<?php
/**
 * Bulk "renew": set a common completed_date on the selected training records
 */
require_once(__DIR__ . '/../hr_auth_check.php');
header('Content-Type: application/json');

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo json_encode(['success' => false, 'message' => 'Metodo non consentito.']);
    exit;
}

// $pdo and $currentUserId from hr_auth_check.php

$completedDate = trim($_POST['completed_date'] ?? '');
$ids           = $_POST['training_ids'] ?? [];

if (!is_array($ids)) {
    $ids = [];
}
$ids = array_values(array_unique(array_filter(array_map('intval', $ids), fn($v) => $v > 0)));

if ($completedDate === '' || !DateTime::createFromFormat('Y-m-d', $completedDate)) {
    echo json_encode(['success' => false, 'message' => 'Indicare una data valida.']);
    exit;
}
if (empty($ids)) {
    echo json_encode(['success' => false, 'message' => 'Selezionare almeno un record.']);
    exit;
}

try {
    $pdo->beginTransaction();

    // Load each record with its topic default frequency
    $rowStmt = $pdo->prepare("
        SELECT et.id, et.employee_id, et.completed_date, et.next_due_date,
               et.update_frequency_months, tt.default_frequency_months
        FROM employee_trainings et
        JOIN training_topics tt ON tt.id = et.training_topic_id
        WHERE et.id = :id
    ");
    $upd = $pdo->prepare("
        UPDATE employee_trainings
        SET completed_date = :cd, next_due_date = :nd, updated_at = NOW()
        WHERE id = :id
    ");
    $logStmt = $pdo->prepare("
        INSERT INTO employee_training_log
            (employee_id, training_id, action, field, old_value, new_value, changed_by, changed_at)
        VALUES
            (:eid, :tid, 'updated', :field, :old_v, :new_v, :cb, NOW())
    ");

    $updated = 0;
    foreach ($ids as $id) {
        $rowStmt->execute(['id' => $id]);
        $row = $rowStmt->fetch(PDO::FETCH_ASSOC);
        if (!$row) {
            continue;
        }

        // Effective frequency: per-record override, else topic default
        $effFreq = $row['update_frequency_months'] !== null
            ? (int)$row['update_frequency_months']
            : ($row['default_frequency_months'] !== null ? (int)$row['default_frequency_months'] : null);

        $nextDue = null;
        if ($effFreq !== null && $effFreq > 0) {
            $d = DateTime::createFromFormat('Y-m-d', $completedDate);
            if ($d) {
                $d->modify('+' . $effFreq . ' months');
                $nextDue = $d->format('Y-m-d');
            }
        }

        $upd->execute(['cd' => $completedDate, 'nd' => $nextDue, 'id' => $id]);

        if ((string)$row['completed_date'] !== (string)$completedDate) {
            $logStmt->execute([
                'eid' => $row['employee_id'], 'tid' => $id, 'field' => 'completed_date',
                'old_v' => $row['completed_date'], 'new_v' => $completedDate, 'cb' => $currentUserId,
            ]);
        }
        if ((string)$row['next_due_date'] !== (string)$nextDue) {
            $logStmt->execute([
                'eid' => $row['employee_id'], 'tid' => $id, 'field' => 'next_due_date',
                'old_v' => $row['next_due_date'], 'new_v' => $nextDue, 'cb' => $currentUserId,
            ]);
        }
        $updated++;
    }

    $pdo->commit();
    echo json_encode([
        'success' => true,
        'updated' => $updated,
        'message' => $updated . ' record aggiornat' . ($updated === 1 ? 'o' : 'i') . '.',
    ]);
} catch (Exception $e) {
    if ($pdo->inTransaction()) $pdo->rollBack();
    echo json_encode(['success' => false, 'message' => $e->getMessage()]);
}