<?php

require_once __DIR__ . '/auth_check.php';

mnt_require_permission('maintenance.calendar.view');

/**
 * FullCalendar feed for maintenance due dates.
 * Optional filters: type=scheduled|extraordinary, category=<id>
 */
try {
    $pdo = mnt_pdo();

    $start = (string)($_GET['start'] ?? date('Y-m-01', strtotime('-6 months')));
    $end   = (string)($_GET['end'] ?? date('Y-m-t', strtotime('+12 months')));
    $type  = (string)($_GET['type'] ?? '');
    $categoryId = (int)($_GET['category'] ?? 0);

    // Le attrezzature dismesse o fuori servizio restano fuori dalle viste di
    // pianificazione: è a questo che serve lo stato (capitolato §1).
    $where = [
        "m.is_active = 1",
        "e.status = 'active'",
        "m.next_due_date IS NOT NULL",
        "m.next_due_date BETWEEN ? AND ?",
    ];
    $params = [substr($start, 0, 10), substr($end, 0, 10)];

    if (array_key_exists($type, mnt_intervention_types())) {
        $where[] = "m.intervention_type = ?";
        $params[] = $type;
    }
    if ($categoryId > 0) {
        $where[] = "e.category_id = ?";
        $params[] = $categoryId;
    }

    $stmt = $pdo->prepare("
        SELECT m.id, m.title, m.code, m.next_due_date, m.alert_days, m.is_critical, m.intervention_type,
               e.id AS equipment_id, e.name AS equipment_name,
               c.color AS category_color
        FROM maint_maintenances m
        INNER JOIN inv_equipment e ON e.id = m.equipment_id
        LEFT JOIN inv_categories c ON c.id = e.category_id
        WHERE " . implode(' AND ', $where) . "
        ORDER BY m.next_due_date ASC
    ");
    $stmt->execute($params);

    $events = [];

    foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $row) {
        $state = mnt_due_state($row['next_due_date'], (int)$row['alert_days']);

        // Overdue/soon override the category colour so urgency wins visually
        $color = $state === 'overdue' ? '#dc3545' : ($state === 'due_soon' ? '#f0a202' : ($row['category_color'] ?: '#2f7d8f'));

        $events[] = [
            'id' => (int)$row['id'],
            'title' => ($row['code'] ? $row['code'] . ' — ' : '') . $row['equipment_name'] . ': ' . $row['title'],
            'start' => $row['next_due_date'],
            'allDay' => true,
            'backgroundColor' => $color,
            'borderColor' => $color,
            'extendedProps' => [
                'equipmentId' => (int)$row['equipment_id'],
                'equipmentName' => $row['equipment_name'],
                'maintenanceTitle' => $row['title'],
                'isCritical' => (int)$row['is_critical'] === 1,
                'state' => $state,
                'type' => $row['intervention_type'],
            ],
        ];
    }

    echo json_encode($events);
} catch (Throwable $e) {
    http_response_code(500);
    echo json_encode(['error' => $e->getMessage()]);
}