<?php
session_start();
if (!isset($_SESSION['user_id'])) {
    header('Location: login.php');
    exit;
}

// Role check for inventory panel
$userRole = $_SESSION['user_role'] ?? '';
$allowedRoles = ['Administrador', 'admin', 'Control Logistico'];
if (!in_array($userRole, $allowedRoles)) {
    header('Location: dashboard.php?error=access_denied');
    exit();
}
require_once 'layout_header.php';
require_once 'db/config.php';

try {
    $pdo = db();

    // 1. Datos para las tarjetas de resumen
    $total_productos = $pdo->query("SELECT COUNT(*) FROM products")->fetchColumn();
    $total_sedes = $pdo->query("SELECT COUNT(*) FROM sedes")->fetchColumn();
    $total_stock = $pdo->query("SELECT COUNT(*) FROM unidades_inventario WHERE estado = 'En Almacén'")->fetchColumn();

    // 2. Datos para la tabla de inventario
    $sedes_stmt = $pdo->query("SELECT id, nombre FROM sedes ORDER BY nombre");
    $sedes = $sedes_stmt->fetchAll(PDO::FETCH_ASSOC);

    $products_stmt = $pdo->query("SELECT id, nombre, sku FROM products ORDER BY nombre");
    $products = $products_stmt->fetchAll(PDO::FETCH_ASSOC);

    $stock_stmt = $pdo->query("SELECT producto_id, sede_id, COUNT(*) as quantity FROM unidades_inventario WHERE estado = 'En Almacén' GROUP BY producto_id, sede_id");
    $stock_data = $stock_stmt->fetchAll(PDO::FETCH_ASSOC);

    $inventario = [];
    foreach ($products as $product) {
        $inventario[$product['id']] = [
            'nombre' => $product['nombre'],
            'sku' => $product['sku'],
            'total' => 0,
            'sedes' => array_fill_keys(array_column($sedes, 'id'), 0)
        ];
    }

    foreach ($stock_data as $stock_item) {
        if (isset($inventario[$stock_item['producto_id']])) {
            $inventario[$stock_item['producto_id']]['sedes'][$stock_item['sede_id']] = $stock_item['quantity'];
            $inventario[$stock_item['producto_id']]['total'] += $stock_item['quantity'];
        }
    }

    // 3. Datos para gráficos
    $stock_por_sede_stmt = $pdo->query("
        SELECT s.nombre, SUM(ss.quantity) as total_stock
        FROM sedes s JOIN stock_sedes ss ON s.id = ss.sede_id
        GROUP BY s.nombre HAVING total_stock > 0 ORDER BY s.nombre
    ");
    $stock_por_sede = $stock_por_sede_stmt->fetchAll(PDO::FETCH_ASSOC);
    
    $sede_chart_labels_array = array_column($stock_por_sede, 'nombre');
    $sede_chart_data_array = array_column($stock_por_sede, 'total_stock');

    $colores_sedes = [];
    $colores_default = ['#FF6384', '#FFCE56', '#4BC0C0', '#9966FF', '#FF9F40'];
    $color_map = [
        'Almacen Principal' => '#28a745', // Verde
        'ALIDRV' => '#FFCE56', // Amarillo
        'LIMA' => '#36A2EB' // Azul
    ];
    $default_color_idx = 0;
    foreach ($sede_chart_labels_array as $label) {
        $color_asignado = null;
        foreach ($color_map as $sede => $color) {
            if (strcasecmp($label, $sede) == 0) {
                $color_asignado = $color;
                break;
            }
        }

        if ($color_asignado) {
            $colores_sedes[] = $color_asignado;
        } else {
            $colores_sedes[] = $colores_default[$default_color_idx % count($colores_default)];
            $default_color_idx++;
        }
    }

    $sede_chart_labels = json_encode($sede_chart_labels_array);
    $sede_chart_data = json_encode($sede_chart_data_array);
    $sede_chart_colors = json_encode($colores_sedes);

    $stock_por_producto_stmt = $pdo->query("
        SELECT p.nombre, SUM(ss.quantity) as total_stock
        FROM products p JOIN stock_sedes ss ON p.id = ss.product_id
        GROUP BY p.nombre HAVING total_stock > 0 ORDER BY total_stock DESC LIMIT 15
    ");
    $stock_por_producto = $stock_por_producto_stmt->fetchAll(PDO::FETCH_ASSOC);
    $producto_chart_labels = json_encode(array_column($stock_por_producto, 'nombre'));
    $producto_chart_data = json_encode(array_column($stock_por_producto, 'total_stock'));

    // 4. Datos para el historial de movimientos (últimos 50)
    $movements_stmt = $pdo->query("
        SELECT sm.movement_date, p.nombre as product_name, s.nombre as sede_name, sm.quantity, sm.type
        FROM stock_movements sm
        JOIN products p ON sm.product_id = p.id
        JOIN sedes s ON sm.sede_id = s.id
        ORDER BY sm.created_at DESC
        LIMIT 50
    ");
    $movements = $movements_stmt->fetchAll(PDO::FETCH_ASSOC);

} catch (PDOException $e) {
    echo "<div class='alert alert-danger'>Error al conectar o consultar la base de datos: " . $e->getMessage() . "</div>";
    require_once 'layout_footer.php';
    die();
}
?>

<div class="container-fluid mt-4">
    <div class="d-flex justify-content-between align-items-center mb-4">
        <h1>Dashboard de Inventario</h1>
        <div>
            <a href="registro_entrada.php" class="btn btn-success"><i class="fa fa-plus"></i> Registrar Entrada</a>
            <a href="registro_salida.php" class="btn btn-danger"><i class="fa fa-minus"></i> Registrar Salida</a>
        </div>
    </div>

    <!-- Tarjetas de Resumen -->
    <div class="row mb-4">
        <div class="col-md-4">
            <div class="card text-white bg-primary mb-3">
                <div class="card-body">
                    <h5 class="card-title">Total de Productos</h5>
                    <p class="card-text fs-4"><?php echo $total_productos; ?></p>
                </div>
            </div>
        </div>
        <div class="col-md-4">
            <div class="card text-white bg-success mb-3">
                <div class="card-body">
                    <h5 class="card-title">Sedes Activas</h5>
                    <p class="card-text fs-4"><?php echo $total_sedes; ?></p>
                </div>
            </div>
        </div>
        <div class="col-md-4">
            <div class="card text-white bg-info mb-3">
                <div class="card-body">
                    <h5 class="card-title">Unidades Totales en Stock</h5>
                    <p class="card-text fs-4"><?php echo $total_stock ?: 0; ?></p>
                </div>
            </div>
        </div>
    </div>

    <!-- Sección de Gráficos -->
    <div class="row mb-4">
        <div class="col-lg-6 mb-4">
            <div class="card h-100">
                <div class="card-header"><h5 class="m-0">Distribución por Sede</h5></div>
                <div class="card-body d-flex justify-content-center align-items-center">
                    <canvas id="distribucionSedeChart" style="max-height: 300px;"></canvas>
                </div>
            </div>
        </div>
        <div class="col-lg-6 mb-4">
            <div class="card h-100">
                <div class="card-header"><h5 class="m-0">Top 15 Productos con Más Stock</h5></div>
                <div class="card-body"><canvas id="stockProductoChart"></canvas></div>
            </div>
        </div>
    </div>

    <!-- Tabla de Inventario Detallado -->
    <div class="card mb-4">
        <div class="card-header"><h5 class="m-0">Inventario por Sede</h5></div>
        <div class="card-body">
            <div class="table-responsive">
                <table class="table table-bordered table-hover">
                    <thead class="thead-light">
                        <tr>
                            <th>Producto</th>
                            <th>SKU</th>
                            <th class="text-center">Stock Total</th>
                            <?php foreach ($sedes as $sede): ?>
                                <th class="text-center"><?php echo htmlspecialchars($sede['nombre']); ?></th>
                            <?php endforeach; ?>
                        </tr>
                    </thead>
                    <tbody>
                        <?php if (empty($inventario)): ?>
                            <tr><td colspan="<?php echo count($sedes) + 3; ?>" class="text-center">No hay productos.</td></tr>
                        <?php else: ?>
                            <?php foreach ($inventario as $product_id => $datos_producto): ?>
                                <tr>
                                    <td><?php echo htmlspecialchars($datos_producto['nombre']); ?></td>
                                    <td><?php echo htmlspecialchars($datos_producto['sku']); ?></td>
                                    <td class="text-center fw-bold"><?php echo $datos_producto['total']; ?></td>
                                    <?php foreach ($datos_producto['sedes'] as $sede_id => $cantidad): ?>
                                        <td class="text-center">
                                            <?php if ($cantidad > 0): ?>
                                                <a href="#" class="ver-codigos" data-product-id="<?php echo $product_id; ?>" data-sede-id="<?php echo $sede_id; ?>">
                                                    <?php echo $cantidad; ?>
                                                </a>
                                            <?php else: ?>
                                                0
                                            <?php endif; ?>
                                        </td>
                                    <?php endforeach; ?>
                                </tr>
                            <?php endforeach; ?>
                        <?php endif; ?>
                    </tbody>
                </table>
            </div>
        </div>
    </div>

    <!-- Historial de Movimientos -->
    <div class="card">
        <div class="card-header"><h5 class="m-0">Historial de Movimientos Recientes</h5></div>
        <div class="card-body">
            <div class="table-responsive">
                <table class="table table-striped table-hover">
                    <thead class="thead-light">
                        <tr>
                            <th>Fecha</th>
                            <th>Producto</th>
                            <th>Sede</th>
                            <th class="text-center">Cantidad</th>
                            <th class="text-center">Tipo</th>
                        </tr>
                    </thead>
                    <tbody>
                        <?php if (empty($movements)): ?>
                            <tr><td colspan="5" class="text-center">No hay movimientos registrados.</td></tr>
                        <?php else: ?>
                            <?php foreach ($movements as $mov): ?>
                                <tr>
                                    <td><?php echo htmlspecialchars(date("d/m/Y", strtotime($mov['movement_date']))); ?></td>
                                    <td><?php echo htmlspecialchars($mov['product_name']); ?></td>
                                    <td><?php echo htmlspecialchars($mov['sede_name']); ?></td>
                                    <td class="text-center"><?php echo htmlspecialchars($mov['quantity']); ?></td>
                                    <td class="text-center">
                                        <?php if ($mov['type'] == 'entrada'): ?>
                                            <span class="badge bg-success">Entrada</span>
                                        <?php else: ?>
                                            <span class="badge bg-danger">Salida</span>
                                        <?php endif; ?>
                                    </td>
                                </tr>
                            <?php endforeach; ?>
                        <?php endif; ?>
                    </tbody>
                </table>
            </div>
        </div>
    </div>
</div>

<script src="https://cdn.jsdelivr.net/npm/chart.js?v=<?php echo time(); ?>"></script>
<script>
document.addEventListener('DOMContentLoaded', function () {
    const sedeLabels = <?php echo $sede_chart_labels; ?>;
    const sedeData = <?php echo $sede_chart_data; ?>;
    const sedeColors = <?php echo $sede_chart_colors; ?>;
    if (sedeLabels.length > 0) {
        const ctxSede = document.getElementById('distribucionSedeChart').getContext('2d');
        new Chart(ctxSede, {
            type: 'pie',
            data: { labels: sedeLabels, datasets: [{ label: 'Stock', data: sedeData, backgroundColor: sedeColors }] },
            options: { responsive: true, maintainAspectRatio: false, plugins: { legend: { position: 'bottom' } } }
        });
    }

    const productoLabels = <?php echo $producto_chart_labels; ?>;
    const productoData = <?php echo $producto_chart_data; ?>;
    if (productoLabels.length > 0) {
        const ctxProducto = document.getElementById('stockProductoChart').getContext('2d');
        new Chart(ctxProducto, {
            type: 'bar',
            data: { labels: productoLabels, datasets: [{ label: 'Cantidad en Stock', data: productoData, backgroundColor: 'rgba(54, 162, 235, 0.6)', borderColor: 'rgba(54, 162, 235, 1)', borderWidth: 1 }] },
            options: {
                indexAxis: 'y', responsive: true, plugins: { legend: { display: false }, title: { display: true, text: 'Stock por Producto' } },
                scales: { x: { beginAtZero: true } }
            }
        });
    }
});
</script>

<?php require_once 'layout_footer.php'; ?>

<!-- Modal para mostrar los códigos de barras -->
<div class="modal fade" id="codesModal" tabindex="-1" aria-labelledby="codesModalLabel" aria-hidden="true">
  <div class="modal-dialog modal-dialog-scrollable">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title" id="codesModalLabel">Códigos de Barras</h5>
        <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
      </div>
      <div class="modal-body">
        <p><strong>Producto:</strong> <span id="modalProductName"></span></p>
        <div id="codesTableContainer"></div>
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Cerrar</button>
      </div>
    </div>
  </div>
</div>

<script>
$(document).ready(function() {
    $('.ver-codigos').on('click', function(e) {
        e.preventDefault();

        var productId = $(this).data('product-id');
        var sedeId = $(this).data('sede-id');
        var productName = $(this).closest('tr').find('td:first').text();

        $('#modalProductName').text(productName);
        $('#codesTableContainer').html('<p>Cargando...</p>');

        var myModal = new bootstrap.Modal(document.getElementById('codesModal'));
        myModal.show();

        $.ajax({
            url: 'get_barcodes_by_product_and_sede.php',
            type: 'GET',
            dataType: 'json',
            data: {
                product_id: productId,
                sede_id: sedeId
            },
            success: function(data) {
                
                function getBadgeClass(estado) {
                    if (estado === 'En Almacén') return 'bg-success';
                    if (estado === 'Vendido') return 'bg-danger';
                    if (estado === 'Generado') return 'bg-info';
                    return 'bg-secondary';
                }

                let tableHtml = '<table class="table table-bordered table-striped"><thead><tr><th>Código</th><th>Estado</th></tr></thead><tbody>';
                if (data.length > 0) {
                    data.forEach(item => {
                        const badgeClass = getBadgeClass(item.estado);
                        tableHtml += '<tr><td>' + item.codigo_unico + '</td><td><span class="badge ' + badgeClass + '">' + item.estado + '</span></td></tr>';
                    });
                } else {
                    tableHtml += '<tr><td colspan="2" class="text-center">No se encontraron unidades.</td></tr>';
                }
                tableHtml += '</tbody></table>';
                $('#codesTableContainer').html(tableHtml);
            },
            error: function() {
                $('#codesTableContainer').html('<p class="text-danger">Error al cargar los códigos.</p>');
            }
        });
    });
});
</script>