect.select2({ placeholder: "-- Select Company --" });
    userSelect.select2({ placeholder: "-- Select Client --" });
    $('.inventory-select').select2({ placeholder: "-- Select Product --" });

    // 1. Dynamic Client Loading
    companySelect.on('change', function() {
        const companyId = this.value;
        userSelect.html('<option value="">-- Loading --</option>').trigger('change');
        
        if (!companyId) {
            userSelect.html('<option value="">-- Select Client --</option>').trigger('change');
            return;
        }

        fetch(`{{ route('admin.invoices.clients-by-company') }}?company_id=${companyId}`)
            .then(res => res.json())
            .then(data => {
                userSelect.html('<option value="">-- Select Client --</option>');
                data.forEach(client => {
                    userSelect.append(new Option(client.name, client.id));
                });
                userSelect.trigger('change');
            });
    });

    // 2. Row Management
    function setupRow(row) {
        const select = $(row).find('.inventory-select');
        select.on('change', updateRowPrice);
        $(row).find('.qty-input').on('input', calculateTotals);
        $(row).find('.price-input').on('input', calculateTotals);
        $(row).find('.discount-input').on('input', calculateTotals);
        $(row).find('.remove-row').on('click', function() {
            select.select2('destroy');
            row.remove();
            calculateTotals();
        });
    }

    function addRow() {
        const content = template.innerHTML.replace(/INDEX/g, rowIndex++);
        const tr = document.createElement('tr');
        tr.className = 'item-row';
        tr.innerHTML = content;
        itemsBody.appendChild(tr);
        
        $(tr).find('.inventory-select').select2({ placeholder: "-- Select Product --" });
        setupRow(tr);
        calculateTotals();
    }

    function updateRowPrice(e) {
        const option = e.target.selectedOptions[0];
        const row = e.target.closest('tr');
        if (option && option.dataset.price) {
            row.querySelector('.price-input').value = parseFloat(option.dataset.price).toFixed(2);
        }
        calculateTotals();
    }

    function calculateTotals() {
        let subtotal = 0;
        let totalTax = 0;
        
        document.querySelectorAll('.item-row').forEach(row => {
            const qty = parseFloat(row.querySelector('.qty-input').value) || 0;
            const price = parseFloat(row.querySelector('.price-input').value) || 0;
            const discount = parseFloat(row.querySelector('.discount-input').value) || 0;
            const select = row.querySelector('.inventory-select');
            const taxRate = select.selectedOptions[0] ? parseFloat(select.selectedOptions[0].dataset.tax || 0) : 0;

            const lineSubtotal = qty * price;
            const lineAfterDiscount = lineSubtotal - discount;
            const lineTax = (lineAfterDiscount * taxRate) / 100;
            const lineTotal = lineAfterDiscount + lineTax;

            row.querySelector('.line-total').textContent = `$${lineTotal.toFixed(2)}`;
            
            subtotal += lineAfterDiscount;
            totalTax += lineTax;
        });

        const grandTotal = subtotal + totalTax;

        document.getElementById('subtotalDisplay').textContent = `$${subtotal.toFixed(2)}`;
        document.getElementById('taxDisplay').textContent = `$${totalTax.toFixed(2)}`;
        document.getElementById('grandTotalDisplay').textContent = `$${grandTotal.toFixed(2)}`;
    }

    addItemBtn.addEventListener('click', addRow);
    
    // Setup existing rows
    document.querySelectorAll('.item-row').forEach(setupRow);
    calculateTotals();
});
</script>
@endpush
@endsection