@extends('layouts.app')
@section('title', 'Edit Product - ' . setting('system_name'))

@section('content')
<div class="app-wrapper">
    <div class="app-main">
        <main class="app-content p-4">
            
            <!-- Header Section -->
            <div class="d-flex align-items-center justify-content-between mb-4 flex-wrap gap-3">
                <div>
                    <h1 class="h4 fw-bold mb-1">Edit Product: {{ $product->name }}</h1>
                    <p class="text-muted small mb-0 text-uppercase tracking-wider fw-semibold">
                        Modify product details and inventory settings
                    </p>
                </div>
                <div class="d-flex gap-2">
                    <a href="{{ route('products.index') }}" class="btn btn-outline-secondary btn-sm shadow-sm px-3">
                        <i class="bi bi-arrow-left me-1"></i> Back to List
                    </a>
                </div>
            </div>

            @if ($errors->any())
                <div class="alert alert-danger border-0 shadow-sm mb-4">
                    <div class="d-flex align-items-center mb-2">
                        <i class="bi bi-exclamation-triangle-fill me-2"></i>
                        <strong class="small">Please fix the following errors:</strong>
                    </div>
                    <ul class="mb-0 x-small fw-semibold ps-3">
                        @foreach ($errors->all() as $error)
                            <li>{{ $error }}</li>
                        @endforeach
                    </ul>
                </div>
            @endif

            <form action="{{ route('products.update', $product) }}" method="POST" enctype="multipart/form-data" id="productForm">
                @csrf
                @method('PUT')

                <div class="row g-4">
                    <!-- Left Column: General Info & Pricing -->
                    <div class="col-lg-8">
                        
                        <!-- General Information Card -->
                        <div class="card border-0 shadow-sm mb-4 overflow-hidden">
                            <div class="card-header bg-white py-3 border-0">
                                <h5 class="mb-0 fw-bold h6 text-primary"><i class="bi bi-info-circle me-2"></i>General Information</h5>
                            </div>
                            <div class="card-body p-4 pt-0">
                                <div class="row g-3">
                                    <div class="col-md-12">
                                        <label class="form-label small fw-bold text-muted">Product Name <span class="text-danger">*</span></label>
                                        <input type="text" class="form-control @error('name') is-invalid @enderror" 
                                               name="name" placeholder="e.g. Paracetamol 500mg" value="{{ old('name', $product->name) }}" required>
                                    </div>
                                    <div class="col-md-6">
                                        <label class="form-label small fw-bold text-muted">SKU (Stock Keeping Unit)</label>
                                        <div class="input-group">
                                            <span class="input-group-text border-0 bg-light"><i class="bi bi-upc-scan"></i></span>
                                            <input type="text" class="form-control border-0 bg-light shadow-none" 
                                                   name="sku" placeholder="Auto-generated if empty" value="{{ old('sku', $product->sku) }}">
                                        </div>
                                    </div>
                                    <div class="col-md-6">
                                        <label class="form-label small fw-bold text-muted">Category</label>
                                        <div class="d-flex gap-2">
                                            <select class="form-select border-0 bg-light shadow-none" name="category_id">
                                                <option value="">No Category</option>
                                                @foreach ($categories as $category)
                                                    <option value="{{ $category->id }}" @selected(old('category_id', $product->category_id) == $category->id)>
                                                        {{ $category->name }}
                                                    </option>
                                                @endforeach
                                            </select>
                                            <a href="{{ route('categories.index') }}" class="btn btn-light btn-sm d-flex align-items-center px-3 border shadow-sm">+</a>
                                        </div>
                                    </div>
                                    <div class="col-md-6">
                                        <label class="form-label small fw-bold text-muted">Brand / Manufacturer</label>
                                        <div class="d-flex gap-2">
                                            <select class="form-select border-0 bg-light shadow-none" name="brand_id">
                                                <option value="">No Brand</option>
                                                @foreach ($brands as $brand)
                                                    <option value="{{ $brand->id }}" @selected(old('brand_id', $product->brand_id) == $brand->id)>
                                                        {{ $brand->name }}
                                                    </option>
                                                @endforeach
                                            </select>
                                            <a href="{{ route('brands.index') }}" class="btn btn-light btn-sm d-flex align-items-center px-3 border shadow-sm">+</a>
                                        </div>
                                    </div>
                                    <div class="col-md-6">
                                        <label class="form-label small fw-bold text-muted">Unit of Measure</label>
                                        <select class="form-select border-0 bg-light shadow-none" name="unit_id">
                                            <option value="">Select Unit</option>
                                            @foreach ($units as $unit)
                                                <option value="{{ $unit->id }}" @selected(old('unit_id', $product->unit_id) == $unit->id)>
                                                    {{ $unit->name }} ({{ $unit->short_name }})
                                                </option>
                                            @endforeach
                                        </select>
                                    </div>
                                </div>
                            </div>
                        </div>

                        <!-- Pricing & Margin Card -->
                        <div class="card border-0 shadow-sm mb-4 overflow-hidden">
                            <div class="card-header bg-white py-3 border-0">
                                <h5 class="mb-0 fw-bold h6 text-primary"><i class="bi bi-cash-stack me-2"></i>Pricing & Margins</h5>
                            </div>
                            <div class="card-body p-4 pt-0">
                                <div class="row g-3">
                                    <div class="col-md-6">
                                        <label class="form-label small fw-bold text-muted">Purchase Price <span class="text-danger">*</span></label>
                                        <div class="input-group">
                                            <span class="input-group-text border-0 bg-light">MWK</span>
                                            <input type="number" class="form-control border-0 bg-light shadow-none fw-bold" 
                                                   name="purchase_price" step="1" min="0" value="{{ old('purchase_price', (float) $product->purchase_price) }}" required>
                                        </div>
                                    </div>
                                    <div class="col-md-6">
                                        <label class="form-label small fw-bold text-muted">Selling Price <span class="text-danger">*</span></label>
                                        <div class="input-group">
                                            <span class="input-group-text border-0 bg-light">MWK</span>
                                            <input type="number" class="form-control border-0 bg-light shadow-none fw-bold text-primary" 
                                                   name="selling_price" step="1" min="0" value="{{ old('selling_price', (float) $product->selling_price) }}" required>
                                        </div>
                                    </div>
                                    <div class="col-12">
                                        <div class="p-3 rounded-3 bg-light d-flex align-items-center justify-content-between border">
                                            <div>
                                                <div class="small fw-bold text-muted text-uppercase x-small mb-1">Estimated Profit Margin</div>
                                                <div class="h5 mb-0 fw-bold" id="profitDisplay">MWK 0.00</div>
                                            </div>
                                            <div class="text-end">
                                                <div class="badge rounded-pill px-3 py-2 fs-6 bg-success" id="marginBadge">0%</div>
                                            </div>
                                        </div>
                                    </div>
                                </div>
                            </div>
                        </div>

                        <!-- Description -->
                        <div class="card border-0 shadow-sm mb-4 overflow-hidden">
                            <div class="card-header bg-white py-3 border-0">
                                <h5 class="mb-0 fw-bold h6 text-primary"><i class="bi bi-card-text me-2"></i>Product Description</h5>
                            </div>
                            <div class="card-body p-4 pt-0">
                                <textarea class="form-control border-0 bg-light shadow-none" name="description" rows="4" placeholder="Enter clinical notes, usage instructions, or composition details...">{{ old('description', $product->description) }}</textarea>
                            </div>
                        </div>
                    </div>

                    <!-- Right Column: Inventory & Supplier -->
                    <div class="col-lg-4">
                        
                        <!-- Inventory Stats Card -->
                        <div class="card border-0 shadow-sm mb-4 overflow-hidden border-top border-4 border-primary">
                            <div class="card-header bg-white py-3 border-0">
                                <h5 class="mb-0 fw-bold h6 text-primary"><i class="bi bi-box-seam me-2"></i>Inventory Status</h5>
                            </div>
                            <div class="card-body p-4 pt-0 text-center">
                                <div class="p-3 rounded-3 bg-primary mb-3 shadow-sm">
                                    <div class="small fw-bold text-white opacity-75 text-uppercase x-small">Current Stock</div>
                                    <div class="h3 fw-bold mb-0 text-white">{{ number_format($product->current_stock) }}</div>
                                </div>
                                <div class="d-grid">
                                    <a href="{{ route('stock-adjustments.create', ['product_id' => $product->id]) }}" class="btn btn-primary btn-sm fw-semibold">
                                        <i class="bi bi-arrow-repeat me-1"></i> Adjust Stock
                                    </a>
                                </div>
                                <div class="row g-2">
                                    <div class="col-12 text-start">
                                        <label class="form-label small fw-bold text-muted">Alert Quantity</label>
                                        <input type="number" class="form-control border-0 bg-light shadow-none" 
                                               name="alert_quantity" step="1" min="0" value="{{ old('alert_quantity', (float) $product->alert_quantity) }}">
                                    </div>
                                    <div class="col-12 text-start">
                                        <label class="form-label small fw-bold text-muted">Earliest Expiry in Stock</label>
                                        <div class="form-control border-0 bg-light">
                                            {{ $product->expiry_date ? \Carbon\Carbon::parse($product->expiry_date)->format('d M Y') : 'Not set' }}
                                        </div>
                                        <small class="text-muted x-small">Each batch has its own expiry date, see <a href="#batches">Batches</a> below</small>
                                    </div>
                                </div>
                            </div>
                        </div>

                        <!-- Supplier Card -->
                        <div class="card border-0 shadow-sm mb-4 overflow-hidden">
                            <div class="card-header bg-white py-3 border-0 d-flex justify-content-between align-items-center">
                                <h5 class="mb-0 fw-bold h6 text-primary"><i class="bi bi-truck me-2"></i>Supplier</h5>
                                <button type="button" class="btn btn-primary btn-sm rounded-pill px-3" data-bs-toggle="modal" data-bs-target="#addSupplierModal">
                                    <i class="bi bi-plus-lg"></i> New
                                </button>
                            </div>
                            <div class="card-body p-4 pt-0">
                                <select class="form-select border-0 bg-light shadow-none mb-3" name="supplier_id" id="supplierSelect">
                                    <option value="">Select Supplier</option>
                                    @foreach ($suppliers as $supplier)
                                        <option value="{{ $supplier->id }}" 
                                                data-contact="{{ $supplier->contact_person ?? 'N/A' }}"
                                                data-phone="{{ $supplier->phone ?? 'N/A' }}"
                                                data-email="{{ $supplier->email ?? 'N/A' }}"
                                                @selected(old('supplier_id', $product->supplier_id) == $supplier->id)>
                                            {{ $supplier->name }}
                                        </option>
                                    @endforeach
                                </select>
                                
                                <div id="supplierPreview" class="p-3 rounded-3 bg-light border" style="display: none;">
                                    <div class="small fw-bold text-dark mb-1" id="previewName">Supplier Name</div>
                                    <div class="text-muted x-small mb-1"><i class="bi bi-person me-1"></i> <span id="previewContact">Contact</span></div>
                                    <div class="text-muted x-small"><i class="bi bi-telephone me-1"></i> <span id="previewPhone">Phone</span></div>
                                </div>
                            </div>
                        </div>

                        <!-- Image Card -->
                        <div class="card border-0 shadow-sm mb-4 overflow-hidden">
                            <div class="card-header bg-white py-3 border-0">
                                <h5 class="mb-0 fw-bold h6 text-primary"><i class="bi bi-image me-2"></i>Product Image</h5>
                            </div>
                            <div class="card-body p-4 pt-0">
                                <div class="image-upload-wrapper border-2 border-dashed rounded-3 p-4 text-center bg-light">
                                    <input type="file" name="image" id="imageInput" class="d-none" accept="image/*">
                                    <div id="imagePlaceholder" class="{{ $product->image ? 'd-none' : '' }}">
                                        <i class="bi bi-cloud-arrow-up fs-1 text-muted opacity-50 mb-2 d-block"></i>
                                        <button type="button" class="btn btn-outline-primary btn-sm px-4" onclick="document.getElementById('imageInput').click()">Browse Image</button>
                                        <p class="x-small text-muted mt-2 mb-0">JPEG, PNG up to 5MB</p>
                                    </div>
                                    <div id="imagePreview" class="{{ $product->image ? '' : 'd-none' }}">
                                        <img src="{{ $product->image ? asset('storage/' . $product->image) : '' }}" class="img-fluid rounded-3 mb-2 shadow-sm" style="max-height: 150px;">
                                        <button type="button" class="btn btn-danger btn-sm px-3" onclick="resetImage()">Remove</button>
                                    </div>
                                </div>
                            </div>
                        </div>

                    </div>
                </div>

                <!-- Footer Actions -->
                <div class="sticky-bottom bg-white border-top p-3 shadow-lg d-flex justify-content-end gap-2 mt-4 mx-n4 mb-n4 rounded-bottom">
                    <button type="button" onclick="history.back()" class="btn btn-light border px-4 fw-bold">Cancel</button>
                    <button type="submit" class="btn btn-primary px-5 fw-bold shadow">
                        <i class="bi bi-check-circle me-2"></i>Update Product
                    </button>
                </div>
            </form>

            <!-- Batches: each delivery with its own expiry date -->
            <div class="card border-0 shadow-sm mt-4" id="batches">
                <div class="card-header bg-white py-3 border-0 d-flex justify-content-between align-items-center flex-wrap gap-2">
                    <div>
                        <h5 class="mb-0 fw-bold h6 text-primary"><i class="bi bi-layers me-2"></i>Batches</h5>
                        <small class="text-muted">Sales use up the batch that expires first. Add new batches with Adjust Stock.</small>
                    </div>
                    <a href="{{ route('stock-adjustments.create', ['product_id' => $product->id]) }}" class="btn btn-outline-primary btn-sm">
                        <i class="bi bi-plus-lg me-1"></i> Receive New Batch
                    </a>
                </div>
                <div class="table-responsive">
                    <table class="table table-hover align-middle mb-0 small">
                        <thead class="bg-light text-muted text-uppercase x-small fw-bold">
                            <tr>
                                <th class="ps-4">Batch No</th>
                                <th>Expiry Date</th>
                                <th>Received</th>
                                <th class="text-end">Received Qty</th>
                                <th class="text-end">In Stock</th>
                                <th>Status</th>
                                <th class="pe-4 text-end"></th>
                            </tr>
                        </thead>
                        <tbody>
                            @php $statusBadges = ['expired' => ['danger', 'Expired'], 'expiring' => ['warning', 'Expiring Soon'], 'valid' => ['success', 'Valid'], 'none' => ['secondary', 'No Expiry']]; @endphp
                            @forelse($batches as $batch)
                                @php [$badgeClass, $badgeText] = (float) $batch->quantity_remaining > 0 ? $statusBadges[$batch->expiryStatus()] : ['secondary', 'Used Up']; @endphp
                                <tr class="{{ (float) $batch->quantity_remaining > 0 ? '' : 'text-muted' }}">
                                    <td class="ps-4">
                                        <input type="text" name="batch_no" form="batch-form-{{ $batch->id }}" value="{{ $batch->batch_no }}"
                                               class="form-control form-control-sm border-0 bg-light" maxlength="100" required style="min-width: 120px">
                                    </td>
                                    <td>
                                        <input type="date" name="expiry_date" form="batch-form-{{ $batch->id }}" value="{{ $batch->expiry_date?->format('Y-m-d') }}"
                                               class="form-control form-control-sm border-0 bg-light" style="min-width: 140px">
                                    </td>
                                    <td>{{ ($batch->received_at ?? $batch->created_at)->format('d M Y') }}</td>
                                    <td class="text-end">{{ (float) $batch->quantity_received }}</td>
                                    <td class="text-end fw-bold">{{ (float) $batch->quantity_remaining }}</td>
                                    <td><span class="badge rounded-pill bg-{{ $badgeClass }}-subtle text-{{ $badgeClass }} border border-{{ $badgeClass }}">{{ $badgeText }}</span></td>
                                    <td class="pe-4 text-end text-nowrap">
                                        <button type="submit" form="batch-form-{{ $batch->id }}" class="btn btn-sm btn-outline-primary">Save</button>
                                        @if((float) $batch->quantity_remaining > 0)
                                            <a href="{{ route('stock-adjustments.create', ['product_id' => $product->id]) }}" class="btn btn-sm btn-outline-secondary" title="Remove stock from a batch with Stock Out">Adjust</a>
                                        @endif
                                    </td>
                                </tr>
                            @empty
                                <tr>
                                    <td colspan="7" class="text-center py-4 text-muted">No batches yet. Stock received is added as a batch.</td>
                                </tr>
                            @endforelse
                        </tbody>
                    </table>
                </div>
                @foreach($batches as $batch)
                    <form id="batch-form-{{ $batch->id }}" method="POST" action="{{ route('product-batches.update', $batch) }}" class="d-none">
                        @csrf
                        @method('PUT')
                    </form>
                @endforeach
            </div>
        </main>
    </div>
</div>

<!-- Add Supplier Modal -->
<div class="modal fade" id="addSupplierModal" tabindex="-1" aria-hidden="true">
    <div class="modal-dialog modal-dialog-centered">
        <div class="modal-content border-0 shadow-lg">
            <div class="modal-header border-0 bg-primary text-white">
                <h5 class="modal-title fw-bold h6"><i class="bi bi-person-plus me-2"></i>Add Quick Supplier</h5>
                <button type="button" class="btn-close btn-close-white" data-bs-dismiss="modal"></button>
            </div>
            <form id="addSupplierForm">
                <div class="modal-body p-4">
                    <div class="row g-3">
                        <div class="col-12">
                            <label class="form-label small fw-bold text-muted">Supplier Name *</label>
                            <input type="text" class="form-control border-0 bg-light" name="name" required placeholder="e.g. MedLab Pharma">
                        </div>
                        <div class="col-md-6">
                            <label class="form-label small fw-bold text-muted">Contact Person</label>
                            <input type="text" class="form-control border-0 bg-light" name="contact_person" placeholder="e.g. John Doe">
                        </div>
                        <div class="col-md-6">
                            <label class="form-label small fw-bold text-muted">Phone Number</label>
                            <input type="tel" class="form-control border-0 bg-light" name="phone" placeholder="+265...">
                        </div>
                        <div class="col-12">
                            <label class="form-label small fw-bold text-muted">Email Address</label>
                            <input type="email" class="form-control border-0 bg-light" name="email" placeholder="supplier@example.com">
                        </div>
                    </div>
                </div>
                <div class="modal-footer border-0 p-4 pt-0">
                    <button type="button" class="btn btn-light border" data-bs-dismiss="modal">Discard</button>
                    <button type="submit" class="btn btn-primary px-4 fw-bold shadow">Create Supplier</button>
                </div>
            </form>
        </div>
    </div>
</div>

<style>
    .x-small { font-size: 0.7rem; }
    .tracking-wider { letter-spacing: 1px; }
    .border-dashed { border-style: dashed !important; }
    .sticky-bottom { position: sticky; bottom: 0; z-index: 1020; }
    
    .form-control:focus, .form-select:focus {
        background-color: #fff !important;
        border: 1px solid #0d6efd !important;
        box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.1) !important;
    }
</style>

@section('scripts')
<script>
    document.addEventListener('DOMContentLoaded', function() {
        const pInput = document.querySelector('input[name="purchase_price"]');
        const sInput = document.querySelector('input[name="selling_price"]');
        const profitDisplay = document.getElementById('profitDisplay');
        const marginBadge = document.getElementById('marginBadge');
        
        function updateMargins() {
            const p = parseFloat(pInput.value) || 0;
            const s = parseFloat(sInput.value) || 0;
            const profit = s - p;
            const margin = p > 0 ? (profit / p) * 100 : 0;
            
            profitDisplay.textContent = 'MWK ' + profit.toLocaleString(undefined, {minimumFractionDigits: 2});
            marginBadge.textContent = margin.toFixed(1) + '%';
            
            marginBadge.className = 'badge rounded-pill px-3 py-2 fs-6 ' + 
                (margin < 10 ? 'bg-danger' : (margin < 25 ? 'bg-warning text-dark' : 'bg-success'));
        }

        pInput.addEventListener('input', updateMargins);
        sInput.addEventListener('input', updateMargins);
        updateMargins();

        // Supplier Preview Logic
        const supplierSelect = document.getElementById('supplierSelect');
        const supplierPreview = document.getElementById('supplierPreview');
        const previewName = document.getElementById('previewName');
        const previewContact = document.getElementById('previewContact');
        const previewPhone = document.getElementById('previewPhone');

        function updateSupplierPreview() {
            const opt = supplierSelect.options[supplierSelect.selectedIndex];
            if (supplierSelect.value) {
                previewName.textContent = opt.text;
                previewContact.textContent = opt.dataset.contact || 'N/A';
                previewPhone.textContent = opt.dataset.phone || 'N/A';
                supplierPreview.style.display = 'block';
            } else {
                supplierPreview.style.display = 'none';
            }
        }

        supplierSelect.addEventListener('change', updateSupplierPreview);
        updateSupplierPreview();

        // Image Preview Logic
        const imageInput = document.getElementById('imageInput');
        const imagePlaceholder = document.getElementById('imagePlaceholder');
        const imagePreview = document.getElementById('imagePreview');
        const previewImg = imagePreview.querySelector('img');

        imageInput.addEventListener('change', function() {
            const file = this.files[0];
            if (file) {
                const reader = new FileReader();
                reader.onload = function(e) {
                    previewImg.src = e.target.result;
                    imagePlaceholder.classList.add('d-none');
                    imagePreview.classList.remove('d-none');
                }
                reader.readAsDataURL(file);
            }
        });

        window.resetImage = function() {
            imageInput.value = '';
            imagePlaceholder.classList.remove('d-none');
            imagePreview.classList.add('d-none');
        };

        // Modal Form Handling
        const supplierForm = document.getElementById('addSupplierForm');
        supplierForm.addEventListener('submit', function(e) {
            e.preventDefault();
            const btn = this.querySelector('button[type="submit"]');
            const originalText = btn.innerHTML;
            btn.innerHTML = '<span class="spinner-border spinner-border-sm me-2"></span>Creating...';
            btn.disabled = true;

            const formData = new FormData(this);
            fetch('{{ route('contacts.store.supplier') }}', {
                method: 'POST',
                body: formData,
                headers: {
                    'X-CSRF-TOKEN': '{{ csrf_token() }}',
                    'Accept': 'application/json'
                }
            })
            .then(res => res.json())
            .then(data => {
                if (data.success) {
                    const newOpt = new Option(data.supplier.name, data.supplier.id);
                    newOpt.dataset.contact = data.supplier.contact_person || 'N/A';
                    newOpt.dataset.phone = data.supplier.phone || 'N/A';
                    newOpt.dataset.email = data.supplier.email || 'N/A';
                    
                    supplierSelect.add(newOpt);
                    supplierSelect.value = data.supplier.id;
                    updateSupplierPreview();
                    
                    bootstrap.Modal.getInstance(document.getElementById('addSupplierModal')).hide();
                    supplierForm.reset();
                } else {
                    alert('Error: ' + data.message);
                }
            })
            .catch(err => alert('An unexpected error occurred.'))
            .finally(() => {
                btn.innerHTML = originalText;
                btn.disabled = false;
            });
        });
    });
</script>
@endsection
@endsection