<?php
$pageTitle = 'Recordatorios';
require_once __DIR__ . '/../includes/db.php';
require_once __DIR__ . '/includes/admin-header.php';

$db = getDB();

$errors  = [];
$success = '';
$today   = date('Y-m-d');

// ── Handle POST actions ─────────────────────────────────────────
if ($_SERVER['REQUEST_METHOD'] === 'POST' && csrfValidate()) {
    $action = $_POST['action'] ?? '';

    switch ($action) {

        // ── Add reminder ──────────────────────────────────────────
        case 'add_reminder':
            $titulo      = trim($_POST['titulo'] ?? '');
            $descripcion = trim($_POST['descripcion'] ?? '');
            $fecha       = trim($_POST['fecha'] ?? '');
            $clienteId   = (int)($_POST['cliente_id'] ?? 0);
            $tramiteId   = (int)($_POST['tramite_id'] ?? 0);

            if ($titulo === '') {
                $errors[] = 'El t&iacute;tulo es obligatorio.';
            }
            if ($fecha === '' || !preg_match('/^\d{4}-\d{2}-\d{2}$/', $fecha)) {
                $errors[] = 'La fecha es obligatoria y debe ser v&aacute;lida.';
            }

            if (empty($errors)) {
                $stmt = $db->prepare("INSERT INTO recordatorios
                    (cliente_id, tramite_id, titulo, descripcion, fecha, completado, created_at)
                    VALUES (?, ?, ?, ?, ?, 0, NOW())");
                $stmt->execute([
                    $clienteId > 0 ? $clienteId : null,
                    $tramiteId > 0 ? $tramiteId : null,
                    $titulo,
                    $descripcion,
                    $fecha,
                ]);
                header('Location: recordatorios.php?added=1' . (!empty($_GET['show_completed']) ? '&show_completed=1' : ''));
                exit;
            }
            break;

        // ── Complete reminder ─────────────────────────────────────
        case 'complete_reminder':
            $id = (int)($_POST['reminder_id'] ?? 0);
            if ($id > 0) {
                $stmt = $db->prepare("UPDATE recordatorios SET completado = 1 WHERE id = ?");
                $stmt->execute([$id]);
            }
            header('Location: recordatorios.php?completed=1' . (!empty($_GET['show_completed']) ? '&show_completed=1' : ''));
            exit;

        // ── Delete reminder ───────────────────────────────────────
        case 'delete_reminder':
            $id = (int)($_POST['reminder_id'] ?? 0);
            if ($id > 0) {
                $stmt = $db->prepare("DELETE FROM recordatorios WHERE id = ?");
                $stmt->execute([$id]);
            }
            header('Location: recordatorios.php?deleted=1' . (!empty($_GET['show_completed']) ? '&show_completed=1' : ''));
            exit;
    }
}

// ── Flash messages from redirect ────────────────────────────────
if (isset($_GET['added']))     $success = 'Recordatorio creado correctamente.';
if (isset($_GET['completed']))  $success = 'Recordatorio marcado como completado.';
if (isset($_GET['deleted']))    $success = 'Recordatorio eliminado correctamente.';

// ── Filters & pagination ────────────────────────────────────────
$showCompleted = isset($_GET['show_completed']) && $_GET['show_completed'] === '1';
$page    = max(1, (int)($_GET['page'] ?? 1));
$perPage = 20;
$offset  = ($page - 1) * $perPage;

// Build WHERE clause
$where  = '';
$params = [];
if (!$showCompleted) {
    $where = 'WHERE r.completado = 0';
}

// Count total
$countSql  = "SELECT COUNT(*) FROM recordatorios r $where";
$countStmt = $db->prepare($countSql);
$countStmt->execute($params);
$totalRecordatorios = $countStmt->fetchColumn();
$totalPages         = max(1, (int)ceil($totalRecordatorios / $perPage));

if ($page > $totalPages) $page = $totalPages;
$offset = ($page - 1) * $perPage;

// Fetch reminders with client name
$sql = "SELECT r.*, c.nombre AS cliente_nombre
        FROM recordatorios r
        LEFT JOIN clientes c ON r.cliente_id = c.id
        $where
        ORDER BY r.fecha ASC
        LIMIT $perPage OFFSET $offset";
$stmt = $db->prepare($sql);
$stmt->execute($params);
$recordatorios = $stmt->fetchAll();

// Count overdue (for badge in header)
$stmtOverdue = $db->prepare("SELECT COUNT(*) FROM recordatorios WHERE completado = 0 AND fecha < ?");
$stmtOverdue->execute([$today]);
$countOverdue = (int)$stmtOverdue->fetchColumn();

// Fetch clients for dropdown
$clientesStmt = $db->query("SELECT id, nombre FROM clientes ORDER BY nombre ASC");
$clientesList = $clientesStmt->fetchAll();

// Fetch tramites for dropdown
$tramitesStmt = $db->query("SELECT t.id, t.tipo, c.nombre AS cliente_nombre
    FROM tramites t
    LEFT JOIN clientes c ON t.cliente_id = c.id
    ORDER BY t.created_at DESC LIMIT 100");
$tramitesList = $tramitesStmt->fetchAll();
$tipoLabels = [
    'visa'               => 'Visa',
    'sentri'             => 'Sentri/Global',
    'pasaporte'          => 'Pasaporte',
    'adelanto_cita'      => 'Adelanto Cita',
    'doble_nacionalidad' => 'Doble Nacionalidad',
];
?>

<div class="admin-content__header">
    <h1>
        <i class="fas fa-bell"></i> Recordatorios
        <?php if ($countOverdue > 0): ?>
            <span class="badge badge--danger" style="font-size: 0.5em; vertical-align: middle;">
                <?= $countOverdue ?> vencido<?= $countOverdue > 1 ? 's' : '' ?>
            </span>
        <?php endif; ?>
    </h1>
    <p>Gestiona tus recordatorios y tareas pendientes</p>
</div>

<!-- Success / Error messages -->
<?php if ($success !== ''): ?>
    <div class="alert alert--success" style="padding: 0.75rem 1rem; margin-bottom: 1rem; border-radius: 0.5rem; background: var(--admin-success-light); color: #155724; border: 1px solid #C3E6CB;">
        <i class="fas fa-check-circle"></i> <?= $success ?>
    </div>
<?php endif; ?>

<?php if (!empty($errors)): ?>
    <div class="alert alert--danger" style="padding: 0.75rem 1rem; margin-bottom: 1rem; border-radius: 0.5rem; background: var(--admin-danger-light); color: #721C24; border: 1px solid #F5C6CB;">
        <i class="fas fa-exclamation-circle"></i>
        <ul style="margin: 0.25rem 0 0 1.25rem; padding: 0;">
            <?php foreach ($errors as $e): ?>
                <li><?= $e ?></li>
            <?php endforeach; ?>
        </ul>
    </div>
<?php endif; ?>

<!-- Add Reminder Form -->
<div class="card" style="margin-bottom: 1.5rem;">
    <div class="card__header" style="padding: 1rem 1.25rem; border-bottom: 1px solid var(--admin-gray-200); font-weight: 600;">
        <i class="fas fa-plus-circle"></i> Nuevo Recordatorio
    </div>
    <div class="card__body">
        <form method="POST" action="recordatorios.php<?= $showCompleted ? '?show_completed=1' : '' ?>">
            <?= csrfField() ?>
            <input type="hidden" name="action" value="add_reminder">

            <div style="display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; margin-bottom: 1rem;">
                <div class="form-group" style="margin-bottom: 0;">
                    <label>T&iacute;tulo <span class="required">*</span></label>
                    <input type="text" name="titulo" class="form-control" required
                           value="<?= htmlspecialchars($_POST['titulo'] ?? '') ?>"
                           placeholder="Ej: Llamar al cliente...">
                </div>

                <div class="form-group" style="margin-bottom: 0;">
                    <label>Fecha <span class="required">*</span></label>
                    <input type="date" name="fecha" class="form-control" required
                           value="<?= htmlspecialchars($_POST['fecha'] ?? $today) ?>">
                </div>

                <div class="form-group" style="margin-bottom: 0;">
                    <label>Cliente <small>(opcional)</small></label>
                    <select name="cliente_id" class="form-control">
                        <option value="0">-- Ninguno --</option>
                        <?php foreach ($clientesList as $cl): ?>
                            <option value="<?= (int)$cl['id'] ?>" <?= ((int)($_POST['cliente_id'] ?? 0) === (int)$cl['id']) ? 'selected' : '' ?>>
                                <?= htmlspecialchars($cl['nombre']) ?>
                            </option>
                        <?php endforeach; ?>
                    </select>
                </div>

                <div class="form-group" style="margin-bottom: 0;">
                    <label>Tr&aacute;mite <small>(opcional)</small></label>
                    <select name="tramite_id" class="form-control">
                        <option value="0">-- Ninguno --</option>
                        <?php foreach ($tramitesList as $tr): ?>
                            <option value="<?= (int)$tr['id'] ?>" <?= ((int)($_POST['tramite_id'] ?? 0) === (int)$tr['id']) ? 'selected' : '' ?>>
                                #<?= (int)$tr['id'] ?> - <?= htmlspecialchars($tipoLabels[$tr['tipo']] ?? $tr['tipo']) ?> (<?= htmlspecialchars($tr['cliente_nombre'] ?? 'Sin cliente') ?>)
                            </option>
                        <?php endforeach; ?>
                    </select>
                </div>
            </div>

            <div class="form-group" style="margin-bottom: 1rem;">
                <label>Descripci&oacute;n <small>(opcional)</small></label>
                <textarea name="descripcion" class="form-control" rows="2"
                          placeholder="Detalles adicionales del recordatorio..."><?= htmlspecialchars($_POST['descripcion'] ?? '') ?></textarea>
            </div>

            <button type="submit" class="btn btn--primary">
                <i class="fas fa-plus"></i> Agregar Recordatorio
            </button>
        </form>
    </div>
</div>

<!-- Toolbar: Filter toggle -->
<div class="toolbar">
    <div class="toolbar__left">
        <?php if ($showCompleted): ?>
            <a href="recordatorios.php" class="btn btn--sm btn--secondary">
                <i class="fas fa-eye-slash"></i> Ocultar completados
            </a>
        <?php else: ?>
            <a href="recordatorios.php?show_completed=1" class="btn btn--sm btn--secondary">
                <i class="fas fa-eye"></i> Mostrar todos
            </a>
        <?php endif; ?>
        <span style="margin-left: 0.75rem; color: var(--admin-gray-600); font-size: var(--admin-font-sm);">
            <?= $totalRecordatorios ?> recordatorio<?= $totalRecordatorios !== 1 ? 's' : '' ?>
            <?= !$showCompleted ? ' pendiente' . ($totalRecordatorios !== 1 ? 's' : '') : ' en total' ?>
        </span>
    </div>
</div>

<!-- Reminders List -->
<div class="card">
    <div class="card__body">
        <?php if (empty($recordatorios)): ?>
            <div class="table-empty">
                <i class="fas fa-bell"></i>
                <p><?= !$showCompleted ? 'No hay recordatorios pendientes.' : 'No hay recordatorios registrados a&uacute;n.' ?></p>
            </div>
        <?php else: ?>
            <div class="table-responsive">
                <table class="admin-table">
                    <thead>
                        <tr>
                            <th style="width: 110px;">Fecha</th>
                            <th>T&iacute;tulo</th>
                            <th>Descripci&oacute;n</th>
                            <th>Cliente</th>
                            <?php if ($showCompleted): ?>
                                <th>Estado</th>
                            <?php endif; ?>
                            <th style="width: 180px;">Acciones</th>
                        </tr>
                    </thead>
                    <tbody>
                        <?php foreach ($recordatorios as $r):
                            // Determine color coding
                            $fechaR = $r['fecha'];
                            $isCompleted = (int)$r['completado'] === 1;
                            if ($isCompleted) {
                                $rowStyle = 'opacity: 0.6;';
                                $dateClass = 'secondary';
                            } elseif ($fechaR < $today) {
                                $rowStyle = 'background: rgba(220, 53, 69, 0.06);';
                                $dateClass = 'danger';
                            } elseif ($fechaR === $today) {
                                $rowStyle = 'background: rgba(255, 193, 7, 0.1);';
                                $dateClass = 'warning';
                            } else {
                                $rowStyle = '';
                                $dateClass = 'success';
                            }
                        ?>
                        <tr style="<?= $rowStyle ?>">
                            <td>
                                <span class="badge badge--<?= $dateClass ?>">
                                    <?= date('d/m/Y', strtotime($fechaR)) ?>
                                </span>
                            </td>
                            <td>
                                <strong><?= htmlspecialchars($r['titulo']) ?></strong>
                            </td>
                            <td>
                                <?php
                                $desc = $r['descripcion'] ?? '';
                                echo htmlspecialchars(mb_strlen($desc) > 80 ? mb_substr($desc, 0, 80) . '...' : $desc);
                                ?>
                            </td>
                            <td>
                                <?php if ($r['cliente_id'] && $r['cliente_nombre']): ?>
                                    <a href="cliente-detalle.php?id=<?= (int)$r['cliente_id'] ?>" style="color: var(--admin-primary); text-decoration: none;">
                                        <?= htmlspecialchars($r['cliente_nombre']) ?>
                                    </a>
                                <?php else: ?>
                                    <span style="color: var(--admin-gray-500);">-</span>
                                <?php endif; ?>
                            </td>
                            <?php if ($showCompleted): ?>
                                <td>
                                    <?php if ($isCompleted): ?>
                                        <span class="badge badge--success"><i class="fas fa-check"></i> Completado</span>
                                    <?php else: ?>
                                        <span class="badge badge--primary">Pendiente</span>
                                    <?php endif; ?>
                                </td>
                            <?php endif; ?>
                            <td>
                                <div style="display: flex; gap: 0.5rem;">
                                    <?php if (!$isCompleted): ?>
                                        <form method="POST" action="recordatorios.php<?= $showCompleted ? '?show_completed=1' : '' ?>" style="display: inline;">
                                            <?= csrfField() ?>
                                            <input type="hidden" name="action" value="complete_reminder">
                                            <input type="hidden" name="reminder_id" value="<?= (int)$r['id'] ?>">
                                            <button type="submit" class="btn btn--sm btn--success" title="Marcar como completado">
                                                <i class="fas fa-check"></i>
                                            </button>
                                        </form>
                                    <?php endif; ?>
                                    <form method="POST" action="recordatorios.php<?= $showCompleted ? '?show_completed=1' : '' ?>" style="display: inline;"
                                          onsubmit="return confirm('&iquest;Eliminar este recordatorio?');">
                                        <?= csrfField() ?>
                                        <input type="hidden" name="action" value="delete_reminder">
                                        <input type="hidden" name="reminder_id" value="<?= (int)$r['id'] ?>">
                                        <button type="submit" class="btn btn--sm btn--danger" title="Eliminar">
                                            <i class="fas fa-trash"></i>
                                        </button>
                                    </form>
                                </div>
                            </td>
                        </tr>
                        <?php endforeach; ?>
                    </tbody>
                </table>
            </div>

            <!-- Pagination -->
            <?php if ($totalPages > 1): ?>
            <div class="pagination">
                <?php
                $queryParams = '';
                if ($showCompleted) $queryParams .= '&show_completed=1';
                ?>
                <a href="?page=1<?= $queryParams ?>" class="pagination__link <?= $page <= 1 ? 'pagination__link--disabled' : '' ?>">
                    <i class="fas fa-angle-double-left"></i>
                </a>
                <a href="?page=<?= $page - 1 ?><?= $queryParams ?>" class="pagination__link <?= $page <= 1 ? 'pagination__link--disabled' : '' ?>">
                    <i class="fas fa-angle-left"></i>
                </a>

                <?php
                $start = max(1, $page - 2);
                $end   = min($totalPages, $page + 2);
                for ($i = $start; $i <= $end; $i++):
                ?>
                <a href="?page=<?= $i ?><?= $queryParams ?>" class="pagination__link <?= $i === $page ? 'pagination__link--active' : '' ?>">
                    <?= $i ?>
                </a>
                <?php endfor; ?>

                <a href="?page=<?= $page + 1 ?><?= $queryParams ?>" class="pagination__link <?= $page >= $totalPages ? 'pagination__link--disabled' : '' ?>">
                    <i class="fas fa-angle-right"></i>
                </a>
                <a href="?page=<?= $totalPages ?><?= $queryParams ?>" class="pagination__link <?= $page >= $totalPages ? 'pagination__link--disabled' : '' ?>">
                    <i class="fas fa-angle-double-right"></i>
                </a>

                <span class="pagination__info">
                    P&aacute;gina <?= $page ?> de <?= $totalPages ?> (<?= $totalRecordatorios ?> recordatorios)
                </span>
            </div>
            <?php endif; ?>
        <?php endif; ?>
    </div>
</div>

<?php require_once __DIR__ . '/includes/admin-footer.php'; ?>