<?php
// transit/enrollment/import_roster.php — المشرف يرفع كشف الطلاب (CSV)
// POST: file (CSV: student_id, name), semester?, notes?

require_once __DIR__ . '/../../transit/connect_admin.php';

if (!isset($_FILES['file']) || $_FILES['file']['error'] !== UPLOAD_ERR_OK) {
    jsonError('No valid file uploaded', 400);
}

$ext = strtolower(pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION));
if (!in_array($ext, ['csv', 'txt'])) jsonError('Only CSV files are supported', 400);

$semester = filterRequest('semester') ?: date('Y') . '-S1';
$notes    = filterRequest('notes');

$rows = [];
if (($handle = fopen($_FILES['file']['tmp_name'], 'r')) !== false) {
    $headers = null;
    while (($line = fgetcsv($handle, 0, ',')) !== false) {
        if ($headers === null) { $headers = array_map('strtolower', array_map('trim', $line)); continue; }
        $row = array_combine($headers, $line);
        if ($row) $rows[] = $row;
    }
    fclose($handle);
}

if (empty($rows)) jsonError('CSV file is empty or invalid', 400);

$totalRows = count($rows);
$transit_con->prepare(
    "INSERT INTO transit_rosters (org_id, uploaded_by, filename, total_rows, semester, notes)
     VALUES (?,?,?,?,?,?)"
)->execute([$transit_org_id, $transit_admin_id, $_FILES['file']['name'], $totalRows, $semester, $notes]);
$rosterId = (int)$transit_con->lastInsertId();

$insertSt = $transit_con->prepare(
    "INSERT IGNORE INTO transit_enrollments
     (org_id, passenger_id, student_id, member_name, verify_method, status, roster_id)
     VALUES (?,NULL,?,?,'roster_manual','pending',?)"
);

$matchedRows = 0;
$newEnroll   = 0;

foreach ($rows as $row) {
    $sid  = trim($row['student_id'] ?? $row['id'] ?? '');
    $name = trim($row['name'] ?? $row['full_name'] ?? '');
    if (!$sid) continue;

    $encSid = $encryptionHelper->encryptData($sid);

    $chk = $transit_con->prepare(
        "SELECT id, passenger_id FROM transit_enrollments WHERE org_id=? AND student_id=? LIMIT 1"
    );
    $chk->execute([$transit_org_id, $encSid]);
    $existing = $chk->fetch();

    if ($existing) {
        $transit_con->prepare(
            "UPDATE transit_enrollments SET member_name=?, roster_id=? WHERE id=?"
        )->execute([$name, $rosterId, $existing['id']]);
        if ($existing['passenger_id']) $matchedRows++;
    } else {
        $insertSt->execute([$transit_org_id, $encSid, $name, $rosterId]);
        $newEnroll++;
    }
}

$transit_con->prepare(
    "UPDATE transit_rosters SET matched_rows=?, new_enrollments=? WHERE id=?"
)->execute([$matchedRows, $newEnroll, $rosterId]);

jsonSuccess([
    'roster_id'       => $rosterId,
    'total_rows'      => $totalRows,
    'new_enrollments' => $newEnroll,
    'matched'         => $matchedRows,
], 'Roster imported successfully');