<?php

require_once __DIR__ . '/../lib/activity.php';

$tokenRec = require_valid_token();
require_role(['admin', 'supervisor'], $tokenRec);

if ($method !== 'GET') {
    json_error('METHOD_NOT_ALLOWED', 'Method not allowed', 405);
}

$clientCode = trim($_GET['clientCode'] ?? '');
$exportAll  = (strpos($route, 'export_all') !== false) || isset($_GET['export_all']);

[$pdo, $tmpDb, $lockFp] = qdb_open(false);
[$rbacClause, $rbacParams] = rbac_client_filter($tokenRec, 'cl');

$clientFilter = '';
$params = $rbacParams;
if (!$exportAll) {
    if ($clientCode === '') {
        qdb_discard($tmpDb, $lockFp);
        json_error('MISSING_PARAM', 'clientCode query param required', 400);
    }
    $clientFilter = ' AND cl.clientCode = :cc';
    $params[':cc'] = $clientCode;
}

$sql = "
    SELECT cl.clientCode, cl.coachID,
           co.username AS coachUsername,
           sv.username AS supervisorUsername
    FROM client cl
    LEFT JOIN coach co ON co.coachID = cl.coachID
    LEFT JOIN supervisor sv ON sv.supervisorID = co.supervisorID
    WHERE ($rbacClause) $clientFilter
    ORDER BY cl.clientCode
";
$stmt = $pdo->prepare($sql);
$stmt->execute($params);
$clients = $stmt->fetchAll(PDO::FETCH_ASSOC);

if (!$exportAll && empty($clients)) {
    qdb_discard($tmpDb, $lockFp);
    json_error('NOT_FOUND', 'Client not found or not authorized', 404);
}

$subStmt = $pdo->prepare("
    SELECT qs.submissionID, qs.clientCode, qs.questionnaireID, qs.submissionVersion,
           qs.status, qs.startedAt, qs.completedAt, qs.uploadedAt, qs.sumPoints,
           qs.submittedByRole, qn.name AS questionnaireName
    FROM questionnaire_submission qs
    JOIN questionnaire qn ON qn.questionnaireID = qs.questionnaireID
    WHERE qs.clientCode = :cc
    ORDER BY qs.uploadedAt, qs.submissionVersion
");

$ansStmt = $pdo->prepare("
    SELECT sa.questionID, sa.answerOptionID, sa.freeTextValue, sa.numericValue,
           q.defaultText AS questionText, ao.defaultText AS optionText
    FROM submission_answer sa
    JOIN question q ON q.questionID = sa.questionID
    LEFT JOIN answer_option ao ON ao.answerOptionID = sa.answerOptionID
    WHERE sa.submissionID = :sid
    ORDER BY q.orderIndex
");

$rows = [];
foreach ($clients as $cl) {
    $cc = $cl['clientCode'];
    $subStmt->execute([':cc' => $cc]);
    foreach ($subStmt->fetchAll(PDO::FETCH_ASSOC) as $sub) {
        $ansStmt->execute([':sid' => $sub['submissionID']]);
        $answers = $ansStmt->fetchAll(PDO::FETCH_ASSOC);
        if (empty($answers)) {
            $rows[] = build_export_row($cl, $sub, null);
            continue;
        }
        foreach ($answers as $a) {
            $rows[] = build_export_row($cl, $sub, $a);
        }
    }
}

qdb_discard($tmpDb, $lockFp);

try {
    [$pdoW, $tmpDbW, $lockFpW] = qdb_open(true);
    log_activity(
        $pdoW,
        $tokenRec,
        'client_data_exported',
        'client',
        $exportAll ? '*' : $clientCode,
        $exportAll ? 'Exported all client data' : "Exported data for $clientCode",
        ['exportAll' => $exportAll, 'clientCode' => $exportAll ? null : $clientCode, 'rowCount' => count($rows)]
    );
    qdb_save($tmpDbW, $lockFpW);
} catch (Throwable $e) {
    if (isset($tmpDbW, $lockFpW)) qdb_discard($tmpDbW, $lockFpW);
    error_log('Activity log failed on export: ' . $e->getMessage());
}

$filename = $exportAll
    ? 'clients_export_' . date('Y-m-d') . '.csv'
    : 'client_' . preg_replace('/[^a-zA-Z0-9_-]/', '_', $clientCode) . '_export.csv';

header('Content-Type: text/csv; charset=UTF-8');
header('Content-Disposition: attachment; filename="' . $filename . '"');
echo "\xEF\xBB\xBF";

$out = fopen('php://output', 'w');
$headers = [
    'clientCode', 'coach', 'supervisor', 'questionnaireID', 'questionnaireName',
    'submissionVersion', 'submissionID', 'status', 'sumPoints',
    'startedAt', 'completedAt', 'uploadedAt', 'submittedByRole',
    'questionText', 'answerOption', 'freeTextValue', 'numericValue',
];
fputcsv($out, $headers);
foreach ($rows as $r) {
    fputcsv($out, [
        $r['clientCode'],
        $r['coach'],
        $r['supervisor'],
        $r['questionnaireID'],
        $r['questionnaireName'],
        $r['submissionVersion'],
        $r['submissionID'],
        $r['status'],
        $r['sumPoints'],
        $r['startedAt'],
        $r['completedAt'],
        $r['uploadedAt'],
        $r['submittedByRole'],
        $r['questionText'],
        $r['answerOption'],
        $r['freeTextValue'],
        $r['numericValue'],
    ]);
}
fclose($out);
exit;

function build_export_row(array $cl, array $sub, ?array $a): array {
    $fmt = static function ($ms) {
        if ($ms === null || $ms === '') return '';
        return date('Y-m-d H:i', (int)($ms / 1000));
    };
    $answerVal = '';
    if ($a) {
        if (!empty($a['optionText'])) {
            $answerVal = $a['optionText'];
        } elseif ($a['freeTextValue'] !== null && $a['freeTextValue'] !== '') {
            $answerVal = $a['freeTextValue'];
        } elseif ($a['numericValue'] !== null) {
            $answerVal = (string)$a['numericValue'];
        }
    }
    return [
        'clientCode'         => $cl['clientCode'],
        'coach'              => $cl['coachUsername'] ?? $cl['coachID'] ?? '',
        'supervisor'         => $cl['supervisorUsername'] ?? '',
        'questionnaireID'    => $sub['questionnaireID'],
        'questionnaireName'  => $sub['questionnaireName'] ?? '',
        'submissionVersion'  => (int)$sub['submissionVersion'],
        'submissionID'       => $sub['submissionID'],
        'status'             => $sub['status'],
        'sumPoints'          => $sub['sumPoints'] !== null ? (int)$sub['sumPoints'] : '',
        'startedAt'          => $fmt($sub['startedAt']),
        'completedAt'        => $fmt($sub['completedAt']),
        'uploadedAt'         => $fmt($sub['uploadedAt']),
        'submittedByRole'    => $sub['submittedByRole'] ?? '',
        'questionText'       => $a['questionText'] ?? '',
        'answerOption'       => $answerVal,
        'freeTextValue'      => $a['freeTextValue'] ?? '',
        'numericValue'       => $a['numericValue'] !== null ? $a['numericValue'] : '',
    ];
}